From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] Add __GFP_MOVABLE for callers to flag allocations that may be migrated From: Peter Zijlstra In-Reply-To: <20061204113051.4e90b249.akpm@osdl.org> References: <20061130170746.GA11363@skynet.ie> <20061130173129.4ebccaa2.akpm@osdl.org> <20061201110103.08d0cf3d.akpm@osdl.org> <20061204140747.GA21662@skynet.ie> <20061204113051.4e90b249.akpm@osdl.org> Content-Type: text/plain Date: Mon, 04 Dec 2006 21:37:20 +0100 Message-Id: <1165264640.23363.18.camel@lappy> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Mel Gorman , clameter@sgi.com, Linux Memory Management List , Linux Kernel Mailing List , Andy Whitcroft List-ID: On Mon, 2006-12-04 at 11:30 -0800, Andrew Morton wrote: > I'd also like to pin down the situation with lumpy-reclaim versus > anti-fragmentation. No offence, but I would of course prefer to avoid > merging the anti-frag patches simply based on their stupendous size. It > seems to me that lumpy-reclaim is suitable for the e1000 problem, but > perhaps not for the hugetlbpage problem. Whereas anti-fragmentation adds > vastly more code, but can address both problems? Or something. >>From my understanding they complement each other nicely. Without some form of anti fragmentation there is no guarantee lumpy reclaim will ever free really high order pages. Although it might succeed nicely for the network sized allocations we now have problems with. - Andy, do you have any number on non largepage order allocations? But anti fragmentation as per Mel's patches is not good enough to provide largepage allocations since we would need to shoot down most of the LRU to obtain such a large contiguous area. Lumpy reclaim however can quickly achieve these sizes. -- 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