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Date:	Tue, 25 Sep 2012 13:57:26 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Arun Sharma <asharma@...com>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	David Ahern <dsahern@...il.com>, Jiri Olsa <jolsa@...hat.com>
Subject: Re: [RFC/PATCHSET 00/15] perf report: Add support to accumulate hist periods

Ping.  Any comments for this?

Arun, thanks for testing!
Namhyung


On Thu, 13 Sep 2012 16:19:56 +0900, Namhyung Kim wrote:
> Hi,
>
> This is my first attempt to implement cumulative hist period report.
> This work begins from Arun's SORT_INCLUSIVE patch [1] but I completely
> rewrote it from scratch.
>
> It basically adds period in a sample to every node in the callchain.
> A hist_entry now has an additional fields to keep the cumulative
> period if --cumulate option is given on perf report.
>
> Let me show you an example:
>
>   $ cat abc.c
>   #define barrier() asm volatile("" ::: "memory")
>   
>   void a(void)
>   {
>   	int i;
>   
>   	for (i = 0; i < 1000000; i++)
>   		barrier();
>   }
>   
>   void b(void)
>   {
>   	a();
>   }
>   
>   void c(void)
>   {
>   	b();
>   }
>   
>   int main(void)
>   {
>   	c();
>   
>   	return 0;
>   }
>   
> With this simple program I ran perf record and report:
>
>   $ perf record -g -e cycles:u ./abc
>   $ perf report -g none --stdio
>   [snip]
>   # Overhead  Command       Shared Object                      Symbol
>   # ........  .......  ..................  ..........................
>   #
>       93.35%      abc  abc                 [.] a                     
>        5.17%      abc  ld-2.15.so          [.] _dl_map_object_from_fd
>        1.13%      abc  ld-2.15.so          [.] _dl_start             
>        0.29%      abc  libpthread-2.15.so  [.] __libc_close          
>        0.07%      abc  [kernel.kallsyms]   [k] page_fault            
>        0.00%      abc  ld-2.15.so          [.] _start                
>   
> When --cumulate option is given, it'll be shown like this:
>
>    $ perf report --cumulate
>    (...)
>    +  93.63%  abc  libc-2.15.so        [.] __libc_start_main
>    +  93.35%  abc  abc                 [.] main
>    +  93.35%  abc  abc                 [.] c
>    +  93.35%  abc  abc                 [.] b
>    +  93.35%  abc  abc                 [.] a
>    +   5.17%  abc  ld-2.15.so          [.] _dl_map_object
>    +   5.17%  abc  ld-2.15.so          [.] _dl_map_object_from_fd
>    +   1.13%  abc  ld-2.15.so          [.] _dl_start_user
>    +   1.13%  abc  ld-2.15.so          [.] _dl_start
>    +   0.29%  abc  perf                [.] main
>    +   0.29%  abc  perf                [.] run_builtin
>    +   0.29%  abc  perf                [.] cmd_record
>    +   0.29%  abc  libpthread-2.15.so  [.] __libc_close
>    +   0.07%  abc  ld-2.15.so          [.] _start
>    +   0.07%  abc  [kernel.kallsyms]   [k] page_fault
>    
> (This output came from TUI since stdio bothered by callchains)
>
> As you can see __libc_start_main -> main -> c -> b -> a callchain show
> up in the output.
>
> It might have some rough edges or even bugs, but I really want to
> release it and get reviews.  In fact I saw some very large percentage
> or 'inf' on some callchain nodes when expanding.
>
> It currently ignores samples don't have symbol info when accumulating
> periods along the callchain.  Otherwise it resulted in very strangely
> large output since every node in the callchain would be added into a
> single entry which has NULL dso/sym.  Simply ignoring them solved the
> problem and I couldn't come up with a better solution.
>
> This patchset is based on current acme/perf/core + my small fixes [2],[3].
> You can also get this series on my tree at:
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git  perf/cumulate-v1
>
> Any comments are welcome, thanks.
> Namhyung
>
> [1] https://lkml.org/lkml/2012/3/31/6
> [2] https://lkml.org/lkml/2012/9/11/546
> [3] https://lkml.org/lkml/2012/9/12/51
>
>
> Namhyung Kim (15):
>   perf hists: Add missing period_* fields when collapsing a hist entry
>   perf hists: Introduce struct he_stat
>   perf hists: Move he->stat.nr_events initialization to a template
>   perf hists: Convert hist entry functions to use struct he_stat
>   perf hists: Add more helpers for hist entry stat
>   perf hists: Add support for accumulated stat of hist entry
>   perf hists: Check if accumulated when adding a hist entry
>   perf callchain: Add a couple of callchain helpers
>   perf hists: Let add_hist_entry to make a hist entry template
>   perf hists: Accumulate hist entry stat based on the callchain
>   perf hists: Sort hist entries by accumulated period
>   perf ui/hist: Add support to accumulated hist stat
>   perf ui/browser: Add support to accumulated hist stat
>   perf ui/gtk: Add support to accumulated hist stat
>   perf report: Add --cumulate option
>
>  tools/perf/builtin-report.c    |   8 ++
>  tools/perf/ui/browsers/hists.c |  12 +-
>  tools/perf/ui/gtk/browser.c    |   5 +-
>  tools/perf/ui/hist.c           |  74 ++++++++++---
>  tools/perf/ui/stdio/hist.c     |   2 +-
>  tools/perf/util/callchain.c    |  15 +++
>  tools/perf/util/callchain.h    |  17 +++
>  tools/perf/util/hist.c         | 242 +++++++++++++++++++++++++++++++++--------
>  tools/perf/util/sort.h         |  17 ++-
>  tools/perf/util/symbol.h       |   1 +
>  10 files changed, 318 insertions(+), 75 deletions(-)
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