linux-kernel - Re: [tip:perf/urgent] perf/x86/cqm: Fix CQM handling of grouping events into a cache

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Message-ID: <20160321145741.GC11676@codeblueprint.co.uk>
Date:	Mon, 21 Mar 2016 14:57:41 +0000
From:	Matt Fleming <matt@...eblueprint.co.uk>
To:	hpa@...or.com, eranian@...gle.com, linux-kernel@...r.kernel.org,
	tony.luck@...el.com, brgerst@...il.com, peterz@...radead.org,
	bp@...en8.de, tglx@...utronix.de, vikas.shivappa@...ux.intel.com,
	dsahern@...il.com, dvlasenk@...hat.com, jolsa@...hat.com,
	luto@...capital.net, mingo@...nel.org, acme@...hat.com,
	torvalds@...ux-foundation.org, namhyung@...nel.org,
	vincent.weaver@...ne.edu, alexander.shishkin@...ux.intel.com
Cc:	linux-tip-commits@...r.kernel.org
Subject: Re: [tip:perf/urgent] perf/x86/cqm: Fix CQM handling of grouping
 events into a cache_group

On Mon, 21 Mar, at 02:51:29AM, tip-bot for Vikas Shivappa wrote:
> Commit-ID:  a223c1c7ab4cc64537dc4b911f760d851683768a
> Gitweb:     http://git.kernel.org/tip/a223c1c7ab4cc64537dc4b911f760d851683768a
> Author:     Vikas Shivappa <vikas.shivappa@...ux.intel.com>
> AuthorDate: Thu, 10 Mar 2016 15:32:07 -0800
> Committer:  Ingo Molnar <mingo@...nel.org>
> CommitDate: Mon, 21 Mar 2016 09:08:18 +0100
> 
> perf/x86/cqm: Fix CQM handling of grouping events into a cache_group
> 
> Currently CQM (cache quality of service monitoring) is grouping all
> events belonging to same PID to use one RMID. However its not counting
> all of these different events. Hence we end up with a count of zero
> for all events other than the group leader.
 
The reason that was done originally was because reporting for all events
in a group led to duplicate values, since you'd be emitting the same
RMID value multiple times.

Is this no longer a problem?