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From: Namhyung Kim <>
To: David Ahern <>
Cc: "Arnaldo Carvalho de Melo" <>,
	"Adrian Hunter" <>,
	"Jiri Olsa" <>, "Ingo Molnar" <>,
	"Frédéric Weisbecker" <>,
	"Linux Kernel Mailing List" <>
Subject: Re: heads up/RFC: 'perf trace' using ordered_events
Date: Wed, 11 Mar 2015 09:33:57 +0900	[thread overview]
Message-ID: <20150311003357.GH943@sejong> (raw)
In-Reply-To: <>

Hi David,

On Tue, Mar 10, 2015 at 08:25:27AM -0600, David Ahern wrote:
> On 3/10/15 12:06 AM, Namhyung Kim wrote:
> >Hi Arnaldo,
> >
> >On Mon, Mar 09, 2015 at 10:21:35AM -0300, Arnaldo Carvalho de Melo wrote:
> >>For trace I need to take advantage of the fact that each mmap is ordered
> >>already and then just sort by the timestamp in the mmap head, etc.
> >>
> >>In retrospect, the file should have kept that ordering, i.e.
> >>have one file per mmap, that would be saved in parallel, without any of
> >>
> >>But I have to experiment with that, leaving the existing code around to
> >>deal with older files.
> >
> >It seems like what you said is almost same as my multi-thread work.
> >It saves data files per mmap and then merges them with an index
> >table so that they can be processed in parallel.
> I think you and Jiri both have worked on saving a file per mmap. Where does
> that stand? I would like to try it out.

It's available on perf/threaded-v3 branch in my tree.

You can see the description and numbers at

Also you can index your data file and then process with multi-thread:

  $ perf data index -i -o
  $ perf report --multi-thread -i


> With the 1024 cpu systems I am seeing 5GB files in 1 second runs and perf is
> not handling it well. The perf-script/perf-report (stdio) will 'hang' for 45
> minutes munging through the file. I have to connect gdb from time to time to
> verify it is making progress (file_offset is increasing). I believe what
> happens is that there is 'no round' -- it has to process all mmaps (1024
> cpus and 6 or 7 events) through the ordered events queue before it can push
> out results. I need to look at that once I figure out the task scheduler
> problem.
> David
> --
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      reply	other threads:[~2015-03-11  0:39 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-03 16:49 Arnaldo Carvalho de Melo
2015-03-04  1:01 ` Namhyung Kim
2015-03-04  1:07   ` Arnaldo Carvalho de Melo
2015-03-07 12:45     ` Adrian Hunter
2015-03-09 13:21       ` Arnaldo Carvalho de Melo
2015-03-10  6:06         ` Namhyung Kim
2015-03-10 14:25           ` David Ahern
2015-03-11  0:33             ` Namhyung Kim [this message]

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