Re: [PATCH v3 3/3] perf tools: Add 'cgroup-switches' software event

From: Namhyung Kim
Date: Mon Apr 19 2021 - 14:02:49 EST


Hi Arnaldo,

Could you please pick this up? The kernel part is landed in the
tip.git already.

Thanks,
Namhyung

On Wed, Feb 10, 2021 at 5:33 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> It counts how often cgroups are changed actually during the context
> switches.
>
> # perf stat -a -e context-switches,cgroup-switches -a sleep 1
>
> Performance counter stats for 'system wide':
>
> 11,267 context-switches
> 10,950 cgroup-switches
>
> 1.015634369 seconds time elapsed
>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/include/uapi/linux/perf_event.h | 1 +
> tools/perf/util/parse-events.c | 4 ++++
> tools/perf/util/parse-events.l | 1 +
> 3 files changed, 6 insertions(+)
>
> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> index b15e3447cd9f..16b9538ad89b 100644
> --- a/tools/include/uapi/linux/perf_event.h
> +++ b/tools/include/uapi/linux/perf_event.h
> @@ -112,6 +112,7 @@ enum perf_sw_ids {
> PERF_COUNT_SW_EMULATION_FAULTS = 8,
> PERF_COUNT_SW_DUMMY = 9,
> PERF_COUNT_SW_BPF_OUTPUT = 10,
> + PERF_COUNT_SW_CGROUP_SWITCHES = 11,
>
> PERF_COUNT_SW_MAX, /* non-ABI */
> };
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 42c84adeb2fb..09ff678519f3 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -145,6 +145,10 @@ struct event_symbol event_symbols_sw[PERF_COUNT_SW_MAX] = {
> .symbol = "bpf-output",
> .alias = "",
> },
> + [PERF_COUNT_SW_CGROUP_SWITCHES] = {
> + .symbol = "cgroup-switches",
> + .alias = "",
> + },
> };
>
> #define __PERF_EVENT_FIELD(config, name) \
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 9db5097317f4..88f203bb6fab 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -347,6 +347,7 @@ emulation-faults { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_EM
> dummy { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY); }
> duration_time { return tool(yyscanner, PERF_TOOL_DURATION_TIME); }
> bpf-output { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_BPF_OUTPUT); }
> +cgroup-switches { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_CGROUP_SWITCHES); }
>
> /*
> * We have to handle the kernel PMU event cycles-ct/cycles-t/mem-loads/mem-stores separately.
> --
> 2.30.0.478.g8a0d178c01-goog
>