linux-kernel - Re: [PATCH v5 00/20] Introduce threaded trace streaming for basic perf record operation

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Message-ID: <CAM9d7cj_nLM2PfSpCjRGKTHdY5G641StHSRgQT-ohWOvJsKEAA@mail.gmail.com>
Date:   Thu, 6 May 2021 21:47:38 -0700
From:   Namhyung Kim <namhyung@...nel.org>
To:     "Bayduraev, Alexey V" <alexey.v.bayduraev@...ux.intel.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...hat.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Alexander Antonov <alexander.antonov@...ux.intel.com>,
        Alexei Budankov <abudankov@...wei.com>
Subject: Re: [PATCH v5 00/20] Introduce threaded trace streaming for basic
 perf record operation

On Thu, May 6, 2021 at 5:44 AM Bayduraev, Alexey V
<alexey.v.bayduraev@...ux.intel.com> wrote:
>
> Hi,
>
> On 06.05.2021 9:20, Namhyung Kim wrote:
> > Hello,
> >
> > On Tue, May 4, 2021 at 12:05 AM Alexey Bayduraev
> > <alexey.v.bayduraev@...ux.intel.com> wrote:
> >>
> <SNIP>>>
> >> Basic analysis of data directories is provided in perf report mode.
> >> Raw dump and aggregated reports are available for data directories,
> >> still with no memory consumption optimizations.
> >
> > Do you have an idea how to improve it?
> >
> > I have to say again that I don't like merely adding more threads to
> > record.  Yeah, parallelizing the perf record is good, but we have to
> > think about the perf report (and others) too.
>
> There is your idea about separating tracking records and process them
> first, but these changes can be much larger than my patch and I think
> they looks like independent patch and could be introduced as extension
> of parallel data loading.
>
> I also thought and experimented with the intermediate flushing of
> the ordered queue. This is simple for per-cpu data files (sorted
> by time), but not clear for arbitrary CPU masks.
>
> I think my patch can be the first step to introduce parallel mode
> to the perf tool. It just extends perf-record (already used in our
> vtune tool) and allows to load parallel data in experimental mode.
> Next patches could optimize and extend parallel data loading.

Yeah I agree that we can change it incrementally and good to
know that you are thinking about the next step. :)

Thanks,
Namhyung