From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751151AbWBMCOO (ORCPT ); Sun, 12 Feb 2006 21:14:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751152AbWBMCOO (ORCPT ); Sun, 12 Feb 2006 21:14:14 -0500 Received: from smtp.osdl.org ([65.172.181.4]:49621 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751151AbWBMCOO (ORCPT ); Sun, 12 Feb 2006 21:14:14 -0500 Date: Sun, 12 Feb 2006 18:13:12 -0800 From: Andrew Morton To: Hugh Dickins Cc: wli@holomorphy.com, nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org, "David S. Miller" Subject: Re: [PATCH 1/3] compound page: use page[1].lru Message-Id: <20060212181312.11392d12.akpm@osdl.org> In-Reply-To: References: <20060212135457.2a3d3b37.akpm@osdl.org> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > > On Sun, 12 Feb 2006, Andrew Morton wrote: > > > > I'm scratching my head over flush_dcache_page() on, say, sparc64. For > > example, the one in fs/direct-io.c. With this patch, we'll call > > flush_dcache_page_impl(), which at least won't crash. Before the patch I > > think we'd just do random stuff. > > A head-scratching business indeed. I think your description is right. > > I haven't looked up the intersection of the set of arches which have > hugetlb with the set of arches which do something in flush_dcache_page, > but maybe you have, and found sparc64 the only or most significant. We have a page which has no ->mapping, but lo, it's mmapped by userspace and can be MAP_SHARED between different CPUs and processes. Yes, I suspect it'll do the wrong thing in unpleasantly subtle ways. (cc's davem and runs away).