lkml.org 
[lkml]   [2011]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [3.2-rc2] loop device balance_dirty_pages_nr throttling hang
On Tue, Nov 22, 2011 at 08:17:07AM -0500, Theodore Tso wrote:
>
> On Nov 22, 2011, at 5:49 AM, Dave Chinner wrote:
>
> > But, I just noticed that the discard that mkfs.ext4 will result
> > in all the extents being discarded in the underlying image file
> > (due to the fact the loopback device now supports hole
> > punching), so the previous state of the image file is getting
> > trashed by the mkfs.ext4 execution, too. I think I already had a
> > ext4 filesystem in some state before I started running this
> > manual prealloc test....
>
> Which version of mkfs.ext4 are you using? We've disabled the
> discard by default (unless configured in via a command-line option
> or a /etc/mke2fs.conf setting since no distribution apparently
> wants to be responsible for running supplying a command that
> causes a crap SSD to turning into a brick; personally, I'd blame
> the manufacturer of the crap SSD, but….)

Whatever I've got installed on my test machines. The machien I
reproduced the problem originally on with sparse files is runningi
mke2fs 1.42-WIP (16-Oct-2011) which is the latest in Debian
unstable, the other that is using a real 17TB array is running
mke2fs 1.42-WIP (02-Jul-2011). I saw the discard occurring

BTW, on a 5PB sparse image file I get this error from the latest
mke2fs above:

$ ls -lh /mnt/scratch/scratch.img
-rw------- 1 root root 4.9P Nov 23 06:50 /mnt/scratch/scratch.img
$ sudo mkfs.ext4 /dev/loop0
mke2fs 1.42-WIP (16-Oct-2011)
/dev/loop0: Cannot create filesystem with requested number of inodes while setting up superblock
$

This version does emit that it is discarding blocks:

$ sudo mkfs.ext4 /dev/loop0
mke2fs 1.42-WIP (16-Oct-2011)
Discarding device blocks: done
Filesystem label=
.....


Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com
--
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/

\
 
 \ /
  Last update: 2011-11-22 20:59    [W:0.399 / U:0.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site