From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.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>
Subject: Re: [PATCHSET v3 0/3] perf tools: Minor improvements in event synthesis
Date: Wed, 3 Feb 2021 10:09:53 -0300 [thread overview]
Message-ID: <20210203130953.GA854763@kernel.org> (raw)
In-Reply-To: <YBlIJzIZ1nEesWS9@krava>
Em Tue, Feb 02, 2021 at 01:40:07PM +0100, Jiri Olsa escreveu:
> On Tue, Feb 02, 2021 at 06:01:15PM +0900, Namhyung Kim wrote:
> > Hello,
> >
> > This is to optimize the event synthesis during perf record.
> >
> > Changes in v3:
> > * remove unnecessary pid check
> > * update change log in patch #2
>
> Acked-by: Jiri Olsa <jolsa@redhat.com>
Thanks, applied.
- Arnaldo
> thanks,
> jirka
>
> >
> > The first patch is to reduce memory usage when many threads are used.
> > The second is to avoid unncessary syscalls for kernel threads. And
> > the last one is to reduce the number of threads to iterate when new
> > threads are being created at the same time.
> >
> > Unfortunately there's no dramatic improvement here but I can see ~5%
> > gain in the 'perf bench internals synthesize' on a big machine.
> > (The numbers are not stable though)
> >
> >
> > Before:
> > # perf bench internals synthesize --mt -M1 -I 100
> > # Running 'internals/synthesize' benchmark:
> > Computing performance of multi threaded perf event synthesis by
> > synthesizing events on CPU 0:
> > Number of synthesis threads: 1
> > Average synthesis took: 68831.480 usec (+- 101.450 usec)
> > Average num. events: 9982.000 (+- 0.000)
> > Average time per event 6.896 usec
> >
> >
> > After:
> > # perf bench internals synthesize --mt -M1 -I 100
> > # Running 'internals/synthesize' benchmark:
> > Computing performance of multi threaded perf event synthesis by
> > synthesizing events on CPU 0:
> > Number of synthesis threads: 1
> > Average synthesis took: 65036.370 usec (+- 158.121 usec)
> > Average num. events: 9982.000 (+- 0.000)
> > Average time per event 6.515 usec
> >
> >
> > Thanks,
> > Namhyung
> >
> >
> > Namhyung Kim (3):
> > perf tools: Use /proc/<PID>/task/<TID>/status for synthesis
> > perf tools: Skip MMAP record synthesis for kernel threads
> > perf tools: Use scandir() to iterate threads
> >
> > tools/perf/util/synthetic-events.c | 83 +++++++++++++++++++-----------
> > 1 file changed, 53 insertions(+), 30 deletions(-)
> >
> > --
> > 2.30.0.365.g02bc693789-goog
> >
>
--
- Arnaldo
prev parent reply other threads:[~2021-02-03 13:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 9:01 [PATCHSET v3 0/3] perf tools: Minor improvements in event synthesis Namhyung Kim
2021-02-02 9:01 ` [PATCH 1/3] perf tools: Use /proc/<PID>/task/<TID>/status for synthesis Namhyung Kim
2021-02-02 9:01 ` [PATCH 2/3] perf tools: Skip MMAP record synthesis for kernel threads Namhyung Kim
2021-02-02 9:01 ` [PATCH 3/3] perf tools: Use scandir() to iterate threads Namhyung Kim
2021-02-02 12:40 ` [PATCHSET v3 0/3] perf tools: Minor improvements in event synthesis Jiri Olsa
2021-02-03 13:09 ` Arnaldo Carvalho de Melo [this message]
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