From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271038AbUJUWlf (ORCPT ); Thu, 21 Oct 2004 18:41:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271041AbUJUWkL (ORCPT ); Thu, 21 Oct 2004 18:40:11 -0400 Received: from mail-relay-2.tiscali.it ([213.205.33.42]:28876 "EHLO mail-relay-2.tiscali.it") by vger.kernel.org with ESMTP id S271038AbUJUWfb (ORCPT ); Thu, 21 Oct 2004 18:35:31 -0400 Date: Fri, 22 Oct 2004 00:36:13 +0200 From: Andrea Arcangeli To: Andrew Morton Cc: Dave Kleikamp , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] zap_pte_range should not mark non-uptodate pages dirty Message-ID: <20041021223613.GA8756@dualathlon.random> References: <1098393346.7157.112.camel@localhost> <20041021144531.22dd0d54.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041021144531.22dd0d54.akpm@osdl.org> X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 21, 2004 at 02:45:31PM -0700, Andrew Morton wrote: > Maybe we should revisit invalidate_inode_pages2(). It used to be an > invariant that "pages which are mapped into process address space are > always uptodate". We broke that (good) invariant and we're now seeing > some fallout. There may be more. such invariant doesn't exists since 2.4.10. There's no way to get mmaps reload data from disk without breaking such an invariant. It's not even for the write side, it's buffered read against O_DIRECT write that requires breaking such invariant. Either you fix it the above way, or you remove the BUG() in pdflush and you simply clear the dirty bit without doing anything, both are fine, peraphs we should do both, but the above is good to have anyways since it's more efficient to not even show the not uptodate pages to pdflush. From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 22 Oct 2004 00:36:13 +0200 From: Andrea Arcangeli Subject: Re: [PATCH] zap_pte_range should not mark non-uptodate pages dirty Message-ID: <20041021223613.GA8756@dualathlon.random> References: <1098393346.7157.112.camel@localhost> <20041021144531.22dd0d54.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041021144531.22dd0d54.akpm@osdl.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Dave Kleikamp , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Thu, Oct 21, 2004 at 02:45:31PM -0700, Andrew Morton wrote: > Maybe we should revisit invalidate_inode_pages2(). It used to be an > invariant that "pages which are mapped into process address space are > always uptodate". We broke that (good) invariant and we're now seeing > some fallout. There may be more. such invariant doesn't exists since 2.4.10. There's no way to get mmaps reload data from disk without breaking such an invariant. It's not even for the write side, it's buffered read against O_DIRECT write that requires breaking such invariant. Either you fix it the above way, or you remove the BUG() in pdflush and you simply clear the dirty bit without doing anything, both are fine, peraphs we should do both, but the above is good to have anyways since it's more efficient to not even show the not uptodate pages to pdflush. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org