Re: [PATCHSET 0/4] perf report: Support folded callchain output (v4)

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Nov 03, 2015 at 09:52:07PM +0900, Namhyung Kim escreveu:
> Hello,
> 
> This is what Brendan requested on the perf-users mailing list [1] to
> support FlameGraphs [2] more efficiently.  This patchset adds a few
> more callchain options to adjust the output for it.
> 
>  * changes in v4)
>   - add missing doc update
>   - cleanup/fix callchain value print code
>   - add Acked-by from Brendan and Jiri

Do those Acked-by stand? Things changed, the values moved from the end
of the line to the start, etc.

You said you would consider having a --no-hists, but I see nothing about
it in this patchkit.

Some more comments below.

- Arnaldo

>  * changes in v3)
>   - put the value before callchains
>   - fix compile error
> 
> 
> At first, 'folded' output mode was added.  The folded output puts the
> value, a space and all calchain nodes separated by semicolons.  Now it
> only supports --stdio as other UI provides some way of folding and/or
> expanding callchains dynamically.
> 
> The value is now can be one of 'percent', 'period', or 'count'.  The
> percent is current default output and the period is the raw number of
> sample periods.  The count is the number of samples for each callchain.
> 
> Here's an example:
> 
>   $ perf report --no-children --show-nr-samples --stdio -g folded,count
>   ...
>     39.93%     80  swapper  [kernel.vmlinux]  [k] intel_idel
>   57 intel_idle;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary
>   23 intel_idle;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;rest_init;...
> 
> 
>   $ perf report --no-children --stdio -g percent

So, in this first one you show the percent in both

>   ...
>     39.93%  swapper  [kernel.vmlinux]  [k] intel_idel
>             |
>             ---intel_idle
>                cpuidle_enter_state
>                cpuidle_enter
>                call_cpuidle
>                cpu_startup_entry
>                |
>                |--28.63%-- start_secondary
>                |
>                 --11.30%-- rest_init
> 
> 
>   $ perf report --no-children --stdio --show-total-period -g period
>   ...

then here you _add_ the period to the hist_entry line, but...

>     39.93%   13018705  swapper  [kernel.vmlinux]  [k] intel_idel
>             |
>             ---intel_idle
>                cpuidle_enter_state
>                cpuidle_enter
>                call_cpuidle
>                cpu_startup_entry
>                |

_replace_ the percentage with the period in the callchains.

Can't we have the same effect in both? I.e. I would expect the 39.93% to
simply be replaced with that 13018705.

>                |--9334403-- start_secondary
>                |
>                 --3684302-- rest_init
> 
> 
>   $ perf report --no-children --stdio --show-nr-samples -g count
>   ...
>     39.93%     80  swapper  [kernel.vmlinux]  [k] intel_idel

Ditto for count

>             |
>             ---intel_idle
>                cpuidle_enter_state
>                cpuidle_enter
>                call_cpuidle
>                cpu_startup_entry
>                |
>                |--57-- start_secondary
>                |
>                 --23-- rest_init
> 
> 
> You can get it from 'perf/callchain-fold-v4' branch on my tree:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
> 
> Any comments are welcome, thanks
> Namhyung
> 
> 
> [1] http://www.spinics.net/lists/linux-perf-users/msg02498.html
> [2] http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html
> 
> 
> Namhyung Kim (4):
>   perf report: Support folded callchain mode on --stdio
>   perf callchain: Abstract callchain print function
>   perf callchain: Add count fields to struct callchain_node
>   perf report: Add callchain value option
> 
>  tools/perf/Documentation/perf-report.txt | 13 +++--
>  tools/perf/builtin-report.c              |  4 +-
>  tools/perf/ui/browsers/hists.c           |  8 +--
>  tools/perf/ui/gtk/hists.c                |  8 +--
>  tools/perf/ui/stdio/hist.c               | 93 ++++++++++++++++++++++++++------
>  tools/perf/util/callchain.c              | 87 +++++++++++++++++++++++++++++-
>  tools/perf/util/callchain.h              | 24 ++++++++-
>  tools/perf/util/util.c                   |  3 +-
>  8 files changed, 205 insertions(+), 35 deletions(-)
> 
> -- 
> 2.6.2