From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262011AbTJAG7S (ORCPT ); Wed, 1 Oct 2003 02:59:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262041AbTJAG7S (ORCPT ); Wed, 1 Oct 2003 02:59:18 -0400 Received: from fw.osdl.org ([65.172.181.6]:59034 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S262011AbTJAG7O (ORCPT ); Wed, 1 Oct 2003 02:59:14 -0400 Date: Wed, 1 Oct 2003 00:00:15 -0700 From: Andrew Morton To: Andi Kleen Cc: jamie@shareable.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Mutilated form of Andi Kleen's AMD prefetch errata patch Message-Id: <20031001000015.69007e85.akpm@osdl.org> In-Reply-To: References: <7F740D512C7C1046AB53446D3720017304AFCF@scsmsx402.sc.intel.com.suse.lists.linux.kernel> <20031001053833.GB1131@mail.shareable.org.suse.lists.linux.kernel> <20030930224853.15073447.akpm@osdl.org.suse.lists.linux.kernel> <20031001061348.GE1131@mail.shareable.org.suse.lists.linux.kernel> <20030930233258.37ed9f7f.akpm@osdl.org.suse.lists.linux.kernel> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen wrote: > > Andrew Morton writes: > > > Looking at Andi's patch, it is also a dead box if the fault happens inside > > down_write(mmap_sem). That should be fixed, methinks. > > The only way to fix all that would be to move the instruction checks early > into the fast path. Well the deadlock avoidance only needs to happen if the fault occured in kernel mode. Presumably most faults are in userspace, so most of the overhead can be avoided.