[JFFS2] Running fsstress on JFFS2 causing freeze

[JFFS2] Running fsstress on JFFS2 causing freeze

[rohit h]

Hello everyone.
I am running a filesystem testing application "fsstress" on JFFS2.
The JFFS2 code is from linux-2.6.22 kernel.All the processes spawned
by fsstress do filesystem operations on the JFFS2 partition.After some
time all the processes go into "UNINTERRUPTIBLE SLEEP" state as shown.

bash-2.05a# ps -aux
  PID  Uid     VmSize Stat Command
    1 root        140 S   init [3]
    2 root            SW< [kthreadd]
    3 root            SWN [ksoftirqd/0]
    4 root            SW< [watchdog/0]
    5 root            SW< [events/0]
    6 root            SW< [khelper]
   36 root            SW< [kblockd/0]
   37 root            SW< [omap2_mcspi/0]
   53 root            SW  [pdflush]
   54 root            SW< [kswapd0]
   55 root            SW< [aio/0]
  156 root            SW< [mtdblockd]
  166 root            SW< [kmmcd]
  170 root            SW< [rpciod/0]
  186 root        260 S   /sbin/syslogd
  191 root        120 S   /usr/sbin/inetd
  197 root        892 S   /bin/bash
  200 root            SWN [jffs2_gcd_mtd1]
  201 root        208 S   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  312 root        280 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  313 root        372 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  314 root        392 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  315 root        488 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  316 root        388 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  317 root        376 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  318 root        404 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  319 root        396 D   /tools/fsstress -p 8 -n 100000 -d /tmp -l 0
  337 root        684 R   ps -aux

I checked the entry in /proc/process_id/wchan for each of the sleeping
processes.
( wchan gives the function the process is currently executing ).
Here is the output:
jffs2_garbage_collect_thread -> this is for jffs2_gcd_mtd1
do_wait
jffs2_mknod
jffs2_do_link
lock_rename
jffs2_write_inode_range
lock_rename
lock_rename
lock_rename
lock_rename

I have the feel that there is a deadlock.
Does anybody have any idea about this?
Thanks,
Rohit

Re: [JFFS2] Running fsstress on JFFS2 causing freeze

[Adrian Hunter]

rohit h wrote:
> ( wchan gives the function the process is currently executing ).

A better way is to dump the task list to the console, which you can probably do like this:

	sudo echo t > /proc/sysrq-trigger

	dmesg > my_console_messages.txt

(More information in the kernel source in Documentation/sysrq.txt or search the internet for "sysrq")

Then send us my_console_messages.txt

Re: [JFFS2] Running fsstress on JFFS2 causing freeze

[Adrian Hunter]

rohit h wrote:
> Hello everyone.
> I am running a filesystem testing application "fsstress" on JFFS2.
> The JFFS2 code is from linux-2.6.22 kernel.All the processes spawned
> by fsstress do filesystem operations on the JFFS2 partition.After some
> time all the processes go into "UNINTERRUPTIBLE SLEEP" state as shown.

It is probably the same issue described here:

http://lists.infradead.org/pipermail/linux-mtd/2008-April/021039.html

Re: [JFFS2] Running fsstress on JFFS2 causing freeze

[rohit h]

On Tue, Apr 15, 2008 at 6:47 PM, Adrian Hunter
<ext-adrian.hunter@nokia.com> wrote:
> rohit h wrote:
>
> > Hello everyone.
> > I am running a filesystem testing application "fsstress" on JFFS2.
> > The JFFS2 code is from linux-2.6.22 kernel.All the processes spawned
> > by fsstress do filesystem operations on the JFFS2 partition.After some
> > time all the processes go into "UNINTERRUPTIBLE SLEEP" state as shown.
> >
>
>  It is probably the same issue described here:
>
>  http://lists.infradead.org/pipermail/linux-mtd/2008-April/021039.html
>
>
Thanks a lot.
I'll  test the patch and post the the results.
Rohit

Re: [JFFS2] Running fsstress on JFFS2 causing freeze

[rohit h]

Yup, the patch solves the deadlock.

On Thu, Apr 17, 2008 at 2:28 PM, rohit h <hrohit85@gmail.com> wrote:
> Thanks a lot.
> I'll  test the patch and post the the results.
> Rohit
>