Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261460AbTI3N2S (ORCPT ); Tue, 30 Sep 2003 09:28:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261459AbTI3N2S (ORCPT ); Tue, 30 Sep 2003 09:28:18 -0400 Received: from pix-525-pool.redhat.com ([66.187.233.200]:39730 "EHLO lacrosse.corp.redhat.com") by vger.kernel.org with ESMTP id S261460AbTI3N1u (ORCPT ); Tue, 30 Sep 2003 09:27:50 -0400 Date: Tue, 30 Sep 2003 14:27:29 +0100 From: Dave Jones To: bill davidsen Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] Athlon Prefetch workaround for 2.6.0test6 Message-ID: <20030930132729.GB23333@redhat.com> Mail-Followup-To: Dave Jones , bill davidsen , linux-kernel@vger.kernel.org References: <20030929125629.GA1746@averell> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 29, 2003 at 09:02:39PM +0000, bill davidsen wrote: > In article <20030929125629.GA1746@averell>, Andi Kleen wrote: > > | It removes the previous dumb in kernel workaround for this and shrinks the > | kernel by >10k. > | > | Small behaviour change is that a SIGBUS fault for a *_user access will > | cause an EFAULT now, no SIGBUS. > | > | This version addresses all criticism that I got for previous versions. > | > | - Only checks on AMD K7+ CPUs. > | - Computes linear address for VM86 mode or code segments > | with non zero base. > | - Some cleanup > | - No pointer comparisons > | - More comments > > I have to try this on a P4 and K7, but WRT "Only checks on AMD K7+ CPUs" > I hope you meant "only generates code if AMD CPU is target" and not that > the code size penalty is still there for CPUs which don't need it. NO NO NO NO NO. This *has* to be there on a P4 kernel too, as we can now boot those on a K7 too. The 'code size penalty' you talk about is in the region of a few hundred bytes. Much less than a page. There are far more obvious bloat candidates. Dave -- Dave Jones http://www.codemonkey.org.uk - 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/