From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 10 Jul 2007 14:24:59 +0100 Subject: Re: -mm merge plans -- anti-fragmentation Message-ID: <20070710132459.GB9426@skynet.ie> References: <20070710102043.GA20303@skynet.ie> <1184065445.5281.16.camel@lappy> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1184065445.5281.16.camel@lappy> From: mel@skynet.ie (Mel Gorman) Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: Andrew Morton , npiggin@suse.de, kenchen@google.com, jschopp@austin.ibm.com, apw@shadowen.org, kamezawa.hiroyu@jp.fujitsu.com, y-goto@jp.fujitsu.com, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On (10/07/07 13:04), Peter Zijlstra didst pronounce: > On Tue, 2007-07-10 at 11:20 +0100, Mel Gorman wrote: > > > > > > lumpy-reclaim-v4.patch > > > > This patch is really what lumpy reclaim is. I believe Peter has looked > > at this and was happy enough at the time although he is cc'd here again > > in case this has changed. This is mainly useful with either grouping > > pages by mobility or the ZONE_MOVABLE stuff. However, at the time the > > patch was proposed, there was a feeling that it might help jumbo frame > > allocation on e1000's and maybe if fsblock optimistically uses > > contiguous pages it would have an application. I would like to see it go > > through to see does it help e1000 at least. > > I'm not seeing how this will help e1000 (and other jumbo drivers). They > typically allocate using GFP_ATOMIC, so in order to satisfy those you'd > need to either have a higher order watermark or do atomic defrag of the > free space. > It does help somewhat indirectly and in an unsatisfactory manner. When the higher watermarks are breached, the atomic allocation will still succeeed but kswapd will be poked to reclaim at a given order. This is similar to the problems SLUB hits when it uses high-orders frequently. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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