perf sched timehist: Add --next option

The --next option shows the next task for each context switch, providing
more context for the sequence of scheduler events.

  $ perf sched timehist --next | head
  Samples do not have callchains.
       time  cpu task name  waittime schdelay run time
                 [tid/pid]     (msec) (msec) (msec)
  ---------- --- ---------- --------- ------ -----
  374.793792 [0] <idle>         0.000  0.000 0.000 next: rngd[1524]
  374.793801 [0] rngd[1524]     0.000  0.000 0.009 next: swapper/0[0]
  374.794048 [7] <idle>         0.000  0.000 0.000 next: yes[30884]
  374.794066 [7] yes[30884]     0.000  0.000 0.018 next: swapper/7[0]
  374.794126 [2] <idle>         0.000  0.000 0.000 next: rngd[1524]
  374.794140 [2] rngd[1524]     0.325  0.006 0.013 next: swapper/2[0]
  374.794281 [3] <idle>         0.000  0.000 0.000 next: perf[31070]

Signed-off-by: Brendan Gregg <bgregg@netflix.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1489456589-32555-1-git-send-email-bgregg@netflix.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Brendan Gregg 2017-03-14 01:56:29 +00:00 committed by Arnaldo Carvalho de Melo
parent d890a98c92
commit 292c4a8f98
2 changed files with 24 additions and 5 deletions

View File

@ -132,6 +132,10 @@ OPTIONS for 'perf sched timehist'
--migrations::
Show migration events.
-n::
--next::
Show next task.
-I::
--idle-hist::
Show idle-related events only.

View File

@ -221,6 +221,7 @@ struct perf_sched {
unsigned int max_stack;
bool show_cpu_visual;
bool show_wakeups;
bool show_next;
bool show_migrations;
bool show_state;
u64 skipped_samples;
@ -1897,14 +1898,18 @@ static char task_state_char(struct thread *thread, int state)
}
static void timehist_print_sample(struct perf_sched *sched,
struct perf_evsel *evsel,
struct perf_sample *sample,
struct addr_location *al,
struct thread *thread,
u64 t, int state)
{
struct thread_runtime *tr = thread__priv(thread);
const char *next_comm = perf_evsel__strval(evsel, sample, "next_comm");
const u32 next_pid = perf_evsel__intval(evsel, sample, "next_pid");
u32 max_cpus = sched->max_cpu + 1;
char tstr[64];
char nstr[30];
u64 wait_time;
timestamp__scnprintf_usec(t, tstr, sizeof(tstr));
@ -1937,7 +1942,12 @@ static void timehist_print_sample(struct perf_sched *sched,
if (sched->show_state)
printf(" %5c ", task_state_char(thread, state));
if (sched->show_wakeups)
if (sched->show_next) {
snprintf(nstr, sizeof(nstr), "next: %s[%d]", next_comm, next_pid);
printf(" %-*s", comm_width, nstr);
}
if (sched->show_wakeups && !sched->show_next)
printf(" %-*s", comm_width, "");
if (thread->tid == 0)
@ -2531,7 +2541,7 @@ static int timehist_sched_change_event(struct perf_tool *tool,
}
if (!sched->summary_only)
timehist_print_sample(sched, sample, &al, thread, t, state);
timehist_print_sample(sched, evsel, sample, &al, thread, t, state);
out:
if (sched->hist_time.start == 0 && t >= ptime->start)
@ -3341,6 +3351,7 @@ 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('n', "next", &sched.show_next, "Show next task"),
OPT_BOOLEAN('M', "migrations", &sched.show_migrations, "Show migration events"),
OPT_BOOLEAN('V', "cpu-visual", &sched.show_cpu_visual, "Add CPU visual"),
OPT_BOOLEAN('I', "idle-hist", &sched.idle_hist, "Show idle events only"),
@ -3438,10 +3449,14 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
if (argc)
usage_with_options(timehist_usage, timehist_options);
}
if (sched.show_wakeups && sched.summary_only) {
pr_err(" Error: -s and -w are mutually exclusive.\n");
if ((sched.show_wakeups || sched.show_next) &&
sched.summary_only) {
pr_err(" Error: -s and -[n|w] are mutually exclusive.\n");
parse_options_usage(timehist_usage, timehist_options, "s", true);
if (sched.show_wakeups)
parse_options_usage(NULL, timehist_options, "w", true);
if (sched.show_next)
parse_options_usage(NULL, timehist_options, "n", true);
return -EINVAL;
}