Re: [PATCH v2 4/6] perf sched timehist: Add option to specify time window of interest

From: Arnaldo Carvalho de Melo
Date: Tue Nov 29 2016 - 13:56:54 EST


Em Tue, Nov 29, 2016 at 10:15:44AM -0700, David Ahern escreveu:
> Add option to allow user to control analysis window. e.g., collect data
> for time window and analyze a segment of interest within that window.

Trying to test this I got:

[root@jouet ~]# perf sched timehist
No trace sample to read. Did you call 'perf record -R'?
[root@jouet ~]#

Could you please provide a better error message?

The perf.data file had this:

[root@jouet ~]# perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
[root@jouet ~]#

- Arnaldo

> Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
> ---
> tools/perf/Documentation/perf-sched.txt | 8 ++++++
> tools/perf/builtin-sched.c | 51 +++++++++++++++++++++++++++++----
> 2 files changed, 53 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
> index 121c60da03e5..7775b1eb2bee 100644
> --- a/tools/perf/Documentation/perf-sched.txt
> +++ b/tools/perf/Documentation/perf-sched.txt
> @@ -132,6 +132,14 @@ OPTIONS for 'perf sched timehist'
> --migrations::
> Show migration events.
>
> +--time::
> + Only analyze samples within given time window: <start>,<stop>. Times
> + have the format seconds.microseconds. If start is not given (i.e., time
> + string is ',x.y') then analysis starts at the beginning of the file. If
> + stop time is not given (i.e, time string is 'x.y,') then analysis goes
> + to end of file.
> +
> +
> SEE ALSO
> --------
> linkperf:perf-record[1]
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 4f9e7cba4ebf..870d94cd20ba 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -15,6 +15,7 @@
> #include "util/color.h"
> #include "util/stat.h"
> #include "util/callchain.h"
> +#include "util/time-utils.h"
>
> #include <subcmd/parse-options.h>
> #include "util/trace-event.h"
> @@ -205,6 +206,8 @@ struct perf_sched {
> bool show_wakeups;
> bool show_migrations;
> u64 skipped_samples;
> + const char *time_str;
> + struct perf_time_interval ptime;
> };
>
> /* per thread run time data */
> @@ -1837,13 +1840,14 @@ static void timehist_header(struct perf_sched *sched)
> static void timehist_print_sample(struct perf_sched *sched,
> struct perf_sample *sample,
> struct addr_location *al,
> - struct thread *thread)
> + struct thread *thread,
> + u64 t)
> {
> struct thread_runtime *tr = thread__priv(thread);
> u32 max_cpus = sched->max_cpu + 1;
> char tstr[64];
>
> - timestamp__scnprintf_usec(sample->time, tstr, sizeof(tstr));
> + timestamp__scnprintf_usec(t, tstr, sizeof(tstr));
> printf("%15s [%04d] ", tstr, sample->cpu);
>
> if (sched->show_cpu_visual) {
> @@ -2194,7 +2198,8 @@ static int timehist_sched_wakeup_event(struct perf_tool *tool,
> tr->ready_to_run = sample->time;
>
> /* show wakeups if requested */
> - if (sched->show_wakeups)
> + if (sched->show_wakeups &&
> + !perf_time__skip_sample(&sched->ptime, sample->time))
> timehist_print_wakeup_event(sched, sample, machine, thread);
>
> return 0;
> @@ -2288,10 +2293,11 @@ static int timehist_sched_change_event(struct perf_tool *tool,
> struct machine *machine)
> {
> struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
> + struct perf_time_interval *ptime = &sched->ptime;
> struct addr_location al;
> struct thread *thread;
> struct thread_runtime *tr = NULL;
> - u64 tprev;
> + u64 tprev, t = sample->time;
> int rc = 0;
>
> if (machine__resolve(machine, &al, sample) < 0) {
> @@ -2318,9 +2324,35 @@ static int timehist_sched_change_event(struct perf_tool *tool,
>
> tprev = perf_evsel__get_time(evsel, sample->cpu);
>
> - timehist_update_runtime_stats(tr, sample->time, tprev);
> + /*
> + * If start time given:
> + * - sample time is under window user cares about - skip sample
> + * - tprev is under window user cares about - reset to start of window
> + */
> + if (ptime->start && ptime->start > t)
> + goto out;
> +
> + if (ptime->start > tprev)
> + tprev = ptime->start;
> +
> + /*
> + * If end time given:
> + * - previous sched event is out of window - we are done
> + * - sample time is beyond window user cares about - reset it
> + * to close out stats for time window interest
> + */
> + if (ptime->end) {
> + if (tprev > ptime->end)
> + goto out;
> +
> + if (t > ptime->end)
> + t = ptime->end;
> + }
> +
> + timehist_update_runtime_stats(tr, t, tprev);
> +
> if (!sched->summary_only)
> - timehist_print_sample(sched, sample, &al, thread);
> + timehist_print_sample(sched, sample, &al, thread, t);
>
> out:
> if (tr) {
> @@ -2583,6 +2615,11 @@ static int perf_sched__timehist(struct perf_sched *sched)
>
> symbol__init(&session->header.env);
>
> + if (perf_time__parse_str(&sched->ptime, sched->time_str) != 0) {
> + pr_err("Invalid time string\n");
> + return -EINVAL;
> + }
> +
> if (timehist_check_attr(sched, evlist) != 0)
> goto out;
>
> @@ -2997,6 +3034,8 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
> 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_STRING(0, "time", &sched.time_str, "str",
> + "Time span for analysis (start,stop)"),
> OPT_PARENT(sched_options)
> };
>
> --
> 2.7.4 (Apple Git-66)