From: Chris Mason <clm@fb.com>
To: Julien Muchembled <jm@jmuchemb.eu>
Cc: <linux-btrfs@vger.kernel.org>
Subject: Re: kernel >= 3.16 saturates I/O endlessly and without reason
Date: Tue, 11 Nov 2014 15:30:58 -0500 [thread overview]
Message-ID: <1415737858.25389.0@mail.thefacebook.com> (raw)
In-Reply-To: <54626D23.20701@jmuchemb.eu>
On Tue, Nov 11, 2014 at 3:10 PM, Julien Muchembled <jm@jmuchemb.eu>
wrote:
> Hello,
>
> I upgraded my kernel from 3.15.10 to 3.17.2 and after a while, btrfs
> kworkers started to read/write data at maximum speed for hours
> whereas I was doing nothing. So I rebooted with kernel 3.15.10 and
> hopefully everything went back to normal. Later attempts to upgrade
> to 3.16.7 or 3.17.2 showed the same issue, immediately at boot or
> after a while.
>
> In order to investigate a little, I copied the partition and mounted
> it in qemu (snapshot mode, with cow file in tmpfs, debian kernel
> 3.16.7-2). I could see that btrfs always wrote the same ~8MB in loop.
> qemu used all cpu and when I stopped it, it wrote 190G and the
> generation number raised from 625955 to 853922.
>
> I dumped the FS with btrfs-image. The restored FS has the same issue
> so I can send the image (78M) to anyone who would like to debug.
Which mount options are you using? This sounds like something in
autodefrag...
-chris
next prev parent reply other threads:[~2014-11-11 20:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-11 20:10 kernel >= 3.16 saturates I/O endlessly and without reason Julien Muchembled
2014-11-11 20:30 ` Chris Mason [this message]
2014-11-11 21:05 ` Julien Muchembled
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=1415737858.25389.0@mail.thefacebook.com \
--to=clm@fb.com \
--cc=jm@jmuchemb.eu \
--cc=linux-btrfs@vger.kernel.org \
/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