Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753541Ab1C1Mkv (ORCPT ); Mon, 28 Mar 2011 08:40:51 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:52799 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119Ab1C1Mku (ORCPT ); Mon, 28 Mar 2011 08:40:50 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=j4AIaN31xxYWHN/vuml+wQVDUT+76oKCGcd+FpvbwW8qUmi+1VUVCVgu8db9narcvu QSE7btGDNwe2PPZK3P2A5X498nOah8OReWiUm0LaErgdoD86wB/6rZyQ0qP4ZzSLN+bg kvO/FYaEDDWuBy8XRzTB7ChufYjprCdAIijXQ= Date: Mon, 28 Mar 2011 21:40:25 +0900 From: Minchan Kim To: Peter Zijlstra Cc: KOSAKI Motohiro , linux-kernel@vger.kernel.org, Andrew Morton , David Rientjes , Linus Torvalds , Rik van Riel , Oleg Nesterov , linux-mm , Andrey Vagin , Hugh Dickins , KAMEZAWA Hiroyuki , "Luis Claudio R. Goncalves" Subject: Re: [PATCH 2/5] Revert "oom: give the dying task a higher priority" Message-ID: <20110328124025.GC1892@barrios-desktop> References: <20110315153801.3526.A69D9226@jp.fujitsu.com> <20110322194721.B05E.A69D9226@jp.fujitsu.com> <20110322200657.B064.A69D9226@jp.fujitsu.com> <20110324152757.GC1938@barrios-desktop> <1301305896.4859.8.camel@twins> <20110328122125.GA1892@barrios-desktop> <1301315307.4859.13.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1301315307.4859.13.camel@twins> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1992 Lines: 46 On Mon, Mar 28, 2011 at 02:28:27PM +0200, Peter Zijlstra wrote: > On Mon, 2011-03-28 at 21:21 +0900, Minchan Kim wrote: > > Hi Peter, > > > > On Mon, Mar 28, 2011 at 11:51:36AM +0200, Peter Zijlstra wrote: > > > On Fri, 2011-03-25 at 00:27 +0900, Minchan Kim wrote: > > > > > > > > At that time, I thought that routine is meaningless in non-RT scheduler. > > > > So I Cced Peter but don't get the answer. > > > > I just want to confirm it. > > > > > > Probably lost somewhere in the mess that is my inbox :/, what is the > > > full question? > > > > The question is we had a routine which change rt.time_slice with HZ to > > accelarate task exit. But when we applied 93b43fa5508, we found it isn't effective > > any more about normal task. So we removed it. Is it right? > > rt.time_slice is only relevant to SCHED_RR, since you seem to use > SCHED_FIFO (which runs for as long as the task is runnable), its > completely irrelevant. > > > And Kosaki is about to revert 93b43fa5508 to find out the problem of this thread > > and Luis said he has a another solution to replace 93b43fa5508. > > If rt.time_slice handleing is effective, we should restore it until Luis's patch > > will be merged. > > Right, so only SCHED_RR is affected by time_slice, it will be > decremented on tick (so anything that avoids ticks will also avoid the > decrement) and once it reaches 0 the task will be queued at the tail of > its static priority and reset the slice. If there is no other task on > that same priority we'll again schedule that task. > > In short, don't use SCHED_RR and don't worry about time_slice. There was meaningless code in there. I guess it was in there from CFS. Thanks for the explanation, Peter. -- Kind regards, Minchan Kim -- 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/