From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f176.google.com (mail-lb0-f176.google.com [209.85.217.176]) by kanga.kvack.org (Postfix) with ESMTP id CCF2C9003CD for ; Mon, 3 Aug 2015 09:24:39 -0400 (EDT) Received: by lbqc9 with SMTP id c9so52339240lbq.1 for ; Mon, 03 Aug 2015 06:24:39 -0700 (PDT) Received: from gum.cmpxchg.org (gum.cmpxchg.org. [85.214.110.215]) by mx.google.com with ESMTPS id cx3si13964181wib.115.2015.08.03.06.24.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 03 Aug 2015 06:24:38 -0700 (PDT) Date: Mon, 3 Aug 2015 09:23:58 -0400 From: Johannes Weiner Subject: Re: [PATCH 2/3] mm: make workingset detection logic memcg aware Message-ID: <20150803132358.GA18399@cmpxchg.org> References: <9662034e14549b9e1445684f674063ce8b092cb0.1438599199.git.vdavydov@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9662034e14549b9e1445684f674063ce8b092cb0.1438599199.git.vdavydov@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: To: Vladimir Davydov Cc: Andrew Morton , Michal Hocko , Minchan Kim , Rik van Riel , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, Aug 03, 2015 at 03:04:22PM +0300, Vladimir Davydov wrote: > @@ -179,8 +180,9 @@ static void unpack_shadow(void *shadow, > eviction = entry; > > *zone = NODE_DATA(nid)->node_zones + zid; > + *lruvec = mem_cgroup_page_lruvec(page, *zone); > > - refault = atomic_long_read(&(*zone)->inactive_age); > + refault = atomic_long_read(&(*lruvec)->inactive_age); > mask = ~0UL >> (NODES_SHIFT + ZONES_SHIFT + > RADIX_TREE_EXCEPTIONAL_SHIFT); > /* You can not compare an eviction shadow entry from one lruvec with the inactive age of another lruvec. The inactive ages are not related and might differ significantly: memcgs are created ad hoc, memory hotplug, page allocator fairness drift. In those cases the result will be pure noise. As much as I would like to see a simpler way, I am pessimistic that there is a way around storing memcg ids in the shadow entries. -- 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