Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 2 Aug 2002 11:41:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 2 Aug 2002 11:41:48 -0400 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:28177 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Fri, 2 Aug 2002 11:41:47 -0400 Date: Fri, 2 Aug 2002 08:46:38 -0700 (PDT) From: Linus Torvalds To: davidm@hpl.hp.com cc: Alan Cox , , Subject: Re: adjust prefetch in free_one_pgd() In-Reply-To: <15690.42924.410428.28956@napali.hpl.hp.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 997 Lines: 28 On Fri, 2 Aug 2002, David Mosberger wrote: > > I thought the prefetches API intended this to be a safe operation? Well, any _sane_ prefetch API would be safe. However, there is known-broken hardware out there, in which a prefetch from IO space will kill the machine. Personally, I would just say that we should disable prefetch on such clearly broken hardware, but since it's Alans favourite machine (some early AMD Athlon if I remember correctly), I think Alan will disagree ;) > It's definitely not an issue on ia64: there, prefetches against > uncached memory translations are automatically canceled. That's true of just about any other architecture too. I think the AMD case is an erratum, so even on AMD it is _supposed_ to work. Linus - 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/