From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 2945A6B004A for ; Thu, 9 Sep 2010 10:32:58 -0400 (EDT) Date: Thu, 9 Sep 2010 09:32:52 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails In-Reply-To: <20100909135523.GA340@csn.ul.ie> Message-ID: References: <1283504926-2120-1-git-send-email-mel@csn.ul.ie> <1283504926-2120-4-git-send-email-mel@csn.ul.ie> <20100908163956.C930.A69D9226@jp.fujitsu.com> <20100909124138.GQ29263@csn.ul.ie> <20100909135523.GA340@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: KOSAKI Motohiro , Andrew Morton , Linux Kernel List , linux-mm@kvack.org, Rik van Riel , Johannes Weiner , Minchan Kim , KAMEZAWA Hiroyuki List-ID: On Thu, 9 Sep 2010, Mel Gorman wrote: > > This will have the effect of never sending IPIs for slab allocations since > > they do not do allocations for orders > PAGE_ALLOC_COSTLY_ORDER. > > > > The question is how severe is that? There is somewhat of an expectation > that the lower orders free naturally so it the IPI justified? That said, > our historical behaviour would have looked like > > if (!page && !drained && order) { > drain_all_pages(); > draiained = true; > goto retry; > } > > Play it safe for now and go with that? I am fine with no IPIs for order <= COSTLY. Just be aware that this is a change that may have some side effects. Lets run some tests and see how it affect the issues that we are seeing. -- 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