From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx167.postini.com [74.125.245.167]) by kanga.kvack.org (Postfix) with SMTP id DEB026B0005 for ; Wed, 10 Apr 2013 10:14:50 -0400 (EDT) Date: Wed, 10 Apr 2013 15:14:45 +0100 From: Mel Gorman Subject: Re: [PATCH 0/10] Reduce system disruption due to kswapd V2 Message-ID: <20130410141445.GD3710@suse.de> References: <1365505625-9460-1-git-send-email-mgorman@suse.de> <0000013defd666bf-213d70fc-dfbd-4a50-82ed-e9f4f7391b55-000000@email.amazonses.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <0000013defd666bf-213d70fc-dfbd-4a50-82ed-e9f4f7391b55-000000@email.amazonses.com> Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , Jiri Slaby , Valdis Kletnieks , Rik van Riel , Zlatko Calusic , Johannes Weiner , dormando , Satoru Moriya , Michal Hocko , Linux-MM , LKML On Tue, Apr 09, 2013 at 05:27:18PM +0000, Christoph Lameter wrote: > One additional measure that may be useful is to make kswapd prefer one > specific processor on a socket. Two benefits arise from that: > > 1. Better use of cpu caches and therefore higher speed, less > serialization. > Considering the volume of pages that kswapd can scan when it's active I would expect that it trashes its cache anyway. The L1 cache would be flushed after scanning struct pages for just a few MB of memory. > 2. Reduction of the disturbances to one processor. > I've never checked it but I would have expected kswapd to stay on the same processor for significant periods of time. Have you experienced problems where kswapd bounces around on CPUs within a node causing workload disruption? -- Mel Gorman SUSE Labs -- 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