From 8f0a056fcb2f83a069fb5d60c2383304b7456687 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 3 Nov 2008 23:15:55 -0500 Subject: ftrace: introduce ftrace_preempt_disable()/enable() Impact: add new ftrace-plugin internal APIs Parts of the tracer needs to be careful about schedule recursion. If the NEED_RESCHED flag is set, a preempt_enable will call schedule. Inside the schedule function, the NEED_RESCHED flag is cleared. The problem arises when a trace happens in the schedule function but before NEED_RESCHED is cleared. The race is as follows: schedule() >> tracer called trace_function() preempt_disable() [ record trace ] preempt_enable() <<- here's the issue. [check NEED_RESCHED] schedule() [ Repeat the above, over and over again ] The naive approach is simply to use preempt_enable_no_schedule instead. The problem with that approach is that, although we solve the schedule recursion issue, we now might lose a preemption check when not in the schedule function. trace_function() preempt_disable() [ record trace ] [Interrupt comes in and sets NEED_RESCHED] preempt_enable_no_resched() [continue without scheduling] The way ftrace handles this problem is with the following approach: int resched; resched = need_resched(); preempt_disable_notrace(); [record trace] if (resched) preempt_enable_no_sched_notrace(); else preempt_enable_notrace(); This may seem like the opposite of what we want. If resched is set then we call the "no_sched" version?? The reason we do this is because if NEED_RESCHED is set before we disable preemption, there's two reasons for that: 1) we are in an atomic code path 2) we are already on our way to the schedule function, and maybe even in the schedule function, but have yet to clear the flag. Both the above cases we do not want to schedule. This solution has already been implemented within the ftrace infrastructure. But the problem is that it has been implemented several times. This patch encapsulates this code to two nice functions. resched = ftrace_preempt_disable(); [ record trace] ftrace_preempt_enable(resched); This way the tracers do not need to worry about getting it right. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8465ad05270..10c6dae7689 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -419,4 +419,52 @@ enum trace_iterator_flags { extern struct tracer nop_trace; +/** + * ftrace_preempt_disable - disable preemption scheduler safe + * + * When tracing can happen inside the scheduler, there exists + * cases that the tracing might happen before the need_resched + * flag is checked. If this happens and the tracer calls + * preempt_enable (after a disable), a schedule might take place + * causing an infinite recursion. + * + * To prevent this, we read the need_recshed flag before + * disabling preemption. When we want to enable preemption we + * check the flag, if it is set, then we call preempt_enable_no_resched. + * Otherwise, we call preempt_enable. + * + * The rational for doing the above is that if need resched is set + * and we have yet to reschedule, we are either in an atomic location + * (where we do not need to check for scheduling) or we are inside + * the scheduler and do not want to resched. + */ +static inline int ftrace_preempt_disable(void) +{ + int resched; + + resched = need_resched(); + preempt_disable_notrace(); + + return resched; +} + +/** + * ftrace_preempt_enable - enable preemption scheduler safe + * @resched: the return value from ftrace_preempt_disable + * + * This is a scheduler safe way to enable preemption and not miss + * any preemption checks. The disabled saved the state of preemption. + * If resched is set, then we were either inside an atomic or + * are inside the scheduler (we would have already scheduled + * otherwise). In this case, we do not want to call normal + * preempt_enable, but preempt_enable_no_resched instead. + */ +static inline void ftrace_preempt_enable(int resched) +{ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + #endif /* _LINUX_KERNEL_TRACE_H */ -- cgit v1.2.3-70-g09d2 From b2a866f9344cb30d7ddf5d67b5b8393daf8bef07 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 3 Nov 2008 23:15:57 -0500 Subject: ftrace: function tracer with irqs disabled Impact: disable interrupts during trace entry creation (as opposed to preempt) To help with performance, I set the ftracer to not disable interrupts, and only to disable preemption. If an interrupt occurred, it would not be traced, because the function tracer protects itself from recursion. This may be faster, but the trace output might miss some traces. This patch makes the fuction trace disable interrupts, but it also adds a runtime feature to disable preemption instead. It does this by having two different tracer functions. When the function tracer is enabled, it will check to see which version is requested (irqs disabled or preemption disabled). Then it will use the corresponding function as the tracer. Irq disabling is the default behaviour, but if the user wants better performance, with the chance of missing traces, then they can choose the preempt disabled version. Running hackbench 3 times with the irqs disabled and 3 times with the preempt disabled function tracer yielded: tracing type times entries recorded ------------ -------- ---------------- irq disabled 43.393 166433066 43.282 166172618 43.298 166256704 preempt disabled 38.969 159871710 38.943 159972935 39.325 161056510 Average: irqs disabled: 43.324 166287462 preempt disabled: 39.079 160300385 preempt is 10.8 percent faster than irqs disabled. I wrote a patch to count function trace recursion and reran hackbench. With irq disabled: 1,150 times the function tracer did not trace due to recursion. with preempt disabled: 5,117,718 times. The thousand times with irq disabled could be due to NMIs, or simply a case where it called a function that was not protected by notrace. But we also see that a large amount of the trace is lost with the preempt version. Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Cc: Andrew Morton Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 40 +++++++++++++++++++++++++++++++++++++++- kernel/trace/trace.h | 1 + 2 files changed, 40 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3e7bf5eb900..d576dbd6def 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -244,6 +244,7 @@ static const char *trace_options[] = { "stacktrace", "sched-tree", "ftrace_printk", + "ftrace_preempt", NULL }; @@ -891,7 +892,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) #ifdef CONFIG_FUNCTION_TRACER static void -function_trace_call(unsigned long ip, unsigned long parent_ip) +function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; @@ -917,6 +918,37 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) ftrace_preempt_enable(resched); } +static void +function_trace_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + int pc; + + if (unlikely(!ftrace_function_enabled)) + return; + + /* + * Need to use raw, since this must be called before the + * recursive protection is performed. + */ + raw_local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + pc = preempt_count(); + trace_function(tr, data, ip, parent_ip, flags, pc); + } + + atomic_dec(&data->disabled); + raw_local_irq_restore(flags); +} + static struct ftrace_ops trace_ops __read_mostly = { .func = function_trace_call, @@ -925,6 +957,12 @@ static struct ftrace_ops trace_ops __read_mostly = void tracing_start_function_trace(void) { ftrace_function_enabled = 0; + + if (trace_flags & TRACE_ITER_PREEMPTONLY) + trace_ops.func = function_trace_call_preempt_only; + else + trace_ops.func = function_trace_call; + register_ftrace_function(&trace_ops); if (tracer_enabled) ftrace_function_enabled = 1; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 10c6dae7689..bb547e933af 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -415,6 +415,7 @@ enum trace_iterator_flags { TRACE_ITER_STACKTRACE = 0x100, TRACE_ITER_SCHED_TREE = 0x200, TRACE_ITER_PRINTK = 0x400, + TRACE_ITER_PREEMPTONLY = 0x800, }; extern struct tracer nop_trace; -- cgit v1.2.3-70-g09d2 From d7ad44b697c9d13e445ddc7d16f736fbac333249 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 31 Oct 2008 13:20:08 +0100 Subject: tracing/fastboot: use sched switch tracer from boot tracer Impact: enhance boot trace output with scheduling events Use the sched_switch tracer from the boot tracer. We also can trace schedule events inside the initcalls. Sched tracing is disabled after the initcall has finished and then reenabled before the next one is started. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 ++ kernel/trace/trace.h | 1 + kernel/trace/trace_boot.c | 6 ++++++ kernel/trace/trace_sched_switch.c | 6 +++--- 4 files changed, 12 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e4c40c868d6..50d7018163f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3251,6 +3251,8 @@ __init static int tracer_alloc_buffers(void) register_tracer(&nop_trace); #ifdef CONFIG_BOOT_TRACER + /* We don't want to launch sched_switch tracer yet */ + global_trace.ctrl = 0; register_tracer(&boot_tracer); current_trace = &boot_tracer; current_trace->init(&global_trace); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8465ad05270..9911277b268 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -49,6 +49,7 @@ struct ftrace_entry { unsigned long parent_ip; }; extern struct tracer boot_tracer; +extern struct tracer sched_switch_trace; /* Used by the boot tracer */ /* * Context switch trace entry - which task (and prio) we switched from/to: diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index d104d5b4641..6bbc8794a6d 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -27,10 +27,14 @@ void start_boot_trace(void) void enable_boot_trace(void) { + if (pre_initcalls_finished) + tracing_start_cmdline_record(); } void disable_boot_trace(void) { + if (pre_initcalls_finished) + tracing_stop_cmdline_record(); } void reset_boot_trace(struct trace_array *tr) @@ -45,6 +49,8 @@ static void boot_trace_init(struct trace_array *tr) for_each_cpu_mask(cpu, cpu_possible_map) tracing_reset(tr, cpu); + + sched_switch_trace.init(tr); } static void boot_trace_ctrl_update(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 96620c71430..9d7bdac331d 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -127,6 +127,7 @@ static void tracing_start_sched_switch(void) long ref; mutex_lock(&tracepoint_mutex); + tracer_enabled = 1; ref = atomic_inc_return(&sched_ref); if (ref == 1) tracing_sched_register(); @@ -138,6 +139,7 @@ static void tracing_stop_sched_switch(void) long ref; mutex_lock(&tracepoint_mutex); + tracer_enabled = 0; ref = atomic_dec_and_test(&sched_ref); if (ref) tracing_sched_unregister(); @@ -158,12 +160,10 @@ static void start_sched_trace(struct trace_array *tr) { sched_switch_reset(tr); tracing_start_cmdline_record(); - tracer_enabled = 1; } static void stop_sched_trace(struct trace_array *tr) { - tracer_enabled = 0; tracing_stop_cmdline_record(); } @@ -190,7 +190,7 @@ static void sched_switch_trace_ctrl_update(struct trace_array *tr) stop_sched_trace(tr); } -static struct tracer sched_switch_trace __read_mostly = +struct tracer sched_switch_trace __read_mostly = { .name = "sched_switch", .init = sched_switch_trace_init, -- cgit v1.2.3-70-g09d2 From 9036990d462e09366f7297a2d1da6582c3e6b1d3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 5 Nov 2008 16:05:44 -0500 Subject: ftrace: restructure tracing start/stop infrastructure Impact: change where tracing is started up and stopped Currently, when a new tracer is selected via echo'ing a tracer name into the current_tracer file, the startup is only done if tracing_enabled is set to one. If tracing_enabled is changed to zero (by echo'ing 0 into the tracing_enabled file) a full shutdown is performed. The full startup and shutdown of a tracer can be expensive and the user can lose out traces when echo'ing in 0 to the tracing_enabled file, because the process takes too long. There can also be places that the user would like to start and stop the tracer several times and doing the full startup and shutdown of a tracer might be too expensive. This patch performs the full startup and shutdown when a tracer is selected. It also adds a way to do a quick start or stop of a tracer. The quick version is just a flag that prevents the tracing from taking place, but the overhead of the code is still there. For example, the startup of a tracer may enable tracepoints, or enable the function tracer. The stop and start will just set a flag to have the tracer ignore the calls when the tracepoint or function trace is called. The overhead of the tracer may still be present when the tracer is stopped, but no tracing will occur. Setting the tracer to the 'nop' tracer (or any other tracer) will perform the shutdown of the tracer which will disable the tracepoint or disable the function tracer. The tracing_enabled file will simply start or stop tracing. This change is all internal. The end result for the user should be the same as before. If tracing_enabled is not set, no trace will happen. If tracing_enabled is set, then the trace will happen. The tracing_enabled variable is static between tracers. Enabling tracing_enabled and going to another tracer will keep tracing_enabled enabled. Same is true with disabling tracing_enabled. This patch will now provide a fast start/stop method to the users for enabling or disabling tracing. Note: There were two methods to the struct tracer that were never used: The methods start and stop. These were to be used as a hook to the reading of the trace output, but ended up not being necessary. These two methods are now used to enable the start and stop of each tracer, in case the tracer needs to do more than just not write into the buffer. For example, the irqsoff tracer must stop recording max latencies when tracing is stopped. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 64 +++++++++++++++++---------------------- kernel/trace/trace.h | 5 +-- kernel/trace/trace_functions.c | 6 ++++ kernel/trace/trace_irqsoff.c | 41 ++++++++++++++++++++++--- kernel/trace/trace_sched_switch.c | 13 ++++++++ kernel/trace/trace_sched_wakeup.c | 39 +++++++++++++++++++++--- 6 files changed, 120 insertions(+), 48 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 113aea9447e..ff1e9ed9b58 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -150,6 +150,19 @@ static DEFINE_PER_CPU(struct trace_array_cpu, max_data); /* tracer_enabled is used to toggle activation of a tracer */ static int tracer_enabled = 1; +/** + * tracing_is_enabled - return tracer_enabled status + * + * This function is used by other tracers to know the status + * of the tracer_enabled flag. Tracers may use this function + * to know if it should enable their features when starting + * up. See irqsoff tracer for an example (start_irqsoff_tracer). + */ +int tracing_is_enabled(void) +{ + return tracer_enabled; +} + /* function tracing enabled */ int ftrace_function_enabled; @@ -1041,8 +1054,7 @@ void tracing_start_function_trace(void) trace_ops.func = function_trace_call; register_ftrace_function(&trace_ops); - if (tracer_enabled) - ftrace_function_enabled = 1; + ftrace_function_enabled = 1; } void tracing_stop_function_trace(void) @@ -1189,10 +1201,6 @@ static void *s_start(struct seq_file *m, loff_t *pos) atomic_inc(&trace_record_cmdline_disabled); - /* let the tracer grab locks here if needed */ - if (current_trace->start) - current_trace->start(iter); - if (*pos != iter->pos) { iter->ent = NULL; iter->cpu = 0; @@ -1219,14 +1227,7 @@ static void *s_start(struct seq_file *m, loff_t *pos) static void s_stop(struct seq_file *m, void *p) { - struct trace_iterator *iter = m->private; - atomic_dec(&trace_record_cmdline_disabled); - - /* let the tracer release locks here if needed */ - if (current_trace && current_trace == iter->trace && iter->trace->stop) - iter->trace->stop(iter); - mutex_unlock(&trace_types_lock); } @@ -2056,10 +2057,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) m->private = iter; /* stop the trace while dumping */ - if (iter->tr->ctrl) { - tracer_enabled = 0; - ftrace_function_enabled = 0; - } + tracing_stop(); if (iter->trace && iter->trace->open) iter->trace->open(iter); @@ -2104,14 +2102,7 @@ int tracing_release(struct inode *inode, struct file *file) iter->trace->close(iter); /* reenable tracing if it was previously enabled */ - if (iter->tr->ctrl) { - tracer_enabled = 1; - /* - * It is safe to enable function tracing even if it - * isn't used - */ - ftrace_function_enabled = 1; - } + tracing_start(); mutex_unlock(&trace_types_lock); seq_release(inode, file); @@ -2449,11 +2440,10 @@ static ssize_t tracing_ctrl_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct trace_array *tr = filp->private_data; char buf[64]; int r; - r = sprintf(buf, "%ld\n", tr->ctrl); + r = sprintf(buf, "%u\n", tracer_enabled); return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); } @@ -2481,16 +2471,18 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf, val = !!val; mutex_lock(&trace_types_lock); - if (tr->ctrl ^ val) { - if (val) + if (tracer_enabled ^ val) { + if (val) { tracer_enabled = 1; - else + if (current_trace->start) + current_trace->start(tr); + tracing_start(); + } else { tracer_enabled = 0; - - tr->ctrl = val; - - if (current_trace && current_trace->ctrl_update) - current_trace->ctrl_update(tr); + tracing_stop(); + if (current_trace->stop) + current_trace->stop(tr); + } } mutex_unlock(&trace_types_lock); @@ -3372,7 +3364,7 @@ __init static int tracer_alloc_buffers(void) #endif /* All seems OK, enable tracing */ - global_trace.ctrl = tracer_enabled; + global_trace.ctrl = 1; tracing_disabled = 0; atomic_notifier_chain_register(&panic_notifier_list, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cc14a6bc109..3422489fad5 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -237,11 +237,11 @@ struct tracer { const char *name; void (*init)(struct trace_array *tr); void (*reset)(struct trace_array *tr); + void (*start)(struct trace_array *tr); + void (*stop)(struct trace_array *tr); void (*open)(struct trace_iterator *iter); void (*pipe_open)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter); - void (*start)(struct trace_iterator *iter); - void (*stop)(struct trace_iterator *iter); ssize_t (*read)(struct trace_iterator *iter, struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos); @@ -282,6 +282,7 @@ struct trace_iterator { long idx; }; +int tracing_is_enabled(void); void trace_wake_up(void); void tracing_reset(struct trace_array *tr, int cpu); int tracing_open_generic(struct inode *inode, struct file *filp); diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 0f85a64003d..9f1b0de7128 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -62,11 +62,17 @@ static void function_trace_ctrl_update(struct trace_array *tr) stop_function_trace(tr); } +static void function_trace_start(struct trace_array *tr) +{ + function_reset(tr); +} + static struct tracer function_trace __read_mostly = { .name = "function", .init = function_trace_init, .reset = function_trace_reset, + .start = function_trace_start, .ctrl_update = function_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_function, diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 9c74071c10e..a87a20fa3fc 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -353,15 +353,28 @@ void trace_preempt_off(unsigned long a0, unsigned long a1) } #endif /* CONFIG_PREEMPT_TRACER */ +/* + * save_tracer_enabled is used to save the state of the tracer_enabled + * variable when we disable it when we open a trace output file. + */ +static int save_tracer_enabled; + static void start_irqsoff_tracer(struct trace_array *tr) { register_ftrace_function(&trace_ops); - tracer_enabled = 1; + if (tracing_is_enabled()) { + tracer_enabled = 1; + save_tracer_enabled = 1; + } else { + tracer_enabled = 0; + save_tracer_enabled = 0; + } } static void stop_irqsoff_tracer(struct trace_array *tr) { tracer_enabled = 0; + save_tracer_enabled = 0; unregister_ftrace_function(&trace_ops); } @@ -389,17 +402,29 @@ static void irqsoff_tracer_ctrl_update(struct trace_array *tr) stop_irqsoff_tracer(tr); } +static void irqsoff_tracer_start(struct trace_array *tr) +{ + irqsoff_tracer_reset(tr); + tracer_enabled = 1; + save_tracer_enabled = 1; +} + +static void irqsoff_tracer_stop(struct trace_array *tr) +{ + tracer_enabled = 0; + save_tracer_enabled = 0; +} + static void irqsoff_tracer_open(struct trace_iterator *iter) { /* stop the trace while dumping */ - if (iter->tr->ctrl) - stop_irqsoff_tracer(iter->tr); + tracer_enabled = 0; } static void irqsoff_tracer_close(struct trace_iterator *iter) { - if (iter->tr->ctrl) - start_irqsoff_tracer(iter->tr); + /* restart tracing */ + tracer_enabled = save_tracer_enabled; } #ifdef CONFIG_IRQSOFF_TRACER @@ -414,6 +439,8 @@ static struct tracer irqsoff_tracer __read_mostly = .name = "irqsoff", .init = irqsoff_tracer_init, .reset = irqsoff_tracer_reset, + .start = irqsoff_tracer_start, + .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, .ctrl_update = irqsoff_tracer_ctrl_update, @@ -440,6 +467,8 @@ static struct tracer preemptoff_tracer __read_mostly = .name = "preemptoff", .init = preemptoff_tracer_init, .reset = irqsoff_tracer_reset, + .start = irqsoff_tracer_start, + .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, .ctrl_update = irqsoff_tracer_ctrl_update, @@ -468,6 +497,8 @@ static struct tracer preemptirqsoff_tracer __read_mostly = .name = "preemptirqsoff", .init = preemptirqsoff_tracer_init, .reset = irqsoff_tracer_reset, + .start = irqsoff_tracer_start, + .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, .ctrl_update = irqsoff_tracer_ctrl_update, diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 888944d3409..91c699be8c8 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -186,11 +186,24 @@ static void sched_switch_trace_ctrl_update(struct trace_array *tr) stop_sched_trace(tr); } +static void sched_switch_trace_start(struct trace_array *tr) +{ + sched_switch_reset(tr); + tracing_start_sched_switch(); +} + +static void sched_switch_trace_stop(struct trace_array *tr) +{ + tracing_stop_sched_switch(); +} + struct tracer sched_switch_trace __read_mostly = { .name = "sched_switch", .init = sched_switch_trace_init, .reset = sched_switch_trace_reset, + .start = sched_switch_trace_start, + .stop = sched_switch_trace_stop, .ctrl_update = sched_switch_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_sched_switch, diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 7bc4abf6fca..240577bc8ba 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -262,6 +262,12 @@ out: atomic_dec(&wakeup_trace->data[cpu]->disabled); } +/* + * save_tracer_enabled is used to save the state of the tracer_enabled + * variable when we disable it when we open a trace output file. + */ +static int save_tracer_enabled; + static void start_wakeup_tracer(struct trace_array *tr) { int ret; @@ -300,7 +306,13 @@ static void start_wakeup_tracer(struct trace_array *tr) register_ftrace_function(&trace_ops); - tracer_enabled = 1; + if (tracing_is_enabled()) { + tracer_enabled = 1; + save_tracer_enabled = 1; + } else { + tracer_enabled = 0; + save_tracer_enabled = 0; + } return; fail_deprobe_wake_new: @@ -312,6 +324,7 @@ fail_deprobe: static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; + save_tracer_enabled = 0; unregister_ftrace_function(&trace_ops); unregister_trace_sched_switch(probe_wakeup_sched_switch); unregister_trace_sched_wakeup_new(probe_wakeup); @@ -343,18 +356,32 @@ static void wakeup_tracer_ctrl_update(struct trace_array *tr) stop_wakeup_tracer(tr); } +static void wakeup_tracer_start(struct trace_array *tr) +{ + wakeup_reset(tr); + tracer_enabled = 1; + save_tracer_enabled = 1; +} + +static void wakeup_tracer_stop(struct trace_array *tr) +{ + tracer_enabled = 0; + save_tracer_enabled = 0; +} + static void wakeup_tracer_open(struct trace_iterator *iter) { /* stop the trace while dumping */ - if (iter->tr->ctrl) - stop_wakeup_tracer(iter->tr); + tracer_enabled = 0; } static void wakeup_tracer_close(struct trace_iterator *iter) { /* forget about any processes we were recording */ - if (iter->tr->ctrl) - start_wakeup_tracer(iter->tr); + if (save_tracer_enabled) { + wakeup_reset(iter->tr); + tracer_enabled = 1; + } } static struct tracer wakeup_tracer __read_mostly = @@ -362,6 +389,8 @@ static struct tracer wakeup_tracer __read_mostly = .name = "wakeup", .init = wakeup_tracer_init, .reset = wakeup_tracer_reset, + .start = wakeup_tracer_start, + .stop = wakeup_tracer_stop, .open = wakeup_tracer_open, .close = wakeup_tracer_close, .ctrl_update = wakeup_tracer_ctrl_update, -- cgit v1.2.3-70-g09d2 From 75f5c47da386445ba0c5a8b7e3ca0c906e763369 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 7 Nov 2008 22:36:02 -0500 Subject: ftrace: fix boot trace sched startup Impact: boot tracer startup modified The boot tracer calls into some of the schedule tracing private functions that should not be exported. This patch cleans it up, and makes way for further changes in the ftrace infrastructure. This patch adds a api to assign a tracer array to the schedule context switch tracer. Signed-off-by: Steven Rostedt Acked-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 +- kernel/trace/trace_boot.c | 9 +++++++-- kernel/trace/trace_sched_switch.c | 15 ++++++++++++++- 3 files changed, 22 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3422489fad5..db12e16137e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -49,7 +49,6 @@ struct ftrace_entry { unsigned long parent_ip; }; extern struct tracer boot_tracer; -extern struct tracer sched_switch_trace; /* Used by the boot tracer */ /* * Context switch trace entry - which task (and prio) we switched from/to: @@ -325,6 +324,7 @@ void trace_function(struct trace_array *tr, void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); +void tracing_cmdline_assign_trace(struct trace_array *tr); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index bd5046c9deb..662cb919890 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -39,7 +39,12 @@ void disable_boot_trace(void) static void reset_boot_trace(struct trace_array *tr) { - sched_switch_trace.reset(tr); + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); } static void boot_trace_init(struct trace_array *tr) @@ -50,7 +55,7 @@ static void boot_trace_init(struct trace_array *tr) for_each_cpu_mask(cpu, cpu_possible_map) tracing_reset(tr, cpu); - sched_switch_trace.init(tr); + tracing_cmdline_assign_trace(tr); } static void boot_trace_ctrl_update(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 91c699be8c8..fbf05df7134 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -152,6 +152,19 @@ void tracing_stop_cmdline_record(void) tracing_stop_sched_switch(); } +/** + * tracing_cmdline_assign_trace - assign a trace array for ctx switch + * @tr: trace array pointer to assign + * + * Some tracers might want to record the context switches in their + * trace. This function lets those tracers assign the trace array + * to use. + */ +void tracing_cmdline_assign_trace(struct trace_array *tr) +{ + ctx_trace = tr; +} + static void start_sched_trace(struct trace_array *tr) { sched_switch_reset(tr); @@ -197,7 +210,7 @@ static void sched_switch_trace_stop(struct trace_array *tr) tracing_stop_sched_switch(); } -struct tracer sched_switch_trace __read_mostly = +static struct tracer sched_switch_trace __read_mostly = { .name = "sched_switch", .init = sched_switch_trace_init, -- cgit v1.2.3-70-g09d2 From e168e0516e476070faa9e8e7b23dfcba79b76d82 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 7 Nov 2008 22:36:02 -0500 Subject: ftrace: fix sched_switch API Impact: fix for sched_switch that broke dynamic ftrace startup The commit: tracing/fastboot: use sched switch tracer from boot tracer broke the API of the sched_switch trace. The use of the tracing_start/stop_cmdline record is for only recording the cmdline, NOT recording the schedule switches themselves. Seeing that the boot tracer broke the API to do something that it wanted, this patch adds a new interface for the API while puting back the original interface of the old API. Signed-off-by: Steven Rostedt Acked-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 4 +++- kernel/trace/trace_boot.c | 6 ++--- kernel/trace/trace_sched_switch.c | 50 +++++++++++++++++++++++++++++++-------- 3 files changed, 46 insertions(+), 14 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index db12e16137e..25abfc45f08 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -324,7 +324,9 @@ void trace_function(struct trace_array *tr, void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); -void tracing_cmdline_assign_trace(struct trace_array *tr); +void tracing_sched_switch_assign_trace(struct trace_array *tr); +void tracing_stop_sched_switch_record(void); +void tracing_start_sched_switch_record(void); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 662cb919890..0203c105401 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -28,13 +28,13 @@ void start_boot_trace(void) void enable_boot_trace(void) { if (pre_initcalls_finished) - tracing_start_cmdline_record(); + tracing_start_sched_switch_record(); } void disable_boot_trace(void) { if (pre_initcalls_finished) - tracing_stop_cmdline_record(); + tracing_stop_sched_switch_record(); } static void reset_boot_trace(struct trace_array *tr) @@ -55,7 +55,7 @@ static void boot_trace_init(struct trace_array *tr) for_each_cpu_mask(cpu, cpu_possible_map) tracing_reset(tr, cpu); - tracing_cmdline_assign_trace(tr); + tracing_sched_switch_assign_trace(tr); } static void boot_trace_ctrl_update(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index fbf05df7134..79410db64d6 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -125,20 +125,16 @@ static void tracing_sched_unregister(void) static void tracing_start_sched_switch(void) { mutex_lock(&sched_register_mutex); - if (!(sched_ref++)) { - tracer_enabled = 1; + if (!(sched_ref++)) tracing_sched_register(); - } mutex_unlock(&sched_register_mutex); } static void tracing_stop_sched_switch(void) { mutex_lock(&sched_register_mutex); - if (!(--sched_ref)) { + if (!(--sched_ref)) tracing_sched_unregister(); - tracer_enabled = 0; - } mutex_unlock(&sched_register_mutex); } @@ -153,14 +149,48 @@ void tracing_stop_cmdline_record(void) } /** - * tracing_cmdline_assign_trace - assign a trace array for ctx switch + * tracing_start_sched_switch_record - start tracing context switches + * + * Turns on context switch tracing for a tracer. + */ +void tracing_start_sched_switch_record(void) +{ + if (unlikely(!ctx_trace)) { + WARN_ON(1); + return; + } + + tracing_start_sched_switch(); + + mutex_lock(&sched_register_mutex); + tracer_enabled++; + mutex_unlock(&sched_register_mutex); +} + +/** + * tracing_stop_sched_switch_record - start tracing context switches + * + * Turns off context switch tracing for a tracer. + */ +void tracing_stop_sched_switch_record(void) +{ + mutex_lock(&sched_register_mutex); + tracer_enabled--; + WARN_ON(tracer_enabled < 0); + mutex_unlock(&sched_register_mutex); + + tracing_stop_sched_switch(); +} + +/** + * tracing_sched_switch_assign_trace - assign a trace array for ctx switch * @tr: trace array pointer to assign * * Some tracers might want to record the context switches in their * trace. This function lets those tracers assign the trace array * to use. */ -void tracing_cmdline_assign_trace(struct trace_array *tr) +void tracing_sched_switch_assign_trace(struct trace_array *tr) { ctx_trace = tr; } @@ -168,12 +198,12 @@ void tracing_cmdline_assign_trace(struct trace_array *tr) static void start_sched_trace(struct trace_array *tr) { sched_switch_reset(tr); - tracing_start_cmdline_record(); + tracing_start_sched_switch_record(); } static void stop_sched_trace(struct trace_array *tr) { - tracing_stop_cmdline_record(); + tracing_stop_sched_switch_record(); } static void sched_switch_trace_init(struct trace_array *tr) -- cgit v1.2.3-70-g09d2 From bbf5b1a0cecb56de6236db8b01c5bfb7ab8ba8b2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 7 Nov 2008 22:36:02 -0500 Subject: ftrace: remove ctrl_update method Impact: Remove the ctrl_update tracer method With the new quick start/stop method of tracing, the ctrl_update method is out of date. