From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 4B7576B003D for ; Wed, 18 Mar 2009 19:54:39 -0400 (EDT) Received: from spaceape9.eur.corp.google.com (spaceape9.eur.corp.google.com [172.28.16.143]) by smtp-out.google.com with ESMTP id n2INsZ76009023 for ; Wed, 18 Mar 2009 23:54:35 GMT Received: from wf-out-1314.google.com (wfg24.prod.google.com [10.142.7.24]) by spaceape9.eur.corp.google.com with ESMTP id n2INsLQl016256 for ; Wed, 18 Mar 2009 16:54:34 -0700 Received: by wf-out-1314.google.com with SMTP id 24so342647wfg.15 for ; Wed, 18 Mar 2009 16:54:33 -0700 (PDT) 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 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Linus Torvalds Cc: Andrew Morton , linux-kernel , linux-mm , guichaz@gmail.com, Alex Khesin , Mike Waychison , Rohit Seth , Nick Piggin , Peter Zijlstra List-ID: 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, 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: email@kvack.org