From f76e9154736e9ab47b64940d0062f19c80225b7f Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 24 Apr 2008 01:31:46 -0400 Subject: [ARM] latencytop support Available for !SMP only at the moment. From Russell: |Basically, if a thread is running on a CPU, thread_saved_fp() is invalid. |So, the question is: what guarantees do we have here that 'tsk' is not |running on another CPU? Signed-off-by: Nicolas Pitre Tested-by: Lennert Buytenhek Signed-off-by: Lennert Buytenhek --- arch/arm/kernel/stacktrace.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) (limited to 'arch/arm/kernel/stacktrace.c') diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index ae31deb2d06..90e0c35ae60 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -36,6 +36,7 @@ EXPORT_SYMBOL(walk_stackframe); #ifdef CONFIG_STACKTRACE struct stack_trace_data { struct stack_trace *trace; + unsigned int no_sched_functions; unsigned int skip; }; @@ -43,27 +44,52 @@ static int save_trace(struct stackframe *frame, void *d) { struct stack_trace_data *data = d; struct stack_trace *trace = data->trace; + unsigned long addr = frame->lr; + if (data->no_sched_functions && in_sched_functions(addr)) + return 0; if (data->skip) { data->skip--; return 0; } - trace->entries[trace->nr_entries++] = frame->lr; + trace->entries[trace->nr_entries++] = addr; return trace->nr_entries >= trace->max_entries; } -void save_stack_trace(struct stack_trace *trace) +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { struct stack_trace_data data; unsigned long fp, base; data.trace = trace; data.skip = trace->skip; - base = (unsigned long)task_stack_page(current); - asm("mov %0, fp" : "=r" (fp)); + base = (unsigned long)task_stack_page(tsk); + + if (tsk != current) { +#ifdef CONFIG_SMP + /* + * What guarantees do we have here that 'tsk' + * is not running on another CPU? + */ + BUG(); +#else + data.no_sched_functions = 1; + fp = thread_saved_fp(tsk); +#endif + } else { + data.no_sched_functions = 0; + asm("mov %0, fp" : "=r" (fp)); + } walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); } #endif -- cgit v1.2.3-70-g09d2 From 7b4c9505f2fd82b117dd015b561f723b9a5dab79 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 3 Jul 2008 09:17:55 +0200 Subject: stacktrace: export save_stack_trace[_tsk] Andrew Morton reported this against linux-next: ERROR: ".save_stack_trace" [tests/backtracetest.ko] undefined! Reported-by: Andrew Morton Signed-off-by: Ingo Molnar --- arch/arm/kernel/stacktrace.c | 1 + arch/avr32/kernel/stacktrace.c | 1 + arch/mips/kernel/stacktrace.c | 1 + arch/powerpc/kernel/stacktrace.c | 1 + arch/s390/kernel/stacktrace.c | 2 ++ arch/sh/kernel/stacktrace.c | 1 + arch/sparc64/kernel/stacktrace.c | 1 + 7 files changed, 8 insertions(+) (limited to 'arch/arm/kernel/stacktrace.c') diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index ae31deb2d06..6b3ffde5dea 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -66,4 +66,5 @@ void save_stack_trace(struct stack_trace *trace) walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data); } +EXPORT_SYMBOL_GPL(save_stack_trace); #endif diff --git a/arch/avr32/kernel/stacktrace.c b/arch/avr32/kernel/stacktrace.c index 9a68190bbff..f4bdb448049 100644 --- a/arch/avr32/kernel/stacktrace.c +++ b/arch/avr32/kernel/stacktrace.c @@ -51,3 +51,4 @@ void save_stack_trace(struct stack_trace *trace) fp = frame->fp; } } +EXPORT_SYMBOL_GPL(save_stack_trace); diff --git a/arch/mips/kernel/stacktrace.c b/arch/mips/kernel/stacktrace.c index ebd9db8d1ec..5eb4681a73d 100644 --- a/arch/mips/kernel/stacktrace.c +++ b/arch/mips/kernel/stacktrace.c @@ -73,3 +73,4 @@ void save_stack_trace(struct stack_trace *trace) prepare_frametrace(regs); save_context_stack(trace, regs); } +EXPORT_SYMBOL_GPL(save_stack_trace); diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index 96294403843..9861f17258d 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -44,3 +44,4 @@ void save_stack_trace(struct stack_trace *trace) sp = newsp; } } +EXPORT_SYMBOL_GPL(save_stack_trace); diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 85e46a5d0e0..57571f10270 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -81,6 +81,7 @@ void save_stack_trace(struct stack_trace *trace) S390_lowcore.thread_info, S390_lowcore.thread_info + THREAD_SIZE, 1); } +EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { @@ -93,3 +94,4 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } +EXPORT_SYMBOL_GPL(save_stack_trace_tsk); diff --git a/arch/sh/kernel/stacktrace.c b/arch/sh/kernel/stacktrace.c index d41e561be20..1b2ae35c4a7 100644 --- a/arch/sh/kernel/stacktrace.c +++ b/arch/sh/kernel/stacktrace.c @@ -34,3 +34,4 @@ void save_stack_trace(struct stack_trace *trace) } } } +EXPORT_SYMBOL_GPL(save_stack_trace); diff --git a/arch/sparc64/kernel/stacktrace.c b/arch/sparc64/kernel/stacktrace.c index c73ce3f4197..49656ed6ab1 100644 --- a/arch/sparc64/kernel/stacktrace.c +++ b/arch/sparc64/kernel/stacktrace.c @@ -47,3 +47,4 @@ void save_stack_trace(struct stack_trace *trace) trace->entries[trace->nr_entries++] = pc; } while (trace->nr_entries < trace->max_entries); } +EXPORT_SYMBOL_GPL(save_stack_trace); -- cgit v1.2.3-70-g09d2