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SubjectRe: [PATCH 2/2] perf, tools: Add --delay support to perf record v2
On Thu, Jan 09, 2014 at 11:29:53AM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> perf stat has a --delay option to delay measuring the workload.
> This is useful to skip measuring the startup phase of the program, which
> is often very different from the main workload.
>
> The same is useful for perf record when sampling. Add --delay to perf record too.
> -D was already taken for record, so there is only a long option.
>
> v2: Don't disable group members (Namhyung Kim)
> Cc: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> tools/perf/Documentation/perf-record.txt | 4 ++++
> tools/perf/builtin-record.c | 9 ++++++++-
> tools/perf/perf.h | 1 +
> tools/perf/util/evsel.c | 3 ++-
> 4 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index 43b42c4..e349151 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -207,6 +207,10 @@ Force the use of per-cpu mmaps. By default, when tasks are specified (i.e. -p,
> forces per-cpu mmaps. A side-effect of that is that inheritance is
> automatically enabled. Add the -i option also to disable inheritance.
>
> +--delay msecs::
> +After starting the program, wait msecs before measuring. This is useful to
> +filter out the startup phase of the program, which is often very different.
> +
> SEE ALSO
> --------
> linkperf:perf-stat[1], linkperf:perf-list[1]
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 7c8020a..110158e 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -506,7 +506,7 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
> * (apart from group members) have enable_on_exec=1 set,
> * so don't spoil it by prematurely enabling them.
> */
> - if (!target__none(&opts->target))
> + if (!target__none(&opts->target) && !opts->initial_delay)
> perf_evlist__enable(evsel_list);
>
> /*
> @@ -515,6 +515,11 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
> if (forks)
> perf_evlist__start_workload(evsel_list);
>
> + if (opts->initial_delay) {
> + usleep(opts->initial_delay * 1000);
> + perf_evlist__enable(evsel_list);
> + }
> +

evsel_list no longer works due to:
6346015 perf record: Remove old evsel_list usage

jirka


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