Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759163AbZDIBD1 (ORCPT ); Wed, 8 Apr 2009 21:03:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755808AbZDIBDR (ORCPT ); Wed, 8 Apr 2009 21:03:17 -0400 Received: from mail.crca.org.au ([67.207.131.56]:37794 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752813AbZDIBDQ (ORCPT ); Wed, 8 Apr 2009 21:03:16 -0400 X-Greylist: delayed 417 seconds by postgrey-1.27 at vger.kernel.org; Wed, 08 Apr 2009 21:03:16 EDT X-Bogosity: Ham, spamicity=0.000000 Subject: Re: [PATCH/RFC] do not count frozen tasks toward load From: Nigel Cunningham Reply-To: ncunningham-lkml@crca.org.au To: Nathan Lynch Cc: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, linux-pm@lists.linux-foundation.org, Ingo Molnar , Andrew Morton , Matt Helsley In-Reply-To: <20090408194512.47a99b95@manatee.lan> References: <20090408194512.47a99b95@manatee.lan> Content-Type: text/plain Date: Thu, 09 Apr 2009 10:56:07 +1000 Message-Id: <1239238567.14883.2.camel@nigel-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1405 Lines: 35 Hi. On Wed, 2009-04-08 at 19:45 -0500, Nathan Lynch wrote: > Freezing tasks via the cgroup freezer causes the load average to climb > because the freezer's current implementation puts frozen tasks in > uninterruptible sleep (D state). > > Some applications which perform job-scheduling functions consult the > load average when making decisions. If a cgroup is frozen, the load > average does not provide a useful measure of the system's utilization > to such applications. This is especially inconvenient if the job > scheduler employs the cgroup freezer as a mechanism for preempting low > priority jobs. Contrast this with using SIGSTOP for the same purpose: > the stopped tasks do not count toward system load. > > Change task_contributes_to_load() to return false if the task is > frozen. This results in /proc/loadavg behavior that better meets > users' expectations. Sounds great to me - TuxOnIce has had code to save and restore the load average for ages because of the same issue. This is much better because it gets to the root of the problem. I'll apply it here, give it a test and hopefully give you an Acked-by shortly. Regards, Nigel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/