From 637e7e864103a7a68c1ce43ada27dfc25c0d113f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 11 Sep 2009 13:55:35 -0400 Subject: tracing: add lock depth to entries This patch adds the lock depth of the big kernel lock to the generic entry header. This way we can see the depth of the lock and help in removing the BKL. Example: # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| /_--=> lock-depth # |||||/ delay # cmd pid |||||| time | caller # \ / |||||| \ | / -0 2.N..3 5902255250us+: lock_acquire: read rcu_read_lock -0 2.N..3 5902255253us+: lock_release: rcu_read_lock -0 2dN..3 5902255257us+: lock_acquire: xtime_lock -0 2dN..4 5902255259us : lock_acquire: clocksource_lock -0 2dN..4 5902255261us+: lock_release: clocksource_lock Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 9 +++++---- kernel/trace/trace_events.c | 5 ++++- kernel/trace/trace_functions_graph.c | 16 ++++++++++++---- kernel/trace/trace_output.c | 10 +++++++++- 4 files changed, 30 insertions(+), 10 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1a37da2e853..3b918283cf9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -886,6 +886,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; + entry->lock_depth = (tsk) ? tsk->lock_depth : 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | @@ -1530,10 +1531,10 @@ static void print_lat_help_header(struct seq_file *m) seq_puts(m, "# | / _----=> need-resched \n"); seq_puts(m, "# || / _---=> hardirq/softirq \n"); seq_puts(m, "# ||| / _--=> preempt-depth \n"); - seq_puts(m, "# |||| / \n"); - seq_puts(m, "# ||||| delay \n"); - seq_puts(m, "# cmd pid ||||| time | caller \n"); - seq_puts(m, "# \\ / ||||| \\ | / \n"); + seq_puts(m, "# |||| /_--=> lock-depth \n"); + seq_puts(m, "# |||||/ delay \n"); + seq_puts(m, "# cmd pid |||||| time | caller \n"); + seq_puts(m, "# \\ / |||||| \\ | / \n"); } static void print_func_help_header(struct seq_file *m) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 28d92027a93..975f324a07e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -86,6 +86,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); + __common_field(int, lock_depth); return ret; } @@ -571,11 +572,13 @@ static int trace_write_header(struct trace_seq *s) "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\n", FIELD(unsigned short, type), FIELD(unsigned char, flags), FIELD(unsigned char, preempt_count), - FIELD(int, pid)); + FIELD(int, pid), + FIELD(int, lock_depth)); } static ssize_t diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index ee791a9650c..48af4937438 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -368,6 +368,7 @@ static enum print_line_t print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) { int hardirq, softirq; + int ret; hardirq = entry->flags & TRACE_FLAG_HARDIRQ; softirq = entry->flags & TRACE_FLAG_SOFTIRQ; @@ -382,6 +383,13 @@ print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) hardirq ? 'h' : softirq ? 's' : '.')) return 0; + if (entry->lock_depth < 0) + ret = trace_seq_putc(s, '.'); + else + ret = trace_seq_printf(s, "%d", entry->lock_depth); + if (!ret) + return 0; + if (entry->preempt_count) return trace_seq_printf(s, "%x", entry->preempt_count); return trace_seq_puts(s, "."); @@ -1001,8 +1009,8 @@ static void print_lat_header(struct seq_file *s) seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); - seq_printf(s, "#%.*s||| / \n", size, spaces); - seq_printf(s, "#%.*s|||| \n", size, spaces); + seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces); + seq_printf(s, "#%.*s|||| / \n", size, spaces); } static void print_graph_headers(struct seq_file *s) @@ -1021,7 +1029,7 @@ static void print_graph_headers(struct seq_file *s) if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) seq_printf(s, " TASK/PID "); if (lat) - seq_printf(s, "||||"); + seq_printf(s, "|||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " DURATION "); seq_printf(s, " FUNCTION CALLS\n"); @@ -1035,7 +1043,7 @@ static void print_graph_headers(struct seq_file *s) if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) seq_printf(s, " | | "); if (lat) - seq_printf(s, "||||"); + seq_printf(s, "|||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " | | "); seq_printf(s, " | | | |\n"); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index be34a6aa7e4..29a370a4558 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -465,6 +465,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { int hardirq, softirq; char comm[TASK_COMM_LEN]; + int ret; trace_find_cmdline(entry->pid, comm); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; @@ -481,9 +482,16 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) hardirq ? 'h' : softirq ? 's' : '.')) return 0; + if (entry->lock_depth < 0) + ret = trace_seq_putc(s, '.'); + else + ret = trace_seq_printf(s, "%d", entry->lock_depth); + if (!ret) + return 0; + if (entry->preempt_count) return trace_seq_printf(s, "%x", entry->preempt_count); - return trace_seq_puts(s, "."); + return trace_seq_putc(s, '.'); } static unsigned long preempt_mark_thresh = 100; -- cgit v1.2.3-70-g09d2