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tracing: adding function timings to function profiler

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If the function graph trace is enabled, the function profiler will
use it to take the timing of the functions.

 cat /debug/tracing/trace_stat/functions

  Function                               Hit    Time
  --------                               ---    ----
  mwait_idle                             127    183028.4 us
  schedule                                26    151997.7 us
  __schedule                              31    151975.1 us
  sys_wait4                                2    74080.53 us
  do_wait                                  2    74077.80 us
  sys_newlstat                           138    39929.16 us
  do_path_lookup                         179    39845.79 us
  vfs_lstat_fd                           138    39761.97 us
  user_path_at                           153    39469.58 us
  path_walk                              179    39435.76 us
  __link_path_walk                       189    39143.73 us
[...]

Note the times are skewed due to the function graph tracer not taking
into account schedules.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This commit is contained in:
Steven Rostedt
2009-03-23 23:12:58 -04:00
parent 493762fc53
commit 0706f1c48c
6 changed files with 117 additions and 19 deletions
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11
kernel/trace/trace.c
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@@ -402,17 +402,6 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
return cnt;
}
static void
trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
s->buffer[len] = 0;
seq_puts(m, s->buffer);
trace_seq_init(s);
}
/**
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
* @tr: tracer