From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id CC4D48D003B for ; Wed, 18 May 2011 02:09:33 -0400 (EDT) Message-ID: <4DD36299.8000108@cs.helsinki.fi> Date: Wed, 18 May 2011 09:09:29 +0300 From: Pekka Enberg MIME-Version: 1.0 Subject: Re: [PATCH 2/4] mm: slub: Do not wake kswapd for SLUBs speculative high-order allocations References: <1305295404-12129-1-git-send-email-mgorman@suse.de> <1305295404-12129-3-git-send-email-mgorman@suse.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Mel Gorman , Andrew Morton , James Bottomley , Colin King , Raghavendra D Prabhu , Jan Kara , Chris Mason , Christoph Lameter , Rik van Riel , Johannes Weiner , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 On 5/17/11 12:10 AM, David Rientjes wrote: > On Fri, 13 May 2011, Mel Gorman wrote: > >> To avoid locking and per-cpu overhead, SLUB optimisically uses >> high-order allocations and falls back to lower allocations if they >> fail. However, by simply trying to allocate, kswapd is woken up to >> start reclaiming at that order. On a desktop system, two users report >> that the system is getting locked up with kswapd using large amounts >> of CPU. Using SLAB instead of SLUB made this problem go away. >> >> This patch prevents kswapd being woken up for high-order allocations. >> Testing indicated that with this patch applied, the system was much >> harder to hang and even when it did, it eventually recovered. >> >> Signed-off-by: Mel Gorman > Acked-by: David Rientjes Christoph? I think this patch is sane although the original rationale was to workaround kswapd problems. Pekka -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org