From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934988AbXG0TnG (ORCPT ); Fri, 27 Jul 2007 15:43:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932944AbXG0Tmz (ORCPT ); Fri, 27 Jul 2007 15:42:55 -0400 Received: from [212.12.190.8] ([212.12.190.8]:33191 "EHLO raad.intranet" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S932975AbXG0Tmz (ORCPT ); Fri, 27 Jul 2007 15:42:55 -0400 From: Al Boldi To: linux-kernel@vger.kernel.org Subject: swap-prefetch: A smart way to make good use of idle resources (was: updatedb) Date: Fri, 27 Jul 2007 22:43:02 +0300 User-Agent: KMail/1.5 MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <200707272243.02336.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org People wrote: > >> I believe the users who say their apps really do get paged back in > >> though, so suspect that's not the case. > > > > Stopping the bush-circumference beating, I do not. -ck (and gentoo) have > > this massive Calimero thing going among their users where people are > > much less interested in technology than in how the nasty big kernel > > meanies are keeping them down (*). > > I think the problem is elsewhere. Users don't say: "My apps get paged > back in." They say: "My system is more responsive". They really don't > care *why* the reaction to a mouse click that takes three seconds with > a mainline kernel is instantaneous with -ck. Nasty big kernel meanies, > OTOH, want to understand *why* a patch helps in order to decide whether > it is really a good idea to merge it. So you've got a bunch of patches > (aka -ck) which visibly improve the overall responsiveness of a desktop > system, but apparently no one can conclusively explain why or how they > achieve that, and therefore they cannot be merged into mainline. > > I don't have a solution to that dilemma either. IMHO, what everybody agrees on, is that swap-prefetch has a positive effect in some cases, and nobody can prove an adverse effect (excluding power consumption). The reason for this positive effect is also crystal clear: It prefetches from swap on idle into free memory, ie: it doesn't force anybody out, and they are the first to be dropped without further swap-out, which sounds really smart. Conclusion: Either prove swap-prefetch is broken, or get this merged quick. Thanks! -- Al