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

From: Arnaldo Carvalho de Melo
Date: Tue Nov 03 2015 - 09:41:31 EST


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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/