From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [patch 10/10] mm: workingset: keep shadow entries in check Date: Thu, 6 Jun 2013 14:31:24 -0400 Message-ID: <20130606183124.GL15721@cmpxchg.org> 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> <20130603171031.GD8923@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 To: Peter Zijlstra Return-path: Content-Disposition: inline In-Reply-To: <20130603171031.GD8923@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Mon, Jun 03, 2013 at 07:10:31PM +0200, Peter Zijlstra wrote: > 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() Ok, I'll give it a look. Thanks. > > > 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? Yeah, and prevent the cross-node bouncing. -- 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