From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754558Ab0LAK2m (ORCPT ); Wed, 1 Dec 2010 05:28:42 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:35336 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754430Ab0LAK2k (ORCPT ); Wed, 1 Dec 2010 05:28:40 -0500 Date: Wed, 1 Dec 2010 11:28:28 +0100 From: Johannes Weiner To: Mel Gorman Cc: Andrea Arcangeli , KOSAKI Motohiro , Andrew Morton , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/7] mm: migration: Allow migration to operate asynchronously and avoid synchronous compaction in the faster path Message-ID: <20101201102828.GM15564@cmpxchg.org> References: <1290440635-30071-1-git-send-email-mel@csn.ul.ie> <1290440635-30071-5-git-send-email-mel@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1290440635-30071-5-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 22, 2010 at 03:43:52PM +0000, Mel Gorman wrote: > Migration synchronously waits for writeback if the initial passes fails. > Callers of memory compaction do not necessarily want this behaviour if the > caller is latency sensitive or expects that synchronous migration is not > going to have a significantly better success rate. > > This patch adds a sync parameter to migrate_pages() allowing the caller to > indicate if wait_on_page_writeback() is allowed within migration or not. For > reclaim/compaction, try_to_compact_pages() is first called asynchronously, > direct reclaim runs and then try_to_compact_pages() is called synchronously > as there is a greater expectation that it'll succeed. > > Signed-off-by: Mel Gorman Acked-by: Johannes Weiner