From: Dave Chinner <david@fromorbit.com>
To: Theodore Tso <tytso@MIT.EDU>
Cc: Wu Fengguang <fengguang.wu@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [3.2-rc2] loop device balance_dirty_pages_nr throttling hang
Date: Wed, 23 Nov 2011 06:56:51 +1100 [thread overview]
Message-ID: <20111122195651.GN2386@dastard> (raw)
In-Reply-To: <ED3D1B07-DEC4-43C8-80A9-739C4973ABF9@mit.edu>
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
prev parent reply other threads:[~2011-11-22 19:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-21 14:20 [3.2-rc2] loop device balance_dirty_pages_nr throttling hang Dave Chinner
2011-11-22 3:56 ` Wu Fengguang
2011-11-22 10:29 ` Dave Chinner
2011-11-22 10:49 ` Dave Chinner
2011-11-22 13:17 ` Theodore Tso
2011-11-22 19:56 ` Dave Chinner [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20111122195651.GN2386@dastard \
--to=david@fromorbit.com \
--cc=fengguang.wu@intel.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tytso@MIT.EDU \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).