From: Eric B Munson <ebmunson@us.ibm.com>
To: Anton Blanchard <anton@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf: Fix performance issue with perf report
Date: Tue, 4 May 2010 12:56:40 +0100 [thread overview]
Message-ID: <20100504115640.GA6380@us.ibm.com> (raw)
In-Reply-To: <20100504111915.GB14636@kryten>
[-- Attachment #1: Type: text/plain, Size: 809 bytes --]
On Tue, 04 May 2010, Anton Blanchard wrote:
>
> On a large machine we spend a lot of time in perf_header__find_attr when
> running perf report.
>
> If we are parsing a file without PERF_SAMPLE_ID then for each sample we call
> perf_header__find_attr and loop through all counter IDs, never finding a match.
> As the machine gets larger there are more per cpu counters and we spend an
> awful lot of time in there.
>
> The patch below initialises each sample id to -1ULL and checks for this in
> perf_header__find_attr. We may need to do something more intelligent eventually
> (eg a hash lookup from counter id to attr) but this at least fixes the most
> common usage of perf report.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Eric B Munson <ebmunson@us.ibm.com>
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]
next prev parent reply other threads:[~2010-05-04 11:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-04 11:19 [PATCH] perf: Fix performance issue with perf report Anton Blanchard
2010-05-04 11:56 ` Eric B Munson [this message]
2010-05-04 17:04 ` [tip:perf/core] " tip-bot for Anton Blanchard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100504115640.GA6380@us.ibm.com \
--to=ebmunson@us.ibm.com \
--cc=a.p.zijlstra@chello.nl \
--cc=acme@redhat.com \
--cc=anton@samba.org \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox