Re: [PATCH v3 0/3] perf: add option to limit callchain stack scanto increase speed
From: Waiman Long
Date: Tue Oct 22 2013 - 15:12:43 EST
On 10/22/2013 02:07 PM, Namhyung Kim wrote:
Hi Waiman,
On Mon, 21 Oct 2013 11:03:36 -0400, Waiman Long wrote:
v2->v3:
- Fix the commit log in the second patch which causes "git am" to fail.
- Remove the 1st patch in v2 as the problem will be fixed by another
patch from Arnaldo.
v1->v2:
- Include a compilation fix patch and a code streamlining patch
into the patch set.
- Use the __stringify() macro in stringify.h instead of adding a
duplicate macro.
- Add the --max-stack option to perf-top as well.
This perf patch set contains the following changes:
Patch 1 - Streamline the append_chain() function to make it run a bit
faster.
Patch 2 - Add a --max-stack option to perf-report to speed up its
processing at the expense of less backtrace information
available.
Patch 3 - Add a similar --max-stack option to perf-top.
At first, thank you for tackling this. It was really a problem using
callchain on non trivial perf session. But there's another effort to
address this problem in other direction. You might want to see below
link [1]. Patch 1/8 does the thing and it seems Arnaldo already merged
it into his tree.
Thank for letting me aware of your patch to address the perf-report
problem. As I am working on resolving scalability problem in large NUMA
machines, I often encounters large perf.data files that took more than
1/2 hour for perf-report to produce anything. It is kind of frustrating
to wait so long. I like the performance improvement in your patch 1/8,
coupled with the max-stack option, it can really speed thing up.
-Longman
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