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 -- kernel/trace/trace.h | 1 - kernel/trace/trace_boot.c | 9 -------- kernel/trace/trace_functions.c | 9 -------- kernel/trace/trace_irqsoff.c | 11 --------- kernel/trace/trace_mmiotrace.c | 11 +++------ kernel/trace/trace_nop.c | 10 -------- kernel/trace/trace_sched_switch.c | 10 -------- kernel/trace/trace_sched_wakeup.c | 9 -------- kernel/trace/trace_selftest.c | 48 +++++++++++++++++++++------------------ kernel/trace/trace_sysprof.c | 10 -------- 11 files changed, 29 insertions(+), 101 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index dbbdacfaaf9..9e83188172a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3357,8 +3357,6 @@ __init static int tracer_alloc_buffers(void) register_tracer(&nop_trace); #ifdef CONFIG_BOOT_TRACER - /* We don't want to launch sched_switch tracer yet */ - global_trace.ctrl = 0; register_tracer(&boot_tracer); current_trace = &boot_tracer; current_trace->init(&global_trace); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 25abfc45f08..e481edaae1c 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -244,7 +244,6 @@ struct tracer { ssize_t (*read)(struct trace_iterator *iter, struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos); - void (*ctrl_update)(struct trace_array *tr); #ifdef CONFIG_FTRACE_STARTUP_TEST int (*selftest)(struct tracer *trace, struct trace_array *tr); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 0203c105401..8f71915e8bb 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -58,14 +58,6 @@ static void boot_trace_init(struct trace_array *tr) tracing_sched_switch_assign_trace(tr); } -static void boot_trace_ctrl_update(struct trace_array *tr) -{ - if (tr->ctrl) - enable_boot_trace(); - else - disable_boot_trace(); -} - static enum print_line_t initcall_print_line(struct trace_iterator *iter) { int ret; @@ -102,7 +94,6 @@ struct tracer boot_tracer __read_mostly = .name = "initcall", .init = boot_trace_init, .reset = reset_boot_trace, - .ctrl_update = boot_trace_ctrl_update, .print_line = initcall_print_line, }; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 9f1b0de7128..e980b872bef 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -54,14 +54,6 @@ static void function_trace_reset(struct trace_array *tr) stop_function_trace(tr); } -static void function_trace_ctrl_update(struct trace_array *tr) -{ - if (tr->ctrl) - start_function_trace(tr); - else - stop_function_trace(tr); -} - static void function_trace_start(struct trace_array *tr) { function_reset(tr); @@ -73,7 +65,6 @@ static struct tracer function_trace __read_mostly = .init = function_trace_init, .reset = function_trace_reset, .start = function_trace_start, - .ctrl_update = function_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_function, #endif diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 3509086cdc4..ffdf592a54e 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -394,14 +394,6 @@ static void irqsoff_tracer_reset(struct trace_array *tr) stop_irqsoff_tracer(tr); } -static void irqsoff_tracer_ctrl_update(struct trace_array *tr) -{ - if (tr->ctrl) - start_irqsoff_tracer(tr); - else - stop_irqsoff_tracer(tr); -} - static void irqsoff_tracer_start(struct trace_array *tr) { tracer_enabled = 1; @@ -442,7 +434,6 @@ static struct tracer irqsoff_tracer __read_mostly = .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, - .ctrl_update = irqsoff_tracer_ctrl_update, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_irqsoff, @@ -470,7 +461,6 @@ static struct tracer preemptoff_tracer __read_mostly = .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, - .ctrl_update = irqsoff_tracer_ctrl_update, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptoff, @@ -500,7 +490,6 @@ static struct tracer preemptirqsoff_tracer __read_mostly = .stop = irqsoff_tracer_stop, .open = irqsoff_tracer_open, .close = irqsoff_tracer_close, - .ctrl_update = irqsoff_tracer_ctrl_update, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptirqsoff, diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index f28484618ff..fa9354e78b5 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -49,15 +49,10 @@ static void mmio_trace_reset(struct trace_array *tr) mmio_trace_array = NULL; } -static void mmio_trace_ctrl_update(struct trace_array *tr) +static void mmio_trace_start(struct trace_array *tr) { pr_debug("in %s\n", __func__); - if (tr->ctrl) { - mmio_reset_data(tr); - enable_mmiotrace(); - } else { - disable_mmiotrace(); - } + mmio_reset_data(tr); } static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) @@ -298,10 +293,10 @@ static struct tracer mmio_tracer __read_mostly = .name = "mmiotrace", .init = mmio_trace_init, .reset = mmio_trace_reset, + .start = mmio_trace_start, .pipe_open = mmio_pipe_open, .close = mmio_close, .read = mmio_read, - .ctrl_update = mmio_trace_ctrl_update, .print_line = mmio_print_line, }; diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 4592b486251..e3c5fbfcdd3 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -42,21 +42,11 @@ static void nop_trace_reset(struct trace_array *tr) stop_nop_trace(tr); } -static void nop_trace_ctrl_update(struct trace_array *tr) -{ - /* When starting a new trace, reset the buffers */ - if (tr->ctrl) - start_nop_trace(tr); - else - stop_nop_trace(tr); -} - struct tracer nop_trace __read_mostly = { .name = "nop", .init = nop_trace_init, .reset = nop_trace_reset, - .ctrl_update = nop_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_nop, #endif diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 79410db64d6..7b73fd11e4a 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -220,15 +220,6 @@ static void sched_switch_trace_reset(struct trace_array *tr) stop_sched_trace(tr); } -static void sched_switch_trace_ctrl_update(struct trace_array *tr) -{ - /* When starting a new trace, reset the buffers */ - if (tr->ctrl) - start_sched_trace(tr); - else - stop_sched_trace(tr); -} - static void sched_switch_trace_start(struct trace_array *tr) { sched_switch_reset(tr); @@ -247,7 +238,6 @@ static struct tracer sched_switch_trace __read_mostly = .reset = sched_switch_trace_reset, .start = sched_switch_trace_start, .stop = sched_switch_trace_stop, - .ctrl_update = sched_switch_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_sched_switch, #endif diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 240577bc8ba..23e54d4e4d9 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -348,14 +348,6 @@ static void wakeup_tracer_reset(struct trace_array *tr) } } -static void wakeup_tracer_ctrl_update(struct trace_array *tr) -{ - if (tr->ctrl) - start_wakeup_tracer(tr); - else - stop_wakeup_tracer(tr); -} - static void wakeup_tracer_start(struct trace_array *tr) { wakeup_reset(tr); @@ -393,7 +385,6 @@ static struct tracer wakeup_tracer __read_mostly = .stop = wakeup_tracer_stop, .open = wakeup_tracer_open, .close = wakeup_tracer_close, - .ctrl_update = wakeup_tracer_ctrl_update, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 90bc752a758..74693434047 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -134,13 +134,13 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, msleep(100); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); ftrace_enabled = 0; /* check the trace buffer */ ret = trace_test_buffer(tr, &count); trace->reset(tr); + tracing_start(); /* we should only have one item */ if (!ret && count != 1) { @@ -148,6 +148,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, ret = -1; goto out; } + out: ftrace_enabled = save_ftrace_enabled; tracer_enabled = save_tracer_enabled; @@ -185,13 +186,13 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); ftrace_enabled = 0; /* check the trace buffer */ ret = trace_test_buffer(tr, &count); trace->reset(tr); + tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); @@ -232,13 +233,13 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) udelay(100); local_irq_enable(); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); if (!ret) ret = trace_test_buffer(&max_tr, &count); trace->reset(tr); + tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); @@ -269,13 +270,13 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) udelay(100); preempt_enable(); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); if (!ret) ret = trace_test_buffer(&max_tr, &count); trace->reset(tr); + tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); @@ -312,27 +313,30 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * local_irq_enable(); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); - if (ret) + if (ret) { + tracing_start(); goto out; + } ret = trace_test_buffer(&max_tr, &count); - if (ret) + if (ret) { + tracing_start(); goto out; + } if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; + tracing_start(); goto out; } /* do the test by disabling interrupts first this time */ tracing_max_latency = 0; - tr->ctrl = 1; - trace->ctrl_update(tr); + tracing_start(); preempt_disable(); local_irq_disable(); udelay(100); @@ -341,8 +345,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * local_irq_enable(); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); if (ret) @@ -358,6 +361,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * out: trace->reset(tr); + tracing_start(); tracing_max_latency = save_max; return ret; @@ -448,8 +452,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) msleep(100); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(tr, NULL); if (!ret) @@ -457,6 +460,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) trace->reset(tr); + tracing_start(); tracing_max_latency = save_max; @@ -485,11 +489,11 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check the trace buffer */ ret = trace_test_buffer(tr, &count); trace->reset(tr); + tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); @@ -513,11 +517,11 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ - tr->ctrl = 0; - trace->ctrl_update(tr); + tracing_stop(); /* check the trace buffer */ ret = trace_test_buffer(tr, &count); trace->reset(tr); + tracing_start(); return ret; } diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 9587d3bcba5..8097430edff 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -275,21 +275,11 @@ static void stack_trace_reset(struct trace_array *tr) stop_stack_trace(tr); } -static void stack_trace_ctrl_update(struct trace_array *tr) -{ - /* When starting a new trace, reset the buffers */ - if (tr->ctrl) - start_stack_trace(tr); - else - stop_stack_trace(tr); -} - static struct tracer stack_trace __read_mostly = { .name = "sysprof", .init = stack_trace_init, .reset = stack_trace_reset, - .ctrl_update = stack_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_sysprof, #endif -- cgit v1.2.3-70-g09d2 From c76f06945be50564f925799ddfb6235ee4c26aa0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 7 Nov 2008 22:36:02 -0500 Subject: ftrace: remove trace array ctrl Impact: remove obsolete variable in trace_array structure With the new start / stop method of ftrace, the ctrl variable in the trace_array structure is now obsolete. Remove it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 20 +++++--------------- kernel/trace/trace.h | 1 - kernel/trace/trace_functions.c | 6 ++---- kernel/trace/trace_irqsoff.c | 7 ++----- kernel/trace/trace_mmiotrace.c | 11 +++++------ kernel/trace/trace_nop.c | 6 ++---- kernel/trace/trace_sched_switch.c | 6 ++---- kernel/trace/trace_sched_wakeup.c | 12 ++++-------- kernel/trace/trace_selftest.c | 8 -------- kernel/trace/trace_sysprof.c | 6 ++---- 10 files changed, 24 insertions(+), 59 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9e83188172a..58435415b36 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -537,7 +537,6 @@ int register_tracer(struct tracer *type) if (type->selftest) { struct tracer *saved_tracer = current_trace; struct trace_array *tr = &global_trace; - int saved_ctrl = tr->ctrl; int i; /* * Run a selftest on this tracer. @@ -550,13 +549,11 @@ int register_tracer(struct tracer *type) tracing_reset(tr, i); } current_trace = type; - tr->ctrl = 0; /* the test is responsible for initializing and enabling */ pr_info("Testing tracer %s: ", type->name); ret = type->selftest(type, tr); /* the test is responsible for resetting too */ current_trace = saved_tracer; - tr->ctrl = saved_ctrl; if (ret) { printk(KERN_CONT "FAILED!\n"); goto out; @@ -966,7 +963,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) int cpu; int pc; - if (tracing_disabled || !tr->ctrl) + if (tracing_disabled) return; pc = preempt_count(); @@ -2820,7 +2817,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, unsigned long val; char buf[64]; int ret; - struct trace_array *tr = filp->private_data; if (cnt >= sizeof(buf)) return -EINVAL; @@ -2840,12 +2836,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, mutex_lock(&trace_types_lock); - if (tr->ctrl) { - cnt = -EBUSY; - pr_info("ftrace: please disable tracing" - " before modifying buffer size\n"); - goto out; - } + tracing_stop(); if (val != global_trace.entries) { ret = ring_buffer_resize(global_trace.buffer, val); @@ -2878,6 +2869,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, if (tracing_disabled) cnt = -ENOMEM; out: + tracing_start(); max_tr.entries = global_trace.entries; mutex_unlock(&trace_types_lock); @@ -2900,9 +2892,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, { char *buf; char *end; - struct trace_array *tr = &global_trace; - if (!tr->ctrl || tracing_disabled) + if (tracing_disabled) return -EINVAL; if (cnt > TRACE_BUF_SIZE) @@ -3131,7 +3122,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) unsigned long flags, irq_flags; int cpu, len = 0, size, pc; - if (!tr->ctrl || tracing_disabled) + if (tracing_disabled) return 0; pc = preempt_count(); @@ -3365,7 +3356,6 @@ __init static int tracer_alloc_buffers(void) #endif /* All seems OK, enable tracing */ - global_trace.ctrl = 1; tracing_disabled = 0; atomic_notifier_chain_register(&panic_notifier_list, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index e481edaae1c..cfda9d219e6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -172,7 +172,6 @@ struct trace_iterator; struct trace_array { struct ring_buffer *buffer; unsigned long entries; - long ctrl; int cpu; cycle_t time_start; struct task_struct *waiter; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index e980b872bef..8693b7a0a5b 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -44,14 +44,12 @@ static void stop_function_trace(struct trace_array *tr) static void function_trace_init(struct trace_array *tr) { - if (tr->ctrl) - start_function_trace(tr); + start_function_trace(tr); } static void function_trace_reset(struct trace_array *tr) { - if (tr->ctrl) - stop_function_trace(tr); + stop_function_trace(tr); } static void function_trace_start(struct trace_array *tr) diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index ffdf592a54e..d919d4eaa7c 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -383,15 +383,12 @@ static void __irqsoff_tracer_init(struct trace_array *tr) irqsoff_trace = tr; /* make sure that the tracer is visible */ smp_wmb(); - - if (tr->ctrl) - start_irqsoff_tracer(tr); + start_irqsoff_tracer(tr); } static void irqsoff_tracer_reset(struct trace_array *tr) { - if (tr->ctrl) - stop_irqsoff_tracer(tr); + stop_irqsoff_tracer(tr); } static void irqsoff_tracer_start(struct trace_array *tr) diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index fa9354e78b5..51bcf370215 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -34,17 +34,16 @@ static void mmio_trace_init(struct trace_array *tr) { pr_debug("in %s\n", __func__); mmio_trace_array = tr; - if (tr->ctrl) { - mmio_reset_data(tr); - enable_mmiotrace(); - } + + mmio_reset_data(tr); + enable_mmiotrace(); } static void mmio_trace_reset(struct trace_array *tr) { pr_debug("in %s\n", __func__); - if (tr->ctrl) - disable_mmiotrace(); + + disable_mmiotrace(); mmio_reset_data(tr); mmio_trace_array = NULL; } diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index e3c5fbfcdd3..2ef1d227e7d 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -32,14 +32,12 @@ static void nop_trace_init(struct trace_array *tr) for_each_online_cpu(cpu) tracing_reset(tr, cpu); - if (tr->ctrl) - start_nop_trace(tr); + start_nop_trace(tr); } static void nop_trace_reset(struct trace_array *tr) { - if (tr->ctrl) - stop_nop_trace(tr); + stop_nop_trace(tr); } struct tracer nop_trace __read_mostly = diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 7b73fd11e4a..be35bdfe2e3 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -209,14 +209,12 @@ static void stop_sched_trace(struct trace_array *tr) static void sched_switch_trace_init(struct trace_array *tr) { ctx_trace = tr; - - if (tr->ctrl) - start_sched_trace(tr); + start_sched_trace(tr); } static void sched_switch_trace_reset(struct trace_array *tr) { - if (tr->ctrl && sched_ref) + if (sched_ref) stop_sched_trace(tr); } diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 23e54d4e4d9..983f2b1478c 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -334,18 +334,14 @@ static void stop_wakeup_tracer(struct trace_array *tr) static void wakeup_tracer_init(struct trace_array *tr) { wakeup_trace = tr; - - if (tr->ctrl) - start_wakeup_tracer(tr); + start_wakeup_tracer(tr); } static void wakeup_tracer_reset(struct trace_array *tr) { - if (tr->ctrl) { - stop_wakeup_tracer(tr); - /* make sure we put back any tasks we are tracing */ - wakeup_reset(tr); - } + stop_wakeup_tracer(tr); + /* make sure we put back any tasks we are tracing */ + wakeup_reset(tr); } static void wakeup_tracer_start(struct trace_array *tr) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 74693434047..ea4e5d3b15d 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -110,7 +110,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, ftrace_set_filter(func_name, strlen(func_name), 1); /* enable tracing */ - tr->ctrl = 1; trace->init(tr); /* Sleep for a 1/10 of a second */ @@ -181,7 +180,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) ftrace_enabled = 1; tracer_enabled = 1; - tr->ctrl = 1; trace->init(tr); /* Sleep for a 1/10 of a second */ msleep(100); @@ -224,7 +222,6 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* reset the max latency */ tracing_max_latency = 0; @@ -261,7 +258,6 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* reset the max latency */ tracing_max_latency = 0; @@ -298,7 +294,6 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * int ret; /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* reset the max latency */ @@ -427,7 +422,6 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) wait_for_completion(&isrt); /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* reset the max latency */ tracing_max_latency = 0; @@ -484,7 +478,6 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr int ret; /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* Sleep for a 1/10 of a second */ msleep(100); @@ -512,7 +505,6 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - tr->ctrl = 1; trace->init(tr); /* Sleep for a 1/10 of a second */ msleep(100); diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 8097430edff..05f753422ae 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -265,14 +265,12 @@ static void stack_trace_init(struct trace_array *tr) { sysprof_trace = tr; - if (tr->ctrl) - start_stack_trace(tr); + start_stack_trace(tr); } static void stack_trace_reset(struct trace_array *tr) { - if (tr->ctrl) - stop_stack_trace(tr); + stop_stack_trace(tr); } static struct tracer stack_trace __read_mostly = -- cgit v1.2.3-70-g09d2 From a309720c876d7ad2e224bfd1982c92ae4364c82e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 7 Nov 2008 22:36:02 -0500 Subject: ftrace: display start of CPU buffer in trace output Impact: change in trace output Because the trace buffers are per cpu ring buffers, the start of the trace can be confusing. If one CPU is very active at the end of the trace, its history will not go as far back as the other CPU traces. This means that output for a particular CPU may not appear for the first part of a trace. To help annotate what is happening, and to prevent any more confusion, this patch adds a line that annotates the start of a CPU buffer output. For example: automount-3495 [001] 184.596443: dnotify_parent <-vfs_write [...] automount-3495 [001] 184.596449: dput <-path_put automount-3496 [002] 184.596450: down_read_trylock <-do_page_fault [...] sshd-3497 [001] 184.597069: up_read <-do_page_fault -0 [000] 184.597074: __exit_idle <-exit_idle [...] automount-3496 [002] 184.597257: filemap_fault <-__do_fault -0 [003] 184.597261: exit_idle <-smp_apic_timer_interrupt Note, parsers of a trace output should always ignore any lines that start with a '#'. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 19 +++++++++++++++++++ kernel/trace/trace.h | 2 ++ 2 files changed, 21 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 58435415b36..f147f198b9a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1478,6 +1478,17 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) trace_seq_putc(s, '\n'); } +static void test_cpu_buff_start(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + + if (cpu_isset(iter->cpu, iter->started)) + return; + + cpu_set(iter->cpu, iter->started); + trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu); +} + static enum print_line_t print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { @@ -1497,6 +1508,8 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) if (entry->type == TRACE_CONT) return TRACE_TYPE_HANDLED; + test_cpu_buff_start(iter); + next_entry = find_next_entry(iter, NULL, &next_ts); if (!next_entry) next_ts = iter->ts; @@ -1612,6 +1625,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) if (entry->type == TRACE_CONT) return TRACE_TYPE_HANDLED; + test_cpu_buff_start(iter); + comm = trace_find_cmdline(iter->ent->pid); t = ns2usecs(iter->ts); @@ -2631,6 +2646,10 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) return -ENOMEM; mutex_lock(&trace_types_lock); + + /* trace pipe does not show start of buffer */ + cpus_setall(iter->started); + iter->tr = &global_trace; iter->trace = current_trace; filp->private_data = iter; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cfda9d219e6..978145088fb 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -277,6 +277,8 @@ struct trace_iterator { unsigned long iter_flags; loff_t pos; long idx; + + cpumask_t started; }; int tracing_is_enabled(void); -- cgit v1.2.3-70-g09d2 From 15e6cb3673ea6277999642802406a764b49391b0 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 11 Nov 2008 07:14:25 +0100 Subject: tracing: add a tracer to catch execution time of kernel functions Impact: add new tracing plugin which can trace full (entry+exit) function calls This tracer uses the low level function return ftrace plugin to measure the execution time of the kernel functions. The first field is the caller of the function, the second is the measured function, and the last one is the execution time in nanoseconds. - v3: - HAVE_FUNCTION_RET_TRACER have been added. Each arch that support ftrace return should enable it. - ftrace_return_stub becomes ftrace_stub. - CONFIG_FUNCTION_RET_TRACER depends now on CONFIG_FUNCTION_TRACER - Return traces printing can be used for other tracers on trace.c - Adapt to the new tracing API (no more ctrl_update callback) - Correct the check of "disabled" during insertion. - Minor changes... Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 14 ++++++ kernel/trace/Makefile | 1 + kernel/trace/ftrace.c | 16 +++++++ kernel/trace/trace.c | 65 +++++++++++++++++++++++---- kernel/trace/trace.h | 35 +++++++++++++++ kernel/trace/trace_functions_return.c | 82 +++++++++++++++++++++++++++++++++++ 6 files changed, 205 insertions(+), 8 deletions(-) create mode 100644 kernel/trace/trace_functions_return.c (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index fc4febc3334..d986216c832 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -9,6 +9,9 @@ config NOP_TRACER config HAVE_FUNCTION_TRACER bool +config HAVE_FUNCTION_RET_TRACER + bool + config HAVE_FUNCTION_TRACE_MCOUNT_TEST bool help @@ -54,6 +57,17 @@ config FUNCTION_TRACER (the bootup default), then the overhead of the instructions is very small and not measurable even in micro-benchmarks. +config FUNCTION_RET_TRACER + bool "Kernel Function return Tracer" + depends on !DYNAMIC_FTRACE + depends on HAVE_FUNCTION_RET_TRACER + depends on FUNCTION_TRACER + help + Enable the kernel to trace a function at its return. + It's first purpose is to trace the duration of functions. + This is done by setting the current return address on the thread + info structure of the current task. + config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" default n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index c8228b1a49e..3e1f361bbc1 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -24,5 +24,6 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o +obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4d2e751bfb1..f03fe74ecd6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1484,3 +1484,19 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, return ret; } +#ifdef CONFIG_FUNCTION_RET_TRACER +trace_function_return_t ftrace_function_return = + (trace_function_return_t)ftrace_stub; +void register_ftrace_return(trace_function_return_t func) +{ + ftrace_function_return = func; +} + +void unregister_ftrace_return(void) +{ + ftrace_function_return = (trace_function_return_t)ftrace_stub; +} +#endif + + + diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 216bbe7547a..a3f7ae9cd8e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -244,13 +244,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs) return nsecs / 1000; } -/* - * TRACE_ITER_SYM_MASK masks the options in trace_flags that - * control the output of kernel symbols. - */ -#define TRACE_ITER_SYM_MASK \ - (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) - /* These must match the bit postions in trace_iterator_flags */ static const char *trace_options[] = { "print-parent", @@ -810,6 +803,35 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } +#ifdef CONFIG_FUNCTION_RET_TRACER +static void __trace_function_return(struct trace_array *tr, + struct trace_array_cpu *data, + struct ftrace_retfunc *trace, + unsigned long flags, + int pc) +{ + struct ring_buffer_event *event; + struct ftrace_ret_entry *entry; + unsigned long irq_flags; + + if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) + return; + + event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_FN_RET; + entry->ip = trace->func; + entry->parent_ip = trace->ret; + entry->rettime = trace->rettime; + entry->calltime = trace->calltime; + ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags); +} +#endif + void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, unsigned long flags, @@ -1038,6 +1060,29 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) raw_local_irq_restore(flags); } +#ifdef CONFIG_FUNCTION_RET_TRACER +void trace_function_return(struct ftrace_retfunc *trace) +{ + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + int pc; + + raw_local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + if (likely(disabled == 1)) { + pc = preempt_count(); + __trace_function_return(tr, data, trace, flags, pc); + } + atomic_dec(&data->disabled); + raw_local_irq_restore(flags); +} +#endif /* CONFIG_FUNCTION_RET_TRACER */ + static struct ftrace_ops trace_ops __read_mostly = { .func = function_trace_call, @@ -1285,7 +1330,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt, # define IP_FMT "%016lx" #endif -static int +int seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) { int ret; @@ -1738,6 +1783,10 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) trace_seq_print_cont(s, iter); break; } + case TRACE_FN_RET: { + return print_return_function(iter); + break; + } } return TRACE_TYPE_HANDLED; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 978145088fb..e40ce0c1469 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -22,6 +22,7 @@ enum trace_type { TRACE_MMIO_RW, TRACE_MMIO_MAP, TRACE_BOOT, + TRACE_FN_RET, __TRACE_LAST_TYPE }; @@ -48,6 +49,15 @@ struct ftrace_entry { unsigned long ip; unsigned long parent_ip; }; + +/* Function return entry */ +struct ftrace_ret_entry { + struct trace_entry ent; + unsigned long ip; + unsigned long parent_ip; + unsigned long long calltime; + unsigned long long rettime; +}; extern struct tracer boot_tracer; /* @@ -218,6 +228,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ TRACE_MMIO_MAP); \ IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \ + IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET); \ __ftrace_bad_type(); \ } while (0) @@ -321,6 +332,8 @@ void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); +void +trace_function_return(struct ftrace_retfunc *trace); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); @@ -393,6 +406,10 @@ extern void *head_page(struct trace_array_cpu *data); extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); extern void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter); + +extern int +seq_print_ip_sym(struct trace_seq *s, unsigned long ip, + unsigned long sym_flags); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); @@ -400,6 +417,17 @@ extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; +/* Standard output formatting function used for function return traces */ +#ifdef CONFIG_FUNCTION_RET_TRACER +extern enum print_line_t print_return_function(struct trace_iterator *iter); +#else +static inline enum print_line_t +print_return_function(struct trace_iterator *iter) +{ + return TRACE_TYPE_UNHANDLED; +} +#endif + /* * trace_iterator_flags is an enumeration that defines bit * positions into trace_flags that controls the output. @@ -422,6 +450,13 @@ enum trace_iterator_flags { TRACE_ITER_PREEMPTONLY = 0x800, }; +/* + * TRACE_ITER_SYM_MASK masks the options in trace_flags that + * control the output of kernel symbols. + */ +#define TRACE_ITER_SYM_MASK \ + (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) + extern struct tracer nop_trace; /** diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c new file mode 100644 index 00000000000..7680b21537d --- /dev/null +++ b/kernel/trace/trace_functions_return.c @@ -0,0 +1,82 @@ +/* + * + * Function return tracer. + * Copyright (c) 2008 Frederic Weisbecker + * Mostly borrowed from function tracer which + * is Copyright (c) Steven Rostedt + * + */ +#include +#include +#include +#include + +#include "trace.h" + + +static void start_return_trace(struct trace_array *tr) +{ + register_ftrace_return(&trace_function_return); +} + +static void stop_return_trace(struct trace_array *tr) +{ + unregister_ftrace_return(); +} + +static void return_trace_init(struct trace_array *tr) +{ + int cpu; + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + + start_return_trace(tr); +} + +static void return_trace_reset(struct trace_array *tr) +{ + stop_return_trace(tr); +} + + +enum print_line_t +print_return_function(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; + struct ftrace_ret_entry *field; + int ret; + + if (entry->type == TRACE_FN_RET) { + trace_assign_type(field, entry); + ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + ret = seq_print_ip_sym(s, field->ip, + trace_flags & TRACE_ITER_SYM_MASK); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + ret = trace_seq_printf(s, " (%llu ns)\n", + field->rettime - field->calltime); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + else + return TRACE_TYPE_HANDLED; + } + return TRACE_TYPE_UNHANDLED; +} + +static struct tracer return_trace __read_mostly = +{ + .name = "return", + .init = return_trace_init, + .reset = return_trace_reset, + .print_line = print_return_function +}; + +static __init int init_return_trace(void) +{ + return register_tracer(&return_trace); +} + +device_initcall(init_return_trace); -- cgit v1.2.3-70-g09d2 From 3f5ec13696fd4a33bde42f385406cbb1d3cc96fd Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 11 Nov 2008 23:21:31 +0100 Subject: tracing/fastboot: move boot tracer structs and funcs into their own header. Impact: Cleanups on the boot tracer and ftrace This patch bring some cleanups about the boot tracer headers. The functions and structures of this tracer have nothing related to ftrace and should have so their own header file. Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- include/linux/ftrace.h | 41 ----------------------------------------- include/trace/boot.h | 43 +++++++++++++++++++++++++++++++++++++++++++ init/main.c | 1 + kernel/trace/trace.h | 1 + 4 files changed, 45 insertions(+), 41 deletions(-) create mode 100644 include/trace/boot.h (limited to 'kernel/trace/trace.h') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index dcbbf72a88b..4fbc4a8b86a 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -287,45 +287,4 @@ extern trace_function_return_t ftrace_function_return; extern void unregister_ftrace_return(void); #endif -/* - * Structure which defines the trace of an initcall. - * You don't have to fill the func field since it is - * only used internally by the tracer. - */ -struct boot_trace { - pid_t caller; - char func[KSYM_NAME_LEN]; - int result; - unsigned long long duration; /* usecs */ - ktime_t calltime; - ktime_t rettime; -}; - -#ifdef CONFIG_BOOT_TRACER -/* Append the trace on the ring-buffer */ -extern void trace_boot(struct boot_trace *it, initcall_t fn); - -/* Tells the tracer that smp_pre_initcall is finished. - * So we can start the tracing - */ -extern void start_boot_trace(void); - -/* Resume the tracing of other necessary events - * such as sched switches - */ -extern void enable_boot_trace(void); - -/* Suspend this tracing. Actually, only sched_switches tracing have - * to be suspended. Initcalls doesn't need it.) - */ -extern void disable_boot_trace(void); -#else -static inline void trace_boot(struct boot_trace *it, initcall_t fn) { } -static inline void start_boot_trace(void) { } -static inline void enable_boot_trace(void) { } -static inline void disable_boot_trace(void) { } -#endif - - - #endif /* _LINUX_FTRACE_H */ diff --git a/include/trace/boot.h b/include/trace/boot.h new file mode 100644 index 00000000000..4cbe64e46cd --- /dev/null +++ b/include/trace/boot.h @@ -0,0 +1,43 @@ +#ifndef _LINUX_TRACE_BOOT_H +#define _LINUX_TRACE_BOOT_H + +/* + * Structure which defines the trace of an initcall. + * You don't have to fill the func field since it is + * only used internally by the tracer. + */ +struct boot_trace { + pid_t caller; + char func[KSYM_NAME_LEN]; + int result; + unsigned long long duration; /* usecs */ + ktime_t calltime; + ktime_t rettime; +}; + +#ifdef CONFIG_BOOT_TRACER +/* Append the trace on the ring-buffer */ +extern void trace_boot(struct boot_trace *it, initcall_t fn); + +/* Tells the tracer that smp_pre_initcall is finished. + * So we can start the tracing + */ +extern void start_boot_trace(void); + +/* Resume the tracing of other necessary events + * such as sched switches + */ +extern void enable_boot_trace(void); + +/* Suspend this tracing. Actually, only sched_switches tracing have + * to be suspended. Initcalls doesn't need it.) + */ +extern void disable_boot_trace(void); +#else +static inline void trace_boot(struct boot_trace *it, initcall_t fn) { } +static inline void start_boot_trace(void) { } +static inline void enable_boot_trace(void) { } +static inline void disable_boot_trace(void) { } +#endif /* CONFIG_BOOT_TRACER */ + +#endif /* __LINUX_TRACE_BOOT_H */ diff --git a/init/main.c b/init/main.c index 4b03cd5656c..16ca1ee071c 100644 --- a/init/main.c +++ b/init/main.c @@ -63,6 +63,7 @@ #include #include #include +#include #include #include diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index e40ce0c1469..f69a5199596 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -8,6 +8,7 @@ #include #include #include +#include enum trace_type { __TRACE_FIRST_TYPE = 0, -- cgit v1.2.3-70-g09d2 From 74239072830ef3f1398edeb1bc1076fc330fd4a2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 11 Nov 2008 23:24:42 +0100 Subject: tracing/fastboot: Use the ring-buffer timestamp for initcall entries Impact: Split the boot tracer entries in two parts: call and return Now that we are using the sched tracer from the boot tracer, we want to use the same timestamp than the ring-buffer to have consistent time captures between sched events and initcall events. So we get rid of the old time capture by the boot tracer and split the initcall events in two parts: call and return. This way we have the ring buffer timestamp of both. An example trace: [ 27.904149584] calling net_ns_init+0x0/0x1c0 @ 1 [ 27.904429624] initcall net_ns_init+0x0/0x1c0 returned 0 after 0 msecs [ 27.904575926] calling reboot_init+0x0/0x20 @ 1 [ 27.904655399] initcall reboot_init+0x0/0x20 returned 0 after 0 msecs [ 27.904800228] calling sysctl_init+0x0/0x30 @ 1 [ 27.905142914] initcall sysctl_init+0x0/0x30 returned 0 after 0 msecs [ 27.905287211] calling ksysfs_init+0x0/0xb0 @ 1 ##### CPU 0 buffer started #### init-1 [000] 27.905395: 1:120:R + [001] 11:115:S ##### CPU 1 buffer started #### -0 [001] 27.905425: 0:140:R ==> [001] 11:115:R init-1 [000] 27.905426: 1:120:D ==> [000] 0:140:R -0 [000] 27.905431: 0:140:R + [000] 4:115:S -0 [000] 27.905451: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905456: 4:115:S ==> [000] 0:140:R udevd-11 [001] 27.905458: 11:115:R + [001] 14:115:R -0 [000] 27.905459: 0:140:R + [000] 4:115:S -0 [000] 27.905462: 0:140:R ==> [000] 4:115:R udevd-11 [001] 27.905462: 11:115:R ==> [001] 14:115:R ksoftirqd/0-4 [000] 27.905467: 4:115:S ==> [000] 0:140:R -0 [000] 27.905470: 0:140:R + [000] 4:115:S -0 [000] 27.905473: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905476: 4:115:S ==> [000] 0:140:R -0 [000] 27.905479: 0:140:R + [000] 4:115:S -0 [000] 27.905482: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905486: 4:115:S ==> [000] 0:140:R udevd-14 [001] 27.905499: 14:120:X ==> [001] 11:115:R udevd-11 [001] 27.905506: 11:115:R + [000] 1:120:D -0 [000] 27.905515: 0:140:R ==> [000] 1:120:R udevd-11 [001] 27.905517: 11:115:S ==> [001] 0:140:R [ 27.905557107] initcall ksysfs_init+0x0/0xb0 returned 0 after 3906 msecs [ 27.905705736] calling init_jiffies_clocksource+0x0/0x10 @ 1 [ 27.905779239] initcall init_jiffies_clocksource+0x0/0x10 returned 0 after 0 msecs [ 27.906769814] calling pm_init+0x0/0x30 @ 1 [ 27.906853627] initcall pm_init+0x0/0x30 returned 0 after 0 msecs [ 27.906997803] calling pm_disk_init+0x0/0x20 @ 1 [ 27.907076946] initcall pm_disk_init+0x0/0x20 returned 0 after 0 msecs [ 27.907222556] calling swsusp_header_init+0x0/0x30 @ 1 [ 27.907294325] initcall swsusp_header_init+0x0/0x30 returned 0 after 0 msecs [ 27.907439620] calling stop_machine_init+0x0/0x50 @ 1 init-1 [000] 27.907485: 1:120:R + [000] 2:115:S init-1 [000] 27.907490: 1:120:D ==> [000] 2:115:R kthreadd-2 [000] 27.907507: 2:115:R + [001] 15:115:R -0 [001] 27.907517: 0:140:R ==> [001] 15:115:R kthreadd-2 [000] 27.907517: 2:115:D ==> [000] 0:140:R -0 [000] 27.907521: 0:140:R + [000] 4:115:S -0 [000] 27.907524: 0:140:R ==> [000] 4:115:R udevd-15 [001] 27.907527: 15:115:D + [000] 2:115:D ksoftirqd/0-4 [000] 27.907537: 4:115:S ==> [000] 2:115:R udevd-15 [001] 27.907537: 15:115:D ==> [001] 0:140:R kthreadd-2 [000] 27.907546: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907550: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907584: 1:120:R + [000] 15: 0:D init-1 [000] 27.907589: 1:120:R + [000] 2:115:S init-1 [000] 27.907593: 1:120:D ==> [000] 15: 0:R udevd-15 [000] 27.907601: 15: 0:S ==> [000] 2:115:R ##### CPU 0 buffer started #### kthreadd-2 [000] 27.907616: 2:115:R + [001] 16:115:R ##### CPU 1 buffer started #### -0 [001] 27.907620: 0:140:R ==> [001] 16:115:R kthreadd-2 [000] 27.907621: 2:115:D ==> [000] 0:140:R udevd-16 [001] 27.907625: 16:115:D + [000] 2:115:D -0 [000] 27.907628: 0:140:R + [000] 4:115:S udevd-16 [001] 27.907629: 16:115:D ==> [001] 0:140:R -0 [000] 27.907631: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.907636: 4:115:S ==> [000] 2:115:R kthreadd-2 [000] 27.907644: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907647: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907657: 1:120:R + [001] 16: 0:D -0 [001] 27.907666: 0:140:R ==> [001] 16: 0:R [ 27.907703862] initcall stop_machine_init+0x0/0x50 returned 0 after 0 msecs [ 27.907850704] calling filelock_init+0x0/0x30 @ 1 [ 27.907926573] initcall filelock_init+0x0/0x30 returned 0 after 0 msecs [ 27.908071327] calling init_script_binfmt+0x0/0x10 @ 1 [ 27.908165195] initcall init_script_binfmt+0x0/0x10 returned 0 after 0 msecs [ 27.908309461] calling init_elf_binfmt+0x0/0x10 @ 1 Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- include/trace/boot.h | 31 ++++++++---- init/main.c | 32 ++++++------ kernel/trace/trace.h | 17 +++++-- kernel/trace/trace_boot.c | 123 +++++++++++++++++++++++++++++++++++----------- 4 files changed, 144 insertions(+), 59 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/include/trace/boot.h b/include/trace/boot.h index 4cbe64e46cd..6b54537eab0 100644 --- a/include/trace/boot.h +++ b/include/trace/boot.h @@ -2,22 +2,30 @@ #define _LINUX_TRACE_BOOT_H /* - * Structure which defines the trace of an initcall. + * Structure which defines the trace of an initcall + * while it is called. * You don't have to fill the func field since it is * only used internally by the tracer. */ -struct boot_trace { +struct boot_trace_call { pid_t caller; char func[KSYM_NAME_LEN]; - int result; - unsigned long long duration; /* usecs */ - ktime_t calltime; - ktime_t rettime; +}; + +/* + * Structure which defines the trace of an initcall + * while it returns. + */ +struct boot_trace_ret { + char func[KSYM_NAME_LEN]; + int result; + unsigned long long duration; /* nsecs */ }; #ifdef CONFIG_BOOT_TRACER -/* Append the trace on the ring-buffer */ -extern void trace_boot(struct boot_trace *it, initcall_t fn); +/* Append the traces on the ring-buffer */ +extern void trace_boot_call(struct boot_trace_call *bt, initcall_t fn); +extern void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn); /* Tells the tracer that smp_pre_initcall is finished. * So we can start the tracing @@ -34,7 +42,12 @@ extern void enable_boot_trace(void); */ extern void disable_boot_trace(void); #else -static inline void trace_boot(struct boot_trace *it, initcall_t fn) { } +static inline +void trace_boot_call(struct boot_trace_call *bt, initcall_t fn) { } + +static inline +void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) { } + static inline void start_boot_trace(void) { } static inline void enable_boot_trace(void) { } static inline void disable_boot_trace(void) { } diff --git a/init/main.c b/init/main.c index 16ca1ee071c..e810196bf2f 100644 --- a/init/main.c +++ b/init/main.c @@ -704,33 +704,35 @@ core_param(initcall_debug, initcall_debug, bool, 0644); int do_one_initcall(initcall_t fn) { int count = preempt_count(); - ktime_t delta; + ktime_t calltime, delta, rettime; char msgbuf[64]; - struct boot_trace it; + struct boot_trace_call call; + struct boot_trace_ret ret; if (initcall_debug) { - it.caller = task_pid_nr(current); - printk("calling %pF @ %i\n", fn, it.caller); - it.calltime = ktime_get(); + call.caller = task_pid_nr(current); + printk("calling %pF @ %i\n", fn, call.caller); + calltime = ktime_get(); + trace_boot_call(&call, fn); enable_boot_trace(); } - it.result = fn(); + ret.result = fn(); if (initcall_debug) { - it.rettime = ktime_get(); - delta = ktime_sub(it.rettime, it.calltime); - it.duration = (unsigned long long) delta.tv64 >> 10; - printk("initcall %pF returned %d after %Ld usecs\n", fn, - it.result, it.duration); - trace_boot(&it, fn); disable_boot_trace(); + rettime = ktime_get(); + delta = ktime_sub(rettime, calltime); + ret.duration = (unsigned long long) delta.tv64 >> 10; + trace_boot_ret(&ret, fn); + printk("initcall %pF returned %d after %Ld usecs\n", fn, + ret.result, ret.duration); } msgbuf[0] = 0; - if (it.result && it.result != -ENODEV && initcall_debug) - sprintf(msgbuf, "error code %d ", it.result); + if (ret.result && ret.result != -ENODEV && initcall_debug) + sprintf(msgbuf, "error code %d ", ret.result); if (preempt_count() != count) { strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); @@ -744,7 +746,7 @@ int do_one_initcall(initcall_t fn) printk("initcall %pF returned with %s\n", fn, msgbuf); } - return it.result; + return ret.result; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f69a5199596..b5f91f198fd 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -22,7 +22,8 @@ enum trace_type { TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, - TRACE_BOOT, + TRACE_BOOT_CALL, + TRACE_BOOT_RET, TRACE_FN_RET, __TRACE_LAST_TYPE @@ -123,9 +124,14 @@ struct trace_mmiotrace_map { struct mmiotrace_map map; }; -struct trace_boot { +struct trace_boot_call { struct trace_entry ent; - struct boot_trace initcall; + struct boot_trace_call boot_call; +}; + +struct trace_boot_ret { + struct trace_entry ent; + struct boot_trace_ret boot_ret; }; /* @@ -228,8 +234,9 @@ extern void __ftrace_bad_type(void); TRACE_MMIO_RW); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ TRACE_MMIO_MAP); \ - IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \ - IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET); \ + IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ + IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ + IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 8f71915e8bb..cb333b7fd11 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -58,35 +58,71 @@ static void boot_trace_init(struct trace_array *tr) tracing_sched_switch_assign_trace(tr); } -static enum print_line_t initcall_print_line(struct trace_iterator *iter) +static enum print_line_t +initcall_call_print_line(struct trace_iterator *iter) { + struct trace_entry *entry = iter->ent; + struct trace_seq *s = &iter->seq; + struct trace_boot_call *field; + struct boot_trace_call *call; + u64 ts; + unsigned long nsec_rem; int ret; + + trace_assign_type(field, entry); + call = &field->boot_call; + ts = iter->ts; + nsec_rem = do_div(ts, 1000000000); + + ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", + (unsigned long)ts, nsec_rem, call->func, call->caller); + + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + else + return TRACE_TYPE_HANDLED; +} + +static enum print_line_t +initcall_ret_print_line(struct trace_iterator *iter) +{ struct trace_entry *entry = iter->ent; - struct trace_boot *field = (struct trace_boot *)entry; - struct boot_trace *it = &field->initcall; struct trace_seq *s = &iter->seq; - struct timespec calltime = ktime_to_timespec(it->calltime); - struct timespec rettime = ktime_to_timespec(it->rettime); - - if (entry->type == TRACE_BOOT) { - ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", - calltime.tv_sec, - calltime.tv_nsec, - it->func, it->caller); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " - "returned %d after %lld msecs\n", - rettime.tv_sec, - rettime.tv_nsec, - it->func, it->result, it->duration); - - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + struct trace_boot_ret *field; + struct boot_trace_ret *init_ret; + u64 ts; + unsigned long nsec_rem; + int ret; + + trace_assign_type(field, entry); + init_ret = &field->boot_ret; + ts = iter->ts; + nsec_rem = do_div(ts, 1000000000); + + ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " + "returned %d after %llu msecs\n", + (unsigned long) ts, + nsec_rem, + init_ret->func, init_ret->result, init_ret->duration); + + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + else return TRACE_TYPE_HANDLED; +} + +static enum print_line_t initcall_print_line(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + + switch (entry->type) { + case TRACE_BOOT_CALL: + return initcall_call_print_line(iter); + case TRACE_BOOT_RET: + return initcall_ret_print_line(iter); + default: + return TRACE_TYPE_UNHANDLED; } - return TRACE_TYPE_UNHANDLED; } struct tracer boot_tracer __read_mostly = @@ -97,11 +133,10 @@ struct tracer boot_tracer __read_mostly = .print_line = initcall_print_line, }; -void trace_boot(struct boot_trace *it, initcall_t fn) +void trace_boot_call(struct boot_trace_call *bt, initcall_t fn) { struct ring_buffer_event *event; - struct trace_boot *entry; - struct trace_array_cpu *data; + struct trace_boot_call *entry; unsigned long irq_flags; struct trace_array *tr = boot_trace; @@ -111,9 +146,37 @@ void trace_boot(struct boot_trace *it, initcall_t fn) /* Get its name now since this function could * disappear because it is in the .init section. */ - sprint_symbol(it->func, (unsigned long)fn); + sprint_symbol(bt->func, (unsigned long)fn); + preempt_disable(); + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, 0); + entry->ent.type = TRACE_BOOT_CALL; + entry->boot_call = *bt; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); + + out: + preempt_enable(); +} + +void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) +{ + struct ring_buffer_event *event; + struct trace_boot_ret *entry; + unsigned long irq_flags; + struct trace_array *tr = boot_trace; + + if (!pre_initcalls_finished) + return; + + sprint_symbol(bt->func, (unsigned long)fn); preempt_disable(); - data = tr->data[smp_processor_id()]; event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq_flags); @@ -121,8 +184,8 @@ void trace_boot(struct boot_trace *it, initcall_t fn) goto out; entry = ring_buffer_event_data(event); tracing_generic_entry_update(&entry->ent, 0, 0); - entry->ent.type = TRACE_BOOT; - entry->initcall = *it; + entry->ent.type = TRACE_BOOT_RET; + entry->boot_ret = *bt; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); trace_wake_up(); -- cgit v1.2.3-70-g09d2 From 52f232cb720a7babb752849cbc2cab2d24021209 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Nov 2008 00:14:40 -0500 Subject: tracing: likely/unlikely branch annotation tracer Impact: new likely/unlikely branch tracer This patch adds a way to record the instances of the likely() and unlikely() branch condition annotations. When "unlikely" is set in /debugfs/tracing/iter_ctrl the unlikely conditions will be added to any of the ftrace tracers. The change takes effect when a new tracer is passed into the current_tracer file. For example: bash-3471 [003] 357.014755: [INCORRECT] sched_info_dequeued:sched_stats.h:177 bash-3471 [003] 357.014756: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014758: [correct] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014759: [correct] account_group_exec_runtime:sched_stats.h:356 bash-3471 [003] 357.014761: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014763: [INCORRECT] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014765: [correct] calc_delta_mine:sched.c:1279 Which shows the normal tracer heading, as well as whether the condition was correct "[correct]" or was mistaken "[INCORRECT]", followed by the function, file name and line number. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 22 ++++++++ kernel/trace/Makefile | 6 +++ kernel/trace/trace.c | 29 +++++++++++ kernel/trace/trace.h | 39 +++++++++++++++ kernel/trace/trace_unlikely.c | 114 ++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 210 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a604f24c755..8abcaf821be 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -175,6 +175,28 @@ config TRACE_UNLIKELY_PROFILE Say N if unsure. +config TRACING_UNLIKELY + bool + help + Selected by tracers that will trace the likely and unlikely + conditions. This prevents the tracers themselves from being + profiled. Profiling the tracing infrastructure can only happen + when the likelys and unlikelys are not being traced. + +config UNLIKELY_TRACER + bool "Trace likely/unlikely instances" + depends on TRACE_UNLIKELY_PROFILE + select TRACING_UNLIKELY + help + This traces the events of likely and unlikely condition + calls in the kernel. The difference between this and the + "Trace likely/unlikely profiler" is that this is not a + histogram of the callers, but actually places the calling + events into a running trace buffer to see when and where the + events happened, as well as their results. + + Say N if unsure. + config STACK_TRACER bool "Trace max stack" depends on HAVE_FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 98e70ee2798..c938d03516c 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -10,6 +10,12 @@ CFLAGS_trace_selftest_dynamic.o = -pg obj-y += trace_selftest_dynamic.o endif +# If unlikely tracing is enabled, do not trace these files +ifdef CONFIG_TRACING_UNLIKELY +KBUILD_CFLAGS += '-Dlikely(x)=likely_notrace(x)' +KBUILD_CFLAGS += '-Dunlikely(x)=unlikely_notrace(x)' +endif + obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o obj-$(CONFIG_RING_BUFFER) += ring_buffer.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a3f7ae9cd8e..83d38634bc9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -258,6 +258,9 @@ static const char *trace_options[] = { "sched-tree", "ftrace_printk", "ftrace_preempt", +#ifdef CONFIG_UNLIKELY_TRACER + "unlikely", +#endif NULL }; @@ -1648,6 +1651,18 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) trace_seq_print_cont(s, iter); break; } + case TRACE_UNLIKELY: { + struct trace_unlikely *field; + + trace_assign_type(field, entry); + + trace_seq_printf(s, "[%s] %s:%s:%d\n", + field->correct ? "correct" : "INCORRECT", + field->func, + field->file, + field->line); + break; + } default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } @@ -1787,6 +1802,18 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) return print_return_function(iter); break; } + case TRACE_UNLIKELY: { + struct trace_unlikely *field; + + trace_assign_type(field, entry); + + trace_seq_printf(s, "[%s] %s:%s:%d\n", + field->correct ? "correct" : "INCORRECT", + field->func, + field->file, + field->line); + break; + } } return TRACE_TYPE_HANDLED; } @@ -2592,6 +2619,7 @@ static int tracing_set_tracer(char *buf) if (t == current_trace) goto out; + trace_unlikely_disable(); if (current_trace && current_trace->reset) current_trace->reset(tr); @@ -2599,6 +2627,7 @@ static int tracing_set_tracer(char *buf) if (t->init) t->init(tr); + trace_unlikely_enable(tr); out: mutex_unlock(&trace_types_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b5f91f198fd..9635aa2c4fc 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -22,6 +22,7 @@ enum trace_type { TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, + TRACE_UNLIKELY, TRACE_BOOT_CALL, TRACE_BOOT_RET, TRACE_FN_RET, @@ -134,6 +135,16 @@ struct trace_boot_ret { struct boot_trace_ret boot_ret; }; +#define TRACE_FUNC_SIZE 30 +#define TRACE_FILE_SIZE 20 +struct trace_unlikely { + struct trace_entry ent; + unsigned line; + char func[TRACE_FUNC_SIZE+1]; + char file[TRACE_FILE_SIZE+1]; + char correct; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -236,6 +247,7 @@ extern void __ftrace_bad_type(void); TRACE_MMIO_MAP); \ IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ + IF_ASSIGN(var, ent, struct trace_unlikely, TRACE_UNLIKELY); \ IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ __ftrace_bad_type(); \ } while (0) @@ -456,6 +468,9 @@ enum trace_iterator_flags { TRACE_ITER_SCHED_TREE = 0x200, TRACE_ITER_PRINTK = 0x400, TRACE_ITER_PREEMPTONLY = 0x800, +#ifdef CONFIG_UNLIKELY_TRACER + TRACE_ITER_UNLIKELY = 0x1000, +#endif }; /* @@ -515,4 +530,28 @@ static inline void ftrace_preempt_enable(int resched) preempt_enable_notrace(); } +#ifdef CONFIG_UNLIKELY_TRACER +extern int enable_unlikely_tracing(struct trace_array *tr); +extern void disable_unlikely_tracing(void); +static inline int trace_unlikely_enable(struct trace_array *tr) +{ + if (trace_flags & TRACE_ITER_UNLIKELY) + return enable_unlikely_tracing(tr); + return 0; +} +static inline void trace_unlikely_disable(void) +{ + /* due to races, always disable */ + disable_unlikely_tracing(); +} +#else +static inline int trace_unlikely_enable(struct trace_array *tr) +{ + return 0; +} +static inline void trace_unlikely_disable(void) +{ +} +#endif /* CONFIG_UNLIKELY_TRACER */ + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_unlikely.c b/kernel/trace/trace_unlikely.c index 94932696069..7290e0e7b4e 100644 --- a/kernel/trace/trace_unlikely.c +++ b/kernel/trace/trace_unlikely.c @@ -15,8 +15,122 @@ #include #include "trace.h" +#ifdef CONFIG_UNLIKELY_TRACER + +static int unlikely_tracing_enabled __read_mostly; +static DEFINE_MUTEX(unlikely_tracing_mutex); +static struct trace_array *unlikely_tracer; + +static void +probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) +{ + struct trace_array *tr = unlikely_tracer; + struct ring_buffer_event *event; + struct trace_unlikely *entry; + unsigned long flags, irq_flags; + int cpu, pc; + const char *p; + + /* + * I would love to save just the ftrace_likely_data pointer, but + * this code can also be used by modules. Ugly things can happen + * if the module is unloaded, and then we go and read the + * pointer. This is slower, but much safer. + */ + + if (unlikely(!tr)) + return; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) + goto out; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + + pc = preempt_count(); + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_UNLIKELY; + + /* Strip off the path, only save the file */ + p = f->file + strlen(f->file); + while (p >= f->file && *p != '/') + p--; + p++; + + strncpy(entry->func, f->func, TRACE_FUNC_SIZE); + strncpy(entry->file, p, TRACE_FILE_SIZE); + entry->func[TRACE_FUNC_SIZE] = 0; + entry->file[TRACE_FILE_SIZE] = 0; + entry->line = f->line; + entry->correct = val == expect; + + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + out: + atomic_dec(&tr->data[cpu]->disabled); + local_irq_restore(flags); +} + +static inline +void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) +{ + if (!unlikely_tracing_enabled) + return; + + probe_likely_condition(f, val, expect); +} + +int enable_unlikely_tracing(struct trace_array *tr) +{ + int ret = 0; + + mutex_lock(&unlikely_tracing_mutex); + unlikely_tracer = tr; + /* + * Must be seen before enabling. The reader is a condition + * where we do not need a matching rmb() + */ + smp_wmb(); + unlikely_tracing_enabled++; + mutex_unlock(&unlikely_tracing_mutex); + + return ret; +} + +void disable_unlikely_tracing(void) +{ + mutex_lock(&unlikely_tracing_mutex); + + if (!unlikely_tracing_enabled) + goto out_unlock; + + unlikely_tracing_enabled--; + + out_unlock: + mutex_unlock(&unlikely_tracing_mutex); +} +#else +static inline +void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) +{ +} +#endif /* CONFIG_UNLIKELY_TRACER */ + void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect) { + /* + * I would love to have a trace point here instead, but the + * trace point code is so inundated with unlikely and likely + * conditions that the recursive nightmare that exists is too + * much to try to get working. At least for now. + */ + trace_likely_condition(f, val, expect); + /* FIXME: Make this atomic! */ if (val == expect) f->correct++; -- cgit v1.2.3-70-g09d2 From 2ed84eeb8808cf3c9f039213ca137ffd7d753f0e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Nov 2008 15:24:24 -0500 Subject: trace: rename unlikely profiler to branch profiler Impact: name change of unlikely tracer and profiler Ingo Molnar suggested changing the config from UNLIKELY_PROFILE to BRANCH_PROFILING. I never did like the "unlikely" name so I went one step farther, and renamed all the unlikely configurations to a "BRANCH" variant. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/vsyscall_64.c | 2 +- arch/x86/vdso/vclock_gettime.c | 2 +- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/compiler.h | 19 ++++++++++--------- kernel/trace/Kconfig | 10 +++++----- kernel/trace/Makefile | 7 +++---- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 6 +++--- kernel/trace/trace_unlikely.c | 4 ++-- 9 files changed, 27 insertions(+), 27 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index ece02932ea5..6f3d3d4cd97 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -18,7 +18,7 @@ */ /* Disable profiling for userspace code: */ -#define DISABLE_UNLIKELY_PROFILE +#define DISABLE_BRANCH_PROFILING #include #include diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 6e667631e7d..d9d35824c56 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -10,7 +10,7 @@ */ /* Disable profiling for userspace code: */ -#define DISABLE_UNLIKELY_PROFILE +#define DISABLE_BRANCH_PROFILING #include #include diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index e10beb5335c..a5e4ed9baec 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -45,7 +45,7 @@ #define MCOUNT_REC() #endif -#ifdef CONFIG_TRACE_UNLIKELY_PROFILE +#ifdef CONFIG_TRACE_BRANCH_PROFILING #define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_likely_profile) = .; \ *(_ftrace_likely) \ VMLINUX_SYMBOL(__stop_likely_profile) = .; \ diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 63b7d9089d6..c7d804a7a4d 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -59,26 +59,27 @@ extern void __chk_io_ptr(const volatile void __iomem *); * specific implementations come from the above header files */ -/* - * Note: DISABLE_UNLIKELY_PROFILE can be used by special lowlevel code - * to disable branch tracing on a per file basis. - */ -#if defined(CONFIG_TRACE_UNLIKELY_PROFILE) && !defined(DISABLE_UNLIKELY_PROFILE) -struct ftrace_likely_data { +struct ftrace_branch_data { const char *func; const char *file; unsigned line; unsigned long correct; unsigned long incorrect; }; -void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect); + +/* + * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code + * to disable branch tracing on a per file basis. + */ +#if defined(CONFIG_TRACE_BRANCH_PROFILING) && !defined(DISABLE_BRANCH_PROFILING) +void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #define likely_notrace(x) __builtin_expect(!!(x), 1) #define unlikely_notrace(x) __builtin_expect(!!(x), 0) #define likely_check(x) ({ \ int ______r; \ - static struct ftrace_likely_data \ + static struct ftrace_branch_data \ __attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_likely"))) \ ______f = { \ @@ -93,7 +94,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect); }) #define unlikely_check(x) ({ \ int ______r; \ - static struct ftrace_likely_data \ + static struct ftrace_branch_data \ __attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_unlikely"))) \ ______f = { \ diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 8abcaf821be..9c89526b6b7 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -159,7 +159,7 @@ config BOOT_TRACER selected, because the self-tests are an initcall as well and that would invalidate the boot trace. ) -config TRACE_UNLIKELY_PROFILE +config TRACE_BRANCH_PROFILING bool "Trace likely/unlikely profiler" depends on DEBUG_KERNEL select TRACING @@ -175,7 +175,7 @@ config TRACE_UNLIKELY_PROFILE Say N if unsure. -config TRACING_UNLIKELY +config TRACING_BRANCHES bool help Selected by tracers that will trace the likely and unlikely @@ -183,10 +183,10 @@ config TRACING_UNLIKELY profiled. Profiling the tracing infrastructure can only happen when the likelys and unlikelys are not being traced. -config UNLIKELY_TRACER +config BRANCH_TRACER bool "Trace likely/unlikely instances" - depends on TRACE_UNLIKELY_PROFILE - select TRACING_UNLIKELY + depends on TRACE_BRANCH_PROFILING + select TRACING_BRANCHES help This traces the events of likely and unlikely condition calls in the kernel. The difference between this and the diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index c938d03516c..0087df7ba44 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -11,9 +11,8 @@ obj-y += trace_selftest_dynamic.o endif # If unlikely tracing is enabled, do not trace these files -ifdef CONFIG_TRACING_UNLIKELY -KBUILD_CFLAGS += '-Dlikely(x)=likely_notrace(x)' -KBUILD_CFLAGS += '-Dunlikely(x)=unlikely_notrace(x)' +ifdef CONFIG_TRACING_BRANCHES +KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING endif obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o @@ -31,6 +30,6 @@ obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o -obj-$(CONFIG_TRACE_UNLIKELY_PROFILE) += trace_unlikely.o +obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_unlikely.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d842db14a59..bad59d32a4a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -258,7 +258,7 @@ static const char *trace_options[] = { "sched-tree", "ftrace_printk", "ftrace_preempt", -#ifdef CONFIG_UNLIKELY_TRACER +#ifdef CONFIG_BRANCH_TRACER "unlikely", #endif NULL diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9635aa2c4fc..dccae631294 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -468,7 +468,7 @@ enum trace_iterator_flags { TRACE_ITER_SCHED_TREE = 0x200, TRACE_ITER_PRINTK = 0x400, TRACE_ITER_PREEMPTONLY = 0x800, -#ifdef CONFIG_UNLIKELY_TRACER +#ifdef CONFIG_BRANCH_TRACER TRACE_ITER_UNLIKELY = 0x1000, #endif }; @@ -530,7 +530,7 @@ static inline void ftrace_preempt_enable(int resched) preempt_enable_notrace(); } -#ifdef CONFIG_UNLIKELY_TRACER +#ifdef CONFIG_BRANCH_TRACER extern int enable_unlikely_tracing(struct trace_array *tr); extern void disable_unlikely_tracing(void); static inline int trace_unlikely_enable(struct trace_array *tr) @@ -552,6 +552,6 @@ static inline int trace_unlikely_enable(struct trace_array *tr) static inline void trace_unlikely_disable(void) { } -#endif /* CONFIG_UNLIKELY_TRACER */ +#endif /* CONFIG_BRANCH_TRACER */ #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_unlikely.c b/kernel/trace/trace_unlikely.c index 7290e0e7b4e..856eb3b7f69 100644 --- a/kernel/trace/trace_unlikely.c +++ b/kernel/trace/trace_unlikely.c @@ -15,7 +15,7 @@ #include #include "trace.h" -#ifdef CONFIG_UNLIKELY_TRACER +#ifdef CONFIG_BRANCH_TRACER static int unlikely_tracing_enabled __read_mostly; static DEFINE_MUTEX(unlikely_tracing_mutex); @@ -119,7 +119,7 @@ static inline void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) { } -#endif /* CONFIG_UNLIKELY_TRACER */ +#endif /* CONFIG_BRANCH_TRACER */ void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect) { -- cgit v1.2.3-70-g09d2 From 9f029e83e968e5661d7be045bbcb620dbb909938 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Nov 2008 15:24:24 -0500 Subject: ftrace: rename unlikely iter_ctrl to branch Impact: rename of iter_ctrl unlikely to branch The unlikely name is ugly. This patch converts the iter_ctrl command "unlikely" and "nounlikely" to "branch" and "nobranch" respectively. It also renames a lot of internal functions to use "branch" instead of "unlikely". Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 14 ++++++------ kernel/trace/trace.h | 26 +++++++++++----------- kernel/trace/trace_unlikely.c | 50 +++++++++++++++++++++---------------------- 3 files changed, 45 insertions(+), 45 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bad59d32a4a..4bf070bb527 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -259,7 +259,7 @@ static const char *trace_options[] = { "ftrace_printk", "ftrace_preempt", #ifdef CONFIG_BRANCH_TRACER - "unlikely", + "branch", #endif NULL }; @@ -1651,8 +1651,8 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) trace_seq_print_cont(s, iter); break; } - case TRACE_UNLIKELY: { - struct trace_unlikely *field; + case TRACE_BRANCH: { + struct trace_branch *field; trace_assign_type(field, entry); @@ -1802,8 +1802,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) return print_return_function(iter); break; } - case TRACE_UNLIKELY: { - struct trace_unlikely *field; + case TRACE_BRANCH: { + struct trace_branch *field; trace_assign_type(field, entry); @@ -2619,7 +2619,7 @@ static int tracing_set_tracer(char *buf) if (t == current_trace) goto out; - trace_unlikely_disable(); + trace_branch_disable(); if (current_trace && current_trace->reset) current_trace->reset(tr); @@ -2627,7 +2627,7 @@ static int tracing_set_tracer(char *buf) if (t->init) t->init(tr); - trace_unlikely_enable(tr); + trace_branch_enable(tr); out: mutex_unlock(&trace_types_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index dccae631294..7fbf37b2745 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -22,7 +22,7 @@ enum trace_type { TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, - TRACE_UNLIKELY, + TRACE_BRANCH, TRACE_BOOT_CALL, TRACE_BOOT_RET, TRACE_FN_RET, @@ -137,7 +137,7 @@ struct trace_boot_ret { #define TRACE_FUNC_SIZE 30 #define TRACE_FILE_SIZE 20 -struct trace_unlikely { +struct trace_branch { struct trace_entry ent; unsigned line; char func[TRACE_FUNC_SIZE+1]; @@ -247,7 +247,7 @@ extern void __ftrace_bad_type(void); TRACE_MMIO_MAP); \ IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ - IF_ASSIGN(var, ent, struct trace_unlikely, TRACE_UNLIKELY); \ + IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ __ftrace_bad_type(); \ } while (0) @@ -469,7 +469,7 @@ enum trace_iterator_flags { TRACE_ITER_PRINTK = 0x400, TRACE_ITER_PREEMPTONLY = 0x800, #ifdef CONFIG_BRANCH_TRACER - TRACE_ITER_UNLIKELY = 0x1000, + TRACE_ITER_BRANCH = 0x1000, #endif }; @@ -531,25 +531,25 @@ static inline void ftrace_preempt_enable(int resched) } #ifdef CONFIG_BRANCH_TRACER -extern int enable_unlikely_tracing(struct trace_array *tr); -extern void disable_unlikely_tracing(void); -static inline int trace_unlikely_enable(struct trace_array *tr) +extern int enable_branch_tracing(struct trace_array *tr); +extern void disable_branch_tracing(void); +static inline int trace_branch_enable(struct trace_array *tr) { - if (trace_flags & TRACE_ITER_UNLIKELY) - return enable_unlikely_tracing(tr); + if (trace_flags & TRACE_ITER_BRANCH) + return enable_branch_tracing(tr); return 0; } -static inline void trace_unlikely_disable(void) +static inline void trace_branch_disable(void) { /* due to races, always disable */ - disable_unlikely_tracing(); + disable_branch_tracing(); } #else -static inline int trace_unlikely_enable(struct trace_array *tr) +static inline int trace_branch_enable(struct trace_array *tr) { return 0; } -static inline void trace_unlikely_disable(void) +static inline void trace_branch_disable(void) { } #endif /* CONFIG_BRANCH_TRACER */ diff --git a/kernel/trace/trace_unlikely.c b/kernel/trace/trace_unlikely.c index 856eb3b7f69..e5d5969853a 100644 --- a/kernel/trace/trace_unlikely.c +++ b/kernel/trace/trace_unlikely.c @@ -17,16 +17,16 @@ #ifdef CONFIG_BRANCH_TRACER -static int unlikely_tracing_enabled __read_mostly; -static DEFINE_MUTEX(unlikely_tracing_mutex); -static struct trace_array *unlikely_tracer; +static int branch_tracing_enabled __read_mostly; +static DEFINE_MUTEX(branch_tracing_mutex); +static struct trace_array *branch_tracer; static void -probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) +probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) { - struct trace_array *tr = unlikely_tracer; + struct trace_array *tr = branch_tracer; struct ring_buffer_event *event; - struct trace_unlikely *entry; + struct trace_branch *entry; unsigned long flags, irq_flags; int cpu, pc; const char *p; @@ -54,7 +54,7 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) pc = preempt_count(); entry = ring_buffer_event_data(event); tracing_generic_entry_update(&entry->ent, flags, pc); - entry->ent.type = TRACE_UNLIKELY; + entry->ent.type = TRACE_BRANCH; /* Strip off the path, only save the file */ p = f->file + strlen(f->file); @@ -77,51 +77,51 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) } static inline -void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) +void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) { - if (!unlikely_tracing_enabled) + if (!branch_tracing_enabled) return; probe_likely_condition(f, val, expect); } -int enable_unlikely_tracing(struct trace_array *tr) +int enable_branch_tracing(struct trace_array *tr) { int ret = 0; - mutex_lock(&unlikely_tracing_mutex); - unlikely_tracer = tr; + mutex_lock(&branch_tracing_mutex); + branch_tracer = tr; /* * Must be seen before enabling. The reader is a condition * where we do not need a matching rmb() */ smp_wmb(); - unlikely_tracing_enabled++; - mutex_unlock(&unlikely_tracing_mutex); + branch_tracing_enabled++; + mutex_unlock(&branch_tracing_mutex); return ret; } -void disable_unlikely_tracing(void) +void disable_branch_tracing(void) { - mutex_lock(&unlikely_tracing_mutex); + mutex_lock(&branch_tracing_mutex); - if (!unlikely_tracing_enabled) + if (!branch_tracing_enabled) goto out_unlock; - unlikely_tracing_enabled--; + branch_tracing_enabled--; out_unlock: - mutex_unlock(&unlikely_tracing_mutex); + mutex_unlock(&branch_tracing_mutex); } #else static inline -void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) +void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) { } #endif /* CONFIG_BRANCH_TRACER */ -void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect) +void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect) { /* * I would love to have a trace point here instead, but the @@ -148,7 +148,7 @@ static void * t_next(struct seq_file *m, void *v, loff_t *pos) { struct ftrace_pointer *f = m->private; - struct ftrace_likely_data *p = v; + struct ftrace_branch_data *p = v; (*pos)++; @@ -180,7 +180,7 @@ static void t_stop(struct seq_file *m, void *p) static int t_show(struct seq_file *m, void *v) { - struct ftrace_likely_data *p = v; + struct ftrace_branch_data *p = v; const char *f; unsigned long percent; @@ -252,7 +252,7 @@ static struct ftrace_pointer ftrace_unlikely_pos = { .stop = __stop_unlikely_profile, }; -static __init int ftrace_unlikely_init(void) +static __init int ftrace_branch_init(void) { struct dentry *d_tracer; struct dentry *entry; @@ -275,4 +275,4 @@ static __init int ftrace_unlikely_init(void) return 0; } -device_initcall(ftrace_unlikely_init); +device_initcall(ftrace_branch_init); -- cgit v1.2.3-70-g09d2 From 80e5ea4506791af206266c5921c97f11d3b17866 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Nov 2008 15:24:24 -0500 Subject: ftrace: add tracer called branch Impact: added new branch tracer Currently the tracing of branch profiling (unlikelys and likelys hit) is only activated by the iter_ctrl. This patch adds a tracer called "branch" that will just trace the branch profiling. The advantage of adding this tracer is that it can be added to the ftrace selftests on startup. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 ++ kernel/trace/trace_selftest.c | 23 +++++++++++++++++++++++ kernel/trace/trace_unlikely.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 67 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 7fbf37b2745..9e015f5bea1 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -420,6 +420,8 @@ extern int trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); +extern int trace_selftest_startup_branch(struct tracer *trace, + struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 0728a105dcc..24e6e075e6d 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -13,6 +13,7 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_STACK: case TRACE_PRINT: case TRACE_SPECIAL: + case TRACE_BRANCH: return 1; } return 0; @@ -544,3 +545,25 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) return ret; } #endif /* CONFIG_SYSPROF_TRACER */ + +#ifdef CONFIG_BRANCH_TRACER +int +trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) +{ + unsigned long count; + int ret; + + /* start the tracing */ + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + /* stop the tracing. */ + tracing_stop(); + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + tracing_start(); + + return ret; +} +#endif /* CONFIG_BRANCH_TRACER */ diff --git a/kernel/trace/trace_unlikely.c b/kernel/trace/trace_unlikely.c index e5d5969853a..85265553918 100644 --- a/kernel/trace/trace_unlikely.c +++ b/kernel/trace/trace_unlikely.c @@ -114,6 +114,48 @@ void disable_branch_tracing(void) out_unlock: mutex_unlock(&branch_tracing_mutex); } + +static void start_branch_trace(struct trace_array *tr) +{ + enable_branch_tracing(tr); +} + +static void stop_branch_trace(struct trace_array *tr) +{ + disable_branch_tracing(); +} + +static void branch_trace_init(struct trace_array *tr) +{ + int cpu; + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + + start_branch_trace(tr); +} + +static void branch_trace_reset(struct trace_array *tr) +{ + stop_branch_trace(tr); +} + +struct tracer branch_trace __read_mostly = +{ + .name = "branch", + .init = branch_trace_init, + .reset = branch_trace_reset, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_branch, +#endif +}; + +__init static int init_branch_trace(void) +{ + return register_tracer(&branch_trace); +} + +device_initcall(init_branch_trace); #else static inline void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) -- cgit v1.2.3-70-g09d2 From 12ef7d448613ead2babd41c3ebfa1fe03c20edef Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Nov 2008 17:52:38 -0500 Subject: ftrace: CPU buffer start annotation clean ups Impact: better handling of CPU buffer start annotation Because of the confusion with the per CPU buffers wrapping where one CPU might be more active at the end of the trace than the other CPUs causing that one CPU to have a shorter history. Kernel developers were confused by the "missing" data of that one CPU at the beginning of the trace output. An annotation was added to the trace output to show that the buffer had started: # tracer: function # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | ##### CPU 3 buffer started #### -0 [003] 158.192959: smp_apic_timer_interrupt [...] -0 [003] 161.556520: default_idle ##### CPU 1 buffer started #### -0 [001] 161.592494: hrtimer_force_reprogram [etc] But this annotation gets a bit messy when tracers do not fill the buffers. This patch does a couple of things: One) it adds a flag to trace_options to disable these annotations Two) it does not annotate if the tracer did not overflow its buffer. This makes the output much cleaner. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 16 +++++++++++++++- kernel/trace/trace.h | 1 + 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 240423a9d1a..4a904623e05 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -205,7 +205,8 @@ static DEFINE_MUTEX(trace_types_lock); static DECLARE_WAIT_QUEUE_HEAD(trace_wait); /* trace_flags holds trace_options default values */ -unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK; +unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | + TRACE_ITER_ANNOTATE; /** * trace_wake_up - wake up tasks waiting for trace input @@ -261,6 +262,7 @@ static const char *trace_options[] = { #ifdef CONFIG_BRANCH_TRACER "branch", #endif + "annotate", NULL }; @@ -1113,6 +1115,7 @@ void tracing_stop_function_trace(void) enum trace_file_type { TRACE_FILE_LAT_FMT = 1, + TRACE_FILE_ANNOTATE = 2, }; static void trace_iterator_increment(struct trace_iterator *iter, int cpu) @@ -1532,6 +1535,12 @@ static void test_cpu_buff_start(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; + if (!(trace_flags & TRACE_ITER_ANNOTATE)) + return; + + if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) + return; + if (cpu_isset(iter->cpu, iter->started)) return; @@ -2132,6 +2141,11 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) iter->trace = current_trace; iter->pos = -1; + /* Annotate start of buffers if we had overruns */ + if (ring_buffer_overruns(iter->tr->buffer)) + iter->iter_flags |= TRACE_FILE_ANNOTATE; + + for_each_tracing_cpu(cpu) { iter->buffer_iter[cpu] = diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9e015f5bea1..790ea8c0e1f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -473,6 +473,7 @@ enum trace_iterator_flags { #ifdef CONFIG_BRANCH_TRACER TRACE_ITER_BRANCH = 0x1000, #endif + TRACE_ITER_ANNOTATE = 0x2000, }; /* -- cgit v1.2.3-70-g09d2 From 1c80025a49855b12fa09bb6db71820e3367b1369 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 16 Nov 2008 05:57:26 +0100 Subject: tracing/ftrace: change the type of the init() callback Impact: extend the ->init() method with the ability to fail This bring a way to know if the initialization of a tracer successed. A tracer must return 0 on success and a traditional error (ie: -ENOMEM) if it fails. If a tracer fails to init, it is free to print a detailed warn. The tracing api will not and switch to a new tracer will just return the error from the init callback. Note: this will be used for the return tracer. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 7 ++-- kernel/trace/trace.h | 3 +- kernel/trace/trace_boot.c | 3 +- kernel/trace/trace_branch.c | 3 +- kernel/trace/trace_functions.c | 3 +- kernel/trace/trace_functions_return.c | 3 +- kernel/trace/trace_irqsoff.c | 9 +++-- kernel/trace/trace_mmiotrace.c | 3 +- kernel/trace/trace_nop.c | 3 +- kernel/trace/trace_sched_switch.c | 3 +- kernel/trace/trace_sched_wakeup.c | 3 +- kernel/trace/trace_selftest.c | 66 ++++++++++++++++++++++++++++++----- kernel/trace/trace_sysprof.c | 3 +- 13 files changed, 88 insertions(+), 24 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 80898f4870c..396fda034e3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2638,8 +2638,11 @@ static int tracing_set_tracer(char *buf) current_trace->reset(tr); current_trace = t; - if (t->init) - t->init(tr); + if (t->init) { + ret = t->init(tr); + if (ret) + goto out; + } trace_branch_enable(tr); out: diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 790ea8c0e1f..cdbd5cc22be 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -264,7 +264,8 @@ enum print_line_t { */ struct tracer { const char *name; - void (*init)(struct trace_array *tr); + /* Your tracer should raise a warning if init fails */ + int (*init)(struct trace_array *tr); void (*reset)(struct trace_array *tr); void (*start)(struct trace_array *tr); void (*stop)(struct trace_array *tr); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index cb333b7fd11..a4fa2c57e34 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -47,7 +47,7 @@ static void reset_boot_trace(struct trace_array *tr) tracing_reset(tr, cpu); } -static void boot_trace_init(struct trace_array *tr) +static int boot_trace_init(struct trace_array *tr) { int cpu; boot_trace = tr; @@ -56,6 +56,7 @@ static void boot_trace_init(struct trace_array *tr) tracing_reset(tr, cpu); tracing_sched_switch_assign_trace(tr); + return 0; } static enum print_line_t diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 85265553918..44bd39539d6 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -125,7 +125,7 @@ static void stop_branch_trace(struct trace_array *tr) disable_branch_tracing(); } -static void branch_trace_init(struct trace_array *tr) +static int branch_trace_init(struct trace_array *tr) { int cpu; @@ -133,6 +133,7 @@ static void branch_trace_init(struct trace_array *tr) tracing_reset(tr, cpu); start_branch_trace(tr); + return 0; } static void branch_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 8693b7a0a5b..e74f6d0a321 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -42,9 +42,10 @@ static void stop_function_trace(struct trace_array *tr) tracing_stop_cmdline_record(); } -static void function_trace_init(struct trace_array *tr) +static int function_trace_init(struct trace_array *tr) { start_function_trace(tr); + return 0; } static void function_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c index 7680b21537d..61185f756a1 100644 --- a/kernel/trace/trace_functions_return.c +++ b/kernel/trace/trace_functions_return.c @@ -24,13 +24,14 @@ static void stop_return_trace(struct trace_array *tr) unregister_ftrace_return(); } -static void return_trace_init(struct trace_array *tr) +static int return_trace_init(struct trace_array *tr) { int cpu; for_each_online_cpu(cpu) tracing_reset(tr, cpu); start_return_trace(tr); + return 0; } static void return_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index d919d4eaa7c..7c2e326bbc8 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -416,11 +416,12 @@ static void irqsoff_tracer_close(struct trace_iterator *iter) } #ifdef CONFIG_IRQSOFF_TRACER -static void irqsoff_tracer_init(struct trace_array *tr) +static int irqsoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_IRQS_OFF; __irqsoff_tracer_init(tr); + return 0; } static struct tracer irqsoff_tracer __read_mostly = { @@ -442,11 +443,12 @@ static struct tracer irqsoff_tracer __read_mostly = #endif #ifdef CONFIG_PREEMPT_TRACER -static void preemptoff_tracer_init(struct trace_array *tr) +static int preemptoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_PREEMPT_OFF; __irqsoff_tracer_init(tr); + return 0; } static struct tracer preemptoff_tracer __read_mostly = @@ -471,11 +473,12 @@ static struct tracer preemptoff_tracer __read_mostly = #if defined(CONFIG_IRQSOFF_TRACER) && \ defined(CONFIG_PREEMPT_TRACER) -static void preemptirqsoff_tracer_init(struct trace_array *tr) +static int preemptirqsoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; __irqsoff_tracer_init(tr); + return 0; } static struct tracer preemptirqsoff_tracer __read_mostly = diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 51bcf370215..433d650eda9 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -30,13 +30,14 @@ static void mmio_reset_data(struct trace_array *tr) tracing_reset(tr, cpu); } -static void mmio_trace_init(struct trace_array *tr) +static int mmio_trace_init(struct trace_array *tr) { pr_debug("in %s\n", __func__); mmio_trace_array = tr; mmio_reset_data(tr); enable_mmiotrace(); + return 0; } static void mmio_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 2ef1d227e7d..0e77415caed 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -24,7 +24,7 @@ static void stop_nop_trace(struct trace_array *tr) /* Nothing to do! */ } -static void nop_trace_init(struct trace_array *tr) +static int nop_trace_init(struct trace_array *tr) { int cpu; ctx_trace = tr; @@ -33,6 +33,7 @@ static void nop_trace_init(struct trace_array *tr) tracing_reset(tr, cpu); start_nop_trace(tr); + return 0; } static void nop_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index be35bdfe2e3..863390557b4 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -206,10 +206,11 @@ static void stop_sched_trace(struct trace_array *tr) tracing_stop_sched_switch_record(); } -static void sched_switch_trace_init(struct trace_array *tr) +static int sched_switch_trace_init(struct trace_array *tr) { ctx_trace = tr; start_sched_trace(tr); + return 0; } static void sched_switch_trace_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 983f2b1478c..0067b49746c 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -331,10 +331,11 @@ static void stop_wakeup_tracer(struct trace_array *tr) unregister_trace_sched_wakeup(probe_wakeup); } -static void wakeup_tracer_init(struct trace_array *tr) +static int wakeup_tracer_init(struct trace_array *tr) { wakeup_trace = tr; start_wakeup_tracer(tr); + return 0; } static void wakeup_tracer_reset(struct trace_array *tr) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 5cb64ea061b..88c8eb70f54 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -71,6 +71,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) return ret; } +static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) +{ + printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n", + trace->name, init_ret); +} #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE @@ -111,7 +116,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, ftrace_set_filter(func_name, strlen(func_name), 1); /* enable tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + goto out; + } /* Sleep for a 1/10 of a second */ msleep(100); @@ -181,7 +190,12 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) ftrace_enabled = 1; tracer_enabled = 1; - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + goto out; + } + /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ @@ -223,7 +237,12 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + /* reset the max latency */ tracing_max_latency = 0; /* disable interrupts for a bit */ @@ -272,7 +291,12 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) } /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + /* reset the max latency */ tracing_max_latency = 0; /* disable preemption for a bit */ @@ -321,7 +345,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * } /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + goto out; + } /* reset the max latency */ tracing_max_latency = 0; @@ -449,7 +477,12 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) wait_for_completion(&isrt); /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + /* reset the max latency */ tracing_max_latency = 0; @@ -505,7 +538,12 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr int ret; /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ @@ -532,7 +570,12 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return 0; + } + /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ @@ -554,7 +597,12 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) int ret; /* start the tracing */ - trace->init(tr); + ret = trace->init(tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 05f753422ae..54960edb96d 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -261,11 +261,12 @@ static void stop_stack_trace(struct trace_array *tr) mutex_unlock(&sample_timer_lock); } -static void stack_trace_init(struct trace_array *tr) +static int stack_trace_init(struct trace_array *tr) { sysprof_trace = tr; start_stack_trace(tr); + return 0; } static void stack_trace_reset(struct trace_array *tr) -- cgit v1.2.3-70-g09d2 From 0c726da983de0704254250ef6495ca152e7abcca Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Sun, 16 Nov 2008 16:07:58 +0530 Subject: tracing: branch tracer, fix writing to trace/trace_options Impact: fix trace_options behavior writing to trace/trace_options use the index of the array to find the value of the flag. With branch tracer flag defined conditionally, this breaks writing to trace_options with branch tracer disabled. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 -- kernel/trace/trace.h | 2 -- 2 files changed, 4 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4a904623e05..b04923b72ce 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -259,9 +259,7 @@ static const char *trace_options[] = { "sched-tree", "ftrace_printk", "ftrace_preempt", -#ifdef CONFIG_BRANCH_TRACER "branch", -#endif "annotate", NULL }; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 790ea8c0e1f..b41d7b4c2ca 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -470,9 +470,7 @@ enum trace_iterator_flags { TRACE_ITER_SCHED_TREE = 0x200, TRACE_ITER_PRINTK = 0x400, TRACE_ITER_PREEMPTONLY = 0x800, -#ifdef CONFIG_BRANCH_TRACER TRACE_ITER_BRANCH = 0x1000, -#endif TRACE_ITER_ANNOTATE = 0x2000, }; -- cgit v1.2.3-70-g09d2 From adf9f19574334c9a29a2bc956009fcac7edf1a6b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 17 Nov 2008 19:23:42 +0100 Subject: tracing/ftrace: implement a set_flag callback for tracers Impact: give a way to send specific messages to tracers The current implementation of tracing uses some flags to control the output of general tracers. But we have no way to implement custom flags handling for a specific tracer. This patch proposes a new callback for the struct tracer which called set_flag and a structure that represents a 32 bits variable flag. A tracer can implement a struct tracer_flags on which it puts the initial value of the flag integer. Than it can place a range of flags with their name and their flag mask on the flag integer. The structure that implement a single flag is called struct tracer_opt. These custom flags will be available through the trace_options file like the general tracing flags. Changing their value is done like the other general flags. For example if you have a flag that calls "foo", you can activate it by writing "foo" or "nofoo" on trace_options. Note that the set_flag callback is optional and is only needed if you want the flags changing to be signaled to your tracer and let it to accept or refuse their assignment. V2: Some arrangements in coding style.... Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++---- kernel/trace/trace.h | 26 +++++++++++++++ 2 files changed, 112 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2596b5a968c..9531fddcfb8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -43,6 +43,20 @@ unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; unsigned long __read_mostly tracing_thresh; +/* For tracers that don't implement custom flags */ +static struct tracer_opt dummy_tracer_opt[] = { + { } +}; + +static struct tracer_flags dummy_tracer_flags = { + .val = 0, + .opts = dummy_tracer_opt +}; + +static int dummy_set_flag(u32 old_flags, u32 bit, int set) +{ + return 0; +} /* * Kill all tracing for good (never come back). @@ -529,6 +543,14 @@ int register_tracer(struct tracer *type) } } + if (!type->set_flag) + type->set_flag = &dummy_set_flag; + if (!type->flags) + type->flags = &dummy_tracer_flags; + else + if (!type->flags->opts) + type->flags->opts = dummy_tracer_opt; + #ifdef CONFIG_FTRACE_STARTUP_TEST if (type->selftest) { struct tracer *saved_tracer = current_trace; @@ -2426,10 +2448,13 @@ static ssize_t tracing_trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { + int i; char *buf; int r = 0; int len = 0; - int i; + u32 tracer_flags = current_trace->flags->val; + struct tracer_opt *trace_opts = current_trace->flags->opts; + /* calulate max size */ for (i = 0; trace_options[i]; i++) { @@ -2437,6 +2462,15 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf, len += 3; /* "no" and space */ } + /* + * Increase the size with names of options specific + * of the current tracer. + */ + for (i = 0; trace_opts[i].name; i++) { + len += strlen(trace_opts[i].name); + len += 3; /* "no" and space */ + } + /* +2 for \n and \0 */ buf = kmalloc(len + 2, GFP_KERNEL); if (!buf) @@ -2449,6 +2483,15 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf, r += sprintf(buf + r, "no%s ", trace_options[i]); } + for (i = 0; trace_opts[i].name; i++) { + if (tracer_flags & trace_opts[i].bit) + r += sprintf(buf + r, "%s ", + trace_opts[i].name); + else + r += sprintf(buf + r, "no%s ", + trace_opts[i].name); + } + r += sprintf(buf + r, "\n"); WARN_ON(r >= len + 2); @@ -2459,6 +2502,40 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf, return r; } +/* Try to assign a tracer specific option */ +static int set_tracer_option(struct tracer *trace, char *cmp, int neg) +{ + struct tracer_flags *trace_flags = trace->flags; + struct tracer_opt *opts = NULL; + int ret = 0, i = 0; + int len; + + for (i = 0; trace_flags->opts[i].name; i++) { + opts = &trace_flags->opts[i]; + len = strlen(opts->name); + + if (strncmp(cmp, opts->name, len) == 0) { + ret = trace->set_flag(trace_flags->val, + opts->bit, !neg); + break; + } + } + /* Not found */ + if (!trace_flags->opts[i].name) + return -EINVAL; + + /* Refused to handle */ + if (ret) + return ret; + + if (neg) + trace_flags->val &= ~opts->bit; + else + trace_flags->val |= opts->bit; + + return 0; +} + static ssize_t tracing_trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) @@ -2466,6 +2543,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, char buf[64]; char *cmp = buf; int neg = 0; + int ret; int i; if (cnt >= sizeof(buf)) @@ -2492,11 +2570,13 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, break; } } - /* - * If no option could be set, return an error: - */ - if (!trace_options[i]) - return -EINVAL; + + /* If no option could be set, test the specific tracer options */ + if (!trace_options[i]) { + ret = set_tracer_option(current_trace, cmp, neg); + if (ret) + return ret; + } filp->f_pos += cnt; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 37947f6b92b..9d22618bf99 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -259,6 +259,29 @@ enum print_line_t { TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ }; + +/* + * An option specific to a tracer. This is a boolean value. + * The bit is the bit index that sets its value on the + * flags value in struct tracer_flags. + */ +struct tracer_opt { + const char *name; /* Will appear on the trace_options file */ + u32 bit; /* Mask assigned in val field in tracer_flags */ +}; + +/* + * The set of specific options for a tracer. Your tracer + * have to set the initial value of the flags val. + */ +struct tracer_flags { + u32 val; + struct tracer_opt *opts; +}; + +/* Makes more easy to define a tracer opt */ +#define TRACER_OPT(s, b) .name = #s, .bit = b + /* * A specific tracer, represented by methods that operate on a trace array: */ @@ -280,8 +303,11 @@ struct tracer { struct trace_array *tr); #endif enum print_line_t (*print_line)(struct trace_iterator *iter); + /* If you handled the flag setting, return 0 */ + int (*set_flag)(u32 old_flags, u32 bit, int set); struct tracer *next; int print_max; + struct tracer_flags *flags; }; struct trace_seq { -- cgit v1.2.3-70-g09d2 From 0231022cc32d5f2e7f3c06b75691dda0ad6aec33 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 17 Nov 2008 03:22:41 +0100 Subject: tracing/function-return-tracer: add the overrun field Impact: help to find the better depth of trace We decided to arbitrary define the depth of function return trace as "20". Perhaps this is not enough. To help finding an optimal depth, we measure now the overrun: the number of functions that have been missed for the current thread. By default this is not displayed, we have to do set a particular flag on the return tracer: echo overrun > /debug/tracing/trace_options And the overrun will be printed on the right. As the trace shows below, the current 20 depth is not enough. update_wall_time+0x37f/0x8c0 -> update_xtime_cache (345 ns) (Overruns: 2838) update_wall_time+0x384/0x8c0 -> clocksource_get_next (1141 ns) (Overruns: 2838) do_timer+0x23/0x100 -> update_wall_time (3882 ns) (Overruns: 2838) tick_do_update_jiffies64+0xbf/0x160 -> do_timer (5339 ns) (Overruns: 2838) tick_sched_timer+0x6a/0xf0 -> tick_do_update_jiffies64 (7209 ns) (Overruns: 2838) vgacon_set_cursor_size+0x98/0x120 -> native_io_delay (2613 ns) (Overruns: 274) vgacon_cursor+0x16e/0x1d0 -> vgacon_set_cursor_size (33151 ns) (Overruns: 274) set_cursor+0x5f/0x80 -> vgacon_cursor (36432 ns) (Overruns: 274) con_flush_chars+0x34/0x40 -> set_cursor (38790 ns) (Overruns: 274) release_console_sem+0x1ec/0x230 -> up (721 ns) (Overruns: 274) release_console_sem+0x225/0x230 -> wake_up_klogd (316 ns) (Overruns: 274) con_flush_chars+0x39/0x40 -> release_console_sem (2996 ns) (Overruns: 274) con_write+0x22/0x30 -> con_flush_chars (46067 ns) (Overruns: 274) n_tty_write+0x1cc/0x360 -> con_write (292670 ns) (Overruns: 274) smp_apic_timer_interrupt+0x2a/0x90 -> native_apic_mem_write (330 ns) (Overruns: 274) irq_enter+0x17/0x70 -> idle_cpu (413 ns) (Overruns: 274) smp_apic_timer_interrupt+0x2f/0x90 -> irq_enter (1525 ns) (Overruns: 274) ktime_get_ts+0x40/0x70 -> getnstimeofday (465 ns) (Overruns: 274) ktime_get_ts+0x60/0x70 -> set_normalized_timespec (436 ns) (Overruns: 274) ktime_get+0x16/0x30 -> ktime_get_ts (2501 ns) (Overruns: 274) hrtimer_interrupt+0x77/0x1a0 -> ktime_get (3439 ns) (Overruns: 274) Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/include/asm/thread_info.h | 7 +++++++ arch/x86/kernel/ftrace.c | 10 ++++++--- include/linux/ftrace.h | 2 ++ include/linux/sched.h | 1 + kernel/trace/trace.c | 1 + kernel/trace/trace.h | 1 + kernel/trace/trace_functions_return.c | 38 +++++++++++++++++++++++++++++------ 7 files changed, 51 insertions(+), 9 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index a71158369fd..e90e81ef6ab 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -21,6 +21,7 @@ struct task_struct; struct exec_domain; #include #include +#include struct thread_info { struct task_struct *task; /* main task structure */ @@ -45,6 +46,11 @@ struct thread_info { int curr_ret_stack; /* Stack of return addresses for return function tracing */ struct ftrace_ret_stack ret_stack[FTRACE_RET_STACK_SIZE]; + /* + * Number of functions that haven't been traced + * because of depth overrun. + */ + atomic_t trace_overrun; #endif }; @@ -61,6 +67,7 @@ struct thread_info { .fn = do_no_restart_syscall, \ }, \ .curr_ret_stack = -1,\ + .trace_overrun = ATOMIC_INIT(0) \ } #else #define INIT_THREAD_INFO(tsk) \ diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 924153edd97..356bb1eb6e9 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -353,8 +353,10 @@ static int push_return_trace(unsigned long ret, unsigned long long time, struct thread_info *ti = current_thread_info(); /* The return trace stack is full */ - if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) + if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) { + atomic_inc(&ti->trace_overrun); return -EBUSY; + } index = ++ti->curr_ret_stack; barrier(); @@ -367,7 +369,7 @@ static int push_return_trace(unsigned long ret, unsigned long long time, /* Retrieve a function return address to the trace stack on thread info.