From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx189.postini.com [74.125.245.189]) by kanga.kvack.org (Postfix) with SMTP id E15FD6B0002 for ; Thu, 21 Mar 2013 04:19:04 -0400 (EDT) Date: Thu, 21 Mar 2013 09:19:02 +0100 From: Michal Hocko Subject: Re: [PATCH] mm: page_alloc: Avoid marking zones full prematurely after zone_reclaim() Message-ID: <20130321081902.GD6094@dhcp22.suse.cz> References: <20130320181957.GA1878@suse.de> <514A7163.5070700@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <514A7163.5070700@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: Mel Gorman , Andrew Morton , Hedi Berriche , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu 21-03-13 10:33:07, Simon Jeons wrote: > Hi Mel, > On 03/21/2013 02:19 AM, Mel Gorman wrote: > >The following problem was reported against a distribution kernel when > >zone_reclaim was enabled but the same problem applies to the mainline > >kernel. The reproduction case was as follows > > > >1. Run numactl -m +0 dd if=largefile of=/dev/null > > This allocates a large number of clean pages in node 0 > > I confuse why this need allocate a large number of clean pages? It reads from file and puts pages into the page cache. The pages are not modified so they are clean. Output file is /dev/null so no pages are written. dd doesn't call fadvise(POSIX_FADV_DONTNEED) on the input file by default so pages from the file stay in the page cache -- Michal Hocko SUSE Labs -- 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