linux-kernel - Re: [PATCHSET 0/5] perf tools: Show per-event lost sample count (v2)

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Message-ID: <YxJU5yfFC0bI545e@kernel.org>
Date:   Fri, 2 Sep 2022 16:09:27 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Namhyung Kim <namhyung@...nel.org>, Jiri Olsa <jolsa@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Ian Rogers <irogers@...gle.com>,
        linux-perf-users@...r.kernel.org
Subject: Re: [PATCHSET 0/5] perf tools: Show per-event lost sample count (v2)

Em Fri, Sep 02, 2022 at 08:44:25PM +0300, Adrian Hunter escreveu:
> On 1/09/22 22:57, Namhyung Kim wrote:
> > Hello,
> > 
> > Now we have PERF_FORMAT_LOST support, add it to perf record and report so that
> > it can show number of lost samples per event.  This can be useful if you want
> > to reconstruct number of events from the samples like when using -c option.
> > 
> > Changes in v2)
> >  * fix id_hdr_size calculation  (Adrian)
> >  * fix a memory leak
> >  * display lost samples even if no samples
> >  
> >  
> > Currently it adds PERF_RECORD_LOST_SAMPLES at the end of perf data after reading
> > event values by read(2).  The perf record unconditionally sets the lost bit if
> > the kernel supports it.  Users can see the number with `perf report --stat`.
> > 
> > You can get the code from 'perf/report-lost-v2' brach on
> > 
> >   git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
> > 
> > Thanks,
> > Namhyung
> > 
> > Namhyung Kim (5):
> >   perf tools: Print LOST read format in the verbose mode
> >   perf record: Set PERF_FORMAT_LOST by default
> >   perf record: Read and inject LOST_SAMPLES events
> >   perf hist: Add nr_lost_samples to hist_stats
> >   perf report: Show per-event LOST SAMPLES stat
> 
> Reviewed-by: Adrian Hunter <adrian.hunter@...el.com>

Thanks, applied.

- Arnaldo