linux-kernel - Re: [PATCHSET 00/10] perf tools: Apply percent-limit to callchains (v2)

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Message-ID: <CAM9d7cgqPMJe9RAf89aLoGaZWzNsjioymqARZnB4h48dvvJZ1g@mail.gmail.com>
Date:	Thu, 28 Jan 2016 19:16:43 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Jiri Olsa <jolsa@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>,
	David Ahern <dsahern@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Wang Nan <wangnan0@...wei.com>
Subject: Re: [PATCHSET 00/10] perf tools: Apply percent-limit to callchains (v2)

On Thu, Jan 28, 2016 at 7:14 PM, Namhyung Kim <namhyung@...nel.org> wrote:
> On Thu, Jan 28, 2016 at 5:16 PM, Jiri Olsa <jolsa@...hat.com> wrote:
>> On Thu, Jan 28, 2016 at 12:40:47AM +0900, Namhyung Kim wrote:
>>> Hello,
>>>
>>> This patchset tries to implement percent limit to callchains which was
>>> requested by Andi Kleen.  For some reason, limiting callchains by
>>> (overhead) percentage didn't work well.  This patch fixes it and make
>>> --percent-limit also works for callchains as well as hist entries.
>>>
>>>  * Changes from v1)
>>>   - fix insertion path instead of changing all UI code
>>>   - show percent value even on single path (if needed)
>>>   - change default callchain percent limit
>>>
>>> This is available on 'perf/callchain-limit-v2' branch in my tree:
>>>
>>>   git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
>>>
>>> Any comments are welcome,
>>>
>>> Thanks,
>>> Namhyung
>>> *** BLURB HERE ***
>>>
>>> Namhyung Kim (10):
>>>   perf hists: Fix min callchain hits calculation
>>>   perf hists: Update hists' total period when adding entries
>>>   perf report: Apply --percent-limit to callchains also
>>>   perf report: Get rid of hist_entry__callchain_fprintf()
>>>   perf tools: Pass parent_samples to __callchain__fprintf_graph()
>>>   perf report: Fix percent display in callchains on --stdio
>>>   perf hists browser: Fix dump to show correct callchain style
>>>   perf hists browser: Pass parent_total to callchain print functions
>>>   perf hists browser: Fix percent display in callchains
>>>   perf tools: Change default calchain percent limit to 0.005%
>>
>> also I see extra fo entries with callchain filtered out in stdio mode
>>
>> jirka
>>
>>
>> ---
>>      8.41%  yes      libc-2.21.so      [.] fputs_unlocked
>>             |
>>             ---fputs_unlocked
>>                |
>>                |--5.67%--0x757074756f206472
>>                |
>>                 --2.74%--0x3ba8e0
>>                           0x21e000
>>
>>      2.47%  yes      yes               [.] fputs_unlocked@plt
>>             |
>>             ---fputs_unlocked@plt
>>                0x3ba8e0
>>                0x21e000
>>
>>      0.12%  yes      [kernel.vmlinux]  [k] vfs_write
>>
>>      0.09%  yes      libc-2.21.so      [.] _IO_do_write@@GLIBC_2.2.5
>>
>>      0.08%  yes      [kernel.vmlinux]  [k] entry_SYSCALL_64
>>
>>      0.07%  yes      [kernel.vmlinux]  [k] fsnotify
>>
>>      0.06%  yes      [kernel.vmlinux]  [k] sys_write
>>
>
> I guess it's same for other UI outputs too.
>
> The default limit of hist entries is 0 so it basically shows all
> entries.  But default callchain limit is 0.5% so hist entries under
> 0.5% won't show callchains.

Btw, I changed it to 0.005% in this patchset.  Did you apply all the
patches and run 'perf report' with default value?

Thanks,
Namhyung