diff options
author | Yang Jihong <yangjihong1@huawei.com> | 2021-07-13 19:23:58 +0800 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-07-18 09:36:37 -0300 |
commit | b0f008551f0bf4d5f6db9b5f0e071b02790d6a2e (patch) | |
tree | 911265a67f84dda5f500690f0558faf3ef54b868 /tools/perf | |
parent | 22a665513b34df458da1d3b7ee0b919c3f3d4653 (diff) | |
download | linux-b0f008551f0bf4d5f6db9b5f0e071b02790d6a2e.tar.bz2 |
perf sched: Fix record failure when CONFIG_SCHEDSTATS is not set
The tracepoints trace_sched_stat_{wait, sleep, iowait} are not exposed to user
if CONFIG_SCHEDSTATS is not set, "perf sched record" records the three events.
As a result, the command fails.
Before:
#perf sched record sleep 1
event syntax error: 'sched:sched_stat_wait'
\___ unknown tracepoint
Error: File /sys/kernel/tracing/events/sched/sched_stat_wait not found.
Hint: Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
Solution:
Check whether schedstat tracepoints are exposed. If no, these events are not recorded.
After:
# perf sched record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.163 MB perf.data (1091 samples) ]
# perf sched report
run measurement overhead: 4736 nsecs
sleep measurement overhead: 9059979 nsecs
the run test took 999854 nsecs
the sleep test took 8945271 nsecs
nr_run_events: 716
nr_sleep_events: 785
nr_wakeup_events: 0
...
------------------------------------------------------------
Fixes: 2a09b5de235a6 ("sched/fair: do not expose some tracepoints to user if CONFIG_SCHEDSTATS is not set")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Yafang Shao <laoar.shao@gmail.com>
Link: http://lore.kernel.org/lkml/20210713112358.194693-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r-- | tools/perf/builtin-sched.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index aaf1cde476c9..1ff10d4bccf3 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -3335,6 +3335,16 @@ static void setup_sorting(struct perf_sched *sched, const struct option *options sort_dimension__add("pid", &sched->cmp_pid); } +static bool schedstat_events_exposed(void) +{ + /* + * Select "sched:sched_stat_wait" event to check + * whether schedstat tracepoints are exposed. + */ + return IS_ERR(trace_event__tp_format("sched", "sched_stat_wait")) ? + false : true; +} + static int __cmd_record(int argc, const char **argv) { unsigned int rec_argc, i, j; @@ -3346,21 +3356,33 @@ static int __cmd_record(int argc, const char **argv) "-m", "1024", "-c", "1", "-e", "sched:sched_switch", - "-e", "sched:sched_stat_wait", - "-e", "sched:sched_stat_sleep", - "-e", "sched:sched_stat_iowait", "-e", "sched:sched_stat_runtime", "-e", "sched:sched_process_fork", "-e", "sched:sched_wakeup_new", "-e", "sched:sched_migrate_task", }; + + /* + * The tracepoints trace_sched_stat_{wait, sleep, iowait} + * are not exposed to user if CONFIG_SCHEDSTATS is not set, + * to prevent "perf sched record" execution failure, determine + * whether to record schedstat events according to actual situation. + */ + const char * const schedstat_args[] = { + "-e", "sched:sched_stat_wait", + "-e", "sched:sched_stat_sleep", + "-e", "sched:sched_stat_iowait", + }; + unsigned int schedstat_argc = schedstat_events_exposed() ? + ARRAY_SIZE(schedstat_args) : 0; + struct tep_event *waking_event; /* * +2 for either "-e", "sched:sched_wakeup" or * "-e", "sched:sched_waking" */ - rec_argc = ARRAY_SIZE(record_args) + 2 + argc - 1; + rec_argc = ARRAY_SIZE(record_args) + 2 + schedstat_argc + argc - 1; rec_argv = calloc(rec_argc + 1, sizeof(char *)); if (rec_argv == NULL) @@ -3376,6 +3398,9 @@ static int __cmd_record(int argc, const char **argv) else rec_argv[i++] = strdup("sched:sched_wakeup"); + for (j = 0; j < schedstat_argc; j++) + rec_argv[i++] = strdup(schedstat_args[j]); + for (j = 1; j < (unsigned int)argc; j++, i++) rec_argv[i] = argv[j]; |