Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 21 Jan 2002 19:37:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 21 Jan 2002 19:36:51 -0500 Received: from penguin.e-mind.com ([195.223.140.120]:29792 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Mon, 21 Jan 2002 19:36:46 -0500 Date: Tue, 22 Jan 2002 01:37:43 +0100 From: Andrea Arcangeli To: "David S. Miller" Cc: reid.hekman@ndsu.nodak.edu, linux-kernel@vger.kernel.org, akpm@zip.com.au, alan@lxorg.ukuu.org Subject: Re: Athlon PSE/AGP Bug Message-ID: <20020122013743.M8292@athlon.random> In-Reply-To: <1011610422.13864.24.camel@zeus> <20020121.053724.124970557.davem@redhat.com> <20020121175410.G8292@athlon.random> <20020121.141931.105134927.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i In-Reply-To: <20020121.141931.105134927.davem@redhat.com>; from davem@redhat.com on Mon, Jan 21, 2002 at 02:19:31PM -0800 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 21, 2002 at 02:19:31PM -0800, David S. Miller wrote: > From: Andrea Arcangeli > Date: Mon, 21 Jan 2002 17:54:10 +0100 > > correct, furthmore it cannot even trigger if you invlpg with an address > page aligned (4mbyte aligned in this case) like we would always do in > linux anyways, we never use invlpg on misaligned addresses, no matter if > the page is a 4M or a 4k page. > > That's not true, see the ptrace() helper code. Russell King pointed > this out to me last week and it's on my TODO list to fix it up. Where? :) ptrace doesn't change pagetables, no need to flush any tlb in ptrace. Anyways if the problem is in the nvidia driver they may be really doing an invlpg on a misaligned 4M page address for no good reason, this sounds unlikely though. What's certain is that the stuff into the mainline kernel shouldn't really be affected for the reason you also said previously (we never invalidate 4M pages with invlpg). In the very worst case nvidia guys just need to mask the lower (not significant) bits before passing the address to invlpg, which is going to be a one liner. Andrea - 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/