From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Mark Subject: Re: [PATCH 0/2] Re: Discrepancy in 'df' output between kernel 3.0 and 3.2 for ext4? Date: Tue, 19 Jun 2012 16:01:06 -0500 Message-ID: <4FE0E892.4090603@cleversafe.com> References: <4FD8D731.9070008@cleversafe.com> <1340055909-7683-1-git-send-email-tytso@mit.edu> <4FE0D904.7050401@cleversafe.com> <20120619201325.GE22805@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: Ext4 Developers List To: Ted Ts'o Return-path: Received: from mail131.messagelabs.com ([216.82.242.99]:43681 "EHLO mail131.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751873Ab2FSVBo (ORCPT ); Tue, 19 Jun 2012 17:01:44 -0400 In-Reply-To: <20120619201325.GE22805@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 06/19/2012 03:13 PM, Ted Ts'o wrote: > On Tue, Jun 19, 2012 at 02:54:44PM -0500, Zachary Mark wrote: >> >> Ted, thanks for the patches! I've tested your patches against >> 3.5~rc3. I had to return the machine on which I first spotted the >> problem, but here are results from a box with identical hardware: >> >> df from 3.0: >> Filesystem 1K-blocks Used Available Use% Mounted on >> /dev/sdh1 2907178636 205816 2906972820 1% >> /dev/sdi1 2907178636 1056768 2906121868 1% >> >> df from 3.2.20 (identical to 3.5~rc3 without your patches): >> Filesystem 1K-blocks Used Available Use% Mounted on >> /dev/sdh1 2928733612 21760792 2906972820 1% >> /dev/sdi1 2928733612 22611744 2906121868 1% >> >> >> df from 3.5~rc3 with your patches applied (as they didn't apply to 3.2): >> /dev/sdh1 2907178636 205816 2906972820 1% >> /dev/sdi1 2907178636 1060936 2906117700 1% >> >> sdh1 is mostly empty. sdi1 has about 6700 128k files written to it plus >> everything on sdh1. There seems to be slightly more overhead accounted >> for after your patches. Not sure if this is to be expected or not. > > Hmm... it looks like df output /dev/sdh1 is identical between 3.0 and > 3.5~rc3 with my patches. I'm not sure why there is a difference for > /dev/sdi1. However, I note that the "Available" figure is the same > between 3.0, 3.2.20 and 3.5~rc3 for /dev/sdh1, but there is a > difference in the Available column between 3.2.20 and 3.5~rc3 for > /dev/sdi3. Could it be that some files got written to /dev/sdi > between your test run? > > It would be good if we could get this sorted out. I was pretty > careful to account for all of the fs overhead blocks between when I > did my patch with an empty file system. > > If this can't be accounted by more files being written to /dev/sdi1, > could you send me the (compressed, since they will be large) output of > dumpe2fs for /dev/sdh1 and /dev/sdi1 with the "df" output from your > three test kernel so I can investigate further? > > Thanks, > > - Ted Actually, you're right, I must have screwed up my original test somehow. I just repeated the test. The 3.0 and 3.5~rc3-patched numbers are identical to each other, and the 3.2.20/3.5~rc3-unpatched are also identical to each other. -- Zach