From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id B4F176B01AC for ; Fri, 26 Mar 2010 09:49:52 -0400 (EDT) Date: Fri, 26 Mar 2010 13:49:30 +0000 From: Mel Gorman Subject: Re: [PATCH 02/11] mm,migration: Do not try to migrate unmapped anonymous pages Message-ID: <20100326134930.GA2024@csn.ul.ie> References: <20100325191229.8e3d2ba1.kamezawa.hiroyu@jp.fujitsu.com> <20100325133936.GR2024@csn.ul.ie> <20100326120429.6C98.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100326120429.6C98.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki , Minchan Kim , Andrew Morton , Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, Mar 26, 2010 at 12:07:02PM +0900, KOSAKI Motohiro wrote: > very small nit > > > There were minor changes in how the rcu_read_lock is taken and released > > based on other comments. With your suggestion, the block now looks like; > > > > if (PageAnon(page)) { > > rcu_read_lock(); > > rcu_locked = 1; > > > > /* > > * If the page has no mappings any more, just bail. An > > * unmapped anon page is likely to be freed soon but > > * worse, > > * it's possible its anon_vma disappeared between when > > * the page was isolated and when we reached here while > > * the RCU lock was not held > > */ > > if (!page_mapcount(page) && !PageSwapCache(page)) > > page_mapped? > Will be fixed in V6. Thanks > > goto rcu_unlock; > > > > anon_vma = page_anon_vma(page); > > atomic_inc(&anon_vma->external_refcount); > > } > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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