From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 809566B003D for ; Sun, 13 Dec 2009 23:09:29 -0500 (EST) Message-ID: <4B25BA6E.5010002@redhat.com> Date: Sun, 13 Dec 2009 23:09:18 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH v2] vmscan: limit concurrent reclaimers in shrink_zone References: <20091211164651.036f5340@annuminas.surriel.com> <28c262360912131614h62d8e0f7qf6ea9ab882f446d4@mail.gmail.com> In-Reply-To: <28c262360912131614h62d8e0f7qf6ea9ab882f446d4@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: lwoodman@redhat.com, akpm@linux-foundation.org, KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On 12/13/2009 07:14 PM, Minchan Kim wrote: > On Sat, Dec 12, 2009 at 6:46 AM, Rik van Riel wrote: >> If too many processes are active doing page reclaim in one zone, >> simply go to sleep in shrink_zone(). > I am worried about one. > > Now, we can put too many processes reclaim_wait with NR_UNINTERRUBTIBLE state. > If OOM happens, OOM will kill many innocent processes since > uninterruptible task > can't handle kill signal until the processes free from reclaim_wait list. > > I think reclaim_wait list staying time might be long if VM pressure is heavy. > Is this a exaggeration? > > If it is serious problem, how about this? > > We add new PF_RECLAIM_BLOCK flag and don't pick the process > in select_bad_process. A simpler solution may be to use sleep_on_interruptible, and simply have the process continue into shrink_zone() if it gets a signal. -- All rights reversed. -- 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