perf sched timehist: Handle cpu migration events

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.

Signed-off-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1480091321-35591-1-git-send-email-dsa@cumulusnetworks.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
index fb9e52d65fca2b0f4179aaedc1a5030ed939be5c..121c60da03e524734ec4a23087fcfd543858700e 100644 (file)
--- 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 a49a032f5b155467ad69fe1e1e15fc17f6b599db..4f9e7cba4ebfd0015d776a0b4102e1af14ece60d 100644 (file)
--- 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 */
@@ -2197,6 +2200,87 @@ 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,
@@ -2295,6 +2379,7 @@ 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");
 }
 
@@ -2356,10 +2441,10 @@ 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;
@@ -2460,6 +2545,9 @@ 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,
@@ -2507,6 +2595,10 @@ 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)
@@ -2903,6 +2995,7 @@ 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)
        };