From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764081AbZDIFny (ORCPT ); Thu, 9 Apr 2009 01:43:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762873AbZDIFla (ORCPT ); Thu, 9 Apr 2009 01:41:30 -0400 Received: from hera.kernel.org ([140.211.167.34]:49676 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932374AbZDIFl2 (ORCPT ); Thu, 9 Apr 2009 01:41:28 -0400 Date: Thu, 9 Apr 2009 05:39:32 GMT From: Nathan Lynch To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, matthltc@us.ibm.com, nigel@tuxonice.net, akpm@linux-foundation.org, stable@kernel.org, tglx@linutronix.de, ntl@pobox.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, matthltc@us.ibm.com, nigel@tuxonice.net, akpm@linux-foundation.org, stable@kernel.org, tglx@linutronix.de, ntl@pobox.com, mingo@elte.hu In-Reply-To: <20090408194512.47a99b95@manatee.lan> References: <20090408194512.47a99b95@manatee.lan> Subject: [tip:sched/urgent] sched: do not count frozen tasks toward load Message-ID: Git-Commit-ID: e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Thu, 09 Apr 2009 05:39:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd Gitweb: http://git.kernel.org/tip/e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd Author: Nathan Lynch AuthorDate: Wed, 8 Apr 2009 19:45:12 -0500 Committer: Ingo Molnar CommitDate: Thu, 9 Apr 2009 07:37:02 +0200 sched: do not count frozen tasks toward load 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. Signed-off-by: Nathan Lynch Acked-by: Andrew Morton Acked-by: Nigel Cunningham Tested-by: Nigel Cunningham Cc: Cc: containers@lists.linux-foundation.org Cc: linux-pm@lists.linux-foundation.org Cc: Matt Helsley LKML-Reference: <20090408194512.47a99b95@manatee.lan> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 98e1fe5..b4c38bc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -205,7 +205,8 @@ extern unsigned long long time_sync_thresh; #define task_is_stopped_or_traced(task) \ ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) #define task_contributes_to_load(task) \ - ((task->state & TASK_UNINTERRUPTIBLE) != 0) + ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ + (task->flags & PF_FROZEN) == 0) #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0)