Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262542AbUCOLsg (ORCPT ); Mon, 15 Mar 2004 06:48:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262537AbUCOLsf (ORCPT ); Mon, 15 Mar 2004 06:48:35 -0500 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:60944 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S262542AbUCOLsa (ORCPT ); Mon, 15 Mar 2004 06:48:30 -0500 Date: Mon, 15 Mar 2004 12:49:14 +0100 From: Andrea Arcangeli To: Nick Piggin Cc: Andrew Morton , marcelo.tosatti@cyclades.com, j-nomura@ce.jp.nec.com, linux-kernel@vger.kernel.org, riel@redhat.com, torvalds@osdl.org Subject: Re: [2.4] heavy-load under swap space shortage Message-ID: <20040315114914.GA30940@dualathlon.random> References: <20040310.195707.521627048.nomura@linux.bs1.fc.nec.co.jp> <20040314121503.13247112.akpm@osdl.org> <20040314230138.GV30940@dualathlon.random> <20040314152253.05c58ecc.akpm@osdl.org> <20040315001400.GX30940@dualathlon.random> <4055335B.30402@cyberone.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4055335B.30402@cyberone.com.au> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1145 Lines: 29 Hi Nick, On Mon, Mar 15, 2004 at 03:38:51PM +1100, Nick Piggin wrote: > > > Andrea Arcangeli wrote: > > > > >I don't see other ways to optimize it (and I never enjoyed too much the > >per-zone lru since it has some downside too with a worst case on 2G > >systems). peraphs a further optimization could be a transient per-cpu > >lru refiled only by the page reclaim (so absolutely lazy while lots of > >ram is free), but maybe that's already what you're doing when you say > >"Adding/removing sixteen pages for one taking of the lock". Though the > >fact you say "sixteen pages" sounds like it's not as lazy as it could > >be. > > > > Hi Andrea, > What are the downsides on a 2G system? it is the absolutely worst case since both lru could be of around the same size (800M zone-normal-lru and 1.2G zone-highmem-lru), maximizing the loss of "age" information needed for optimal reclaim decisions. - 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/