From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 3 Sep 2001 17:00:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 3 Sep 2001 17:00:35 -0400 Received: from deimos.hpl.hp.com ([192.6.19.190]:41443 "EHLO deimos.hpl.hp.com") by vger.kernel.org with ESMTP id ; Mon, 3 Sep 2001 17:00:23 -0400 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15251.61303.411698.310497@napali.hpl.hp.com> Date: Mon, 3 Sep 2001 14:00:39 -0700 To: Richard Henderson Cc: David Mosberger , Paul Mackerras , torvalds@transmeta.com, linux-kernel@vger.kernel.org, davem@redhat.com Subject: Re: [PATCH] avoid unnecessary cache flushes In-Reply-To: <20010903134125.B16069@twiddle.net> In-Reply-To: <15247.29338.3671.548678@cargo.ozlabs.ibm.com> <20010903131436.A16069@twiddle.net> <15251.59286.154267.431231@napali.hpl.hp.com> <20010903134125.B16069@twiddle.net> X-Mailer: VM 6.76 under Emacs 20.4.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> On Mon, 3 Sep 2001 13:41:25 -0700, Richard Henderson said: Richard> You can get a missed flush from Richard> bit == 0 flush cache Richard> modify page bit = 0 Richard> bit = 1 Richard> unless this is protected from some outer lock of which I am Richard> not aware. Richard> I do see your point about the early set though. I didn't think there was any path where the kernel would on its own update code after the fact, but I could be missing something. Note, that if it's the user's doing, the user is responsible for ensuring coherence. --david