Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757876AbZCRXyu (ORCPT ); Wed, 18 Mar 2009 19:54:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753184AbZCRXyk (ORCPT ); Wed, 18 Mar 2009 19:54:40 -0400 Received: from smtp-out.google.com ([216.239.33.17]:22322 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945AbZCRXyj (ORCPT ); Wed, 18 Mar 2009 19:54:39 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=PJ/Em11c05VCmLn+Zto9GKeOWj6CKwmxG4I60NTlFLHSsfgfqlvXw+TXQgrSnaSao m0mpCz4MpFeLDrGAN+BYw== MIME-Version: 1.0 In-Reply-To: References: <604427e00903181244w360c5519k9179d5c3e5cd6ab3@mail.gmail.com> <20090318151157.85109100.akpm@linux-foundation.org> <604427e00903181618t66020557kda533d37f51d7e7d@mail.gmail.com> Date: Wed, 18 Mar 2009 16:54:33 -0700 Message-ID: <604427e00903181654y308d57d8w2cb32eab831cf45a@mail.gmail.com> Subject: Re: ftruncate-mmap: pages are lost after writing to mmaped file. From: Ying Han To: Linus Torvalds Cc: Andrew Morton , linux-kernel , linux-mm , guichaz@gmail.com, Alex Khesin , Mike Waychison , Rohit Seth , Nick Piggin , Peter Zijlstra Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 45 On Wed, Mar 18, 2009 at 4:36 PM, Linus Torvalds wrote: > > > On Wed, 18 Mar 2009, Ying Han wrote: >> > >> > Can you say what filesystem, and what mount-flags you use? Iirc, last time >> > we had MAP_SHARED lost writes it was at least partly triggered by the >> > filesystem doing its own flushing independently of the VM (ie ext3 with >> > "data=journal", I think), so that kind of thing does tend to matter. >> >> /etc/fstab >> "/dev/hda1 / ext2 defaults 1 0" > > Sadly, /etc/fstab is not necessarily accurate for the root filesystem. At > least Fedora will ignore the flags in it. > > What does /proc/mounts say? That should be a more reliable indication of > what the kernel actually does. "/dev/root / ext2 rw,errors=continue 0 0" > > That said, I assume the ext2 part is accurate. Maybe that's why people > haven't seen it - I guess most testing was done on ext3. It certainly was > for me. > >> > Ying Han - since you're all set up for testing this and have reproduced it >> > on multiple kernels, can you try it on a few more kernel versions? It >> > would be interesting to both go further back in time (say 2.6.15-ish), >> > _and_ check something like 2.6.21 which had the exact dirty accounting >> > fix. Maybe it's not really an old bug - maybe we re-introduced a bug that >> > was fixed for a while. >> >> I will give a try. > > Thanks, > > 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/