From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755299AbZELPiV (ORCPT ); Tue, 12 May 2009 11:38:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751603AbZELPiF (ORCPT ); Tue, 12 May 2009 11:38:05 -0400 Received: from yw-out-2324.google.com ([74.125.46.30]:19889 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751274AbZELPiC convert rfc822-to-8bit (ORCPT ); Tue, 12 May 2009 11:38:02 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; b=OL8Cdd++tcjuW69uK7cr/6XzOtMyNPeEfVqwzD1rhHQ3opZcj6z+ket9u1OaVs407F ssrheN/TSLZ4hl7+Ib+oTCjpMKqjIMXiiiYnJX46fTXMRvXGWSK0F6Z0AkbM0a78Iyp6 WQcDHu+AGjm/ea9KcavAHkVtd1Ys+hSWnr4zc= MIME-Version: 1.0 In-Reply-To: <87ljp2v6vt.fsf@tac.ki.iif.hu> References: <874ovws94s.fsf@tac.ki.iif.hu> <87ljp2v6vt.fsf@tac.ki.iif.hu> From: Ray Lee Date: Tue, 12 May 2009 08:37:43 -0700 X-Google-Sender-Auth: ec4c982b364e7599 Message-ID: <2c0942db0905120837g702b457bm52a412293925021a@mail.gmail.com> Subject: Re: mmap vs mtime in 2.6.26 and up To: Ferenc Wagner , Christoph Hellwig , Andrew Morton , xfs@oss.sgi.com Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (Adding Christoph Hellwig, xfs list, Andrew Morton to cc:) On Tue, May 12, 2009 at 5:32 AM, Ferenc Wagner wrote: > Hi, > > I've noticed that the last modification times of our RRD files got > stuck after upgrading from 2.6.24 to 2.6.26 (Debian Etch -> Lenny; I > also tested with 2.6.30-rc5, they are still stuck).  It has some > literature, most notably kernel bug #2645, but that's closed long ago > and the resulting patch http://lkml.org/lkml/2008/1/22/370 is present > in my kernels.  Still, the test program (version 3 from the bug report) > gives failures: > > $ ./mmap_test junk > Modifying junk... > Flushing data using sync()... > Failure: time not changed. > Not modifying junk... > Flushing data using msync()... > Success: time not changed. > Not modifying junk... > Flushing data using fsync()... > Success: time not changed. > Modifying junk... > Flushing data using msync()... > Failure: time not changed. > Modifying junk... > Flushing data using fsync()... > Failure: time not changed. > > Is this as expected?  I reckon the bug wasn't solved fully, but it > seems to be worse that that. I don't think that's expected. Further, the test program (v3) from that bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=2645 works for me under ext3, so perhaps this is an xfs-specific issue. > > I don't know if it's related or not, but another anomaly appeared > after the upgrade: minutes-long remount times.  The machine always was > under a fair load (10), but mount /usr -oremount,rw never took > noticeable time.  The IO load pushes two other filesystems.  Now > strace -tt shows: > > [...] > 01:24:08.463813 stat64("/sbin/mount.xfs", 0xbfa40eb0) = -1 ENOENT (No such file or directory) > 01:24:08.463904 mount("/dev/mapper/noc7-usr", "/usr", 0x894a2c8, MS_MGC_VAL|MS_NODEV|MS_REMOUNT, NULL) = 0 > 01:26:58.705387 readlink("/dev", 0xbfa3ef3b, 4096) = -1 EINVAL (Invalid argument) > [...] > > After this, remount ro and rw again are quick for some time. > (I couldn't test this part with 2.6.30-rc5, but again, this may be > totally unrelated.) > > This bug is quite serious in our environment, as it thwarts the backup > software.  The file system is xfs; rw,nosuid,nodev,nobarrier,noquota. > -- > Regards, > Feri.