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From: Namhyung Kim <namhyung@kernel.org>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Stephane Eranian <eranian@google.com>,
	Andi Kleen <ak@linux.intel.com>, Ian Rogers <irogers@google.com>,
	Michael Petlan <mpetlan@redhat.com>
Subject: Re: [PATCH v2] perf/core: Add a new read format to get a number of lost samples
Date: Fri, 10 Sep 2021 15:40:48 -0700	[thread overview]
Message-ID: <CAM9d7cjjjV0uNCNLohFMFizRxvu2vwJBgE-Cge1Y6F3jDuPLNg@mail.gmail.com> (raw)
In-Reply-To: <YTvRNj09IwVfyZr1@krava>

On Fri, Sep 10, 2021 at 2:42 PM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Wed, Sep 08, 2021 at 10:24:20AM -0700, Namhyung Kim wrote:
> > Sometimes we want to know an accurate number of samples even if it's
> > lost.  Currenlty PERF_RECORD_LOST is generated for a ring-buffer which
> > might be shared with other events.  So it's hard to know per-event
> > lost count.
> >
> > Add event->lost_samples field and PERF_FORMAT_LOST to retrieve it from
> > userspace.
>
> hi,
> looks good.. will there be some tools/perf change using this?

Sure, I'll work on the userspace part after this is merged.
I'm thinking about adding LOST_SAMPLES records at the end
of the data section as if they came from the kernel.

Thanks,
Namhyung

  reply	other threads:[~2021-09-10 22:41 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-08 17:24 Namhyung Kim
2021-09-10 21:42 ` Jiri Olsa
2021-09-10 22:40   ` Namhyung Kim [this message]
2021-09-22 19:34     ` Namhyung Kim
2021-10-15  6:29       ` Namhyung Kim

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