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In-Reply-To: <872f5052-788b-fe6d-d0ac-82e9639910d2@linux.intel.com>
From:   Namhyung Kim <namhyung@kernel.org>
Date:   Wed, 28 Oct 2020 16:22:49 +0900
Message-ID: <CAM9d7cifhL--aYn05dYABmqoxGXX6xRC9W+Q+cWSnKqGUPPvzA@mail.gmail.com>
Subject: Re: [PATCH v2 06/15] perf session: load data directory into tool
 process memory
To:     Alexey Budankov <alexey.budankov@linux.intel.com>
Cc:     Jiri Olsa <jolsa@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Tue, Oct 27, 2020 at 11:43 PM Alexey Budankov
<alexey.budankov@linux.intel.com> wrote:
>
>
> On 27.10.2020 15:21, Jiri Olsa wrote:
> > On Tue, Oct 27, 2020 at 10:37:58AM +0300, Alexey Budankov wrote:
> >> I agree perf report OOM issue can exist on really-big servers but data
> >> directories support for report mode for not-so-big servers and desktops
> >> is already enabled with this smaller change. Also really-big-servers
> >> come with really-big amount of memory and collection could possibly be
> >> limited to only interesting phases of execution so the issue could likely
> >> be avoided. At the same time threaded trace streaming could clarify on
> >> real use cases that are blocked by perf report OOM issue and that would
> >> clarify on exact required solution. So perf report OOM issue shouldn't
> >> be the showstopper for upstream of threaded trace streaming.
> >
> > so the short answer is no, right? ;-)
>
> Answer to what question? Resolve OOM in perf report for data directories?
> I don't see a simple solution for that. The next issue after OOM is resolved
> is a very long processing of data directories. And again there is no simple
> solution for that as well. But it still need progress in order to be resolved
> eventually.

I think we should find a better way than just adding all events to the
ordered events queue in memory then processing them one by one.

Separating tracking events (FORK/MMAP/...) might be the first step.

Thanks
Namhyung