Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964837AbWL1AnG (ORCPT ); Wed, 27 Dec 2006 19:43:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964834AbWL1AnF (ORCPT ); Wed, 27 Dec 2006 19:43:05 -0500 Received: from smtp.osdl.org ([65.172.181.25]:46679 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964837AbWL1AnE (ORCPT ); Wed, 27 Dec 2006 19:43:04 -0500 Date: Wed, 27 Dec 2006 16:42:40 -0800 (PST) From: Linus Torvalds To: Martin Schwidefsky cc: Peter Zijlstra , Martin Michlmayr , Hugh Dickins , Nick Piggin , Arjan van de Ven , Andrei Popa , Andrew Morton , Linux Kernel Mailing List , Florian Weimer , Marc Haber , Heiko Carstens , Arnd Bergmann , gordonfarquharson@gmail.com Subject: Re: [PATCH] mm: fix page_mkclean_one (was: 2.6.19 file content corruption on ext3) In-Reply-To: <1167264000.5200.21.camel@localhost> Message-ID: References: <1166571749.10372.178.camel@twins> <1166605296.10372.191.camel@twins> <1166607554.3365.1354.camel@laptopd505.fenrus.org> <1166614001.10372.205.camel@twins> <1166622979.10372.224.camel@twins> <20061220170323.GA12989@deprecation.cyrius.com> <20061220175309.GT30106@deprecation.cyrius.com> <1166652901.30008.1.camel@twins> <1166655805.30008.18.camel@twins> <1166692586.27750.4.camel@localhost> <1166692812.32117.2.camel@twins> <1167264000.5200.21.camel@localhost> 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: 1148 Lines: 30 On Thu, 28 Dec 2006, Martin Schwidefsky wrote: > > For s390 there are two aspects to consider: > 1) the pte values are 100% software controlled. That's fine. In that situation, you shouldn't need any atomic ops at all, I think all our sw page-table operations are already done under the pte lock. The reason x86 needs to be careful is exactly the fact that the hardware will obviously do a lot on its own, and the hardware is _not_ going to honor our page table locking ;) In an all-sw situation, a lot of this should be easier. S390 has _other_ things that are inconvenient (the strange "dirty bit is not in the page tables" thing that makes it look different from everybody else), but hey, it's a balance.. So for s390, ptep_exchange() in my example should be able to be a simple "load old value and store new one", assuming everybody honors the pte lock (and they _should_). 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/