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 82C096B004A for ; Tue, 7 Sep 2010 10:23:53 -0400 (EDT) Date: Tue, 7 Sep 2010 09:23:48 -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: <20100906040243.GA7362@dastard> Message-ID: References: <20100903160026.564fdcc9.akpm@linux-foundation.org> <20100904022545.GD705@dastard> <20100903202101.f937b0bb.akpm@linux-foundation.org> <20100904075840.GE705@dastard> <20100904081414.GF705@dastard> <20100905015400.GA10714@localhost> <20100905021555.GG705@dastard> <20100905060539.GA17450@localhost> <20100905131447.GJ705@dastard> <20100905134554.GA7083@localhost> <20100906040243.GA7362@dastard> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Dave Chinner Cc: Wu Fengguang , Andrew Morton , Mel Gorman , Linux Kernel List , "linux-mm@kvack.org" , Rik van Riel , Johannes Weiner , Minchan Kim , KAMEZAWA Hiroyuki , KOSAKI Motohiro , David Rientjes List-ID: On Mon, 6 Sep 2010, Dave Chinner wrote: > [ 596.628086] [] ? drain_all_pages+0x1c/0x20 > [ 596.628086] [] ? __alloc_pages_nodemask+0x42d/0x700 > [ 596.628086] [] ? kmem_getpages+0x62/0x160 > [ 596.628086] [] ? fallback_alloc+0x196/0x240 fallback_alloc() showing up here means that one page allocator call from SLAB has already failed. SLAB then did an expensive search through all object caches on all nodes to find some available object. There were no objects in queues at all therefore SLAB called the page allocator again (kmem_getpages()). As soon as memory is available (on any node or any cpu, they are all empty) SLAB will repopulate its queues(!). -- 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