*/ static void pop_return_trace(unsigned long *ret, unsigned long long *time, - unsigned long *func) + unsigned long *func, unsigned long *overrun) { int index; @@ -376,6 +378,7 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time, *ret = ti->ret_stack[index].ret; *func = ti->ret_stack[index].func; *time = ti->ret_stack[index].calltime; + *overrun = atomic_read(&ti->trace_overrun); ti->curr_ret_stack--; } @@ -386,7 +389,8 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time, unsigned long ftrace_return_to_handler(void) { struct ftrace_retfunc trace; - pop_return_trace(&trace.ret, &trace.calltime, &trace.func); + pop_return_trace(&trace.ret, &trace.calltime, &trace.func, + &trace.overrun); trace.rettime = cpu_clock(raw_smp_processor_id()); ftrace_function_return(&trace); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index f1af1aab00e..f7ba4ea5e12 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -318,6 +318,8 @@ struct ftrace_retfunc { unsigned long func; /* Current function */ unsigned long long calltime; unsigned long long rettime; + /* Number of functions that overran the depth limit for current task */ + unsigned long overrun; }; #ifdef CONFIG_FUNCTION_RET_TRACER diff --git a/include/linux/sched.h b/include/linux/sched.h index 61c8cc36028..c8e0db46420 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2016,6 +2016,7 @@ static inline void setup_thread_stack(struct task_struct *p, struct task_struct * used. */ task_thread_info(p)->curr_ret_stack = -1; + atomic_set(&task_thread_info(p)->trace_overrun, 0); #endif } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9531fddcfb8..e97c29a6e7b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -853,6 +853,7 @@ static void __trace_function_return(struct trace_array *tr, entry->parent_ip = trace->ret; entry->rettime = trace->rettime; entry->calltime = trace->calltime; + entry->overrun = trace->overrun; ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags); } #endif diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9d22618bf99..2cb12fd98f6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -60,6 +60,7 @@ struct ftrace_ret_entry { unsigned long parent_ip; unsigned long long calltime; unsigned long long rettime; + unsigned long overrun; }; extern struct tracer boot_tracer; diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c index a68564af022..e00d64509c9 100644 --- a/kernel/trace/trace_functions_return.c +++ b/kernel/trace/trace_functions_return.c @@ -14,6 +14,19 @@ #include "trace.h" +#define TRACE_RETURN_PRINT_OVERRUN 0x1 +static struct tracer_opt trace_opts[] = { + /* Display overruns or not */ + { TRACER_OPT(overrun, TRACE_RETURN_PRINT_OVERRUN) }, + { } /* Empty entry */ +}; + +static struct tracer_flags tracer_flags = { + .val = 0, /* Don't display overruns by default */ + .opts = trace_opts +}; + + static int return_trace_init(struct trace_array *tr) { int cpu; @@ -42,26 +55,39 @@ print_return_function(struct trace_iterator *iter) ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); if (!ret) return TRACE_TYPE_PARTIAL_LINE; + ret = seq_print_ip_sym(s, field->ip, trace_flags & TRACE_ITER_SYM_MASK); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_printf(s, " (%llu ns)\n", + + ret = trace_seq_printf(s, " (%llu ns)", field->rettime - field->calltime); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - else - return TRACE_TYPE_HANDLED; + + if (tracer_flags.val & TRACE_RETURN_PRINT_OVERRUN) { + ret = trace_seq_printf(s, " (Overruns: %lu)", + field->overrun); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + ret = trace_seq_printf(s, "\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return TRACE_TYPE_HANDLED; } return TRACE_TYPE_UNHANDLED; } -static struct tracer return_trace __read_mostly = -{ +static struct tracer return_trace __read_mostly = { .name = "return", .init = return_trace_init, .reset = return_trace_reset, - .print_line = print_return_function + .print_line = print_return_function, + .flags = &tracer_flags, }; static __init int init_return_trace(void) -- cgit v1.2.3-70-g09d2 From 02b67518e2b1c490787dac7f35e1204e74fe21ba Mon Sep 17 00:00:00 2001 From: Török Edwin Date: Sat, 22 Nov 2008 13:28:47 +0200 Subject: tracing: add support for userspace stacktraces in tracing/iter_ctrl MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Impact: add new (default-off) tracing visualization feature Usage example: mount -t debugfs nodev /sys/kernel/debug cd /sys/kernel/debug/tracing echo userstacktrace >iter_ctrl echo sched_switch >current_tracer echo 1 >tracing_enabled .... run application ... echo 0 >tracing_enabled Then read one of 'trace','latency_trace','trace_pipe'. To get the best output you can compile your userspace programs with frame pointers (at least glibc + the app you are tracing). Signed-off-by: Török Edwin Signed-off-by: Ingo Molnar --- Documentation/ftrace.txt | 5 ++- arch/x86/kernel/stacktrace.c | 57 +++++++++++++++++++++++++++ include/linux/stacktrace.h | 8 ++++ kernel/trace/trace.c | 93 ++++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace.h | 9 +++++ 5 files changed, 171 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt index 753f4de4b17..79a80f79c06 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/ftrace.txt @@ -324,7 +324,7 @@ output. To see what is available, simply cat the file: cat /debug/tracing/trace_options print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \ - noblock nostacktrace nosched-tree + noblock nostacktrace nosched-tree nouserstacktrace To disable one of the options, echo in the option prepended with "no". @@ -378,6 +378,9 @@ Here are the available options: When a trace is recorded, so is the stack of functions. This allows for back traces of trace sites. + userstacktrace - This option changes the trace. + It records a stacktrace of the current userspace thread. + sched-tree - TBD (any users??) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index a03e7f6d90c..b1515306041 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -6,6 +6,7 @@ #include #include #include +#include #include static void save_stack_warning(void *data, char *msg) @@ -83,3 +84,59 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ + +struct stack_frame { + const void __user *next_fp; + unsigned long return_address; +}; + +static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) +{ + int ret; + + if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) + return 0; + + ret = 1; + pagefault_disable(); + if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) + ret = 0; + pagefault_enable(); + + return ret; +} + +void save_stack_trace_user(struct stack_trace *trace) +{ + /* + * Trace user stack if we are not a kernel thread + */ + if (current->mm) { + const struct pt_regs *regs = task_pt_regs(current); + const void __user *fp = (const void __user *)regs->bp; + + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = regs->ip; + + while (trace->nr_entries < trace->max_entries) { + struct stack_frame frame; + frame.next_fp = NULL; + frame.return_address = 0; + if (!copy_stack_frame(fp, &frame)) + break; + if ((unsigned long)fp < regs->sp) + break; + if (frame.return_address) + trace->entries[trace->nr_entries++] = + frame.return_address; + if (fp == frame.next_fp) + break; + fp = frame.next_fp; + } + } + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index b106fd8e0d5..68de51468f5 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -15,9 +15,17 @@ extern void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace); extern void print_stack_trace(struct stack_trace *trace, int spaces); + +#ifdef CONFIG_X86 +extern void save_stack_trace_user(struct stack_trace *trace); +#else +# define save_stack_trace_user(trace) do { } while (0) +#endif + #else # define save_stack_trace(trace) do { } while (0) # define save_stack_trace_tsk(tsk, trace) do { } while (0) +# define save_stack_trace_user(trace) do { } while (0) # define print_stack_trace(trace, spaces) do { } while (0) #endif diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4ee6f037522..ced8b4fa9f5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -275,6 +275,7 @@ static const char *trace_options[] = { "ftrace_preempt", "branch", "annotate", + "userstacktrace", NULL }; @@ -918,6 +919,44 @@ void __trace_stack(struct trace_array *tr, ftrace_trace_stack(tr, data, flags, skip, preempt_count()); } +static void ftrace_trace_userstack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags, int pc) +{ + struct userstack_entry *entry; + struct stack_trace trace; + struct ring_buffer_event *event; + unsigned long irq_flags; + + if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) + return; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_USER_STACK; + + memset(&entry->caller, 0, sizeof(entry->caller)); + + trace.nr_entries = 0; + trace.max_entries = FTRACE_STACK_ENTRIES; + trace.skip = 0; + trace.entries = entry->caller; + + save_stack_trace_user(&trace); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); +} + +void __trace_userstack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags) +{ + ftrace_trace_userstack(tr, data, flags, preempt_count()); +} + static void ftrace_trace_special(void *__tr, void *__data, unsigned long arg1, unsigned long arg2, unsigned long arg3, @@ -941,6 +980,7 @@ ftrace_trace_special(void *__tr, void *__data, entry->arg3 = arg3; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); ftrace_trace_stack(tr, data, irq_flags, 4, pc); + ftrace_trace_userstack(tr, data, irq_flags, pc); trace_wake_up(); } @@ -979,6 +1019,7 @@ tracing_sched_switch_trace(struct trace_array *tr, entry->next_cpu = task_cpu(next); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); ftrace_trace_stack(tr, data, flags, 5, pc); + ftrace_trace_userstack(tr, data, flags, pc); } void @@ -1008,6 +1049,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, entry->next_cpu = task_cpu(wakee); ring_buffer_unlock_commit(tr->buffer, event, irq_flags); ftrace_trace_stack(tr, data, flags, 6, pc); + ftrace_trace_userstack(tr, data, flags, pc); trace_wake_up(); } @@ -1387,6 +1429,31 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) return ret; } +static int +seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s, + unsigned long sym_flags) +{ + int ret = 1; + unsigned i; + + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { + unsigned long ip = entry->caller[i]; + + if (ip == ULONG_MAX || !ret) + break; + if (i) + ret = trace_seq_puts(s, " <- "); + if (!ip) { + ret = trace_seq_puts(s, "??"); + continue; + } + if (ret /*&& (sym_flags & TRACE_ITER_SYM_ADDR)*/) + ret = trace_seq_printf(s, " <" IP_FMT ">", ip); + } + + return ret; +} + static void print_lat_help_header(struct seq_file *m) { seq_puts(m, "# _------=> CPU# \n"); @@ -1702,6 +1769,16 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) field->line); break; } + case TRACE_USER_STACK: { + struct userstack_entry *field; + + trace_assign_type(field, entry); + + seq_print_userip_objs(field, s, sym_flags); + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; + } default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } @@ -1853,6 +1930,19 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) field->line); break; } + case TRACE_USER_STACK: { + struct userstack_entry *field; + + trace_assign_type(field, entry); + + ret = seq_print_userip_objs(field, s, sym_flags); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + ret = trace_seq_putc(s, '\n'); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + break; + } } return TRACE_TYPE_HANDLED; } @@ -1912,6 +2002,7 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter) break; } case TRACE_SPECIAL: + case TRACE_USER_STACK: case TRACE_STACK: { struct special_entry *field; @@ -2000,6 +2091,7 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter) break; } case TRACE_SPECIAL: + case TRACE_USER_STACK: case TRACE_STACK: { struct special_entry *field; @@ -2054,6 +2146,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter) break; } case TRACE_SPECIAL: + case TRACE_USER_STACK: case TRACE_STACK: { struct special_entry *field; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2cb12fd98f6..17bb4c830b0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -26,6 +26,7 @@ enum trace_type { TRACE_BOOT_CALL, TRACE_BOOT_RET, TRACE_FN_RET, + TRACE_USER_STACK, __TRACE_LAST_TYPE }; @@ -42,6 +43,7 @@ struct trace_entry { unsigned char flags; unsigned char preempt_count; int pid; + int tgid; }; /* @@ -99,6 +101,11 @@ struct stack_entry { unsigned long caller[FTRACE_STACK_ENTRIES]; }; +struct userstack_entry { + struct trace_entry ent; + unsigned long caller[FTRACE_STACK_ENTRIES]; +}; + /* * ftrace_printk entry: */ @@ -240,6 +247,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \ IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ + IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ IF_ASSIGN(var, ent, struct special_entry, 0); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ @@ -500,6 +508,7 @@ enum trace_iterator_flags { TRACE_ITER_PREEMPTONLY = 0x800, TRACE_ITER_BRANCH = 0x1000, TRACE_ITER_ANNOTATE = 0x2000, + TRACE_ITER_USERSTACKTRACE = 0x4000 }; /* -- cgit v1.2.3-70-g09d2 From b54d3de9f3b8956653b06f1a32e9f9321c6d9027 Mon Sep 17 00:00:00 2001 From: Török Edwin Date: Sat, 22 Nov 2008 13:28:48 +0200 Subject: tracing: identify which executable object the userspace address belongs to MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Impact: modify+improve the userstacktrace tracing visualization feature Store thread group leader id, and use it to lookup the address in the process's map. We could have looked up the address on thread's map, but the thread might not exist by the time we are called. The process might not exist either, but if you are reading trace_pipe, that is unlikely. Example usage: mount -t debugfs nodev /sys/kernel/debug cd /sys/kernel/debug/tracing echo userstacktrace >iter_ctrl echo sym-userobj >iter_ctrl echo sched_switch >current_tracer echo 1 >tracing_enabled cat trace_pipe >/tmp/trace& .... run application ... echo 0 >tracing_enabled cat /tmp/trace You'll see stack entries like: /lib/libpthread-2.7.so[+0xd370] You can convert them to function/line using: addr2line -fie /lib/libpthread-2.7.so 0xd370 Or: addr2line -fie /usr/lib/debug/libpthread-2.7.so 0xd370 For non-PIC/PIE executables this won't work: a.out[+0x73b] You need to run the following: addr2line -fie a.out 0x40073b (where 0x400000 is the default load address of a.out) Signed-off-by: Török Edwin Signed-off-by: Ingo Molnar --- Documentation/ftrace.txt | 13 +++++++- kernel/trace/trace.c | 86 ++++++++++++++++++++++++++++++++++++++++++++---- kernel/trace/trace.h | 3 +- 3 files changed, 93 insertions(+), 9 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt index 79a80f79c06..35a78bc6651 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/ftrace.txt @@ -324,7 +324,7 @@ output. To see what is available, simply cat the file: cat /debug/tracing/trace_options print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \ - noblock nostacktrace nosched-tree nouserstacktrace + noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj To disable one of the options, echo in the option prepended with "no". @@ -381,6 +381,17 @@ Here are the available options: userstacktrace - This option changes the trace. It records a stacktrace of the current userspace thread. + sym-userobj - when user stacktrace are enabled, look up which object the + address belongs to, and print a relative address + This is especially useful when ASLR is on, otherwise you don't + get a chance to resolve the address to object/file/line after the app is no + longer running + + The lookup is performed when you read trace,trace_pipe,latency_trace. Example: + + a.out-1623 [000] 40874.465068: /root/a.out[+0x480] <-/root/a.out[+0 +x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6] + sched-tree - TBD (any users??) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ced8b4fa9f5..62776b71b1c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -276,6 +277,7 @@ static const char *trace_options[] = { "branch", "annotate", "userstacktrace", + "sym-userobj", NULL }; @@ -422,6 +424,28 @@ trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) return trace_seq_putmem(s, hex, j); } +static int +trace_seq_path(struct trace_seq *s, struct path *path) +{ + unsigned char *p; + + if (s->len >= (PAGE_SIZE - 1)) + return 0; + p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len); + if (!IS_ERR(p)) { + p = mangle_path(s->buffer + s->len, p, "\n"); + if (p) { + s->len = p - s->buffer; + return 1; + } + } else { + s->buffer[s->len++] = '?'; + return 1; + } + + return 0; +} + static void trace_seq_reset(struct trace_seq *s) { @@ -802,6 +826,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; + entry->tgid = (tsk) ? tsk->tgid : 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | @@ -1429,28 +1454,73 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) return ret; } +static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, + unsigned long ip, unsigned long sym_flags) +{ + struct file *file = NULL; + unsigned long vmstart = 0; + int ret = 1; + + if (mm) { + const struct vm_area_struct *vma = find_vma(mm, ip); + if (vma) { + file = vma->vm_file; + vmstart = vma->vm_start; + } + } + if (file) { + ret = trace_seq_path(s, &file->f_path); + if (ret) + ret = trace_seq_printf(s, "[+0x%lx]", + ip - vmstart); + } + if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file)) + ret = trace_seq_printf(s, " <" IP_FMT ">", ip); + return ret; +} + static int seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s, - unsigned long sym_flags) + unsigned long sym_flags) { + struct mm_struct *mm = NULL; int ret = 1; unsigned i; + if (trace_flags & TRACE_ITER_SYM_USEROBJ) { + struct task_struct *task; + /* + * we do the lookup on the thread group leader, + * since individual threads might have already quit! + */ + rcu_read_lock(); + task = find_task_by_vpid(entry->ent.tgid); + rcu_read_unlock(); + + if (task) + mm = get_task_mm(task); + } + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { unsigned long ip = entry->caller[i]; if (ip == ULONG_MAX || !ret) break; - if (i) + if (i && ret) ret = trace_seq_puts(s, " <- "); if (!ip) { - ret = trace_seq_puts(s, "??"); + if (ret) + ret = trace_seq_puts(s, "??"); continue; } - if (ret /*&& (sym_flags & TRACE_ITER_SYM_ADDR)*/) - ret = trace_seq_printf(s, " <" IP_FMT ">", ip); + if (!ret) + break; + if (ret) + ret = seq_print_user_ip(s, mm, ip, sym_flags); } + if (mm) + mmput(mm); return ret; } @@ -1775,8 +1845,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) trace_assign_type(field, entry); seq_print_userip_objs(field, s, sym_flags); - if (entry->flags & TRACE_FLAG_CONT) - trace_seq_print_cont(s, iter); + trace_seq_putc(s, '\n'); break; } default: @@ -3581,6 +3650,9 @@ void ftrace_dump(void) atomic_inc(&global_trace.data[cpu]->disabled); } + /* don't look at user memory in panic mode */ + trace_flags &= ~TRACE_ITER_SYM_USEROBJ; + printk(KERN_TRACE "Dumping ftrace buffer:\n"); iter.tr = &global_trace; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 17bb4c830b0..28c15c2ebc2 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -508,7 +508,8 @@ enum trace_iterator_flags { TRACE_ITER_PREEMPTONLY = 0x800, TRACE_ITER_BRANCH = 0x1000, TRACE_ITER_ANNOTATE = 0x2000, - TRACE_ITER_USERSTACKTRACE = 0x4000 + TRACE_ITER_USERSTACKTRACE = 0x4000, + TRACE_ITER_SYM_USEROBJ = 0x8000 }; /* -- cgit v1.2.3-70-g09d2 From 8bba1bf5e2434c83f2fe8b1422604ace9bbe4cb8 Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Tue, 25 Nov 2008 09:12:31 +0100 Subject: x86, ftrace: call trace->open() before stopping tracing; add trace->print_header() Add a callback to allow an ftrace plug-in to write its own header. Move the call to trace->open() up a few lines. The changes are required by the BTS ftrace plug-in. Signed-off-by: Markus Metzger Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 11 +++++++---- kernel/trace/trace.h | 1 + 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a45b59e53fb..8df8fdd69c9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2298,7 +2298,9 @@ static int s_show(struct seq_file *m, void *v) seq_printf(m, "# tracer: %s\n", iter->trace->name); seq_puts(m, "#\n"); } - if (iter->iter_flags & TRACE_FILE_LAT_FMT) { + if (iter->trace && iter->trace->print_header) + iter->trace->print_header(m); + else if (iter->iter_flags & TRACE_FILE_LAT_FMT) { /* print nothing if the buffers are empty */ if (trace_empty(iter)) return 0; @@ -2350,6 +2352,10 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) iter->trace = current_trace; iter->pos = -1; + /* Notify the tracer early; before we stop tracing. */ + if (iter->trace && iter->trace->open) + iter->trace->open(iter); + /* Annotate start of buffers if we had overruns */ if (ring_buffer_overruns(iter->tr->buffer)) iter->iter_flags |= TRACE_FILE_ANNOTATE; @@ -2375,9 +2381,6 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) /* stop the trace while dumping */ tracing_stop(); - if (iter->trace && iter->trace->open) - iter->trace->open(iter); - mutex_unlock(&trace_types_lock); out: diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 28c15c2ebc2..717f9f045c6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -311,6 +311,7 @@ struct tracer { int (*selftest)(struct tracer *trace, struct trace_array *tr); #endif + void (*print_header)(struct seq_file *m); enum print_line_t (*print_line)(struct trace_iterator *iter); /* If you handled the flag setting, return 0 */ int (*set_flag)(u32 old_flags, u32 bit, int set); -- cgit v1.2.3-70-g09d2 From 1e9b51c28312f7334394aa30be56ff52c2b65b7e Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Tue, 25 Nov 2008 09:24:15 +0100 Subject: x86, bts, ftrace: a BTS ftrace plug-in prototype Impact: add new ftrace plugin A prototype for a BTS ftrace plug-in. The tracer collects branch trace in a cyclic buffer for each cpu. The tracer is not configurable and the trace for each snapshot is appended when doing cat /debug/tracing/trace. This is a proof of concept that will be extended with future patches to become a (hopefully) useful tool. Signed-off-by: Markus Metzger Signed-off-by: Ingo Molnar --- arch/x86/Kconfig.cpu | 1 + kernel/trace/Kconfig | 11 ++ kernel/trace/Makefile | 1 + kernel/trace/trace.h | 12 +++ kernel/trace/trace_bts.c | 276 +++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 301 insertions(+) create mode 100644 kernel/trace/trace_bts.c (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index b815664fe37..85a78575956 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -515,6 +515,7 @@ config CPU_SUP_UMC_32 config X86_DS def_bool X86_PTRACE_BTS depends on X86_DEBUGCTLMSR + select HAVE_HW_BRANCH_TRACER config X86_PTRACE_BTS bool "Branch Trace Store" diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 9cbf7761f49..620feadff67 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -28,6 +28,9 @@ config HAVE_DYNAMIC_FTRACE config HAVE_FTRACE_MCOUNT_RECORD bool +config HAVE_HW_BRANCH_TRACER + bool + config TRACER_MAX_TRACE bool @@ -233,6 +236,14 @@ config STACK_TRACER Say N if unsure. +config BTS_TRACER + depends on HAVE_HW_BRANCH_TRACER + bool "Trace branches" + select TRACING + help + This tracer records all branches on the system in a circular + buffer giving access to the last N branches for each cpu. + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 1a8c9259dc6..cef4bcb4e82 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -31,5 +31,6 @@ obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o +obj-$(CONFIG_BTS_TRACER) += trace_bts.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 717f9f045c6..3abd645e8af 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -27,6 +27,7 @@ enum trace_type { TRACE_BOOT_RET, TRACE_FN_RET, TRACE_USER_STACK, + TRACE_BTS, __TRACE_LAST_TYPE }; @@ -153,6 +154,12 @@ struct trace_branch { char correct; }; +struct bts_entry { + struct trace_entry ent; + unsigned long from; + unsigned long to; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -258,6 +265,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ + IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\ __ftrace_bad_type(); \ } while (0) @@ -392,6 +400,10 @@ void trace_function(struct trace_array *tr, void trace_function_return(struct ftrace_retfunc *trace); +void trace_bts(struct trace_array *tr, + unsigned long from, + unsigned long to); + void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); void tracing_sched_switch_assign_trace(struct trace_array *tr); diff --git a/kernel/trace/trace_bts.c b/kernel/trace/trace_bts.c new file mode 100644 index 00000000000..23b76e4690e --- /dev/null +++ b/kernel/trace/trace_bts.c @@ -0,0 +1,276 @@ +/* + * BTS tracer + * + * Copyright (C) 2008 Markus Metzger + * + */ + +#include +#include +#include +#include +#include + +#include + +#include "trace.h" + + +#define SIZEOF_BTS (1 << 13) + +static DEFINE_PER_CPU(struct bts_tracer *, tracer); +static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer); + +#define this_tracer per_cpu(tracer, smp_processor_id()) +#define this_buffer per_cpu(buffer, smp_processor_id()) + + +/* + * Information to interpret a BTS record. + * This will go into an in-kernel BTS interface. + */ +static unsigned char sizeof_field; +static unsigned long debugctl_mask; + +#define sizeof_bts (3 * sizeof_field) + +static void bts_trace_cpuinit(struct cpuinfo_x86 *c) +{ + switch (c->x86) { + case 0x6: + switch (c->x86_model) { + case 0x0 ... 0xC: + break; + case 0xD: + case 0xE: /* Pentium M */ + sizeof_field = sizeof(long); + debugctl_mask = (1<<6)|(1<<7); + break; + default: + sizeof_field = 8; + debugctl_mask = (1<<6)|(1<<7); + break; + } + break; + case 0xF: + switch (c->x86_model) { + case 0x0: + case 0x1: + case 0x2: /* Netburst */ + sizeof_field = sizeof(long); + debugctl_mask = (1<<2)|(1<<3); + break; + default: + /* sorry, don't know about them */ + break; + } + break; + default: + /* sorry, don't know about them */ + break; + } +} + +static inline void bts_enable(void) +{ + unsigned long debugctl; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl | debugctl_mask); +} + +static inline void bts_disable(void) +{ + unsigned long debugctl; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl & ~debugctl_mask); +} + +static void bts_trace_reset(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); +} + +static void bts_trace_start_cpu(void *arg) +{ + this_tracer = + ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS, + /* ovfl = */ NULL, /* th = */ (size_t)-1); + if (IS_ERR(this_tracer)) { + this_tracer = NULL; + return; + } + + bts_enable(); +} + +static void bts_trace_start(struct trace_array *tr) +{ + int cpu; + + bts_trace_reset(tr); + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1); +} + +static void bts_trace_stop_cpu(void *arg) +{ + if (this_tracer) { + bts_disable(); + + ds_release_bts(this_tracer); + this_tracer = NULL; + } +} + +static void bts_trace_stop(struct trace_array *tr) +{ + int cpu; + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1); +} + +static int bts_trace_init(struct trace_array *tr) +{ + bts_trace_cpuinit(&boot_cpu_data); + bts_trace_reset(tr); + bts_trace_start(tr); + + return 0; +} + +static void bts_trace_print_header(struct seq_file *m) +{ +#ifdef __i386__ + seq_puts(m, "# CPU# FROM TO FUNCTION\n"); + seq_puts(m, "# | | | |\n"); +#else + seq_puts(m, + "# CPU# FROM TO FUNCTION\n"); + seq_puts(m, + "# | | | |\n"); +#endif +} + +static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *seq = &iter->seq; + struct bts_entry *it; + + trace_assign_type(it, entry); + + if (entry->type == TRACE_BTS) { + int ret; +#ifdef CONFIG_KALLSYMS + char function[KSYM_SYMBOL_LEN]; + sprint_symbol(function, it->from); +#else + char *function = ""; +#endif + + ret = trace_seq_printf(seq, "%4d 0x%lx -> 0x%lx [%s]\n", + entry->cpu, it->from, it->to, function); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE;; + return TRACE_TYPE_HANDLED; + } + return TRACE_TYPE_UNHANDLED; +} + +void trace_bts(struct trace_array *tr, unsigned long from, unsigned long to) +{ + struct ring_buffer_event *event; + struct bts_entry *entry; + unsigned long irq; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, from); + entry->ent.type = TRACE_BTS; + entry->ent.cpu = smp_processor_id(); + entry->from = from; + entry->to = to; + ring_buffer_unlock_commit(tr->buffer, event, irq); +} + +static void trace_bts_at(struct trace_array *tr, size_t index) +{ + const void *raw = NULL; + unsigned long from, to; + int err; + + err = ds_access_bts(this_tracer, index, &raw); + if (err < 0) + return; + + from = *(const unsigned long *)raw; + to = *(const unsigned long *)((const char *)raw + sizeof_field); + + trace_bts(tr, from, to); +} + +static void trace_bts_cpu(void *arg) +{ + struct trace_array *tr = (struct trace_array *) arg; + size_t index = 0, end = 0, i; + int err; + + if (!this_tracer) + return; + + bts_disable(); + + err = ds_get_bts_index(this_tracer, &index); + if (err < 0) + goto out; + + err = ds_get_bts_end(this_tracer, &end); + if (err < 0) + goto out; + + for (i = index; i < end; i++) + trace_bts_at(tr, i); + + for (i = 0; i < index; i++) + trace_bts_at(tr, i); + +out: + bts_enable(); +} + +static void trace_bts_prepare(struct trace_iterator *iter) +{ + int cpu; + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1); +} + +struct tracer bts_tracer __read_mostly = +{ + .name = "bts", + .init = bts_trace_init, + .reset = bts_trace_stop, + .print_header = bts_trace_print_header, + .print_line = bts_trace_print_line, + .start = bts_trace_start, + .stop = bts_trace_stop, + .open = trace_bts_prepare +}; + +__init static int init_bts_trace(void) +{ + return register_tracer(&bts_tracer); +} +device_initcall(init_bts_trace); -- cgit v1.2.3-70-g09d2 From fb52607afcd0629776f1dc9e657647ceae81dd50 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 25 Nov 2008 21:07:04 +0100 Subject: tracing/function-return-tracer: change the name into function-graph-tracer Impact: cleanup This patch changes the name of the "return function tracer" into function-graph-tracer which is a more suitable name for a tracing which makes one able to retrieve the ordered call stack during the code flow. Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 2 +- arch/x86/include/asm/ftrace.h | 4 +- arch/x86/kernel/Makefile | 4 +- arch/x86/kernel/entry_32.S | 12 ++--- arch/x86/kernel/ftrace.c | 12 ++--- include/linux/ftrace.h | 24 ++++----- include/linux/ftrace_irq.h | 2 +- include/linux/sched.h | 2 +- kernel/Makefile | 2 +- kernel/fork.c | 4 +- kernel/sched.c | 2 +- kernel/trace/Kconfig | 19 ++++--- kernel/trace/Makefile | 2 +- kernel/trace/ftrace.c | 26 +++++----- kernel/trace/trace.c | 18 +++---- kernel/trace/trace.h | 12 ++--- kernel/trace/trace_functions_graph.c | 98 ++++++++++++++++++++++++++++++++++++ 17 files changed, 173 insertions(+), 72 deletions(-) create mode 100644 kernel/trace/trace_functions_graph.c (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e49a4fd718f..0842b112768 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -29,7 +29,7 @@ config X86 select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE select HAVE_FUNCTION_TRACER - select HAVE_FUNCTION_RET_TRACER if X86_32 + select HAVE_FUNCTION_GRAPH_TRACER if X86_32 select HAVE_FUNCTION_TRACE_MCOUNT_TEST select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index 754a3e082f9..7e61b4ceb9a 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -28,7 +28,7 @@ struct dyn_arch_ftrace { #endif /* __ASSEMBLY__ */ #endif /* CONFIG_FUNCTION_TRACER */ -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER #ifndef __ASSEMBLY__ @@ -51,6 +51,6 @@ struct ftrace_ret_stack { extern void return_to_handler(void); #endif /* __ASSEMBLY__ */ -#endif /* CONFIG_FUNCTION_RET_TRACER */ +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #endif /* _ASM_X86_FTRACE_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index af2bc36ca1c..64939a0c398 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -14,7 +14,7 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg CFLAGS_REMOVE_ftrace.o = -pg endif -ifdef CONFIG_FUNCTION_RET_TRACER +ifdef CONFIG_FUNCTION_GRAPH_TRACER # Don't trace __switch_to() but let it for function tracer CFLAGS_REMOVE_process_32.o = -pg endif @@ -70,7 +70,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o obj-$(CONFIG_X86_IO_APIC) += io_apic.o obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o -obj-$(CONFIG_FUNCTION_RET_TRACER) += ftrace.o +obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 74defe21ba4..2b1f0f081a6 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1188,9 +1188,9 @@ ENTRY(mcount) cmpl $ftrace_stub, ftrace_trace_function jnz trace -#ifdef CONFIG_FUNCTION_RET_TRACER - cmpl $ftrace_stub, ftrace_function_return - jnz ftrace_return_caller +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + cmpl $ftrace_stub, ftrace_graph_function + jnz ftrace_graph_caller #endif .globl ftrace_stub ftrace_stub: @@ -1215,8 +1215,8 @@ END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_TRACER */ -#ifdef CONFIG_FUNCTION_RET_TRACER -ENTRY(ftrace_return_caller) +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +ENTRY(ftrace_graph_caller) cmpl $0, function_trace_stop jne ftrace_stub @@ -1230,7 +1230,7 @@ ENTRY(ftrace_return_caller) popl %ecx popl %eax ret -END(ftrace_return_caller) +END(ftrace_graph_caller) .globl return_to_handler return_to_handler: diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index bb137f7297e..3595a4c14ab 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -323,7 +323,7 @@ int __init ftrace_dyn_arch_init(void *data) } #endif -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER #ifndef CONFIG_DYNAMIC_FTRACE @@ -389,11 +389,11 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time, */ unsigned long ftrace_return_to_handler(void) { - struct ftrace_retfunc trace; + struct ftrace_graph_ret trace; pop_return_trace(&trace.ret, &trace.calltime, &trace.func, &trace.overrun); trace.rettime = cpu_clock(raw_smp_processor_id()); - ftrace_function_return(&trace); + ftrace_graph_function(&trace); return trace.ret; } @@ -440,12 +440,12 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) ); if (WARN_ON(faulted)) { - unregister_ftrace_return(); + unregister_ftrace_graph(); return; } if (WARN_ON(!