From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 30 Nov 2006 11:42:20 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC][PATCH 0/1] Node-based reclaim/migration In-Reply-To: <6599ad830611301109n8c4637ei338ecb4395c3702b@mail.gmail.com> Message-ID: References: <20061129030655.941148000@menage.corp.google.com> <20061130093105.d872c49d.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830611291631hd6d3e52y971c35708004db00@mail.gmail.com> <6599ad830611300245s5c0f40bdu4231832930e9c023@mail.gmail.com> <20061130201232.7d5f5578.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830611300325h3269a185x5794b0c585d985c0@mail.gmail.com> <6599ad830611301035u36a111dfye8c9414d257ebe07@mail.gmail.com> <6599ad830611301109n8c4637ei338ecb4395c3702b@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Menage Cc: KAMEZAWA Hiroyuki , linux-mm@kvack.org, akpm@osdl.org List-ID: On Thu, 30 Nov 2006, Paul Menage wrote: > On 11/30/06, Christoph Lameter wrote: > > > > F.e. A page cache page may have mapcount == 0. > > OK, I was thinking just about anon pages. > > For pagecache pages, it's safe to access the mapping as long as we've > locked the page, even if mapcount is 0? So we don't have the same > races? We have no problem with the page lock (you actually may not need any locking since there are no references remaining to the page). The trouble is that the vma may have vanished when we try to reestablish the pte. -- 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