From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752464Ab1KWP5M (ORCPT ); Wed, 23 Nov 2011 10:57:12 -0500 Received: from cantor2.suse.de ([195.135.220.15]:50771 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750987Ab1KWP5L (ORCPT ); Wed, 23 Nov 2011 10:57:11 -0500 Date: Wed, 23 Nov 2011 15:57:07 +0000 From: Mel Gorman To: Nai Xia Cc: Shaohua Li , Linux-MM , Andrea Arcangeli , Minchan Kim , Jan Kara , Andy Isaacson , Johannes Weiner , Rik van Riel , LKML Subject: Re: [PATCH 7/7] mm: compaction: Introduce sync-light migration for use by compaction Message-ID: <20111123155707.GP19415@suse.de> References: <1321900608-27687-1-git-send-email-mgorman@suse.de> <1321900608-27687-8-git-send-email-mgorman@suse.de> <1321945011.22361.335.camel@sli10-conroe> <20111123110041.GM19415@suse.de> <20111123134512.GN19415@suse.de> <20111123150810.GO19415@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 23, 2011 at 11:23:19PM +0800, Nai Xia wrote: > > > > This would be functionally equivalent and satisfy THP users > > but I do not see it as being easier to understand or easier > > to maintain than updating the API. If someone in the future > > wanted to use migration without significant stalls without > > being PF_MEMALLOC, they would need to update the API like this. > > There are no users like this today but automatic NUMA migration > > might want to leverage something like MIGRATE_SYNC_LIGHT > > (http://comments.gmane.org/gmane.linux.kernel.mm/70239) > > I see. > So could I say that might be the time and users for my suggestion of > page uptodate check to fit into? > Yes, at that point checking for PageUptodate may be necessary depending on their requirements. -- Mel Gorman SUSE Labs