Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 1 Oct 2001 15:37:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 1 Oct 2001 15:37:42 -0400 Received: from lightning.swansea.linux.org.uk ([194.168.151.1]:20496 "EHLO the-village.bc.nu") by vger.kernel.org with ESMTP id ; Mon, 1 Oct 2001 15:37:37 -0400 Subject: Re: VM: 2.4.10 vs. 2.4.10-ac2 and qsort() To: riel@conectiva.com.br (Rik van Riel) Date: Mon, 1 Oct 2001 20:42:27 +0100 (BST) Cc: lenstra@tiscalinet.it (Lorenzo Allegrucci), linux-kernel@vger.kernel.org, torvalds@transmeta.com (Linus Torvalds) In-Reply-To: from "Rik van Riel" at Oct 01, 2001 04:23:44 PM X-Mailer: ELM [version 2.5 PL6] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > I'm not sure either, since qsort doesn't really have much > locality of reference but just walks all over the place. qsort can be made to perform reasonably well providing you try to cache colour the objects you sort and try to use prefetches a bit. > I wonder how eg. merge sort would perform ... Generally better but thats seperate to the VM issues. > One thing which could make 2.4.10 faster for this single case > is the fact that it doesn't keep any page aging info, so IO > clustering won't be confused by the process accessing its > pages ;) I don't think that is too unusual a case. If the smarter vm is making poorer I/O clustering decisions it wants investigating - 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/