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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1613196.WrfoOBG8ky@agathebauer>
Date:   Wed, 13 Sep 2017 20:51:10 +0200
From:   Milian Wolff <milian.wolff@...b.com>
To:     yuzhoujian <ufo19890607@...il.com>
Cc:     peterz@...radead.org, mingo@...hat.com,
        alexander.shishkin@...ux.intel.com, jolsa@...nel.org,
        dsahern@...il.com, namhyung@...nel.org, yuzhoujian@...ichuxing.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/3] perf script: Add script per-event-dump support

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give in your commit message is outdated: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@...b.com | Senior Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts