Em Tue, Mar 14, 2017 at 01:56:29AM +0000, Brendan Gregg escreveu:
> 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 wait time sch delay
> run time
> [tid/pid] (msec) (msec)
> (msec)
> --------------- ------ ------------------------------ --------- ---------
> ---------
Thanks, applied.
Minor request: when printing tool output in the cset comment, please add
two spaces before all lines, my git-am scripts get confused with that
--- thinking its a separator.
- Arnaldo
> 1136374.793792 [0000] <idle> 0.000 0.000
> 0.000 next: rngd[1524]
> 1136374.793801 [0000] rngd[1524] 0.000 0.000
> 0.009 next: swapper/0[0]
> 1136374.794048 [0007] <idle> 0.000 0.000
> 0.000 next: yes[30884]
> 1136374.794066 [0007] yes[30884] 0.000 0.000
> 0.018 next: swapper/7[0]
> 1136374.794126 [0002] <idle> 0.000 0.000
> 0.000 next: rngd[1524]
> 1136374.794140 [0002] rngd[1524] 0.325 0.006
> 0.013 next: swapper/2[0]
> 1136374.794281 [0003] <idle> 0.000 0.000
> 0.000 next: perf[31070]
>
> Signed-off-by: Brendan Gregg <bgr...@netflix.com>
> ---
> tools/perf/Documentation/perf-sched.txt | 4 ++++
> tools/perf/builtin-sched.c | 29 ++++++++++++++++++++++++-----
> 2 files changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-sched.txt
> b/tools/perf/Documentation/perf-sched.txt
> index d33dedd..a092a24 100644
> --- a/tools/perf/Documentation/perf-sched.txt
> +++ b/tools/perf/Documentation/perf-sched.txt
> @@ -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.
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index b94cf0d..fedc8f2 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -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 +1942,13 @@ 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 +2542,8 @@ 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)
> @@ -3340,6 +3352,7 @@ 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"),
> @@ -3437,10 +3450,16 @@ 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);
> - parse_options_usage(NULL, timehist_options, "w", 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;
> }
>
> --
> 2.7.4
