From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 16F046B01AC for ; Wed, 2 Jun 2010 17:02:35 -0400 (EDT) Received: from wpaz29.hot.corp.google.com (wpaz29.hot.corp.google.com [172.24.198.93]) by smtp-out.google.com with ESMTP id o52L2VAF030399 for ; Wed, 2 Jun 2010 14:02:32 -0700 Received: from pvg16 (pvg16.prod.google.com [10.241.210.144]) by wpaz29.hot.corp.google.com with ESMTP id o52L2UrL018010 for ; Wed, 2 Jun 2010 14:02:30 -0700 Received: by pvg16 with SMTP id 16so475070pvg.5 for ; Wed, 02 Jun 2010 14:02:29 -0700 (PDT) Date: Wed, 2 Jun 2010 14:02:25 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH] oom: remove PF_EXITING check completely In-Reply-To: <20100602155455.GB9622@redhat.com> Message-ID: References: <20100601093951.2430.A69D9226@jp.fujitsu.com> <20100601201843.GA20732@redhat.com> <20100602200732.F518.A69D9226@jp.fujitsu.com> <20100602155455.GB9622@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Oleg Nesterov Cc: KOSAKI Motohiro , LKML , linux-mm , Andrew Morton , KAMEZAWA Hiroyuki , Nick Piggin List-ID: On Wed, 2 Jun 2010, Oleg Nesterov wrote: > > Today, I've thought to make some bandaid patches for this issue. but > > yes, I've reached the same conclusion. > > > > If we think multithread and core dump situation, all fixes are just > > bandaid. We can't remove deadlock chance completely. > > > > The deadlock is certenaly worst result, then, minor PF_EXITING optimization > > doesn't have so much worth. > > Agreed! I was always wondering if it really helps in practice. > Nack, this certainly does help in practice, it prevents needlessly killing additional tasks when one is exiting and may free memory. It's much better to defer killing something temporarily if an eligible task (i.e. one that has a high probability of memory allocations on current's nodes or contributing to its memcg) is exiting. We depend on this check specifically for our use of cpusets, so please don't remove it. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org