From f90a24171a8179a29e5e1532fd5bb94e59b5380e Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 14 Aug 2019 16:20:13 -0300 Subject: [PATCH] perf script: Allow specifying event to switch on processing of other events Sometime we want to only consider events after something happens, so allow discarding events till such events is found, e.g.: Record all scheduler tracepoints and the sys_enter_nanosleep syscall event for the 'sleep 1' workload: # perf record -e sched:*,syscalls:sys_enter_nanosleep sleep 1 [ perf record: Woken up 31 times to write data ] [ perf record: Captured and wrote 0.032 MB perf.data (10 samples) ] # So we have these events in the generated perf data file: # perf evlist sched:sched_kthread_stop sched:sched_kthread_stop_ret sched:sched_waking sched:sched_wakeup sched:sched_wakeup_new sched:sched_switch sched:sched_migrate_task sched:sched_process_free sched:sched_process_exit sched:sched_wait_task sched:sched_process_wait sched:sched_process_fork sched:sched_process_exec sched:sched_stat_wait sched:sched_stat_sleep sched:sched_stat_iowait sched:sched_stat_blocked sched:sched_stat_runtime sched:sched_pi_setprio sched:sched_move_numa sched:sched_stick_numa sched:sched_swap_numa sched:sched_wake_idle_without_ipi syscalls:sys_enter_nanosleep # Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events # Then show all of the events that actually took place in this 'perf record' session: # perf script :13637 13637 [002] 108237.581529: sched:sched_waking: comm=perf pid=13638 prio=120 target_cpu=001 :13637 13637 [002] 108237.581537: sched:sched_wakeup: perf:13638 [120] success=1 CPU:001 sleep 13638 [001] 108237.581992: sched:sched_process_exec: filename=/usr/bin/sleep pid=13638 old_pid=13638 sleep 13638 [001] 108237.582286: syscalls:sys_enter_nanosleep: rqtp: 0x7fff1948ac40, rmtp: 0x00000000 sleep 13638 [001] 108237.582289: sched:sched_stat_runtime: comm=sleep pid=13638 runtime=578104 [ns] vruntime=202889459556 [ns] sleep 13638 [001] 108237.582291: sched:sched_switch: sleep:13638 [120] S ==> swapper/1:0 [120] swapper 0 [001] 108238.582428: sched:sched_waking: comm=sleep pid=13638 prio=120 target_cpu=001 swapper 0 [001] 108238.582458: sched:sched_wakeup: sleep:13638 [120] success=1 CPU:001 sleep 13638 [001] 108238.582698: sched:sched_stat_runtime: comm=sleep pid=13638 runtime=173915 [ns] vruntime=202889633471 [ns] sleep 13638 [001] 108238.582782: sched:sched_process_exit: comm=sleep pid=13638 prio=120 # Now lets see only the ones that took place after a certain "marker": # perf script --switch-on syscalls:sys_enter_nanosleep sleep 13638 [001] 108237.582289: sched:sched_stat_runtime: comm=sleep pid=13638 runtime=578104 [ns] vruntime=202889459556 [ns] sleep 13638 [001] 108237.582291: sched:sched_switch: sleep:13638 [120] S ==> swapper/1:0 [120] swapper 0 [001] 108238.582428: sched:sched_waking: comm=sleep pid=13638 prio=120 target_cpu=001 swapper 0 [001] 108238.582458: sched:sched_wakeup: sleep:13638 [120] success=1 CPU:001 sleep 13638 [001] 108238.582698: sched:sched_stat_runtime: comm=sleep pid=13638 runtime=173915 [ns] vruntime=202889633471 [ns] sleep 13638 [001] 108238.582782: sched:sched_process_exit: comm=sleep pid=13638 prio=120 # Cc: Adrian Hunter Cc: Florian Weimer Cc: Jiri Olsa Cc: Namhyung Kim Cc: William Cohen Link: https://lkml.kernel.org/n/tip-f1oo0ufdhrkx6nhy2lj1ierm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-script.txt | 3 +++ tools/perf/builtin-script.c | 26 ++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt index caaab28f8400..9936819aae1c 100644 --- a/tools/perf/Documentation/perf-script.txt +++ b/tools/perf/Documentation/perf-script.txt @@ -417,6 +417,9 @@ include::itrace.txt[] For itrace only show specified functions and their callees for itrace. Multiple functions can be separated by comma. +--switch-on EVENT_NAME:: + Only consider events after this event is found. + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-script-perl[1], diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 31a529ec139f..d0bc7ccaf7bf 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1616,6 +1616,11 @@ static int perf_sample__fprintf_synth(struct perf_sample *sample, return 0; } +struct evswitch { + struct evsel *on; + bool discarding; +}; + struct perf_script { struct perf_tool tool; struct perf_session *session; @@ -1628,6 +1633,7 @@ struct perf_script { bool show_bpf_events; bool allocated; bool per_event_dump; + struct evswitch evswitch; struct perf_cpu_map *cpus; struct perf_thread_map *threads; int name_width; @@ -1805,6 +1811,13 @@ static void process_event(struct perf_script *script, if (!show_event(sample, evsel, thread, al)) return; + if (script->evswitch.on && script->evswitch.discarding) { + if (script->evswitch.on != evsel) + return; + + script->evswitch.discarding = false; + } + ++es->samples; perf_sample__fprintf_start(sample, thread, evsel, @@ -3395,6 +3408,7 @@ int cmd_script(int argc, const char **argv) struct utsname uts; char *script_path = NULL; const char **__argv; + const char *event_switch_on = NULL; int i, j, err = 0; struct perf_script script = { .tool = { @@ -3538,6 +3552,8 @@ int cmd_script(int argc, const char **argv) "file", "file saving guest os /proc/kallsyms"), OPT_STRING(0, "guestmodules", &symbol_conf.default_guest_modules, "file", "file saving guest os /proc/modules"), + OPT_STRING(0, "switch-on", &event_switch_on, + "event", "Consider events from the first ocurrence of this event"), OPT_END() }; const char * const script_subcommands[] = { "record", "report", NULL }; @@ -3862,6 +3878,16 @@ int cmd_script(int argc, const char **argv) script.range_num); } + if (event_switch_on) { + script.evswitch.on = perf_evlist__find_evsel_by_str(session->evlist, event_switch_on); + if (script.evswitch.on == NULL) { + fprintf(stderr, "switch-on event not found (%s)\n", event_switch_on); + err = -ENOENT; + goto out_delete; + } + script.evswitch.discarding = true; + } + err = __cmd_script(&script); flush_scripting(); -- GitLab