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From: Ingo Molnar <mingo@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Jiri Olsa <jolsa@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
	David Ahern <dsahern@gmail.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Andi Kleen <andi@firstfloor.org>,
	Stephane Eranian <eranian@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1)
Date: Thu, 10 Dec 2015 09:01:18 +0100	[thread overview]
Message-ID: <20151210080118.GA8664@gmail.com> (raw)
In-Reply-To: <1449734015-9148-1-git-send-email-namhyung@kernel.org>


* Namhyung Kim <namhyung@kernel.org> wrote:

> Hello,
> 
> This patchset if an attempt to support multi-threading in perf top.
> In fact, perf top already run on two threads - a worker thread and a
> display thread.  However processing all samples with a single thread
> in a large machine can have scalability problems.
> 
> This patchset extends it to have multiple worker threads to process
> samples concurrently.  Users can control the number of threads using
>  --num-thread option.  And there's a collector thread for passing hist
> entries from worker threads to the display thread.

Could you please make the number of threads default to the number of CPUs?

Since perf top is doing one perf event per CPU anyway, that's a pretty natural 
model.

( I think 'perf record' should use per CPU threads as well to receive events, to 
  address the 'IO overload' problems with -g recording on larger CPU counts. )

Thanks,

	Ingo

  parent reply	other threads:[~2015-12-10  8:01 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-10  7:53 [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 01/16] perf top: Delete half-processed hist entries when exit Namhyung Kim
2015-12-10  9:55   ` 平松雅巳 / HIRAMATU，MASAMI
2015-12-10 18:57     ` Arnaldo Carvalho de Melo
2015-12-14  8:15   ` [tip:perf/core] " tip-bot for Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 02/16] perf top: Fix and cleanup perf_top__record_precise_ip() Namhyung Kim
2015-12-10 19:04   ` Arnaldo Carvalho de Melo
2015-12-11  2:27     ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 03/16] perf top: Factor out warnings about kernel addresses and symbols Namhyung Kim
2015-12-10 19:07   ` Arnaldo Carvalho de Melo
2015-12-14  1:44     ` Namhyung Kim
2015-12-14  2:02       ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 04/16] perf top: Factor out warnings in perf_top__record_precise_ip() Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 05/16] perf top: Show warning messages in the display thread Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 06/16] perf top: Get rid of access to hists->lock in perf_top__record_precise_ip() Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 07/16] perf hists: Pass hists struct to hist_entry_iter struct Namhyung Kim
2015-12-13 23:15   ` Jiri Olsa
2015-12-14  1:45     ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 08/16] perf tools: Export a couple of hist functions Namhyung Kim
2015-12-13 23:17   ` Jiri Olsa
2015-12-10  7:53 ` [PATCH/RFC 09/16] perf tools: Update hist entry's hists pointer Namhyung Kim
2015-12-13 23:23   ` Jiri Olsa
2015-12-13 23:28     ` Jiri Olsa
2015-12-14  1:51       ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 10/16] perf hist: Add events_stats__add() and hists__add_stats() Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 11/16] perf top: Implement basic parallel processing Namhyung Kim
2015-12-14  9:23   ` Jiri Olsa
2015-12-14  9:35     ` Jiri Olsa
2015-12-15  2:08       ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 12/16] perf tools: Reduce lock contention when processing events Namhyung Kim
2015-12-14  8:43   ` Jiri Olsa
2015-12-15  2:03     ` Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 13/16] perf top: Protect the seen list using mutex Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 14/16] perf top: Separate struct perf_top_stats Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 15/16] perf top: Add --num-thread option Namhyung Kim
2015-12-10  7:53 ` [PATCH/RFC 16/16] perf tools: Skip dso front cache for multi-threaded lookup Namhyung Kim
2015-12-10  8:01 ` Ingo Molnar [this message]
2015-12-10  8:49   ` [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim
2015-12-11  8:11     ` Ingo Molnar
2015-12-11 15:01       ` David Ahern
2015-12-14  1:12         ` Namhyung Kim
2015-12-14  9:26         ` Peter Zijlstra
2015-12-14  9:38           ` Ingo Molnar
2015-12-14 14:55             ` David Ahern
2015-12-14 16:26               ` Arnaldo Carvalho de Melo
2015-12-14 16:41                 ` Peter Zijlstra
2015-12-14 17:52                   ` Arnaldo Carvalho de Melo
2015-12-14 16:38             ` Namhyung Kim
2015-12-14 16:56               ` Peter Zijlstra
2015-12-14 17:11                 ` Namhyung Kim
2015-12-14 14:46           ` David Ahern
2015-12-14 17:06             ` Namhyung Kim
2015-12-14 17:54               ` Arnaldo Carvalho de Melo
2015-12-14 16:25           ` Namhyung Kim
2015-12-14 16:44             ` Peter Zijlstra

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