linux-kernel - Re: [PATCH v6 01/25] perf hists browser: Fix percentage update on key press

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Date:	Wed, 17 Feb 2016 08:39:08 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
CC:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Jiri Olsa <jolsa@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	David Ahern <dsahern@...il.com>,
	Andi Kleen <andi@...stfloor.org>,
	Stephane Eranian <eranian@...gle.com>,
	Wang Nan <wangnan0@...wei.com>
Subject: Re: [PATCH v6 01/25] perf hists browser: Fix percentage update on
 key press

Hi Arnaldo,

On Tue, Feb 16, 2016 at 05:53:23PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Feb 16, 2016 at 05:06:08PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Tue, Feb 16, 2016 at 11:08:19PM +0900, Namhyung Kim escreveu:
> > > Currently 'perf top --tui' decrements percentage of all entries on any
> > > key press.  This is because it adds total period as new samples are
> > > added to hists.  As perf-top does it currently but added samples are not
> > > passed to the display thread, the percentages are decresing
> > > continuously.
> > > 
> > > So separate total period stat into a different variable so that it
> > > cannot affect the output total period.  This new total period stats are
> > > used only for calcualating callchain percent limit.
> > 
> > I'm trying to figure this out now, but please next time add a line like
> > 
> > Fixes: aabbccddeeff ("perf tools: buggy commit description")
> > 
> > This helps reviewing as well as to figure out if this needs to go to
> > stable@...nel.org, etc.

OK.

> 
> So this is the one:
> 
> [acme@...andy linux]$ git bisect good
> 0f58474ec835f6fc80af2cde2c7ed5495cd212ba is the first bad commit
> commit 0f58474ec835f6fc80af2cde2c7ed5495cd212ba
> Author: Namhyung Kim <namhyung@...nel.org>
> Date:   Thu Jan 28 00:40:49 2016 +0900
> 
>     perf hists: Update hists' total period when adding entries
>     
>     Currently the hist entry addition path doesn't update total_period of
>     hists and it's calculated during 'resort' path.  But the resort path
>     needs to know the total period before doing its job because it's used
>     for calculating percent limit of callchains in hist entries.
>     
>     So this patch update the total period during the addition path.  It
>     makes the percent limit of callchains working (again).
>     
>     Signed-off-by: Namhyung Kim <namhyung@...nel.org>
>     Cc: Andi Kleen <andi@...stfloor.org>
>     Cc: David Ahern <dsahern@...il.com>
>     Cc: Frederic Weisbecker <fweisbec@...il.com>
>     Cc: Jiri Olsa <jolsa@...nel.org>
>     Cc: Peter Zijlstra <peterz@...radead.org>
>     Cc: Wang Nan <wangnan0@...wei.com>
>     Link: http://lkml.kernel.org/r/1453909257-26015-3-git-send-email-namhyung@kernel.org
>     Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> 
> :040000 040000 ff6b15566490dbc26fdd70af5c7ab09451d9bfcd a27ec8e9f21172b1fa3617498976d04a2fcc2449 M	tools
> [acme@...andy linux]$
> 
> So we this in this cset:
> 
> Fixes: 0f58474ec835 ("perf hists: Update hists' total period when adding entries")
> 
> And it needs to go to stable@...nel.org # v4.4+
> 
> [acme@...andy linux]$ git describe 0f58474ec835f6fc80af2cde2c7ed5495cd212ba
> v4.4-5893-g0f58474ec835
> 
> Please double check this, I'll be OOO in a moment.

I think it's not needed to CC the stable this time.  AFAIK this patch
didn't go to the mainline yet.  It's only in the tip tree.

I think you need to use git name-rev instead of git describe.

  $ git name-rev --tags 0f58474ec835f6fc80af2cde2c7ed5495cd212ba
  0f58474ec835f6fc80af2cde2c7ed5495cd212ba undefined

  $ git branch -r --contains 0f58474ec835f6fc80af2cde2c7ed5495cd212ba
  acme/perf/core

  $ git tag --contains 0f58474ec835f6fc80af2cde2c7ed5495cd212ba
  (nothing)

  $ git remote -v
  acme	  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git  (fetch)
  acme 	  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git  (push)
  origin  git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  (fetch)
  origin  git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  (push)
  ...


Thanks,
Namhyung