Commit-ID: 8388deb3ba4d36ffcae91a2a01cb2ea6f27553e6
Gitweb: http://git.kernel.org/tip/8388deb3ba4d36ffcae91a2a01cb2ea6f27553e6
Author: Namhyung Kim <namhy...@kernel.org>
AuthorDate: Thu, 24 Nov 2016 10:11:14 +0900
Committer: Arnaldo Carvalho de Melo <a...@redhat.com>
CommitDate: Fri, 25 Nov 2016 10:50:57 -0300
perf sched timehist: Enlarge max stack depth by 2
When it records callchains, they will always have 2 scheduler functions
(__schedule + schedule or __schedule + preempt_schedule) and get
ignored. So it should collect 2 more functions to show the expected
number of callchains to user.
Committer Notes:
Example of final result, using the same perf.data file as in the
previous cset comment, but this time redirecting the output of 'perf
sched timehist' to a file instead of copy'n'pasting from xterm:
[root@jouet experimental]# perf sched timehist > /tmp/bla
[root@jouet experimental]# cat /tmp/bla
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
-------- ---- -------------------- ------ ------ -----
6.494998 [01] <idle> 0.000 0.000 0.000
6.495027 [02] perf[519] 0.000 0.000 0.000
schedule_hrtimeout_range_clock <- schedule_hrtimeout_range <-
poll_schedule_timeout <- do_sys_poll <- sys_poll
6.495096 [03] <idle> 0.000 0.000 0.000
6.495100 [03] rcuos/0[9] 0.000 0.005 0.003 rcu_nocb_kthread <-
kthread <- ret_from_fork
6.495113 [01] perf[520] 0.000 0.008 0.114
preempt_schedule_common <- _cond_resched <- wait_for_completion <- stop_one_cpu
<- sched_exec <- do_execveat_common.isra.35
6.495121 [00] <idle> 0.000 0.000 0.000
6.495129 [01] migration/1[17] 0.000 0.003 0.016 smpboot_thread_fn <-
kthread <- ret_from_fork
6.496085 [02] <idle> 0.000 0.000 1.057
6.496096 [02] kworker/u16:1[31169] 0.000 0.004 0.011 worker_thread <-
kthread <- ret_from_fork
6.496096 [03] <idle> 0.003 0.000 0.996
6.496169 [02] <idle> 0.011 0.000 0.072
6.496171 [00] ls[520] 0.008 0.000 1.049 do_exit <-
do_group_exit <- [unknown] <- entry_SYSCALL_64_fastpath
6.496172 [03] gnome-terminal-[4391] 0.000 0.003 0.076
schedule_hrtimeout_range_clock <- schedule_hrtimeout_range <-
poll_schedule_timeout <- do_sys_poll <- sys_poll
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Andi Kleen <a...@firstfloor.org>
Cc: David Ahern <dsah...@gmail.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Stephane Eranian <eran...@google.com>
Link: http://lkml.kernel.org/r/20161124011114.7102-3-namhy...@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/builtin-sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 06be809..a49a032 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1960,7 +1960,7 @@ static bool is_idle_sample(struct perf_sched *sched,
return false;
if (thread__resolve_callchain(thread, cursor, evsel, sample,
- NULL, NULL, sched->max_stack) != 0) {
+ NULL, NULL, sched->max_stack + 2) != 0) {
if (verbose)
error("Failed to resolve callchain. Skipping\n");
