From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261667AbTJHPbt (ORCPT ); Wed, 8 Oct 2003 11:31:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261670AbTJHPbt (ORCPT ); Wed, 8 Oct 2003 11:31:49 -0400 Received: from ausadmmsrr501.aus.amer.dell.com ([143.166.83.88]:41743 "HELO AUSADMMSRR501.aus.amer.dell.com") by vger.kernel.org with SMTP id S261667AbTJHPbr (ORCPT ); Wed, 8 Oct 2003 11:31:47 -0400 X-Server-Uuid: ff595059-9672-488a-bf38-b4dee96ef25b Message-ID: <1065627088.21242.32.camel@localhost.localdomain> From: Matt_Domsch@Dell.com To: hugh@veritas.com cc: riel@redhat.com, marcelo.tosatti@cyclades.com, linux-kernel@vger.kernel.org, benh@kernel.crashing.org Subject: Re: [PATCH] page->flags corruption fix Date: Wed, 8 Oct 2003 10:31:29 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) X-WSS-ID: 139AF2533584476-01-01 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2003-10-08 at 09:49, Hugh Dickins wrote: > On Tue, 7 Oct 2003, Rik van Riel wrote: > > > In the "better safe than sorry" category. Thanks go out to > > Matt Domsch and Robert Hentosh. A similar fix went into the > > 2.6 kernel. Please apply. > > Seven atomic ops in a row, isn't that rather inefficient? Not all arches have atomic_set_mask() and atomic_clear_mask(). asm-arm asm-arm26 asm-h8300 asm-i386 asm-m68k asm-m68knommu asm-ppc asm-s390 asm-sh asm-v850 asm-x86_64 do. > The 2.6 version clears those PG_flags all together in one > non-atomic op - but elsewhere, in prep_new_page. > > Is there an actual test case for why 2.4 now needs this change? There definitely is when RMAP is present - we've reproduced it repeatedly in our labs. We've seen a similar failure with the RHEL2.1 kernel w/o RMAP patches too. So we fully believe it's possible in stock 2.4.x. Thanks, Matt -- Matt Domsch Sr. Software Engineer, Lead Engineer Dell Linux Solutions www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com