On Mon, 24 Sep 2007 11:01:58 -0700
Badari Pulavarty [off-list ref] wrote:

Hi Andy,

I managed to reproduce the dbench problem. (not sure if its the same
thing or not - but symptoms are same). My problem has nothing to do 
with ext3. I can produce it on ext2, jfs also.

Whats happening on my machine is ..

dbench forks of 4 children and sends them a signal to start the work.
3 out of 4 children gets the signal and does the work. One of the child
never gets the signal so, it waits forever in pause(). So, parent waits
for a longtime to kill it.

BTW, I was trying to find out when this problem started showing up.
So far, I managed to track it to 2.6.23-rc4. (2.6.23-rc3 doesn't seem
to have this problem). I am going to do bi-sect and find out which
patch caused this.

I am using dbench-2.0 which consistently reproduces the problem on
my x86-64 box. Did you find anything new with your setup ?

Thanks, Badari.  That sounds like a bit of a showstopper for 2.6.23.
Michal, do you have this regression in the dirt file?