linux-kernel - Re: [PATCH 1/3] perf/core: Update perf_adjust_freq_unthr

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Date:   Tue, 21 Nov 2023 10:21:36 -0800
From:   Namhyung Kim <namhyung@...nel.org>
To:     Mingwei Zhang <mizhang@...gle.com>
Cc:     Ian Rogers <irogers@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [PATCH 1/3] perf/core: Update perf_adjust_freq_unthr_context()

Hi Mingwei,

On Mon, Nov 20, 2023 at 3:24 PM Mingwei Zhang <mizhang@...gle.com> wrote:
>
> On Mon, Nov 20, 2023, Ian Rogers wrote:
> > On Mon, Nov 20, 2023 at 2:19 PM Namhyung Kim <namhyung@...nel.org> wrote:
> > >
> > > It was unnecessarily disabling and enabling PMUs for each event.  It
> > > should be done at PMU level.  Add pmu_ctx->nr_freq counter to check it
> > > at each PMU.  As pmu context has separate active lists for pinned group
> > > and flexible group, factor out a new function to do the job.
> > >
> > > Another minor optimization is that it can skip PMUs w/ CAP_NO_INTERRUPT
> > > even if it needs to unthrottle sampling events.
> > >
> > > Signed-off-by: Namhyung Kim <namhyung@...nel.org>
> >
> > Series:
> > Reviewed-by: Ian Rogers <irogers@...gle.com>
> >
> > Thanks,
> > Ian
> >
>
> Can we have "Cc: stable@...r.kernel.org" for the whole series? This
> series should have a great performance improvement for all VMs in which
> perf sampling events without specifying period.

I was not sure if it's ok to have this performance fix in the stable series.

Thanks,
Namhyung