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From: Ingo Molnar <mingo@elte.hu>
To: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Fix delay accounting regression
Date: Fri, 2 Nov 2007 16:53:58 +0100	[thread overview]
Message-ID: <20071102155358.GA32116@elte.hu> (raw)
In-Reply-To: <20071102142220.24166.49046.sendpatchset@balbir-laptop>


* Balbir Singh <balbir@linux.vnet.ibm.com> wrote:

> Fix the delay accounting regression introduced by commit 
> 75d4ef16a6aa84f708188bada182315f80aab6fa. rq no longer has sched_info 
> data associated with it. task_struct sched_info structure is used by 
> delay accounting to provide back statistics to user space.

no, this really is broken code. sched_clock() is not a generally 
reliable time source so at a minimum the rq->clock fix i mentioned is 
needed. What user-space tools are utilizing delay-accounting by the way? 
We have most of this data available under SCHEDSTATS - how about 
consolidating CONFIG_TASK_DELAY_ACCT into CONFIG_SCHEDSTATS?

	Ingo

  reply	other threads:[~2007-11-02 15:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-02 14:22 [PATCH] Fix delay accounting regression Balbir Singh
2007-11-02 15:53 ` Ingo Molnar [this message]
2007-11-02 16:05   ` Guillaume Chazarain
2007-11-02 16:35   ` Balbir Singh
2007-11-02 16:55   ` Balbir Singh
2007-11-03  8:33     ` Ingo Molnar

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