__kernel_text_address(old))) { - unregister_ftrace_return(); + unregister_ftrace_graph(); *parent = old; return; } @@ -456,4 +456,4 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) *parent = old; } -#endif /* CONFIG_FUNCTION_RET_TRACER */ +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7854d87b97b..b4ac734ad8d 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -115,8 +115,8 @@ extern int ftrace_update_ftrace_func(ftrace_func_t func); extern void ftrace_caller(void); extern void ftrace_call(void); extern void mcount_call(void); -#ifdef CONFIG_FUNCTION_RET_TRACER -extern void ftrace_return_caller(void); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +extern void ftrace_graph_caller(void); #endif /** @@ -315,7 +315,7 @@ ftrace_init_module(struct module *mod, /* * Structure that defines a return function trace. */ -struct ftrace_retfunc { +struct ftrace_graph_ret { unsigned long ret; /* Return address */ unsigned long func; /* Current function */ unsigned long long calltime; @@ -324,22 +324,22 @@ struct ftrace_retfunc { unsigned long overrun; }; -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 /* Type of a callback handler of tracing return function */ -typedef void (*trace_function_return_t)(struct ftrace_retfunc *); +typedef void (*trace_function_graph_t)(struct ftrace_graph_ret *); -extern int register_ftrace_return(trace_function_return_t func); +extern int register_ftrace_graph(trace_function_graph_t func); /* The current handler in use */ -extern trace_function_return_t ftrace_function_return; -extern void unregister_ftrace_return(void); +extern trace_function_graph_t ftrace_graph_function; +extern void unregister_ftrace_graph(void); -extern void ftrace_retfunc_init_task(struct task_struct *t); -extern void ftrace_retfunc_exit_task(struct task_struct *t); +extern void ftrace_graph_init_task(struct task_struct *t); +extern void ftrace_graph_exit_task(struct task_struct *t); #else -static inline void ftrace_retfunc_init_task(struct task_struct *t) { } -static inline void ftrace_retfunc_exit_task(struct task_struct *t) { } +static inline void ftrace_graph_init_task(struct task_struct *t) { } +static inline void ftrace_graph_exit_task(struct task_struct *t) { } #endif #endif /* _LINUX_FTRACE_H */ diff --git a/include/linux/ftrace_irq.h b/include/linux/ftrace_irq.h index 0b4df55d7a7..366a054d0b0 100644 --- a/include/linux/ftrace_irq.h +++ b/include/linux/ftrace_irq.h @@ -2,7 +2,7 @@ #define _LINUX_FTRACE_IRQ_H -#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_RET_TRACER) +#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_GRAPH_TRACER) extern void ftrace_nmi_enter(void); extern void ftrace_nmi_exit(void); #else diff --git a/include/linux/sched.h b/include/linux/sched.h index d02a0ca70ee..7ad48f2a275 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1365,7 +1365,7 @@ struct task_struct { unsigned long default_timer_slack_ns; struct list_head *scm_work_list; -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Index of current stored adress in ret_stack */ int curr_ret_stack; /* Stack of return addresses for return function tracing */ diff --git a/kernel/Makefile b/kernel/Makefile index 03a45e7e87b..703cf3b7389 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -21,7 +21,7 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg CFLAGS_REMOVE_sched_clock.o = -pg CFLAGS_REMOVE_sched.o = -pg endif -ifdef CONFIG_FUNCTION_RET_TRACER +ifdef CONFIG_FUNCTION_GRAPH_TRACER CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address() CFLAGS_REMOVE_module.o = -pg # For __module_text_address() endif diff --git a/kernel/fork.c b/kernel/fork.c index d6e1a3205f6..5f82a999c03 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -140,7 +140,7 @@ void free_task(struct task_struct *tsk) prop_local_destroy_single(&tsk->dirties); free_thread_info(tsk->stack); rt_mutex_debug_task_free(tsk); - ftrace_retfunc_exit_task(tsk); + ftrace_graph_exit_task(tsk); free_task_struct(tsk); } EXPORT_SYMBOL(free_task); @@ -1271,7 +1271,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, total_forks++; spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); - ftrace_retfunc_init_task(p); + ftrace_graph_init_task(p); proc_fork_connector(p); cgroup_post_fork(p); return p; diff --git a/kernel/sched.c b/kernel/sched.c index 388d9db044a..52490bf6b88 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5901,7 +5901,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) * The idle tasks have their own, simple scheduling class: */ idle->sched_class = &idle_sched_class; - ftrace_retfunc_init_task(idle); + ftrace_graph_init_task(idle); } /* diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 620feadff67..eb9b901e077 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -12,7 +12,7 @@ config NOP_TRACER config HAVE_FUNCTION_TRACER bool -config HAVE_FUNCTION_RET_TRACER +config HAVE_FUNCTION_GRAPH_TRACER bool config HAVE_FUNCTION_TRACE_MCOUNT_TEST @@ -63,15 +63,18 @@ config FUNCTION_TRACER (the bootup default), then the overhead of the instructions is very small and not measurable even in micro-benchmarks. -config FUNCTION_RET_TRACER - bool "Kernel Function return Tracer" - depends on HAVE_FUNCTION_RET_TRACER +config FUNCTION_GRAPH_TRACER + bool "Kernel Function Graph Tracer" + depends on HAVE_FUNCTION_GRAPH_TRACER depends on FUNCTION_TRACER help - Enable the kernel to trace a function at its return. - It's first purpose is to trace the duration of functions. - This is done by setting the current return address on the thread - info structure of the current task. + Enable the kernel to trace a function at both its return + and its entry. + It's first purpose is to trace the duration of functions and + draw a call graph for each thread with some informations like + the return value. + This is done by setting the current return address on the current + task structure into a stack of calls. config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index cef4bcb4e82..08c5fe6ddc0 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -29,7 +29,7 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o -obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o +obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o obj-$(CONFIG_BTS_TRACER) += trace_bts.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 53042f118f2..9e19976af72 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -395,11 +395,11 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) unsigned long ip, fl; unsigned long ftrace_addr; -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER if (ftrace_tracing_type == FTRACE_TYPE_ENTER) ftrace_addr = (unsigned long)ftrace_caller; else - ftrace_addr = (unsigned long)ftrace_return_caller; + ftrace_addr = (unsigned long)ftrace_graph_caller; #else ftrace_addr = (unsigned long)ftrace_caller; #endif @@ -1496,13 +1496,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, return ret; } -#ifdef CONFIG_FUNCTION_RET_TRACER +#ifdef CONFIG_FUNCTION_GRAPH_TRACER static atomic_t ftrace_retfunc_active; /* The callback that hooks the return of a function */ -trace_function_return_t ftrace_function_return = - (trace_function_return_t)ftrace_stub; +trace_function_graph_t ftrace_graph_function = + (trace_function_graph_t)ftrace_stub; /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ @@ -1549,7 +1549,7 @@ free: } /* Allocate a return stack for each task */ -static int start_return_tracing(void) +static int start_graph_tracing(void) { struct ftrace_ret_stack **ret_stack_list; int ret; @@ -1569,7 +1569,7 @@ static int start_return_tracing(void) return ret; } -int register_ftrace_return(trace_function_return_t func) +int register_ftrace_graph(trace_function_graph_t func) { int ret = 0; @@ -1584,13 +1584,13 @@ int register_ftrace_return(trace_function_return_t func) goto out; } atomic_inc(&ftrace_retfunc_active); - ret = start_return_tracing(); + ret = start_graph_tracing(); if (ret) { atomic_dec(&ftrace_retfunc_active); goto out; } ftrace_tracing_type = FTRACE_TYPE_RETURN; - ftrace_function_return = func; + ftrace_graph_function = func; ftrace_startup(); out: @@ -1598,12 +1598,12 @@ out: return ret; } -void unregister_ftrace_return(void) +void unregister_ftrace_graph(void) { mutex_lock(&ftrace_sysctl_lock); atomic_dec(&ftrace_retfunc_active); - ftrace_function_return = (trace_function_return_t)ftrace_stub; + ftrace_graph_function = (trace_function_graph_t)ftrace_stub; ftrace_shutdown(); /* Restore normal tracing type */ ftrace_tracing_type = FTRACE_TYPE_ENTER; @@ -1612,7 +1612,7 @@ void unregister_ftrace_return(void) } /* Allocate a return stack for newly created task */ -void ftrace_retfunc_init_task(struct task_struct *t) +void ftrace_graph_init_task(struct task_struct *t) { if (atomic_read(&ftrace_retfunc_active)) { t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH @@ -1626,7 +1626,7 @@ void ftrace_retfunc_init_task(struct task_struct *t) t->ret_stack = NULL; } -void ftrace_retfunc_exit_task(struct task_struct *t) +void ftrace_graph_exit_task(struct task_struct *t) { struct ftrace_ret_stack *ret_stack = t->ret_stack; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8df8fdd69c9..f21ab2c68fd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -878,15 +878,15 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } -#ifdef CONFIG_FUNCTION_RET_TRACER -static void __trace_function_return(struct trace_array *tr, +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +static void __trace_function_graph(struct trace_array *tr, struct trace_array_cpu *data, - struct ftrace_retfunc *trace, + struct ftrace_graph_ret *trace, unsigned long flags, int pc) { struct ring_buffer_event *event; - struct ftrace_ret_entry *entry; + struct ftrace_graph_entry *entry; unsigned long irq_flags; if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) @@ -1177,8 +1177,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) local_irq_restore(flags); } -#ifdef CONFIG_FUNCTION_RET_TRACER -void trace_function_return(struct ftrace_retfunc *trace) +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +void trace_function_graph(struct ftrace_graph_ret *trace) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; @@ -1193,12 +1193,12 @@ void trace_function_return(struct ftrace_retfunc *trace) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { pc = preempt_count(); - __trace_function_return(tr, data, trace, flags, pc); + __trace_function_graph(tr, data, trace, flags, pc); } atomic_dec(&data->disabled); raw_local_irq_restore(flags); } -#endif /* CONFIG_FUNCTION_RET_TRACER */ +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ static struct ftrace_ops trace_ops __read_mostly = { @@ -2001,7 +2001,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) break; } case TRACE_FN_RET: { - return print_return_function(iter); + return print_graph_function(iter); break; } case TRACE_BRANCH: { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3abd645e8af..72b5ef86876 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -57,7 +57,7 @@ struct ftrace_entry { }; /* Function return entry */ -struct ftrace_ret_entry { +struct ftrace_graph_entry { struct trace_entry ent; unsigned long ip; unsigned long parent_ip; @@ -264,7 +264,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ - IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ + IF_ASSIGN(var, ent, struct ftrace_graph_entry, TRACE_FN_RET);\ IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\ __ftrace_bad_type(); \ } while (0) @@ -398,7 +398,7 @@ void trace_function(struct trace_array *tr, unsigned long parent_ip, unsigned long flags, int pc); void -trace_function_return(struct ftrace_retfunc *trace); +trace_function_graph(struct ftrace_graph_ret *trace); void trace_bts(struct trace_array *tr, unsigned long from, @@ -489,11 +489,11 @@ extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; /* Standard output formatting function used for function return traces */ -#ifdef CONFIG_FUNCTION_RET_TRACER -extern enum print_line_t print_return_function(struct trace_iterator *iter); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +extern enum print_line_t print_graph_function(struct trace_iterator *iter); #else static inline enum print_line_t -print_return_function(struct trace_iterator *iter) +print_graph_function(struct trace_iterator *iter) { return TRACE_TYPE_UNHANDLED; } diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c new file mode 100644 index 00000000000..f5bad4624d2 --- /dev/null +++ b/kernel/trace/trace_functions_graph.c @@ -0,0 +1,98 @@ +/* + * + * Function graph tracer. + * Copyright (c) 2008 Frederic Weisbecker + * Mostly borrowed from function tracer which + * is Copyright (c) Steven Rostedt + * + */ +#include +#include +#include +#include + +#include "trace.h" + + +#define TRACE_GRAPH_PRINT_OVERRUN 0x1 +static struct tracer_opt trace_opts[] = { + /* Display overruns or not */ + { TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) }, + { } /* Empty entry */ +}; + +static struct tracer_flags tracer_flags = { + .val = 0, /* Don't display overruns by default */ + .opts = trace_opts +}; + + +static int graph_trace_init(struct trace_array *tr) +{ + int cpu; + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + + return register_ftrace_graph(&trace_function_graph); +} + +static void graph_trace_reset(struct trace_array *tr) +{ + unregister_ftrace_graph(); +} + + +enum print_line_t +print_graph_function(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; + struct ftrace_graph_entry *field; + int ret; + + if (entry->type == TRACE_FN_RET) { + trace_assign_type(field, entry); + ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = seq_print_ip_sym(s, field->ip, + trace_flags & TRACE_ITER_SYM_MASK); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, " (%llu ns)", + field->rettime - field->calltime); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { + ret = trace_seq_printf(s, " (Overruns: %lu)", + field->overrun); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + ret = trace_seq_printf(s, "\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return TRACE_TYPE_HANDLED; + } + return TRACE_TYPE_UNHANDLED; +} + +static struct tracer graph_trace __read_mostly = { + .name = "function-graph", + .init = graph_trace_init, + .reset = graph_trace_reset, + .print_line = print_graph_function, + .flags = &tracer_flags, +}; + +static __init int init_graph_trace(void) +{ + return register_tracer(&graph_trace); +} + +device_initcall(init_graph_trace); -- cgit v1.2.3-70-g09d2 From 287b6e68ca7209caec40b2f44f837c580a413bae Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 26 Nov 2008 00:57:25 +0100 Subject: tracing/function-return-tracer: set a more human readable output Impact: feature This patch sets a C-like output for the function graph tracing. For this aim, we now call two handler for each function: one on the entry and one other on return. This way we can draw a well-ordered call stack. The pid of the previous trace is loosely stored to be compared against the one of the current trace to see if there were a context switch. Without this little feature, the call tree would seem broken at some locations. We could use the sched_tracer to capture these sched_events but this way of processing is much more simpler. 2 spaces have been chosen for indentation to fit the screen while deep calls. The time of execution in nanosecs is printed just after closed braces, it seems more easy this way to find the corresponding function. If the time was printed as a first column, it would be not so easy to find the corresponding function if it is called on a deep depth. I plan to output the return value but on 32 bits CPU, the return value can be 32 or 64, and its difficult to guess on which case we are. I don't know what would be the better solution on X86-32: only print eax (low-part) or even edx (high-part). Actually it's thee same problem when a function return a 8 bits value, the high part of eax could contain junk values... Here is an example of trace: sys_read() { fget_light() { } 526 vfs_read() { rw_verify_area() { security_file_permission() { cap_file_permission() { } 519 } 1564 } 2640 do_sync_read() { pipe_read() { __might_sleep() { } 511 pipe_wait() { prepare_to_wait() { } 760 deactivate_task() { dequeue_task() { dequeue_task_fair() { dequeue_entity() { update_curr() { update_min_vruntime() { } 504 } 1587 clear_buddies() { } 512 add_cfs_task_weight() { } 519 update_min_vruntime() { } 511 } 5602 dequeue_entity() { update_curr() { update_min_vruntime() { } 496 } 1631 clear_buddies() { } 496 update_min_vruntime() { } 527 } 4580 hrtick_update() { hrtick_start_fair() { } 488 } 1489 } 13700 } 14949 } 16016 msecs_to_jiffies() { } 496 put_prev_task_fair() { } 504 pick_next_task_fair() { } 489 pick_next_task_rt() { } 496 pick_next_task_fair() { } 489 pick_next_task_idle() { } 489 ------------8<---------- thread 4 ------------8<---------- finish_task_switch() { } 1203 do_softirq() { __do_softirq() { __local_bh_disable() { } 669 rcu_process_callbacks() { __rcu_process_callbacks() { cpu_quiet() { rcu_start_batch() { } 503 } 1647 } 3128 __rcu_process_callbacks() { } 542 } 5362 _local_bh_enable() { } 587 } 8880 } 9986 kthread_should_stop() { } 669 deactivate_task() { dequeue_task() { dequeue_task_fair() { dequeue_entity() { update_curr() { calc_delta_mine() { } 511 update_min_vruntime() { } 511 } 2813 Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 32 +++++++---- include/linux/ftrace.h | 25 ++++++-- kernel/trace/ftrace.c | 30 +++++----- kernel/trace/trace.c | 67 ++++++++++++++++++---- kernel/trace/trace.h | 28 +++++---- kernel/trace/trace_functions_graph.c | 104 ++++++++++++++++++++++++++-------- kernel/trace/trace_functions_return.c | 98 -------------------------------- 7 files changed, 208 insertions(+), 176 deletions(-) delete mode 100644 kernel/trace/trace_functions_return.c (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 3595a4c14ab..26b2d92d48b 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -347,7 +347,7 @@ void ftrace_nmi_exit(void) /* Add a function return address to the trace stack on thread info.*/ static int push_return_trace(unsigned long ret, unsigned long long time, - unsigned long func) + unsigned long func, int *depth) { int index; @@ -365,21 +365,22 @@ static int push_return_trace(unsigned long ret, unsigned long long time, current->ret_stack[index].ret = ret; current->ret_stack[index].func = func; current->ret_stack[index].calltime = time; + *depth = index; return 0; } /* Retrieve a function return address to the trace stack on thread info.*/ -static void pop_return_trace(unsigned long *ret, unsigned long long *time, - unsigned long *func, unsigned long *overrun) +static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) { int index; index = current->curr_ret_stack; *ret = current->ret_stack[index].ret; - *func = current->ret_stack[index].func; - *time = current->ret_stack[index].calltime; - *overrun = atomic_read(¤t->trace_overrun); + trace->func = current->ret_stack[index].func; + trace->calltime = current->ret_stack[index].calltime; + trace->overrun = atomic_read(¤t->trace_overrun); + trace->depth = index; current->curr_ret_stack--; } @@ -390,12 +391,13 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time, unsigned long ftrace_return_to_handler(void) { struct ftrace_graph_ret trace; - pop_return_trace(&trace.ret, &trace.calltime, &trace.func, - &trace.overrun); + unsigned long ret; + + pop_return_trace(&trace, &ret); trace.rettime = cpu_clock(raw_smp_processor_id()); - ftrace_graph_function(&trace); + ftrace_graph_return(&trace); - return trace.ret; + return ret; } /* @@ -407,6 +409,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) unsigned long old; unsigned long long calltime; int faulted; + struct ftrace_graph_ent trace; unsigned long return_hooker = (unsigned long) &return_to_handler; @@ -452,8 +455,15 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) calltime = cpu_clock(raw_smp_processor_id()); - if (push_return_trace(old, calltime, self_addr) == -EBUSY) + if (push_return_trace(old, calltime, + self_addr, &trace.depth) == -EBUSY) { *parent = old; + return; + } + + trace.func = self_addr; + ftrace_graph_entry(&trace); + } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index b4ac734ad8d..fc2d5498719 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -312,27 +312,40 @@ ftrace_init_module(struct module *mod, #endif +/* + * Structure that defines an entry function trace. + */ +struct ftrace_graph_ent { + unsigned long func; /* Current function */ + int depth; +}; + /* * Structure that defines a return function trace. */ struct ftrace_graph_ret { - unsigned long ret; /* Return address */ unsigned long func; /* Current function */ unsigned long long calltime; unsigned long long rettime; /* Number of functions that overran the depth limit for current task */ unsigned long overrun; + int depth; }; #ifdef CONFIG_FUNCTION_GRAPH_TRACER #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 -/* Type of a callback handler of tracing return function */ -typedef void (*trace_function_graph_t)(struct ftrace_graph_ret *); +/* Type of the callback handlers for tracing function graph*/ +typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ +typedef void (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ + +extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, + trace_func_graph_ent_t entryfunc); + +/* The current handlers in use */ +extern trace_func_graph_ret_t ftrace_graph_return; +extern trace_func_graph_ent_t ftrace_graph_entry; -extern int register_ftrace_graph(trace_function_graph_t func); -/* The current handler in use */ -extern trace_function_graph_t ftrace_graph_function; extern void unregister_ftrace_graph(void); extern void ftrace_graph_init_task(struct task_struct *t); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9e19976af72..7e2d3b91692 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1498,12 +1498,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, #ifdef CONFIG_FUNCTION_GRAPH_TRACER -static atomic_t ftrace_retfunc_active; - -/* The callback that hooks the return of a function */ -trace_function_graph_t ftrace_graph_function = - (trace_function_graph_t)ftrace_stub; +static atomic_t ftrace_graph_active; +/* The callbacks that hook a function */ +trace_func_graph_ret_t ftrace_graph_return = + (trace_func_graph_ret_t)ftrace_stub; +trace_func_graph_ent_t ftrace_graph_entry = + (trace_func_graph_ent_t)ftrace_stub; /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) @@ -1569,7 +1570,8 @@ static int start_graph_tracing(void) return ret; } -int register_ftrace_graph(trace_function_graph_t func) +int register_ftrace_graph(trace_func_graph_ret_t retfunc, + trace_func_graph_ent_t entryfunc) { int ret = 0; @@ -1583,14 +1585,15 @@ int register_ftrace_graph(trace_function_graph_t func) ret = -EBUSY; goto out; } - atomic_inc(&ftrace_retfunc_active); + atomic_inc(&ftrace_graph_active); ret = start_graph_tracing(); if (ret) { - atomic_dec(&ftrace_retfunc_active); + atomic_dec(&ftrace_graph_active); goto out; } ftrace_tracing_type = FTRACE_TYPE_RETURN; - ftrace_graph_function = func; + ftrace_graph_return = retfunc; + ftrace_graph_entry = entryfunc; ftrace_startup(); out: @@ -1602,8 +1605,9 @@ void unregister_ftrace_graph(void) { mutex_lock(&ftrace_sysctl_lock); - atomic_dec(&ftrace_retfunc_active); - ftrace_graph_function = (trace_function_graph_t)ftrace_stub; + atomic_dec(&ftrace_graph_active); + ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; + ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; ftrace_shutdown(); /* Restore normal tracing type */ ftrace_tracing_type = FTRACE_TYPE_ENTER; @@ -1614,7 +1618,7 @@ void unregister_ftrace_graph(void) /* Allocate a return stack for newly created task */ void ftrace_graph_init_task(struct task_struct *t) { - if (atomic_read(&ftrace_retfunc_active)) { + if (atomic_read(&ftrace_graph_active)) { t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH * sizeof(struct ftrace_ret_stack), GFP_KERNEL); @@ -1638,5 +1642,3 @@ void ftrace_graph_exit_task(struct task_struct *t) } #endif - - diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f21ab2c68fd..9d5f7c94f25 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -879,14 +879,38 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -static void __trace_function_graph(struct trace_array *tr, +static void __trace_graph_entry(struct trace_array *tr, + struct trace_array_cpu *data, + struct ftrace_graph_ent *trace, + unsigned long flags, + int pc) +{ + struct ring_buffer_event *event; + struct ftrace_graph_ent_entry *entry; + unsigned long irq_flags; + + if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) + return; + + event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_GRAPH_ENT; + entry->graph_ent = *trace; + ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags); +} + +static void __trace_graph_return(struct trace_array *tr, struct trace_array_cpu *data, struct ftrace_graph_ret *trace, unsigned long flags, int pc) { struct ring_buffer_event *event; - struct ftrace_graph_entry *entry; + struct ftrace_graph_ret_entry *entry; unsigned long irq_flags; if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) @@ -898,12 +922,8 @@ static void __trace_function_graph(struct trace_array *tr, return; entry = ring_buffer_event_data(event); tracing_generic_entry_update(&entry->ent, flags, pc); - entry->ent.type = TRACE_FN_RET; - entry->ip = trace->func; - entry->parent_ip = trace->ret; - entry->rettime = trace->rettime; - entry->calltime = trace->calltime; - entry->overrun = trace->overrun; + entry->ent.type = TRACE_GRAPH_RET; + entry->ret = *trace; ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags); } #endif @@ -1178,7 +1198,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -void trace_function_graph(struct ftrace_graph_ret *trace) +void trace_graph_entry(struct ftrace_graph_ent *trace) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; @@ -1193,7 +1213,28 @@ void trace_function_graph(struct ftrace_graph_ret *trace) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { pc = preempt_count(); - __trace_function_graph(tr, data, trace, flags, pc); + __trace_graph_entry(tr, data, trace, flags, pc); + } + atomic_dec(&data->disabled); + raw_local_irq_restore(flags); +} + +void trace_graph_return(struct ftrace_graph_ret *trace) +{ + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + int pc; + + raw_local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + if (likely(disabled == 1)) { + pc = preempt_count(); + __trace_graph_return(tr, data, trace, flags, pc); } atomic_dec(&data->disabled); raw_local_irq_restore(flags); @@ -2000,9 +2041,11 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter) trace_seq_print_cont(s, iter); break; } - case TRACE_FN_RET: { + case TRACE_GRAPH_RET: { + return print_graph_function(iter); + } + case TRACE_GRAPH_ENT: { return print_graph_function(iter); - break; } case TRACE_BRANCH: { struct trace_branch *field; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 72b5ef86876..ffe1bb1eb62 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -25,7 +25,8 @@ enum trace_type { TRACE_BRANCH, TRACE_BOOT_CALL, TRACE_BOOT_RET, - TRACE_FN_RET, + TRACE_GRAPH_RET, + TRACE_GRAPH_ENT, TRACE_USER_STACK, TRACE_BTS, @@ -56,14 +57,16 @@ struct ftrace_entry { unsigned long parent_ip; }; +/* Function call entry */ +struct ftrace_graph_ent_entry { + struct trace_entry ent; + struct ftrace_graph_ent graph_ent; +}; + /* Function return entry */ -struct ftrace_graph_entry { - struct trace_entry ent; - unsigned long ip; - unsigned long parent_ip; - unsigned long long calltime; - unsigned long long rettime; - unsigned long overrun; +struct ftrace_graph_ret_entry { + struct trace_entry ent; + struct ftrace_graph_ret ret; }; extern struct tracer boot_tracer; @@ -264,7 +267,10 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\ IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ - IF_ASSIGN(var, ent, struct ftrace_graph_entry, TRACE_FN_RET);\ + IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \ + TRACE_GRAPH_ENT); \ + IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ + TRACE_GRAPH_RET); \ IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\ __ftrace_bad_type(); \ } while (0) @@ -397,9 +403,9 @@ void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); -void -trace_function_graph(struct ftrace_graph_ret *trace); +void trace_graph_return(struct ftrace_graph_ret *trace); +void trace_graph_entry(struct ftrace_graph_ent *trace); void trace_bts(struct trace_array *tr, unsigned long from, unsigned long to); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index f5bad4624d2..b6f0cc2a00c 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -13,6 +13,7 @@ #include "trace.h" +#define TRACE_GRAPH_INDENT 2 #define TRACE_GRAPH_PRINT_OVERRUN 0x1 static struct tracer_opt trace_opts[] = { @@ -26,6 +27,8 @@ static struct tracer_flags tracer_flags = { .opts = trace_opts }; +/* pid on the last trace processed */ +static pid_t last_pid = -1; static int graph_trace_init(struct trace_array *tr) { @@ -33,7 +36,8 @@ static int graph_trace_init(struct trace_array *tr) for_each_online_cpu(cpu) tracing_reset(tr, cpu); - return register_ftrace_graph(&trace_function_graph); + return register_ftrace_graph(&trace_graph_return, + &trace_graph_entry); } static void graph_trace_reset(struct trace_array *tr) @@ -41,45 +45,97 @@ static void graph_trace_reset(struct trace_array *tr) unregister_ftrace_graph(); } +/* If the pid changed since the last trace, output this event */ +static int verif_pid(struct trace_seq *s, pid_t pid) +{ + if (last_pid != -1 && last_pid == pid) + return 1; -enum print_line_t -print_graph_function(struct trace_iterator *iter) + last_pid = pid; + return trace_seq_printf(s, "\n------------8<---------- thread %d" + " ------------8<----------\n\n", + pid); +} + +static enum print_line_t +print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s, + struct trace_entry *ent) { - struct trace_seq *s = &iter->seq; - struct trace_entry *entry = iter->ent; - struct ftrace_graph_entry *field; + int i; int ret; - if (entry->type == TRACE_FN_RET) { - trace_assign_type(field, entry); - ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + if (!verif_pid(s, ent->pid)) + return TRACE_TYPE_PARTIAL_LINE; - ret = seq_print_ip_sym(s, field->ip, - trace_flags & TRACE_ITER_SYM_MASK); + for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { + ret = trace_seq_printf(s, " "); if (!ret) return TRACE_TYPE_PARTIAL_LINE; + } + + ret = seq_print_ip_sym(s, call->func, 0); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, "() {\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; +} + +static enum print_line_t +print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, + struct trace_entry *ent) +{ + int i; + int ret; + + if (!verif_pid(s, ent->pid)) + return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_printf(s, " (%llu ns)", - field->rettime - field->calltime); + for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) { + ret = trace_seq_printf(s, " "); if (!ret) return TRACE_TYPE_PARTIAL_LINE; + } + + ret = trace_seq_printf(s, "} "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; - if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { - ret = trace_seq_printf(s, " (Overruns: %lu)", - field->overrun); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_printf(s, "\n"); + if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { + ret = trace_seq_printf(s, " (Overruns: %lu)\n", + trace->overrun); if (!ret) return TRACE_TYPE_PARTIAL_LINE; + } + return TRACE_TYPE_HANDLED; +} + +enum print_line_t +print_graph_function(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; - return TRACE_TYPE_HANDLED; + switch (entry->type) { + case TRACE_GRAPH_ENT: { + struct ftrace_graph_ent_entry *field; + trace_assign_type(field, entry); + return print_graph_entry(&field->graph_ent, s, entry); + } + case TRACE_GRAPH_RET: { + struct ftrace_graph_ret_entry *field; + trace_assign_type(field, entry); + return print_graph_return(&field->ret, s, entry); + } + default: + return TRACE_TYPE_UNHANDLED; } - return TRACE_TYPE_UNHANDLED; } static struct tracer graph_trace __read_mostly = { diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c deleted file mode 100644 index e00d64509c9..00000000000 --- a/kernel/trace/trace_functions_return.c +++ /dev/null @@ -1,98 +0,0 @@ -/* - * - * Function return tracer. - * Copyright (c) 2008 Frederic Weisbecker - * Mostly borrowed from function tracer which - * is Copyright (c) Steven Rostedt - * - */ -#include -#include -#include -#include - -#include "trace.h" - - -#define TRACE_RETURN_PRINT_OVERRUN 0x1 -static struct tracer_opt trace_opts[] = { - /* Display overruns or not */ - { TRACER_OPT(overrun, TRACE_RETURN_PRINT_OVERRUN) }, - { } /* Empty entry */ -}; - -static struct tracer_flags tracer_flags = { - .val = 0, /* Don't display overruns by default */ - .opts = trace_opts -}; - - -static int return_trace_init(struct trace_array *tr) -{ - int cpu; - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); - - return register_ftrace_return(&trace_function_return); -} - -static void return_trace_reset(struct trace_array *tr) -{ - unregister_ftrace_return(); -} - - -enum print_line_t -print_return_function(struct trace_iterator *iter) -{ - struct trace_seq *s = &iter->seq; - struct trace_entry *entry = iter->ent; - struct ftrace_ret_entry *field; - int ret; - - if (entry->type == TRACE_FN_RET) { - trace_assign_type(field, entry); - ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = seq_print_ip_sym(s, field->ip, - trace_flags & TRACE_ITER_SYM_MASK); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_seq_printf(s, " (%llu ns)", - field->rettime - field->calltime); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - if (tracer_flags.val & TRACE_RETURN_PRINT_OVERRUN) { - ret = trace_seq_printf(s, " (Overruns: %lu)", - field->overrun); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } - - ret = trace_seq_printf(s, "\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - return TRACE_TYPE_HANDLED; - } - return TRACE_TYPE_UNHANDLED; -} - -static struct tracer return_trace __read_mostly = { - .name = "return", - .init = return_trace_init, - .reset = return_trace_reset, - .print_line = print_return_function, - .flags = &tracer_flags, -}; - -static __init int init_return_trace(void) -{ - return register_tracer(&return_trace); -} - -device_initcall(init_return_trace); -- cgit v1.2.3-70-g09d2 From 660c7f9be96321fc80026d76411bd15e6f418a72 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 26 Nov 2008 00:16:26 -0500 Subject: ftrace: add thread comm to function graph tracer Impact: enhancement to function graph tracer Export the trace_find_cmdline so the function graph tracer can use it to print the comms of the threads. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 1 + kernel/trace/trace_functions_graph.c | 21 ++++++++++++++++----- 3 files changed, 18 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9d5f7c94f25..5811e0a5f73 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -804,7 +804,7 @@ static void trace_save_cmdline(struct task_struct *tsk) spin_unlock(&trace_cmdline_lock); } -static char *trace_find_cmdline(int pid) +char *trace_find_cmdline(int pid) { char *cmdline = "<...>"; unsigned map; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index ffe1bb1eb62..7adacf349ef 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -450,6 +450,7 @@ struct tracer_switch_ops { struct tracer_switch_ops *next; }; +char *trace_find_cmdline(int pid); #endif /* CONFIG_CONTEXT_SWITCH_TRACER */ #ifdef CONFIG_DYNAMIC_FTRACE diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index b6f0cc2a00c..bbb81e7b6c4 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -32,29 +32,40 @@ static pid_t last_pid = -1; static int graph_trace_init(struct trace_array *tr) { - int cpu; + int cpu, ret; + for_each_online_cpu(cpu) tracing_reset(tr, cpu); - return register_ftrace_graph(&trace_graph_return, + ret = register_ftrace_graph(&trace_graph_return, &trace_graph_entry); + if (ret) + return ret; + tracing_start_cmdline_record(); + + return 0; } static void graph_trace_reset(struct trace_array *tr) { - unregister_ftrace_graph(); + tracing_stop_cmdline_record(); + unregister_ftrace_graph(); } /* If the pid changed since the last trace, output this event */ static int verif_pid(struct trace_seq *s, pid_t pid) { + char *comm; + if (last_pid != -1 && last_pid == pid) return 1; last_pid = pid; - return trace_seq_printf(s, "\n------------8<---------- thread %d" + comm = trace_find_cmdline(pid); + + return trace_seq_printf(s, "\n------------8<---------- thread %s-%d" " ------------8<----------\n\n", - pid); + comm, pid); } static enum print_line_t -- cgit v1.2.3-70-g09d2 From f3f47a6768a29448866da4422b6f6bee485c947f Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 23 Nov 2008 16:49:58 -0800 Subject: tracing: add "power-tracer": C/P state tracer to help power optimization Impact: new "power-tracer" ftrace plugin This patch adds a C/P-state ftrace plugin that will generate detailed statistics about the C/P-states that are being used, so that we can look at detailed decisions that the C/P-state code is making, rather than the too high level "average" that we have today. An example way of using this is: mount -t debugfs none /sys/kernel/debug echo cstate > /sys/kernel/debug/tracing/current_tracer echo 1 > /sys/kernel/debug/tracing/tracing_enabled sleep 1 echo 0 > /sys/kernel/debug/tracing/tracing_enabled cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 4 + arch/x86/kernel/process.c | 16 +++ include/linux/ftrace.h | 29 +++++ kernel/trace/Kconfig | 11 ++ kernel/trace/Makefile | 1 + kernel/trace/trace.h | 7 ++ kernel/trace/trace_power.c | 179 +++++++++++++++++++++++++++++ scripts/trace/power.pl | 108 +++++++++++++++++ 8 files changed, 355 insertions(+) create mode 100644 kernel/trace/trace_power.c create mode 100644 scripts/trace/power.pl (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 8e48c5d4467..88ea02dcb62 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -391,6 +392,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, unsigned int next_perf_state = 0; /* Index into perf table */ unsigned int i; int result = 0; + struct power_trace it; dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu); @@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, } } + trace_power_mark(&it, POWER_PSTATE, next_perf_state); + switch (data->cpu_feature) { case SYSTEM_INTEL_MSR_CAPABLE: cmd.type = SYSTEM_INTEL_MSR_CAPABLE; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c622772744d..c27af49a4ed 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -7,6 +7,7 @@ #include #include #include +#include #include unsigned long idle_halt; @@ -100,6 +101,9 @@ static inline int hlt_use_halt(void) void default_idle(void) { if (hlt_use_halt()) { + struct power_trace it; + + trace_power_start(&it, POWER_CSTATE, 1); current_thread_info()->status &= ~TS_POLLING; /* * TS_POLLING-cleared state must be visible before we @@ -112,6 +116,7 @@ void default_idle(void) else local_irq_enable(); current_thread_info()->status |= TS_POLLING; + trace_power_end(&it); } else { local_irq_enable(); /* loop is done by the caller */ @@ -154,24 +159,31 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait); */ void mwait_idle_with_hints(unsigned long ax, unsigned long cx) { + struct power_trace it; + + trace_power_start(&it, POWER_CSTATE, (ax>>4)+1); if (!need_resched()) { __monitor((void *)¤t_thread_info()->flags, 0, 0); smp_mb(); if (!need_resched()) __mwait(ax, cx); } + trace_power_end(&it); } /* Default MONITOR/MWAIT with no hints, used for default C1 state */ static void mwait_idle(void) { + struct power_trace it; if (!need_resched()) { + trace_power_start(&it, POWER_CSTATE, 1); __monitor((void *)¤t_thread_info()->flags, 0, 0); smp_mb(); if (!need_resched()) __sti_mwait(0, 0); else local_irq_enable(); + trace_power_end(&it); } else local_irq_enable(); } @@ -183,9 +195,13 @@ static void mwait_idle(void) */ static void poll_idle(void) { + struct power_trace it; + + trace_power_start(&it, POWER_CSTATE, 0); local_irq_enable(); while (!need_resched()) cpu_relax(); + trace_power_end(&it); } /* diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7854d87b97b..0df28866620 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -311,6 +311,35 @@ ftrace_init_module(struct module *mod, unsigned long *start, unsigned long *end) { } #endif +enum { + POWER_NONE = 0, + POWER_CSTATE = 1, + POWER_PSTATE = 2, +}; + +struct power_trace { +#ifdef CONFIG_POWER_TRACER + ktime_t stamp; + ktime_t end; + int type; + int state; +#endif +}; + +#ifdef CONFIG_POWER_TRACER +extern void trace_power_start(struct power_trace *it, unsigned int type, + unsigned int state); +extern void trace_power_mark(struct power_trace *it, unsigned int type, + unsigned int state); +extern void trace_power_end(struct power_trace *it); +#else +static inline void trace_power_start(struct power_trace *it, unsigned int type, + unsigned int state) { } +static inline void trace_power_mark(struct power_trace *it, unsigned int type, + unsigned int state) { } +static inline void trace_power_end(struct power_trace *it) { } +#endif + /* * Structure that defines a return function trace. diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 620feadff67..d151aab48ed 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -217,6 +217,17 @@ config BRANCH_TRACER Say N if unsure. +config POWER_TRACER + bool "Trace power consumption behavior" + depends on DEBUG_KERNEL + depends on X86 + select TRACING + help + This tracer helps developers to analyze and optimize the kernels + power management decisions, specifically the C-state and P-state + behavior. + + config STACK_TRACER bool "Trace max stack" depends on HAVE_FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index cef4bcb4e82..acaa06553ec 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -32,5 +32,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o obj-$(CONFIG_BTS_TRACER) += trace_bts.o +obj-$(CONFIG_POWER_TRACER) += trace_power.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3abd645e8af..4c453778a6a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -28,6 +28,7 @@ enum trace_type { TRACE_FN_RET, TRACE_USER_STACK, TRACE_BTS, + TRACE_POWER, __TRACE_LAST_TYPE }; @@ -160,6 +161,11 @@ struct bts_entry { unsigned long to; }; +struct trace_power { + struct trace_entry ent; + struct power_trace state_data; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -266,6 +272,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\ IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\ + IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ __ftrace_bad_type(); \ } while (0) diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c new file mode 100644 index 00000000000..a7172a352f6 --- /dev/null +++ b/kernel/trace/trace_power.c @@ -0,0 +1,179 @@ +/* + * ring buffer based C-state tracer + * + * Arjan van de Ven + * Copyright (C) 2008 Intel Corporation + * + * Much is borrowed from trace_boot.c which is + * Copyright (C) 2008 Frederic Weisbecker + * + */ + +#include +#include +#include +#include +#include + +#include "trace.h" + +static struct trace_array *power_trace; +static int __read_mostly trace_power_enabled; + + +static void start_power_trace(struct trace_array *tr) +{ + trace_power_enabled = 1; +} + +static void stop_power_trace(struct trace_array *tr) +{ + trace_power_enabled = 0; +} + + +static int power_trace_init(struct trace_array *tr) +{ + int cpu; + power_trace = tr; + + trace_power_enabled = 1; + + for_each_cpu_mask(cpu, cpu_possible_map) + tracing_reset(tr, cpu); + return 0; +} + +static enum print_line_t power_print_line(struct trace_iterator *iter) +{ + int ret = 0; + struct trace_entry *entry = iter->ent; + struct trace_power *field ; + struct power_trace *it; + struct trace_seq *s = &iter->seq; + struct timespec stamp; + struct timespec duration; + + trace_assign_type(field, entry); + it = &field->state_data; + stamp = ktime_to_timespec(it->stamp); + duration = ktime_to_timespec(ktime_sub(it->end, it->stamp)); + + if (entry->type == TRACE_POWER) { + if (it->type == POWER_CSTATE) + ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n", + stamp.tv_sec, + stamp.tv_nsec, + it->state, iter->cpu, + duration.tv_sec, + duration.tv_nsec); + if (it->type == POWER_PSTATE) + ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n", + stamp.tv_sec, + stamp.tv_nsec, + it->state, iter->cpu); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; + } + return TRACE_TYPE_UNHANDLED; +} + +static struct tracer power_tracer __read_mostly = +{ + .name = "power", + .init = power_trace_init, + .start = start_power_trace, + .stop = stop_power_trace, + .reset = stop_power_trace, + .print_line = power_print_line, +}; + +static int init_power_trace(void) +{ + return register_tracer(&power_tracer); +} +device_initcall(init_power_trace); + +void trace_power_start(struct power_trace *it, unsigned int type, + unsigned int level) +{ + if (!trace_power_enabled) + return; + + memset(it, 0, sizeof(struct power_trace)); + it->state = level; + it->type = type; + it->stamp = ktime_get(); +} +EXPORT_SYMBOL_GPL(trace_power_start); + + +void trace_power_end(struct power_trace *it) +{ + struct ring_buffer_event *event; + struct trace_power *entry; + struct trace_array_cpu *data; + unsigned long irq_flags; + struct trace_array *tr = power_trace; + + if (!trace_power_enabled) + return; + + preempt_disable(); + it->end = ktime_get(); + data = tr->data[smp_processor_id()]; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, 0); + entry->ent.type = TRACE_POWER; + entry->state_data = *it; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); + + out: + preempt_enable(); +} +EXPORT_SYMBOL_GPL(trace_power_end); + +void trace_power_mark(struct power_trace *it, unsigned int type, + unsigned int level) +{ + struct ring_buffer_event *event; + struct trace_power *entry; + struct trace_array_cpu *data; + unsigned long irq_flags; + struct trace_array *tr = power_trace; + + if (!trace_power_enabled) + return; + + memset(it, 0, sizeof(struct power_trace)); + it->state = level; + it->type = type; + it->stamp = ktime_get(); + preempt_disable(); + it->end = it->stamp; + data = tr->data[smp_processor_id()]; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, 0); + entry->ent.type = TRACE_POWER; + entry->state_data = *it; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); + + out: + preempt_enable(); +} +EXPORT_SYMBOL_GPL(trace_power_mark); diff --git a/scripts/trace/power.pl b/scripts/trace/power.pl new file mode 100644 index 00000000000..4f729b3501e --- /dev/null +++ b/scripts/trace/power.pl @@ -0,0 +1,108 @@ +#!/usr/bin/perl + +# Copyright 2008, Intel Corporation +# +# This file is part of the Linux kernel +# +# This program file is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation; version 2 of the License. +# +# This program is distributed in the hope that it will be useful, but WITHOUT +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +# for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program in a file named COPYING; if not, write to the +# Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, +# Boston, MA 02110-1301 USA +# +# Authors: +# Arjan van de Ven + + +# +# This script turns a cstate ftrace output into a SVG graphic that shows +# historic C-state information +# +# +# cat /sys/kernel/debug/tracing/trace | perl power.pl > out.svg +# + +my @styles; +my $base = 0; + +my @pstate_last; +my @pstate_level; + +$styles[0] = "fill:rgb(0,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[1] = "fill:rgb(0,255,0);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[2] = "fill:rgb(255,0,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[3] = "fill:rgb(255,255,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[4] = "fill:rgb(255,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[5] = "fill:rgb(0,255,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[6] = "fill:rgb(0,128,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[7] = "fill:rgb(0,255,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[8] = "fill:rgb(0,25,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; + + +print " \n"; +print "\n"; + +my $scale = 30000.0; +while (<>) { + my $line = $_; + if ($line =~ /([0-9\.]+)\] CSTATE: Going to C([0-9]) on cpu ([0-9]+) for ([0-9\.]+)/) { + if ($base == 0) { + $base = $1; + } + my $time = $1 - $base; + $time = $time * $scale; + my $C = $2; + my $cpu = $3; + my $y = 400 * $cpu; + my $duration = $4 * $scale; + my $msec = int($4 * 100000)/100.0; + my $height = $C * 20; + $style = $styles[$C]; + + $y = $y + 140 - $height; + + $x2 = $time + 4; + $y2 = $y + 4; + + + print "\n"; + print "C$C $msec\n"; + } + if ($line =~ /([0-9\.]+)\] PSTATE: Going to P([0-9]) on cpu ([0-9]+)/) { + my $time = $1 - $base; + my $state = $2; + my $cpu = $3; + + if (defined($pstate_last[$cpu])) { + my $from = $pstate_last[$cpu]; + my $oldstate = $pstate_state[$cpu]; + my $duration = ($time-$from) * $scale; + + $from = $from * $scale; + my $to = $from + $duration; + my $height = 140 - ($oldstate * (140/8)); + + my $y = 400 * $cpu + 200 + $height; + my $y2 = $y+4; + my $style = $styles[8]; + + print "\n"; + print "P$oldstate (cpu $cpu)\n"; + }; + + $pstate_last[$cpu] = $time; + $pstate_state[$cpu] = $state; + } +} + + +print "\n"; -- cgit v1.2.3-70-g09d2 From e49dc19c6a19ea112fcb94b7c62ec62cdd5c08aa Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 2 Dec 2008 23:50:05 -0500 Subject: ftrace: function graph return for function entry Impact: feature, let entry function decide to trace or not This patch lets the graph tracer entry function decide if the tracing should be done at the end as well. This requires all function graph entry functions return 1 if it should trace, or 0 if the return should not be traced. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/entry_32.S | 3 +++ arch/x86/kernel/entry_64.S | 3 +++ arch/x86/kernel/ftrace.c | 7 ++++++- include/linux/ftrace.h | 2 +- kernel/trace/ftrace.c | 10 +++++++--- kernel/trace/trace.c | 4 +++- kernel/trace/trace.h | 2 +- 7 files changed, 24 insertions(+), 7 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 826682abed1..43ceb3f454b 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1196,6 +1196,9 @@ ENTRY(mcount) #ifdef CONFIG_FUNCTION_GRAPH_TRACER cmpl $ftrace_stub, ftrace_graph_return jnz ftrace_graph_caller + + cmpl $ftrace_graph_entry_stub, ftrace_graph_entry + jnz ftrace_graph_caller #endif .globl ftrace_stub ftrace_stub: diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 9060ba6497e..54e0bbdccb9 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -120,6 +120,9 @@ ENTRY(mcount) #ifdef CONFIG_FUNCTION_GRAPH_TRACER cmpq $ftrace_stub, ftrace_graph_return jnz ftrace_graph_caller + + cmpq $ftrace_graph_entry_stub, ftrace_graph_entry + jnz ftrace_graph_caller #endif .globl ftrace_stub diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index adba8e9a427..d278ad2ebda 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -425,6 +425,7 @@ static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) trace->calltime = current->ret_stack[index].calltime; trace->overrun = atomic_read(¤t->trace_overrun); trace->depth = index; + barrier(); current->curr_ret_stack--; } @@ -506,7 +507,11 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) } trace.func = self_addr; - ftrace_graph_entry(&trace); + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) { + current->curr_ret_stack--; + *parent = old; + } } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 58ca1c3a3f4..469ceb3e85b 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -371,7 +371,7 @@ struct ftrace_graph_ret { #define FTRACE_RETSTACK_ALLOC_SIZE 32 /* Type of the callback handlers for tracing function graph*/ typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ -typedef void (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ +typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, trace_func_graph_ent_t entryfunc); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a44af05ae2d..65b9e863056 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1636,11 +1636,15 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, static atomic_t ftrace_graph_active; +int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) +{ + return 0; +} + /* The callbacks that hook a function */ trace_func_graph_ret_t ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; -trace_func_graph_ent_t ftrace_graph_entry = - (trace_func_graph_ent_t)ftrace_stub; +trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) @@ -1738,7 +1742,7 @@ void unregister_ftrace_graph(void) atomic_dec(&ftrace_graph_active); ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; - ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; + ftrace_graph_entry = ftrace_graph_entry_stub; ftrace_shutdown(FTRACE_STOP_FUNC_RET); mutex_unlock(&ftrace_sysctl_lock); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 380de630ebc..8b6409a62b5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1200,7 +1200,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -void trace_graph_entry(struct ftrace_graph_ent *trace) +int trace_graph_entry(struct ftrace_graph_ent *trace) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; @@ -1219,6 +1219,8 @@ void trace_graph_entry(struct ftrace_graph_ent *trace) } atomic_dec(&data->disabled); local_irq_restore(flags); + + return 1; } void trace_graph_return(struct ftrace_graph_ret *trace) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f96f4e787ff..0565ae9a221 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -412,7 +412,7 @@ void trace_function(struct trace_array *tr, unsigned long flags, int pc); void trace_graph_return(struct ftrace_graph_ret *trace); -void trace_graph_entry(struct ftrace_graph_ent *trace); +int trace_graph_entry(struct ftrace_graph_ent *trace); void trace_bts(struct trace_array *tr, unsigned long from, unsigned long to); -- cgit v1.2.3-70-g09d2 From ea4e2bc4d9f7370e57a343ccb5e7c0ad3222ec3c Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 3 Dec 2008 15:36:57 -0500 Subject: ftrace: graph of a single function This patch adds the file: /debugfs/tracing/set_graph_function which can be used along with the function graph tracer. When this file is empty, the function graph tracer will act as usual. When the file has a function in it, the function graph tracer will only trace that function. For example: # echo blk_unplug > /debugfs/tracing/set_graph_function # cat /debugfs/tracing/trace [...] ------------------------------------------ | 2) make-19003 => kjournald-2219 ------------------------------------------ 2) | blk_unplug() { 2) | dm_unplug_all() { 2) | dm_get_table() { 2) 1.381 us | _read_lock(); 2) 0.911 us | dm_table_get(); 2) 1. 76 us | _read_unlock(); 2) + 12.912 us | } 2) | dm_table_unplug_all() { 2) | blk_unplug() { 2) 0.778 us | generic_unplug_device(); 2) 2.409 us | } 2) 5.992 us | } 2) 0.813 us | dm_table_put(); 2) + 29. 90 us | } 2) + 34.532 us | } You can add up to 32 functions into this file. Currently we limit it to 32, but this may change with later improvements. To add another function, use the append '>>': # echo sys_read >> /debugfs/tracing/set_graph_function # cat /debugfs/tracing/set_graph_function blk_unplug sys_read Using the '>' will clear out the function and write anew: # echo sys_write > /debug/tracing/set_graph_function # cat /debug/tracing/set_graph_function sys_write Note, if you have function graph running while doing this, the small time between clearing it and updating it will cause the graph to record all functions. This should not be an issue because after it sets the filter, only those functions will be recorded from then on. If you need to only record a particular function then set this file first before starting the function graph tracer. In the future this side effect may be corrected. The set_graph_function file is similar to the set_ftrace_filter but it does not take wild cards nor does it allow for more than one function to be set with a single write. There is no technical reason why this is the case, I just do not have the time yet to implement that. Note, dynamic ftrace must be enabled for this to appear because it uses the dynamic ftrace records to match the name to the mcount call sites. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- include/linux/ftrace.h | 46 ++++++++++ include/linux/sched.h | 4 + kernel/trace/ftrace.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace.c | 8 ++ kernel/trace/trace.h | 30 ++++++- 5 files changed, 314 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 469ceb3e85b..b295d3106bf 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -7,6 +7,7 @@ #include #include #include +#include #ifdef CONFIG_FUNCTION_TRACER @@ -391,4 +392,49 @@ static inline void ftrace_graph_init_task(struct task_struct *t) { } static inline void ftrace_graph_exit_task(struct task_struct *t) { } #endif +#ifdef CONFIG_TRACING +#include + +/* flags for current->trace */ +enum { + TSK_TRACE_FL_TRACE_BIT = 0, + TSK_TRACE_FL_GRAPH_BIT = 1, +}; +enum { + TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, + TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, +}; + +static inline void set_tsk_trace_trace(struct task_struct *tsk) +{ + set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); +} + +static inline void clear_tsk_trace_trace(struct task_struct *tsk) +{ + clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); +} + +static inline int test_tsk_trace_trace(struct task_struct *tsk) +{ + return tsk->trace & TSK_TRACE_FL_TRACE; +} + +static inline void set_tsk_trace_graph(struct task_struct *tsk) +{ + set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); +} + +static inline void clear_tsk_trace_graph(struct task_struct *tsk) +{ + clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); +} + +static inline int test_tsk_trace_graph(struct task_struct *tsk) +{ + return tsk->trace & TSK_TRACE_FL_GRAPH; +} + +#endif /* CONFIG_TRACING */ + #endif /* _LINUX_FTRACE_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 2d0a93c3122..4c152e0acc9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1380,6 +1380,10 @@ struct task_struct { */ atomic_t trace_overrun; #endif +#ifdef CONFIG_TRACING + /* state flags for use by tracers */ + unsigned long trace; +#endif }; /* diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 65b9e863056..b17a30350f0 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1320,6 +1320,224 @@ static struct file_operations ftrace_notrace_fops = { .release = ftrace_notrace_release, }; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + +static DEFINE_MUTEX(graph_lock); + +int ftrace_graph_count; +unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; + +static void * +g_next(struct seq_file *m, void *v, loff_t *pos) +{ + unsigned long *array = m->private; + int index = *pos; + + (*pos)++; + + if (index >= ftrace_graph_count) + return NULL; + + return &array[index]; +} + +static void *g_start(struct seq_file *m, loff_t *pos) +{ + void *p = NULL; + + mutex_lock(&graph_lock); + + p = g_next(m, p, pos); + + return p; +} + +static void g_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&graph_lock); +} + +static int g_show(struct seq_file *m, void *v) +{ + unsigned long *ptr = v; + char str[KSYM_SYMBOL_LEN]; + + if (!ptr) + return 0; + + kallsyms_lookup(*ptr, NULL, NULL, NULL, str); + + seq_printf(m, "%s\n", str); + + return 0; +} + +static struct seq_operations ftrace_graph_seq_ops = { + .start = g_start, + .next = g_next, + .stop = g_stop, + .show = g_show, +}; + +static int +ftrace_graph_open(struct inode *inode, struct file *file) +{ + int ret = 0; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + mutex_lock(&graph_lock); + if ((file->f_mode & FMODE_WRITE) && + !(file->f_flags & O_APPEND)) { + ftrace_graph_count = 0; + memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); + } + + if (file->f_mode & FMODE_READ) { + ret = seq_open(file, &ftrace_graph_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = ftrace_graph_funcs; + } + } else + file->private_data = ftrace_graph_funcs; + mutex_unlock(&graph_lock); + + return ret; +} + +static ssize_t +ftrace_graph_read(struct file *file, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + if (file->f_mode & FMODE_READ) + return seq_read(file, ubuf, cnt, ppos); + else + return -EPERM; +} + +static int +ftrace_set_func(unsigned long *array, int idx, char *buffer) +{ + char str[KSYM_SYMBOL_LEN]; + struct dyn_ftrace *rec; + struct ftrace_page *pg; + int found = 0; + int i; + + if (ftrace_disabled) + return -ENODEV; + + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + + if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) + continue; + + kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); + if (strcmp(str, buffer) == 0) { + found = 1; + array[idx] = rec->ip; + break; + } + } + } + spin_unlock(&ftrace_lock); + + return found ? 0 : -EINVAL; +} + +static ssize_t +ftrace_graph_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned char buffer[FTRACE_BUFF_MAX+1]; + unsigned long *array; + size_t read = 0; + ssize_t ret; + int index = 0; + char ch; + + if (!cnt || cnt < 0) + return 0; + + mutex_lock(&graph_lock); + + if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { + ret = -EBUSY; + goto out; + } + + if (file->f_mode & FMODE_READ) { + struct seq_file *m = file->private_data; + array = m->private; + } else + array = file->private_data; + + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + + /* skip white space */ + while (cnt && isspace(ch)) { + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + + if (isspace(ch)) { + *ppos += read; + ret = read; + goto out; + } + + while (cnt && !isspace(ch)) { + if (index < FTRACE_BUFF_MAX) + buffer[index++] = ch; + else { + ret = -EINVAL; + goto out; + } + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + buffer[index] = 0; + + /* we allow only one at a time */ + ret = ftrace_set_func(array, ftrace_graph_count, buffer); + if (ret) + goto out; + + ftrace_graph_count++; + + file->f_pos += read; + + ret = read; + out: + mutex_unlock(&graph_lock); + + return ret; +} + +static const struct file_operations ftrace_graph_fops = { + .open = ftrace_graph_open, + .read = ftrace_graph_read, + .write = ftrace_graph_write, +}; +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { struct dentry *entry; @@ -1347,6 +1565,15 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) pr_warning("Could not create debugfs " "'set_ftrace_notrace' entry\n"); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + entry = debugfs_create_file("set_graph_function", 0444, d_tracer, + NULL, + &ftrace_graph_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'set_graph_function' entry\n"); +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + return 0; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8b6409a62b5..710b39acd81 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1209,6 +1209,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) int cpu; int pc; + if (!ftrace_graph_addr(trace->func)) + return 0; + local_irq_save(flags); cpu = raw_smp_processor_id(); data = tr->data[cpu]; @@ -1217,6 +1220,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) pc = preempt_count(); __trace_graph_entry(tr, data, trace, flags, pc); } + /* Only do the atomic if it is not already set */ + if (!test_tsk_trace_graph(current)) + set_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); @@ -1240,6 +1246,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace) pc = preempt_count(); __trace_graph_return(tr, data, trace, flags, pc); } + if (!trace->depth) + clear_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0565ae9a221..41f026bfc9e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -505,13 +505,41 @@ extern unsigned long trace_flags; /* Standard output formatting function used for function return traces */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern enum print_line_t print_graph_function(struct trace_iterator *iter); + +#ifdef CONFIG_DYNAMIC_FTRACE +/* TODO: make this variable */ +#define FTRACE_GRAPH_MAX_FUNCS 32 +extern int ftrace_graph_count; +extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS]; + +static inline int ftrace_graph_addr(unsigned long addr) +{ + int i; + + if (!ftrace_graph_count || test_tsk_trace_graph(current)) + return 1; + + for (i = 0; i < ftrace_graph_count; i++) { + if (addr == ftrace_graph_funcs[i]) + return 1; + } + + return 0; +} #else +static inline int ftrace_trace_addr(unsigned long addr) +{ + return 1 +} +#endif /* CONFIG_DYNAMIC_FTRACE */ + +#else /* CONFIG_FUNCTION_GRAPH_TRACER */ static inline enum print_line_t print_graph_function(struct trace_iterator *iter) { return TRACE_TYPE_UNHANDLED; } -#endif +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* * trace_iterator_flags is an enumeration that defines bit -- cgit v1.2.3-70-g09d2 From 804a685162a7080386714166776f57255a75238e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 3 Dec 2008 15:36:59 -0500 Subject: ftrace: trace single pid for function graph tracer Impact: New feature This patch makes the changes to set_ftrace_pid apply to the function graph tracer. # echo $$ > /debugfs/tracing/set_ftrace_pid # echo function_graph > /debugfs/tracing/current_tracer Will cause only the current task to be traced. Note, the trace flags are also inherited by child processes, so the children of the shell will also be traced. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 2 +- kernel/trace/trace.c | 3 +++ kernel/trace/trace.h | 10 ++++++++++ 3 files changed, 14 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c5049f54a27..57592a9dd63 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -48,7 +48,7 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* set when tracing only a pid */ -static int ftrace_pid_trace = -1; +int ftrace_pid_trace = -1; /* Quick disabling of function tracer. */ int function_trace_stop; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 710b39acd81..1bd9574404e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1209,6 +1209,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) int cpu; int pc; + if (!ftrace_trace_task(current)) + return 0; + if (!ftrace_graph_addr(trace->func)) return 0; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 41f026bfc9e..95fff37ed97 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -541,6 +541,16 @@ print_graph_function(struct trace_iterator *iter) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ +extern int ftrace_pid_trace; + +static inline int ftrace_trace_task(struct task_struct *task) +{ + if (ftrace_pid_trace < 0) + return 1; + + return test_tsk_trace_trace(task); +} + /* * trace_iterator_flags is an enumeration that defines bit * positions into trace_flags that controls the output. -- cgit v1.2.3-70-g09d2 From 978f3a45d9499c7a447ca7615455cefb63d44165 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 4 Dec 2008 00:26:40 -0500 Subject: ftrace: use struct pid Impact: clean up, extend PID filtering to PID namespaces Eric Biederman suggested using the struct pid for filtering on pids in the kernel. This patch is based off of a demonstration of an implementation that Eric sent me in an email. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 76 +++++++++++++++++++++++++++++---------------------- kernel/trace/trace.h | 4 +-- 2 files changed, 46 insertions(+), 34 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 57592a9dd63..10b1d7c1b1d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -48,7 +48,7 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; /* set when tracing only a pid */ -int ftrace_pid_trace = -1; +struct pid *ftrace_pid_trace; /* Quick disabling of function tracer. */ int function_trace_stop; @@ -153,7 +153,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) else func = ftrace_list_func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -209,7 +209,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_list->next == &ftrace_list_end) { ftrace_func_t func = ftrace_list->func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -239,7 +239,7 @@ static void ftrace_update_pid_func(void) func = ftrace_trace_function; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } else { @@ -1678,18 +1678,40 @@ ftrace_pid_read(struct file *file, char __user *ubuf, char buf[64]; int r; - if (ftrace_pid_trace >= 0) - r = sprintf(buf, "%u\n", ftrace_pid_trace); + if (ftrace_pid_trace) + r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace)); else r = sprintf(buf, "no pid\n"); return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); } +static void clear_ftrace_pid_task(struct pid **pid) +{ + struct task_struct *p; + + do_each_pid_task(*pid, PIDTYPE_PID, p) { + clear_tsk_trace_trace(p); + } while_each_pid_task(*pid, PIDTYPE_PID, p); + put_pid(*pid); + + *pid = NULL; +} + +static void set_ftrace_pid_task(struct pid *pid) +{ + struct task_struct *p; + + do_each_pid_task(pid, PIDTYPE_PID, p) { + set_tsk_trace_trace(p); + } while_each_pid_task(pid, PIDTYPE_PID, p); +} + static ssize_t ftrace_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct pid *pid; char buf[64]; long val; int ret; @@ -1707,40 +1729,30 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf, return ret; mutex_lock(&ftrace_start_lock); - if (ret < 0) { + if (val < 0) { /* disable pid tracing */ - if (ftrace_pid_trace < 0) + if (!ftrace_pid_trace) goto out; - ftrace_pid_trace = -1; + + clear_ftrace_pid_task(&ftrace_pid_trace); } else { - struct task_struct *p; - int found = 0; + pid = find_get_pid(val); - if (ftrace_pid_trace == val) + if (pid == ftrace_pid_trace) { + put_pid(pid); goto out; - - /* - * Find the task that matches this pid. - * TODO: use pid namespaces instead. - */ - rcu_read_lock(); - for_each_process(p) { - if (p->pid == val) { - found = 1; - set_tsk_trace_trace(p); - } else if (test_tsk_trace_trace(p)) - clear_tsk_trace_trace(p); } - rcu_read_unlock(); - if (found) - ftrace_pid_trace = val; - else { - if (ftrace_pid_trace < 0) - goto out; - ftrace_pid_trace = -1; - } + if (ftrace_pid_trace) + clear_ftrace_pid_task(&ftrace_pid_trace); + + if (!pid) + goto out; + + ftrace_pid_trace = pid; + + set_ftrace_pid_task(ftrace_pid_trace); } /* update the function call */ diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95fff37ed97..8b81b4d727b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -541,11 +541,11 @@ print_graph_function(struct trace_iterator *iter) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -extern int ftrace_pid_trace; +extern struct pid *ftrace_pid_trace; static inline int ftrace_trace_task(struct task_struct *task) { - if (ftrace_pid_trace < 0) + if (ftrace_pid_trace) return 1; return test_tsk_trace_trace(task); -- cgit v1.2.3-70-g09d2 From 6b2539302bee8e88c99e3c7d80c16a04dbe5e2ad Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 4 Dec 2008 09:18:28 +0100 Subject: tracing: fix typo and missing inline function Impact: fix build bugs Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8b81b4d727b..b4b7b735184 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -529,7 +529,11 @@ static inline int ftrace_graph_addr(unsigned long addr) #else static inline int ftrace_trace_addr(unsigned long addr) { - return 1 + return 1; +} +static inline int ftrace_graph_addr(unsigned long addr) +{ + return 1; } #endif /* CONFIG_DYNAMIC_FTRACE */ -- cgit v1.2.3-70-g09d2 From 1fd8f2a3f9a91b287a876cef830b21baafc8a799 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 3 Dec 2008 23:45:11 +0100 Subject: tracing/function-graph-tracer: handle ftrace_printk entries Handle the TRACE_PRINT entries from the function grapg tracer and output them as a C comment just below the function that called it, as if it was a comment inside this function. Example with an ftrace_printk inside might_sleep() function: void __might_sleep(char *file, int line) { static unsigned long prev_jiffy; /* ratelimiting */ ftrace_printk("Hi I'm a comment in might_sleep() :-)"); A chunk of a resulting trace: 0) | _reiserfs_free_block() { 0) | reiserfs_read_bitmap_block() { 0) | __bread() { 0) | __getblk() { 0) | __find_get_block() { 0) 0.698 us | mark_page_accessed(); 0) 2.267 us | } 0) | __might_sleep() { 0) | /* Hi I'm a comment in might_sleep() :-) */ 0) 1.321 us | } 0) 5.872 us | } 0) 7.313 us | } 0) 8.718 us | } And this patch brings two minor fixes: - The newline after a switch-out task has disappeared - The "|" sign just before the cpu number on task-switch has been deleted. 0) 0.616 us | pick_next_task_rt(); 0) 1.457 us | _spin_trylock(); 0) 0.653 us | _spin_unlock(); 0) 0.728 us | _spin_trylock(); 0) 0.631 us | _spin_unlock(); 0) 0.729 us | native_load_sp0(); 0) 0.593 us | native_load_tls(); ------------------------------------------ 0) cat-2834 => migrati-3 ------------------------------------------ 0) | finish_task_switch() { 0) 0.841 us | _spin_unlock_irq(); 0) 0.616 us | post_schedule_rt(); 0) 3.882 us | } Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 28 +++++++++++--- kernel/trace/trace.h | 4 +- kernel/trace/trace_functions_graph.c | 72 +++++++++++++++++++++++++++++++++++- kernel/trace/trace_mmiotrace.c | 2 +- 4 files changed, 97 insertions(+), 9 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8b6409a62b5..1ca74c0cee6 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3335,7 +3335,7 @@ static int mark_printk(const char *fmt, ...) int ret; va_list args; va_start(args, fmt); - ret = trace_vprintk(0, fmt, args); + ret = trace_vprintk(0, -1, fmt, args); va_end(args); return ret; } @@ -3564,9 +3564,16 @@ static __init int tracer_init_debugfs(void) return 0; } -int trace_vprintk(unsigned long ip, const char *fmt, va_list args) +int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) { - static DEFINE_SPINLOCK(trace_buf_lock); + /* + * Raw Spinlock because a normal spinlock would be traced here + * and append an irrelevant couple spin_lock_irqsave/ + * spin_unlock_irqrestore traced by ftrace around this + * TRACE_PRINTK trace. + */ + static raw_spinlock_t trace_buf_lock = + (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; static char trace_buf[TRACE_BUF_SIZE]; struct ring_buffer_event *event; @@ -3587,7 +3594,8 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) if (unlikely(atomic_read(&data->disabled))) goto out; - spin_lock_irqsave(&trace_buf_lock, flags); + local_irq_save(flags); + __raw_spin_lock(&trace_buf_lock); len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); len = min(len, TRACE_BUF_SIZE-1); @@ -3601,13 +3609,15 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args) tracing_generic_entry_update(&entry->ent, flags, pc); entry->ent.type = TRACE_PRINT; entry->ip = ip; + entry->depth = depth; memcpy(&entry->buf, trace_buf, len); entry->buf[len] = 0; ring_buffer_unlock_commit(tr->buffer, event, irq_flags); out_unlock: - spin_unlock_irqrestore(&trace_buf_lock, flags); + __raw_spin_unlock(&trace_buf_lock); + local_irq_restore(flags); out: preempt_enable_notrace(); @@ -3625,7 +3635,13 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...) return 0; va_start(ap, fmt); - ret = trace_vprintk(ip, fmt, ap); + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + ret = trace_vprintk(ip, current->curr_ret_stack, fmt, ap); +#else + ret = trace_vprintk(ip, -1, fmt, ap); +#endif + va_end(ap); return ret; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0565ae9a221..fce98898205 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -117,6 +117,7 @@ struct userstack_entry { struct print_entry { struct trace_entry ent; unsigned long ip; + int depth; char buf[]; }; @@ -498,7 +499,8 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); -extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); +extern int +trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args); extern unsigned long trace_flags; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index c66578f2fdc..32b7fb9a19d 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -173,7 +173,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu) */ ret = trace_seq_printf(s, - "\n ------------------------------------------\n |"); + " ------------------------------------------\n"); if (!ret) TRACE_TYPE_PARTIAL_LINE; @@ -477,6 +477,71 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, return TRACE_TYPE_HANDLED; } +static enum print_line_t +print_graph_comment(struct print_entry *trace, struct trace_seq *s, + struct trace_entry *ent, struct trace_iterator *iter) +{ + int i; + int ret; + + /* Pid */ + if (verif_pid(s, ent->pid, iter->cpu) == TRACE_TYPE_PARTIAL_LINE) + return TRACE_TYPE_PARTIAL_LINE; + + /* Cpu */ + if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) { + ret = print_graph_cpu(s, iter->cpu); + if (ret == TRACE_TYPE_PARTIAL_LINE) + return TRACE_TYPE_PARTIAL_LINE; + } + + /* Proc */ + if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) { + ret = print_graph_proc(s, ent->pid); + if (ret == TRACE_TYPE_PARTIAL_LINE) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, " | "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + /* No overhead */ + if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) { + ret = trace_seq_printf(s, " "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + /* No time */ + ret = trace_seq_printf(s, " | "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + /* Indentation */ + if (trace->depth > 0) + for (i = 0; i < (trace->depth + 1) * TRACE_GRAPH_INDENT; i++) { + ret = trace_seq_printf(s, " "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + /* The comment */ + ret = trace_seq_printf(s, "/* %s", trace->buf); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + if (ent->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + + ret = trace_seq_printf(s, " */\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return TRACE_TYPE_HANDLED; +} + + enum print_line_t print_graph_function(struct trace_iterator *iter) { @@ -495,6 +560,11 @@ print_graph_function(struct trace_iterator *iter) trace_assign_type(field, entry); return print_graph_return(&field->ret, s, entry, iter->cpu); } + case TRACE_PRINT: { + struct print_entry *field; + trace_assign_type(field, entry); + return print_graph_comment(field, s, entry, iter); + } default: return TRACE_TYPE_UNHANDLED; } diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 2a98a206acc..2fb6da6523b 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -366,5 +366,5 @@ void mmio_trace_mapping(struct mmiotrace_map *map) int mmio_trace_printk(const char *fmt, va_list args) { - return trace_vprintk(0, fmt, args); + return trace_vprintk(0, -1, fmt, args); } -- cgit v1.2.3-70-g09d2 From 77d683f3e0258d522c5506e7b5fd05c9411184d9 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 4 Dec 2008 23:49:47 +0100 Subject: tracing/ftrace: fix the check of ftrace_trace_task Impact: fix default empty traces on function-graph-tracer The actual ftrace_trace_task() checks if ftrace_pid_trace is allocated and return 1 if it is true. If it is NULL, it will check the bit of pid tracing flag for the current task (which are not set by default). So by default, a task is not traced. Actually all tasks should be traced by default and filter_by_pid when ftrace_pid_trace is allocated. The appropriate condition should be to return 1 if filter_by_pid is set. Signed-off-by: Frederic Weisbecker Acke-dby: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index a71bbe0a363..5ac697065a4 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -551,7 +551,7 @@ extern struct pid *ftrace_pid_trace; static inline int ftrace_trace_task(struct task_struct *task) { - if (ftrace_pid_trace) + if (!ftrace_pid_trace) return 1; return test_tsk_trace_trace(task); -- cgit v1.2.3-70-g09d2 From a93751cab71d63126687551823ed3e70cd85854a Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Thu, 11 Dec 2008 13:53:26 +0100 Subject: x86, bts, ftrace: adapt the hw-branch-tracer to the ds.c interface Impact: restructure code, cleanup Remove BTS bits from the hw-branch-tracer (renamed from bts-tracer) and use the ds interface. Signed-off-by: Markus Metzger Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 4 +- kernel/trace/Makefile | 2 +- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 14 +- kernel/trace/trace_bts.c | 276 --------------------------------------- kernel/trace/trace_hw_branches.c | 205 +++++++++++++++++++++++++++++ 6 files changed, 215 insertions(+), 288 deletions(-) delete mode 100644 kernel/trace/trace_bts.c create mode 100644 kernel/trace/trace_hw_branches.c (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index bde6f03512d..d8bae6f4219 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -251,9 +251,9 @@ config STACK_TRACER Say N if unsure. -config BTS_TRACER +config HW_BRANCH_TRACER depends on HAVE_HW_BRANCH_TRACER - bool "Trace branches" + bool "Trace hw branches" select TRACING help This tracer records all branches on the system in a circular diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 62dc561b667..349d5a93653 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -31,7 +31,7 @@ obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o -obj-$(CONFIG_BTS_TRACER) += trace_bts.o +obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o obj-$(CONFIG_POWER_TRACER) += trace_power.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8ebe0070c47..639344a4d3a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2425,7 +2425,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) /* Notify the tracer early; before we stop tracing. */ if (iter->trace && iter->trace->open) - iter->trace->open(iter); + iter->trace->open(iter); /* Annotate start of buffers if we had overruns */ if (ring_buffer_overruns(iter->tr->buffer)) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5ac697065a4..f07c246dd73 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -28,7 +28,7 @@ enum trace_type { TRACE_GRAPH_RET, TRACE_GRAPH_ENT, TRACE_USER_STACK, - TRACE_BTS, + TRACE_HW_BRANCHES, TRACE_POWER, __TRACE_LAST_TYPE @@ -159,10 +159,10 @@ struct trace_branch { char correct; }; -struct bts_entry { +struct hw_branch_entry { struct trace_entry ent; - unsigned long from; - unsigned long to; + u64 from; + u64 to; }; struct trace_power { @@ -278,7 +278,7 @@ extern void __ftrace_bad_type(void); TRACE_GRAPH_ENT); \ IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ - IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\ + IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ __ftrace_bad_type(); \ } while (0) @@ -414,9 +414,7 @@ void trace_function(struct trace_array *tr, void trace_graph_return(struct ftrace_graph_ret *trace); int trace_graph_entry(struct ftrace_graph_ent *trace); -void trace_bts(struct trace_array *tr, - unsigned long from, - unsigned long to); +void trace_hw_branch(struct trace_array *tr, u64 from, u64 to); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); diff --git a/kernel/trace/trace_bts.c b/kernel/trace/trace_bts.c deleted file mode 100644 index 23b76e4690e..00000000000 --- a/kernel/trace/trace_bts.c +++ /dev/null @@ -1,276 +0,0 @@ -/* - * BTS tracer - * - * Copyright (C) 2008 Markus Metzger - * - */ - -#include -#include -#include -#include -#include - -#include - -#include "trace.h" - - -#define SIZEOF_BTS (1 << 13) - -static DEFINE_PER_CPU(struct bts_tracer *, tracer); -static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer); - -#define this_tracer per_cpu(tracer, smp_processor_id()) -#define this_buffer per_cpu(buffer, smp_processor_id()) - - -/* - * Information to interpret a BTS record. - * This will go into an in-kernel BTS interface. - */ -static unsigned char sizeof_field; -static unsigned long debugctl_mask; - -#define sizeof_bts (3 * sizeof_field) - -static void bts_trace_cpuinit(struct cpuinfo_x86 *c) -{ - switch (c->x86) { - case 0x6: - switch (c->x86_model) { - case 0x0 ... 0xC: - break; - case 0xD: - case 0xE: /* Pentium M */ - sizeof_field = sizeof(long); - debugctl_mask = (1<<6)|(1<<7); - break; - default: - sizeof_field = 8; - debugctl_mask = (1<<6)|(1<<7); - break; - } - break; - case 0xF: - switch (c->x86_model) { - case 0x0: - case 0x1: - case 0x2: /* Netburst */ - sizeof_field = sizeof(long); - debugctl_mask = (1<<2)|(1<<3); - break; - default: - /* sorry, don't know about them */ - break; - } - break; - default: - /* sorry, don't know about them */ - break; - } -} - -static inline void bts_enable(void) -{ - unsigned long debugctl; - - rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); - wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl | debugctl_mask); -} - -static inline void bts_disable(void) -{ - unsigned long debugctl; - - rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); - wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl & ~debugctl_mask); -} - -static void bts_trace_reset(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - -static void bts_trace_start_cpu(void *arg) -{ - this_tracer = - ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS, - /* ovfl = */ NULL, /* th = */ (size_t)-1); - if (IS_ERR(this_tracer)) { - this_tracer = NULL; - return; - } - - bts_enable(); -} - -static void bts_trace_start(struct trace_array *tr) -{ - int cpu; - - bts_trace_reset(tr); - - for_each_cpu_mask(cpu, cpu_possible_map) - smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1); -} - -static void bts_trace_stop_cpu(void *arg) -{ - if (this_tracer) { - bts_disable(); - - ds_release_bts(this_tracer); - this_tracer = NULL; - } -} - -static void bts_trace_stop(struct trace_array *tr) -{ - int cpu; - - for_each_cpu_mask(cpu, cpu_possible_map) - smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1); -} - -static int bts_trace_init(struct trace_array *tr) -{ - bts_trace_cpuinit(&boot_cpu_data); - bts_trace_reset(tr); - bts_trace_start(tr); - - return 0; -} - -static void bts_trace_print_header(struct seq_file *m) -{ -#ifdef __i386__ - seq_puts(m, "# CPU# FROM TO FUNCTION\n"); - seq_puts(m, "# | | | |\n"); -#else - seq_puts(m, - "# CPU# FROM TO FUNCTION\n"); - seq_puts(m, - "# | | | |\n"); -#endif -} - -static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) -{ - struct trace_entry *entry = iter->ent; - struct trace_seq *seq = &iter->seq; - struct bts_entry *it; - - trace_assign_type(it, entry); - - if (entry->type == TRACE_BTS) { - int ret; -#ifdef CONFIG_KALLSYMS - char function[KSYM_SYMBOL_LEN]; - sprint_symbol(function, it->from); -#else - char *function = ""; -#endif - - ret = trace_seq_printf(seq, "%4d 0x%lx -> 0x%lx [%s]\n", - entry->cpu, it->from, it->to, function); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE;; - return TRACE_TYPE_HANDLED; - } - return TRACE_TYPE_UNHANDLED; -} - -void trace_bts(struct trace_array *tr, unsigned long from, unsigned long to) -{ - struct ring_buffer_event *event; - struct bts_entry *entry; - unsigned long irq; - - event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq); - if (!event) - return; - entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0, from); - entry->ent.type = TRACE_BTS; - entry->ent.cpu = smp_processor_id(); - entry->from = from; - entry->to = to; - ring_buffer_unlock_commit(tr->buffer, event, irq); -} - -static void trace_bts_at(struct trace_array *tr, size_t index) -{ - const void *raw = NULL; - unsigned long from, to; - int err; - - err = ds_access_bts(this_tracer, index, &raw); - if (err < 0) - return; - - from = *(const unsigned long *)raw; - to = *(const unsigned long *)((const char *)raw + sizeof_field); - - trace_bts(tr, from, to); -} - -static void trace_bts_cpu(void *arg) -{ - struct trace_array *tr = (struct trace_array *) arg; - size_t index = 0, end = 0, i; - int err; - - if (!this_tracer) - return; - - bts_disable(); - - err = ds_get_bts_index(this_tracer, &index); - if (err < 0) - goto out; - - err = ds_get_bts_end(this_tracer, &end); - if (err < 0) - goto out; - - for (i = index; i < end; i++) - trace_bts_at(tr, i); - - for (i = 0; i < index; i++) - trace_bts_at(tr, i); - -out: - bts_enable(); -} - -static void trace_bts_prepare(struct trace_iterator *iter) -{ - int cpu; - - for_each_cpu_mask(cpu, cpu_possible_map) - smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1); -} - -struct tracer bts_tracer __read_mostly = -{ - .name = "bts", - .init = bts_trace_init, - .reset = bts_trace_stop, - .print_header = bts_trace_print_header, - .print_line = bts_trace_print_line, - .start = bts_trace_start, - .stop = bts_trace_stop, - .open = trace_bts_prepare -}; - -__init static int init_bts_trace(void) -{ - return register_tracer(&bts_tracer); -} -device_initcall(init_bts_trace); diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c new file mode 100644 index 00000000000..ee29e012aa9 --- /dev/null +++ b/kernel/trace/trace_hw_branches.c @@ -0,0 +1,205 @@ +/* + * h/w branch tracer for x86 based on bts + * + * Copyright (C) 2008 Markus Metzger + * + */ + +#include +#include +#include +#include +#include + +#include + +#include "trace.h" + + +#define SIZEOF_BTS (1 << 13) + +static DEFINE_PER_CPU(struct bts_tracer *, tracer); +static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer); + +#define this_tracer per_cpu(tracer, smp_processor_id()) +#define this_buffer per_cpu(buffer, smp_processor_id()) + + +static void bts_trace_reset(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); +} + +static void bts_trace_start_cpu(void *arg) +{ + if (this_tracer) + ds_release_bts(this_tracer); + + this_tracer = + ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS, + /* ovfl = */ NULL, /* th = */ (size_t)-1, + BTS_KERNEL); + if (IS_ERR(this_tracer)) { + this_tracer = NULL; + return; + } +} + +static void bts_trace_start(struct trace_array *tr) +{ + int cpu; + + bts_trace_reset(tr); + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1); +} + +static void bts_trace_stop_cpu(void *arg) +{ + if (this_tracer) { + ds_release_bts(this_tracer); + this_tracer = NULL; + } +} + +static void bts_trace_stop(struct trace_array *tr) +{ + int cpu; + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1); +} + +static int bts_trace_init(struct trace_array *tr) +{ + bts_trace_reset(tr); + bts_trace_start(tr); + + return 0; +} + +static void bts_trace_print_header(struct seq_file *m) +{ + seq_puts(m, + "# CPU# FROM TO FUNCTION\n"); + seq_puts(m, + "# | | | |\n"); +} + +static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *seq = &iter->seq; + struct hw_branch_entry *it; + + trace_assign_type(it, entry); + + if (entry->type == TRACE_HW_BRANCHES) { + if (trace_seq_printf(seq, "%4d ", entry->cpu) && + trace_seq_printf(seq, "0x%016llx -> 0x%016llx ", + it->from, it->to) && + (!it->from || + seq_print_ip_sym(seq, it->from, /* sym_flags = */ 0)) && + trace_seq_printf(seq, "\n")) + return TRACE_TYPE_HANDLED; + return TRACE_TYPE_PARTIAL_LINE;; + } + return TRACE_TYPE_UNHANDLED; +} + +void trace_hw_branch(struct trace_array *tr, u64 from, u64 to) +{ + struct ring_buffer_event *event; + struct hw_branch_entry *entry; + unsigned long irq; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, from); + entry->ent.type = TRACE_HW_BRANCHES; + entry->ent.cpu = smp_processor_id(); + entry->from = from; + entry->to = to; + ring_buffer_unlock_commit(tr->buffer, event, irq); +} + +static void trace_bts_at(struct trace_array *tr, + const struct bts_trace *trace, void *at) +{ + struct bts_struct bts; + int err = 0; + + WARN_ON_ONCE(!trace->read); + if (!trace->read) + return; + + err = trace->read(this_tracer, at, &bts); + if (err < 0) + return; + + switch (bts.qualifier) { + case BTS_BRANCH: + trace_hw_branch(tr, bts.variant.lbr.from, bts.variant.lbr.to); + break; + } +} + +static void trace_bts_cpu(void *arg) +{ + struct trace_array *tr = (struct trace_array *) arg; + const struct bts_trace *trace; + unsigned char *at; + + if (!this_tracer) + return; + + ds_suspend_bts(this_tracer); + trace = ds_read_bts(this_tracer); + if (!trace) + goto out; + + for (at = trace->ds.top; (void *)at < trace->ds.end; + at += trace->ds.size) + trace_bts_at(tr, trace, at); + + for (at = trace->ds.begin; (void *)at < trace->ds.top; + at += trace->ds.size) + trace_bts_at(tr, trace, at); + +out: + ds_resume_bts(this_tracer); +} + +static void trace_bts_prepare(struct trace_iterator *iter) +{ + int cpu; + + for_each_cpu_mask(cpu, cpu_possible_map) + smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1); +} + +struct tracer bts_tracer __read_mostly = +{ + .name = "hw-branch-tracer", + .init = bts_trace_init, + .reset = bts_trace_stop, + .print_header = bts_trace_print_header, + .print_line = bts_trace_print_line, + .start = bts_trace_start, + .stop = bts_trace_stop, + .open = trace_bts_prepare +}; + +__init static int init_bts_trace(void) +{ + return register_tracer(&bts_tracer); +} +device_initcall(init_bts_trace); -- cgit v1.2.3-70-g09d2 From 66896a85cf2890b6bbbc4c9ccdcd296600ffbf89 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 13 Dec 2008 20:18:13 +0100 Subject: tracing/ftrace: add the printk-msg-only option Impact: display ftrace_printk messages "as is" By default, ftrace_printk() messages find their output with some other informations like pid, caller, ... Sometimes a developer just want to have the ftrace_printk left "as is", without other information. This is done by providing a default-off option called printk-msg-only. To enable it, just do `echo printk-msg-only > /debugfs/tracing/trace_options` Before the patch: <...>-2739 [000] 145.692153: __might_sleep: I'm an ftrace_printk msg in __might_sleep <...>-2739 [000] 145.692155: __might_sleep: I'm another ftrace_printk msg in __might_sleep After the patch and the printk-msg-only option enabled: I'm an ftrace_printk msg in __might_sleep I'm another ftrace_printk msg in __might_sleep Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 25 +++++++++++++++++++++++++ kernel/trace/trace.h | 3 ++- 2 files changed, 27 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 639344a4d3a..1a3d6b32978 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -287,6 +287,7 @@ static const char *trace_options[] = { "annotate", "userstacktrace", "sym-userobj", + "printk-msg-only", NULL }; @@ -2265,6 +2266,25 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter) return TRACE_TYPE_HANDLED; } +static enum print_line_t print_printk_msg_only(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; + struct print_entry *field; + int ret; + + trace_assign_type(field, entry); + + ret = trace_seq_printf(s, field->buf); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + + return TRACE_TYPE_HANDLED; +} + static enum print_line_t print_bin_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; @@ -2345,6 +2365,11 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter) return ret; } + if (iter->ent->type == TRACE_PRINT && + trace_flags & TRACE_ITER_PRINTK && + trace_flags & TRACE_ITER_PRINTK_MSGONLY) + return print_printk_msg_only(iter); + if (trace_flags & TRACE_ITER_BIN) return print_bin_fmt(iter); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f07c246dd73..fc75dce7a66 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -578,7 +578,8 @@ enum trace_iterator_flags { TRACE_ITER_BRANCH = 0x1000, TRACE_ITER_ANNOTATE = 0x2000, TRACE_ITER_USERSTACKTRACE = 0x4000, - TRACE_ITER_SYM_USEROBJ = 0x8000 + TRACE_ITER_SYM_USEROBJ = 0x8000, + TRACE_ITER_PRINTK_MSGONLY = 0x10000 }; /* -- cgit v1.2.3-70-g09d2 From 213cc060797378059a28ebc5c539f3e9a80160bd Mon Sep 17 00:00:00 2001 From: Pekka J Enberg Date: Fri, 19 Dec 2008 12:08:39 +0200 Subject: ftrace: introduce tracing_reset_online_cpus() helper Impact: cleanup This patch factors out common code from multiple tracers into a tracing_reset_online_cpus() function and converts the tracers to use it. Signed-off-by: Pekka Enberg Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 10 ++++++++++ kernel/trace/trace.h | 1 + kernel/trace/trace_boot.c | 12 +----------- kernel/trace/trace_functions.c | 14 ++------------ kernel/trace/trace_hw_branches.c | 14 ++------------ kernel/trace/trace_mmiotrace.c | 6 +----- kernel/trace/trace_sched_switch.c | 14 ++------------ kernel/trace/trace_sysprof.c | 12 +----------- 8 files changed, 20 insertions(+), 63 deletions(-) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0eb6d48347f..79db26e8216 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -679,6 +679,16 @@ void tracing_reset(struct trace_array *tr, int cpu) ftrace_enable_cpu(); } +void tracing_reset_online_cpus(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); +} + #define SAVED_CMDLINES 128 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fc75dce7a66..cc7a4f86403 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -374,6 +374,7 @@ struct trace_iterator { int tracing_is_enabled(void); void trace_wake_up(void); void tracing_reset(struct trace_array *tr, int cpu); +void tracing_reset_online_cpus(struct trace_array *tr); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); void init_tracer_sysprof_debugfs(struct dentry *d_tracer); diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index a4fa2c57e34..3ccebde2848 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -37,16 +37,6 @@ void disable_boot_trace(void) tracing_stop_sched_switch_record(); } -static void reset_boot_trace(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - static int boot_trace_init(struct trace_array *tr) { int cpu; @@ -130,7 +120,7 @@ struct tracer boot_tracer __read_mostly = { .name = "initcall", .init = boot_trace_init, - .reset = reset_boot_trace, + .reset = tracing_reset_online_cpus, .print_line = initcall_print_line, }; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index e74f6d0a321..9236d7e25a1 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -16,20 +16,10 @@ #include "trace.h" -static void function_reset(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - static void start_function_trace(struct trace_array *tr) { tr->cpu = get_cpu(); - function_reset(tr); + tracing_reset_online_cpus(tr); put_cpu(); tracing_start_cmdline_record(); @@ -55,7 +45,7 @@ static void function_trace_reset(struct trace_array *tr) static void function_trace_start(struct trace_array *tr) { - function_reset(tr); + tracing_reset_online_cpus(tr); } static struct tracer function_trace __read_mostly = diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c index ee29e012aa9..b6a3e20a49a 100644 --- a/kernel/trace/trace_hw_branches.c +++ b/kernel/trace/trace_hw_branches.c @@ -25,16 +25,6 @@ static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer); #define this_buffer per_cpu(buffer, smp_processor_id()) -static void bts_trace_reset(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - static void bts_trace_start_cpu(void *arg) { if (this_tracer) @@ -54,7 +44,7 @@ static void bts_trace_start(struct trace_array *tr) { int cpu; - bts_trace_reset(tr); + tracing_reset_online_cpus(tr); for_each_cpu_mask(cpu, cpu_possible_map) smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1); @@ -78,7 +68,7 @@ static void bts_trace_stop(struct trace_array *tr) static int bts_trace_init(struct trace_array *tr) { - bts_trace_reset(tr); + tracing_reset_online_cpus(tr); bts_trace_start(tr); return 0; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 2fb6da6523b..fffcb069f1d 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -22,14 +22,10 @@ static unsigned long prev_overruns; static void mmio_reset_data(struct trace_array *tr) { - int cpu; - overrun_detected = false; prev_overruns = 0; - tr->time_start = ftrace_now(tr->cpu); - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); + tracing_reset_online_cpus(tr); } static int mmio_trace_init(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 781d72ef873..add2c1fdae9 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -72,16 +72,6 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) local_irq_restore(flags); } -static void sched_switch_reset(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - static int tracing_sched_register(void) { int ret; @@ -197,7 +187,7 @@ void tracing_sched_switch_assign_trace(struct trace_array *tr) static void start_sched_trace(struct trace_array *tr) { - sched_switch_reset(tr); + tracing_reset_online_cpus(tr); tracing_start_sched_switch_record(); } @@ -221,7 +211,7 @@ static void sched_switch_trace_reset(struct trace_array *tr) static void sched_switch_trace_start(struct trace_array *tr) { - sched_switch_reset(tr); + tracing_reset_online_cpus(tr); tracing_start_sched_switch(); } diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 54960edb96d..01becf1f19f 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -234,20 +234,10 @@ static void stop_stack_timers(void) stop_stack_timer(cpu); } -static void stack_reset(struct trace_array *tr) -{ - int cpu; - - tr->time_start = ftrace_now(tr->cpu); - - for_each_online_cpu(cpu) - tracing_reset(tr, cpu); -} - static void start_stack_trace(struct trace_array *tr) { mutex_lock(&sample_timer_lock); - stack_reset(tr); + tracing_reset_online_cpus(tr); start_stack_timers(); tracer_enabled = 1; mutex_unlock(&sample_timer_lock); -- cgit v1.2.3-70-g09d2