Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161129AbVKDKFH (ORCPT ); Fri, 4 Nov 2005 05:05:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161130AbVKDKFG (ORCPT ); Fri, 4 Nov 2005 05:05:06 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:14515 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S1161129AbVKDKFF (ORCPT ); Fri, 4 Nov 2005 05:05:05 -0500 Date: Fri, 4 Nov 2005 02:04:29 -0800 From: Paul Jackson To: Arjan van de Ven Cc: akpm@osdl.org, mingo@elte.hu, pbadari@gmail.com, torvalds@osdl.org, jdike@addtoit.com, rob@landley.net, nickpiggin@yahoo.com.au, gh@us.ibm.com, kamezawa.hiroyu@jp.fujitsu.com, haveblue@us.ibm.com, mel@csn.ul.ie, mbligh@mbligh.org, kravetz@us.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, lhms-devel@lists.sourceforge.net Subject: Re: [patch] swapin rlimit Message-Id: <20051104020429.104c27b3.pj@sgi.com> In-Reply-To: <1131092322.2799.3.camel@laptopd505.fenrus.org> References: <200511021747.45599.rob@landley.net> <43699573.4070301@yahoo.com.au> <200511030007.34285.rob@landley.net> <20051103163555.GA4174@ccure.user-mode-linux.org> <1131035000.24503.135.camel@localhost.localdomain> <20051103205202.4417acf4.akpm@osdl.org> <20051104072628.GA20108@elte.hu> <20051103233628.12ed1eee.akpm@osdl.org> <1131092322.2799.3.camel@laptopd505.fenrus.org> Organization: SGI X-Mailer: Sylpheed version 2.0.0beta5 (GTK+ 2.4.9; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1018 Lines: 21 Arjan wrote: > doing this from userspace is tricky; what if the task dies of natural > causes and the pid gets reused, between the time the userspace app reads > the value and the time it decides the time is up and time for a kill.... > (and on a busy server that can be quite a bit of time) If pids are being reused within seconds of their being freed up, then the batch managers running on the big HPC systems I care about are so screwed it isn't even funny. They depend heavily on being able to identify the task pids in a job and then doing something to those tasks (suspend, kill, gather stats, ...). -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401 - 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/