From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 9 May 2002 09:01:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 9 May 2002 09:01:30 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:16247 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Thu, 9 May 2002 09:01:28 -0400 Date: Thu, 9 May 2002 15:01:46 +0200 From: Andrea Arcangeli To: "David S. Miller" Cc: hugh@veritas.com, torvalds@transmeta.com, akpm@zip.com.au, cr@sap.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] double flush_page_to_ram Message-ID: <20020509150146.O12382@dualathlon.random> In-Reply-To: <20020509.045643.27562731.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.22.1i X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 09, 2002 at 04:56:43AM -0700, David S. Miller wrote: > From: Hugh Dickins > Date: Thu, 9 May 2002 13:03:52 +0100 (BST) > > filemap_nopage and shmem_nopage do flush_page_to_ram before returning > page, but do_no_page also does flush_page_to_ram on any page it slots > into the user address space. It's memory.c's business, remove it from > shmem and filemap (and cut outdated comment from when filemap copied). > > Wrong, consider the case where we do early COW in do_no_page, you miss > a flush on the new-new page. so you mean we need a flush_page_to_ram also before the copy_user_highpage to be sure we copy uptodate contents of the pagecache? (possibly mapped writeable elsewhere in the user address space?) If not then I don't see how non-flushed pagecache can be mapped into user address space. Andrea