From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f182.google.com (mail-wi0-f182.google.com [209.85.212.182]) by kanga.kvack.org (Postfix) with ESMTP id C75656B0038 for ; Fri, 9 Jan 2015 07:51:20 -0500 (EST) Received: by mail-wi0-f182.google.com with SMTP id h11so2098752wiw.3 for ; Fri, 09 Jan 2015 04:51:20 -0800 (PST) Received: from gum.cmpxchg.org (gum.cmpxchg.org. [85.214.110.215]) by mx.google.com with ESMTPS id p10si19114797wjx.72.2015.01.09.04.51.20 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Jan 2015 04:51:20 -0800 (PST) Date: Fri, 9 Jan 2015 07:51:09 -0500 From: Johannes Weiner Subject: Re: [PATCH v2] vmscan: force scan offline memory cgroups Message-ID: <20150109125109.GA14475@phnom.home.cmpxchg.org> References: <20150108170349.GA32079@phnom.home.cmpxchg.org> <1420790983-20270-1-git-send-email-vdavydov@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1420790983-20270-1-git-send-email-vdavydov@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: Vladimir Davydov Cc: Andrew Morton , Michal Hocko , Tejun Heo , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Fri, Jan 09, 2015 at 11:09:43AM +0300, Vladimir Davydov wrote: > Since commit b2052564e66d ("mm: memcontrol: continue cache reclaim from > offlined groups") pages charged to a memory cgroup are not reparented > when the cgroup is removed. Instead, they are supposed to be reclaimed > in a regular way, along with pages accounted to online memory cgroups. > > However, an lruvec of an offline memory cgroup will sooner or later get > so small that it will be scanned only at low scan priorities (see > get_scan_count()). Therefore, if there are enough reclaimable pages in > big lruvecs, pages accounted to offline memory cgroups will never be > scanned at all, wasting memory. > > Fix this by unconditionally forcing scanning dead lruvecs from kswapd. > > Signed-off-by: Vladimir Davydov Looks good to me now, thank you. Acked-by: Johannes Weiner -- 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