Re: [GIT PULL 00/10] perf/core improvements and fixes

From: Paolo Bonzini
Date: Tue Jun 21 2016 - 06:18:35 EST




On 21/06/2016 05:11, Brendan Gregg wrote:
>>> > > - Add stackcollapse.py script to help generating flame graphs (Paolo Bonzini)
>> >
>> > I think this is already done by '-g folded'. Please see:
>> >
>> > http://www.brendangregg.com/blog/2016-04-30/linux-perf-folded.html
>> >
> Pretty much. Two similar solutions were developed around the same
> time. Although I have to use some awk to get "perf -g folded" in the
> exact right format, and stackcollapse-perf.py does that directly.

Yes, the idea for stackcollapse-perf.py was:

- to do everything directly and emit "the right" format for the
flamegraph tools. This however is a very minimal output, and it's not
necessarily the best for perf in general.

- to provide an example of visiting callgraphs from the scripting
interface, since it's not really documented. From the commit message:
"Add stackcollapse.py script as an example of parsing call chains, and
also of using optparse to access command line options".

Paolo