From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755265AbYIWFc7 (ORCPT ); Tue, 23 Sep 2008 01:32:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751472AbYIWFcs (ORCPT ); Tue, 23 Sep 2008 01:32:48 -0400 Received: from gate.crashing.org ([63.228.1.57]:57276 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754783AbYIWFcr (ORCPT ); Tue, 23 Sep 2008 01:32:47 -0400 Subject: Re: PTE access rules & abstraction From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Nick Piggin Cc: Jeremy Fitzhardinge , Linux Memory Management List , Linux Kernel list , Hugh Dickins In-Reply-To: <20080923031037.GA11907@wotan.suse.de> References: <1221846139.8077.25.camel@pasglop> <48D739B2.1050202@goop.org> <1222117551.12085.39.camel@pasglop> <20080923031037.GA11907@wotan.suse.de> Content-Type: text/plain Date: Tue, 23 Sep 2008 15:31:26 +1000 Message-Id: <1222147886.12085.93.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-09-23 at 05:10 +0200, Nick Piggin wrote: > We are getting better slowly I think (eg. you note that set_pte_at is > no longer used as a generic "do anything"), but I won't dispute that > this whole area could use an overhaul; a document for all the rules, > a single person or point of responsibility for those rules... Can we nowadays -rely- on set_pte_at() never being called to overwrite an already valid PTE ? I mean, it looks like the generic code doesn't do it anymore but I wonder if it's reasonable to forbid that from coming back ? That would allow me to remove some hacks in ppc64 and simplify some upcoming ppc32 code. Cheers, Ben.