From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id F13A76B0253 for ; Thu, 3 Mar 2016 03:22:57 -0500 (EST) Received: by mail-wm0-f43.google.com with SMTP id l68so21016870wml.1 for ; Thu, 03 Mar 2016 00:22:57 -0800 (PST) Received: from mail-wm0-f41.google.com (mail-wm0-f41.google.com. [74.125.82.41]) by mx.google.com with ESMTPS id 17si47336353wjv.159.2016.03.03.00.22.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Mar 2016 00:22:57 -0800 (PST) Received: by mail-wm0-f41.google.com with SMTP id n186so120100616wmn.1 for ; Thu, 03 Mar 2016 00:22:56 -0800 (PST) Date: Thu, 3 Mar 2016 09:22:55 +0100 From: Michal Hocko Subject: Re: kswapd consumes 100% CPU when highest zone is small Message-ID: <20160303082254.GA26202@dhcp22.suse.cz> References: <20160302173639.GD26701@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Jerry Lee Cc: linux-mm@kvack.org On Thu 03-03-16 10:23:03, Jerry Lee wrote: > On 3 March 2016 at 01:36, Michal Hocko wrote: > > > On Wed 02-03-16 14:20:38, Jerry Lee wrote: [...] > > > Is there anything I could do to totally get rid of the problem? > > > > I would try to sacrifice those few megs and get rid of zone normal > > completely. AFAIR mem=4G should limit the max_pfn to 4G so DMA32 should > > cover the shole memory. > > > > I came up with a patch that seem to work well on my system. But, I > am afraid that it breaks the rule that all zones must be balanced for > order-0 request and It may cause some other side-effect? I thought > that the patch is just a workaround (a bad one) and not a cure-all. One thing I haven't noticed previously is that you are running on the 3.12 kernel. I vaguely remember there were some fixes for small zones. Not sure it would work for such a small zone but it would be worth trying I guess. Could you retest with 4.4? -- Michal Hocko 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