Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759329Ab0FQB4T (ORCPT ); Wed, 16 Jun 2010 21:56:19 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:34278 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756742Ab0FQBvj (ORCPT ); Wed, 16 Jun 2010 21:51:39 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: "Luis Claudio R. Goncalves" Subject: Re: [PATCH 9/9] oom: give the dying task a higher priority Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , LKML , linux-mm , Andrew Morton , David Rientjes , KAMEZAWA Hiroyuki , Oleg Nesterov In-Reply-To: <20100616195447.GH5009@uudg.org> References: <20100616153120.GH9278@barrios-desktop> <20100616195447.GH5009@uudg.org> Message-Id: <20100617084943.FB45.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Thu, 17 Jun 2010 10:51:35 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1502 Lines: 41 > On Thu, Jun 17, 2010 at 12:31:20AM +0900, Minchan Kim wrote: > | > /* > | > * We give our sacrificial lamb high priority and access to > | > * all the memory it needs. That way it should be able to > | > * exit() and clear out its resources quickly... > | > */ > | > p->rt.time_slice = HZ; > | > set_tsk_thread_flag(p, TIF_MEMDIE); > ... > | > + if (rt_task(p)) { > | > + p->rt.time_slice = HZ; > | > + return; > > I am not sure the code above will have any real effect for an RT task. > Kosaki-san, was this change motivated by test results or was it just a code > cleanup? I ask that out of curiosity. just cleanup. ok, I remove this dubious code. > > | I have a question from long time ago. > | If we change rt.time_slice _without_ setscheduler, is it effective? > | I mean scheduler pick up the task faster than other normal task? > > $ git log --pretty=oneline -Stime_slice mm/oom_kill.c > 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2 > > This code ("time_slice = HZ;") is around for quite a while and > probably comes from a time where having a big time slice was enough to be > sure you would be the next on the line. I would say sched_setscheduler is > indeed necessary. ok -- 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/