From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262730AbUHRHJ5 (ORCPT ); Wed, 18 Aug 2004 03:09:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263555AbUHRHJ5 (ORCPT ); Wed, 18 Aug 2004 03:09:57 -0400 Received: from mx1.elte.hu ([157.181.1.137]:42936 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S262730AbUHRHJz (ORCPT ); Wed, 18 Aug 2004 03:09:55 -0400 Date: Wed, 18 Aug 2004 09:11:12 +0200 From: Ingo Molnar To: Jens Maurer Cc: Linux Kernel , Andrew Morton , Arjan van de Ven Subject: Re: [PATCH] Use x86 SSE instructions for clear_page, copy_page Message-ID: <20040818071112.GA11543@elte.hu> References: <4121A211.8080902@gmx.net> <20040818070013.GA11048@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040818070013.GA11048@elte.hu> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > executed SSE code? You are corrupting those registers. doh - should read before i write. The code is perfectly fine. Arjan's cache arguments remain. What i'd suggest to test is the precise speed of compiling the kernel, fully done in ramfs. (if you dont have enough RAM for this then compile a portion of the kernel.) For the testing, add a /proc/sys switch to turn the SSE functions on/off runtime, hence you can eliminate the effects of page placement. If the compilation timings are stable enough then you can try the runtime switch to see whether it has any effect. There should be a small but visible change (in one direction or the other), as compilation brings in lots of new pages and copies around stuff too. Ingo