From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) by kanga.kvack.org (Postfix) with ESMTP id 1CD046B0031 for ; Wed, 4 Dec 2013 08:00:44 -0500 (EST) Received: by mail-ee0-f43.google.com with SMTP id c13so2367591eek.30 for ; Wed, 04 Dec 2013 05:00:43 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTP id m44si1477284eeo.247.2013.12.04.05.00.42 for ; Wed, 04 Dec 2013 05:00:42 -0800 (PST) Date: Wed, 4 Dec 2013 13:00:38 +0000 From: Mel Gorman Subject: Re: high kswapd CPU usage when executing binaries from NFS w/ CMA and COMPACTION Message-ID: <20131204130038.GY11295@suse.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Florian Fainelli Cc: "linux-kernel@vger.kernel.org" , mhocko@suse.cz, hannes@cmpxchg.org, riel@redhat.com, linux-mm@kvack.org, m.szyprowski@samsung.com, marc.ceeeee@gmail.com On Tue, Dec 03, 2013 at 06:30:28PM -0800, Florian Fainelli wrote: > Hi all, > > I am experiencing high kswapd CPU usage on an ARMv7 system running > 3.8.13 when executing relatively large binaries from NFS. When this > happens kswapd consumes around 55-60% CPU usage and the applications > takes a huge time to load. > There were a number of changes made related to how and when kswapd stalls, particularly when pages are dirty. Brief check confirms that git log v3.8..v3.12 --pretty=one --author "Mel Gorman" mm/vmscan.c NFS dirty pages are problematic for compaction as dirty pages cannot be migrated until cleaned. I'd suggest checking if current mainline suffers the same problem and if not, focus on patches related to dirty page handling and kswapd throttling in mm/vmscan.c as backport candidates. -- 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