Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261653AbUCPNrR (ORCPT ); Tue, 16 Mar 2004 08:47:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261674AbUCPNrR (ORCPT ); Tue, 16 Mar 2004 08:47:17 -0500 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:41742 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S261653AbUCPNrP (ORCPT ); Tue, 16 Mar 2004 08:47:15 -0500 Date: Tue, 16 Mar 2004 14:47:56 +0100 From: Andrea Arcangeli To: Marcelo Tosatti Cc: Andrew Morton , 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: <20040316134756.GW30940@dualathlon.random> References: <20040314152253.05c58ecc.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 1565 Lines: 45 On Tue, Mar 16, 2004 at 03:31:33AM -0300, Marcelo Tosatti wrote: > > > On Sun, 14 Mar 2004, Andrew Morton wrote: > > > Andrea Arcangeli wrote: > > > > > > > > > > > Having a magic knob is a weak solution: the majority of people who are > > > > affected by this problem won't know to turn it on. > > > > > > that's why I turned it _on_ by default in my tree ;) > > > > So maybe Marcelo should apply this patch, and also turn it on by default. > > Hhhmm, not so easy I guess. What about the added overhead of > lru_cache_add() for every anonymous page created? > > I bet this will cause problems for users which are happy with the current > behaviour. Wont it? the lru_cache_add is happening in 2.4 mainline, the only point of the patch is to _avoid_ calling lru_cache_add (tunable with a sysctl so you can get to the old behaviour of calling lru_cache_add for every anon page). > Andrea, do you have any numbers (or at least estimates) for the added > overhead of instantly addition of anon pages to the LRU? That would be > cool to know. I've the numbers for the removed overhead, that's significant in some workload, but only in the >=16-ways. > Obviously we dont have, and dont want to, such things in 2.4. agreed ;) > Anyway, it seems this discussion is being productive. Glad! yep! - 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/