Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752652AbZDWIH5 (ORCPT ); Thu, 23 Apr 2009 04:07:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760646AbZDWIA3 (ORCPT ); Thu, 23 Apr 2009 04:00:29 -0400 Received: from sous-sol.org ([216.99.217.87]:44428 "EHLO x200.localdomain" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760655AbZDWIA2 (ORCPT ); Thu, 23 Apr 2009 04:00:28 -0400 Message-Id: <20090423072725.432395010@sous-sol.org> User-Agent: quilt/0.47-1 Date: Thu, 23 Apr 2009 00:21:21 -0700 From: Chris Wright To: linux-kernel@vger.kernel.org, stable@kernel.org, jejb@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Nathan Lynch , Nigel Cunningham , containers@lists.linux-foundation.org, linux-pm@lists.linux-foundation.org, Matt Helsley , Ingo Molnar Subject: [patch 061/100] sched: do not count frozen tasks toward load References: <20090423072020.428683652@sous-sol.org> Content-Disposition: inline; filename=sched-do-not-count-frozen-tasks-toward-load.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2301 Lines: 56 -stable review patch. If anyone has any objections, please let us know. --------------------- From: Nathan Lynch upstream commit: e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd 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 Signed-off-by: Chris Wright --- include/linux/sched.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -202,7 +202,8 @@ extern unsigned long long time_sync_thre #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) -- 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/