From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 8 May 2007 14:15:42 +0100 (IST) From: Mel Gorman Subject: Re: SLUB: Reduce antifrag max order In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@linux-foundation.org, linux-mm@kvack.org List-ID: On Sat, 5 May 2007, Christoph Lameter wrote: > My test systems fails to obtain order 4 allocs after prolonged use. > So the Antifragmentation patches are unable to guarantee order 4 > blocks after a while (straight compile, edit load). > Anti-frag still depends on reclaim to take place and I imagine you have not altered min_free_kbytes to keep pages free. Also, I don't think kswapd is currently making any effort to keep blocks free at a known desired order although I'm cc'ing Andy Whitcroft to confirm. As the kernel gives up easily when order > PAGE_ALLOC_COSTLY_ORDER, prehaps you should be using PAGE_ALLOC_COSTLY_ORDER instead of DEFAULT_ANTIFRAG_MAX_ORDER for SLUB. > Reduce the the max order if antifrag measures are detected to 3. > > Signed-off-by: Christoph Lameter > > --- > mm/slub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: slub/mm/slub.c > =================================================================== > --- slub.orig/mm/slub.c 2007-05-05 09:19:32.000000000 -0700 > +++ slub/mm/slub.c 2007-05-05 09:22:00.000000000 -0700 > @@ -129,7 +129,7 @@ > * If antifragmentation methods are in effect then increase the > * slab sizes to increase performance > */ > -#define DEFAULT_ANTIFRAG_MAX_ORDER 4 > +#define DEFAULT_ANTIFRAG_MAX_ORDER 3 > #define DEFAULT_ANTIFRAG_MIN_OBJECTS 16 > > /* > -- 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