Re: [PATCH] perf timehist: Handle cpu migration events
From: Arnaldo Carvalho de Melo
Date: Fri Nov 25 2016 - 14:06:29 EST
Em Fri, Nov 25, 2016 at 09:28:41AM -0700, David Ahern escreveu:
> From: David Ahern <dsahern@xxxxxxxxx>
>
> Add handlers for sched:sched_migrate_task event. Total number of migrations
> is added to summary display and -M/--migrations can be used to show
> migration events.
Thanks, applied.
> Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/Documentation/perf-sched.txt | 4 ++
> tools/perf/builtin-sched.c | 97 ++++++++++++++++++++++++++++++++-
> 2 files changed, 99 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
> index fb9e52d65fca..121c60da03e5 100644
> --- a/tools/perf/Documentation/perf-sched.txt
> +++ b/tools/perf/Documentation/perf-sched.txt
> @@ -128,6 +128,10 @@ OPTIONS for 'perf sched timehist'
> --wakeups::
> Show wakeup events.
>
> +-M::
> +--migrations::
> + Show migration events.
> +
> SEE ALSO
> --------
> linkperf:perf-record[1]
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 829468defa07..2706809bc3e4 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -203,6 +203,7 @@ struct perf_sched {
> unsigned int max_stack;
> bool show_cpu_visual;
> bool show_wakeups;
> + bool show_migrations;
> u64 skipped_samples;
> };
>
> @@ -216,6 +217,8 @@ struct thread_runtime {
>
> struct stats run_stats;
> u64 total_run_time;
> +
> + u64 migrations;
> };
>
> /* per event run time data */
> @@ -2175,6 +2178,87 @@ static int timehist_sched_wakeup_event(struct perf_tool *tool,
> return 0;
> }
>
> +static void timehist_print_migration_event(struct perf_sched *sched,
> + struct perf_evsel *evsel,
> + struct perf_sample *sample,
> + struct machine *machine,
> + struct thread *migrated)
> +{
> + struct thread *thread;
> + char tstr[64];
> + u32 max_cpus = sched->max_cpu + 1;
> + u32 ocpu, dcpu;
> +
> + if (sched->summary_only)
> + return;
> +
> + max_cpus = sched->max_cpu + 1;
> + ocpu = perf_evsel__intval(evsel, sample, "orig_cpu");
> + dcpu = perf_evsel__intval(evsel, sample, "dest_cpu");
> +
> + thread = machine__findnew_thread(machine, sample->pid, sample->tid);
> + if (thread == NULL)
> + return;
> +
> + if (timehist_skip_sample(sched, thread) &&
> + timehist_skip_sample(sched, migrated)) {
> + return;
> + }
> +
> + timestamp__scnprintf_usec(sample->time, tstr, sizeof(tstr));
> + printf("%15s [%04d] ", tstr, sample->cpu);
> +
> + if (sched->show_cpu_visual) {
> + u32 i;
> + char c;
> +
> + printf(" ");
> + for (i = 0; i < max_cpus; ++i) {
> + c = (i == sample->cpu) ? 'm' : ' ';
> + printf("%c", c);
> + }
> + printf(" ");
> + }
> +
> + printf(" %-*s ", comm_width, timehist_get_commstr(thread));
> +
> + /* dt spacer */
> + printf(" %9s %9s %9s ", "", "", "");
> +
> + printf("migrated: %s", timehist_get_commstr(migrated));
> + printf(" cpu %d => %d", ocpu, dcpu);
> +
> + printf("\n");
> +}
> +
> +static int timehist_migrate_task_event(struct perf_tool *tool,
> + union perf_event *event __maybe_unused,
> + struct perf_evsel *evsel,
> + struct perf_sample *sample,
> + struct machine *machine)
> +{
> + struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
> + struct thread *thread;
> + struct thread_runtime *tr = NULL;
> + /* want pid of migrated task not pid in sample */
> + const u32 pid = perf_evsel__intval(evsel, sample, "pid");
> +
> + thread = machine__findnew_thread(machine, 0, pid);
> + if (thread == NULL)
> + return -1;
> +
> + tr = thread__get_runtime(thread);
> + if (tr == NULL)
> + return -1;
> +
> + tr->migrations++;
> +
> + /* show migrations if requested */
> + timehist_print_migration_event(sched, evsel, sample, machine, thread);
> +
> + return 0;
> +}
> +
> static int timehist_sched_change_event(struct perf_tool *tool,
> union perf_event *event,
> struct perf_evsel *evsel,
> @@ -2273,6 +2357,7 @@ static void print_thread_runtime(struct thread *t,
> print_sched_time(r->run_stats.max, 6);
> printf(" ");
> printf("%5.2f", stddev);
> + printf(" %5" PRIu64, r->migrations);
> printf("\n");
> }
>
> @@ -2334,10 +2419,10 @@ static void timehist_print_summary(struct perf_sched *sched,
>
> printf("\nRuntime summary\n");
> printf("%*s parent sched-in ", comm_width, "comm");
> - printf(" run-time min-run avg-run max-run stddev\n");
> + printf(" run-time min-run avg-run max-run stddev migrations\n");
> printf("%*s (count) ", comm_width, "");
> printf(" (msec) (msec) (msec) (msec) %%\n");
> - printf("%.105s\n", graph_dotted_line);
> + printf("%.117s\n", graph_dotted_line);
>
> machine__for_each_thread(m, show_thread_runtime, &totals);
> task_count = totals.task_count;
> @@ -2438,6 +2523,9 @@ static int perf_sched__timehist(struct perf_sched *sched)
> { "sched:sched_wakeup", timehist_sched_wakeup_event, },
> { "sched:sched_wakeup_new", timehist_sched_wakeup_event, },
> };
> + const struct perf_evsel_str_handler migrate_handlers[] = {
> + { "sched:sched_migrate_task", timehist_migrate_task_event, },
> + };
> struct perf_data_file file = {
> .path = input_name,
> .mode = PERF_DATA_MODE_READ,
> @@ -2485,6 +2573,10 @@ static int perf_sched__timehist(struct perf_sched *sched)
> if (!perf_session__has_traces(session, "record -R"))
> goto out;
>
> + if (sched->show_migrations &&
> + perf_session__set_tracepoints_handlers(session, migrate_handlers))
> + goto out;
> +
> /* pre-allocate struct for per-CPU idle stats */
> sched->max_cpu = session->header.env.nr_cpus_online;
> if (sched->max_cpu == 0)
> @@ -2881,6 +2973,7 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
> OPT_BOOLEAN('S', "with-summary", &sched.summary,
> "Show all syscalls and summary with statistics"),
> OPT_BOOLEAN('w', "wakeups", &sched.show_wakeups, "Show wakeup events"),
> + OPT_BOOLEAN('M', "migrations", &sched.show_migrations, "Show migration events"),
> OPT_BOOLEAN('V', "cpu-visual", &sched.show_cpu_visual, "Add CPU visual"),
> OPT_PARENT(sched_options)
> };
> --
> 2.7.4 (Apple Git-66)