Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759590Ab3FCRLI (ORCPT ); Mon, 3 Jun 2013 13:11:08 -0400 Received: from merlin.infradead.org ([205.233.59.134]:35261 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758883Ab3FCRLE (ORCPT ); Mon, 3 Jun 2013 13:11:04 -0400 Date: Mon, 3 Jun 2013 19:10:31 +0200 From: Peter Zijlstra To: Johannes Weiner Cc: linux-mm@kvack.org, Andi Kleen , Andrea Arcangeli , Andrew Morton , Greg Thelen , Christoph Hellwig , Hugh Dickins , Jan Kara , KOSAKI Motohiro , Mel Gorman , Minchan Kim , Rik van Riel , Michel Lespinasse , Seth Jennings , Roman Gushchin , metin d , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [patch 10/10] mm: workingset: keep shadow entries in check Message-ID: <20130603171031.GD8923@twins.programming.kicks-ass.net> References: <1369937046-27666-1-git-send-email-hannes@cmpxchg.org> <1369937046-27666-11-git-send-email-hannes@cmpxchg.org> <20130603082209.GG5910@twins.programming.kicks-ass.net> <20130603150154.GE15576@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130603150154.GE15576@cmpxchg.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1875 Lines: 39 On Mon, Jun 03, 2013 at 11:01:54AM -0400, Johannes Weiner wrote: > On Mon, Jun 03, 2013 at 10:22:09AM +0200, Peter Zijlstra wrote: > > On Thu, May 30, 2013 at 02:04:06PM -0400, Johannes Weiner wrote: > > > 2. a list of files that contain shadow entries is maintained. If the > > > global number of shadows exceeds a certain threshold, a shrinker is > > > activated that reclaims old entries from the mappings. This is > > > heavy-handed but it should not be a common case and is only there > > > to protect from accidentally/maliciously induced OOM kills. > > > > Grrr.. another global files list. We've been trying rather hard to get > > rid of the first one :/ > > > > I see why you want it but ugh. > > I'll try to make it per-SB like the inode list. It probably won't be > per-SB shrinkers because of the global nature of the shadow limit, but > at least per-SB inode lists should be doable. per have per-cpu-per-sb lists, see file_sb_list_{add,del} and do_file_list_for_each_entry() > > I have similar worries for your global time counter, large machines > > might thrash on that one cacheline. > > Fair enough. > > So I'm trying the following idea: instead of the global time counter, > have per-zone time counters and store the zone along with those local > timestamps in the shadow entries (nid | zid | time). On refault, we > can calculate the zone-local distance first and then use the inverse > of the zone's eviction proportion to scale it to a global distance. The thinking is since that's the same granularity as the zone lock, you're likely to at least trash the zone lock in equal measure? -- 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/