[OpenAFS] apparent OpenAFS and Pre-emptible Linux Kernel issues

[Ryan Underwood]

hello,

It appears that the openafs kernel module needs to be fixed for compatibility
with the pre-emptible Linux kernel.  I have been running 2.4.21-pre5 for
a long time, as well as previous versions, with no problem at all (OpenAFS
1.2.7 from Debian).  Recently I upgraded to a 2.4.21-pre6 for the security
update, and also decided to try the preemption patch.

Everything went smoothly with the new kernel and it performed much better
than the old one without preemption, but after a while of using my machine
(couple hours) I started randomly losing contact with the fileservers,
even though nothing was wrong on the fileserver end (i.e. could still ping
it, /afs still accessible from other boxes).  In addition fs checks indicated
they were up.  I could shutdown and restart the openafs-client, and after
a few minutes of working, the same thing would happen again.

I found this post from a fellow with apparently the same problem:
https://lists.openafs.org/pipermail/openafs-info/2002-November/007133.html

I upgraded to OpenAFS 1.2.8 and rebuilt the client module and tried again
with the same (poor) results.  So I rebuilt the kernel without preemptible
and rebuilt the openafs-client.  The problem hasn't happened again since
I rebooted.

I have no idea where to start tracking this down and don't really have
the time at the moment.  It would be excellent if someone could look into
this, as the pre-emptible patches are now in 2.5 mainline and eventually
this may become an issue anyway.

The preemptible patch is available here:
http://www.tech9.net/rml/linux/

The 2.4.21-pre1 patch should apply mostly cleanly against 2.4.21-pre6.. I
had to do a couple hand merges but nothing big.  The performance improvement
on a loaded desktop is really noticeable, so it would be nice if openafs
would work with this patch.

Thanks!
-- 
Ryan Underwood, <nemesis at icequake.net>, icq=10317253