From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 30 Nov 2006 12:00:40 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC][PATCH 0/1] Node-based reclaim/migration In-Reply-To: <6599ad830611301153i231765a0ke46846bcb73258d6@mail.gmail.com> Message-ID: References: <20061129030655.941148000@menage.corp.google.com> <6599ad830611300245s5c0f40bdu4231832930e9c023@mail.gmail.com> <20061130201232.7d5f5578.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830611300325h3269a185x5794b0c585d985c0@mail.gmail.com> <6599ad830611301035u36a111dfye8c9414d257ebe07@mail.gmail.com> <6599ad830611301109n8c4637ei338ecb4395c3702b@mail.gmail.com> <6599ad830611301153i231765a0ke46846bcb73258d6@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: > > > > 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. > > > > Why is that a problem? If the vma has gone away, then there's no need > to reestablish the pte. And remove_file_migration_ptes() appears to be > adequately protected against races with unlink_file_vma() since they > both take i_mmap_sem. We are talking about anonymous pages here. You cannot figure out that the vma is gone since that was the only connection to the process. Hmm... Not true we still have a migration pte in that processes space. But we cannot find the process without the anon_vma. -- 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