Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936845Ab3DJOOw (ORCPT ); Wed, 10 Apr 2013 10:14:52 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54855 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936822Ab3DJOOu (ORCPT ); Wed, 10 Apr 2013 10:14:50 -0400 Date: Wed, 10 Apr 2013 15:14:45 +0100 From: Mel Gorman 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 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> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1053 Lines: 28 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/