6.9-stable review patch. If anyone has any objections, please let me know.
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From: Yang Jihong yangjihong@bytedance.com
[ Upstream commit 6e4b398770d5023eb6383da9360a23bd537c155b ]
When 'perf sched' enables the call-graph recording, sample_type of dummy event does not have PERF_SAMPLE_CALLCHAIN, timehist_check_attr() checks that the evsel does not have a callchain, and set show_callchain to 0.
Currently 'perf sched timehist' only saves callchain when processing the 'sched:sched_switch event', timehist_check_attr() only needs to determine whether the event has PERF_SAMPLE_CALLCHAIN.
Before:
# perf sched record -g true [ perf record: Woken up 0 times to write data ] [ perf record: Captured and wrote 4.153 MB perf.data (7536 samples) ] # perf sched timehist Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) --------------- ------ ------------------------------ --------- --------- --------- 147851.826019 [0000] perf[285035] 0.000 0.000 0.000 147851.826029 [0000] migration/0[15] 0.000 0.003 0.009 147851.826063 [0001] perf[285035] 0.000 0.000 0.000 147851.826069 [0001] migration/1[21] 0.000 0.003 0.006 <SNIP>
After:
# perf sched record -g true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.572 MB perf.data (822 samples) ] # perf sched timehist time cpu task name waittime sch delay runtime [tid/pid] (msec) (msec) (msec) ----------- --- --------------- -------- -------- ----- 4193.035164 [0] perf[277062] 0.000 0.000 0.000 __traceiter_sched_switch <- __traceiter_sched_switch <- __sched_text_start <- preempt_schedule_common <- __cond_resched <- __wait_for_common <- wait_for_completion 4193.035174 [0] migration/0[15] 0.000 0.003 0.009 __traceiter_sched_switch <- __traceiter_sched_switch <- __sched_text_start <- smpboot_thread_fn <- kthread <- ret_from_fork 4193.035207 [1] perf[277062] 0.000 0.000 0.000 __traceiter_sched_switch <- __traceiter_sched_switch <- __sched_text_start <- preempt_schedule_common <- __cond_resched <- __wait_for_common <- wait_for_completion 4193.035214 [1] migration/1[21] 0.000 0.003 0.007 __traceiter_sched_switch <- __traceiter_sched_switch <- __sched_text_start <- smpboot_thread_fn <- kthread <- ret_from_fork <SNIP>
Fixes: 9c95e4ef06572349 ("perf evlist: Add evlist__findnew_tracking_event() helper") Reviewed-by: Ian Rogers irogers@google.com Signed-off-by: Yang Jihong yangjihong@bytedance.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ingo Molnar mingo@redhat.com Cc: James Clark james.clark@arm.com Cc: Jiri Olsa jolsa@kernel.org Cc: Kan Liang kan.liang@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Yang Jihong yangjihong1@huawei.com Link: https://lore.kernel.org/r/20240401062724.1006010-2-yangjihong@bytedance.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-sched.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index b248c433529a8..1bfb223473715 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -2963,8 +2963,11 @@ static int timehist_check_attr(struct perf_sched *sched, return -1; }
- if (sched->show_callchain && !evsel__has_callchain(evsel)) { - pr_info("Samples do not have callchains.\n"); + /* only need to save callchain related to sched_switch event */ + if (sched->show_callchain && + evsel__name_is(evsel, "sched:sched_switch") && + !evsel__has_callchain(evsel)) { + pr_info("Samples of sched_switch event do not have callchains.\n"); sched->show_callchain = 0; symbol_conf.use_callchain = 0; }