Re: [PATCH 0/3] perf script: Add script per-event-dump support

From: Milian Wolff
Date: Wed Sep 13 2017 - 14:51:19 EST


On Mittwoch, 13. September 2017 17:10:30 CEST yuzhoujian wrote:
> Introduce a new option to print trace output to files named by the
> monitored events and update perf-script documentation accordingly.
>
> Shown below is output of perf script command with the newly introduced
> option.
>
> $perf record -e cycles -e context-switches -ag -- sleep 10
> $perf script --per-event-dump
> $ls /
> cycles.stacks context-switches.stacks
>
> Without per-event-dump support, drawing flamegraphs for different events
> is really hard. You can only monitor one event at a time for perf record.
> Using this option, we can get the trace output files named by the monitored
> events, and could draw flamegraphs according to the event's name.

Not going to argue for or against this patch, but I think the reasoning you
give in your commit message is outdated:

https://github.com/brendangregg/FlameGraph/commit/
4b7b3169ed303d33fb710e1b9de235b84cc119d3

I.e. with a recent FlameGraph, you can generate flame graphs for different
events just fine, without any intermediate step.

Cheers

--
Milian Wolff | milian.wolff@xxxxxxxx | Senior Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts