Re: Unplugging of SBP-2 devices still does not work

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

Ben Collins wrote on 2005-07-26:
> Sounds like it is probably hanging in sbp2 while it is trying to logout.

I don't think so. According to dmesg with SBP2_DEBUGs enabled,
scsi_remove_device() is entered but sbp2_logout_device() not.
IOW scsi_remove_device() is not completed. (I'm using sbp2 rev
1316 which calls scsi_remove_device() before logout. Also, I'm
on 2.6.13-rc4 now.)

> Perhaps you can turn on spinlock debug to see if there is a deadlock
> somewhere? Check wstat for the knodemgrd process aswell, see what it is
> waiting for.

I did not enable spinlock debugging yet.
Here is more process info for now:
# ps lx
F   UID   PID  PPID PRI  NI   VSZ  RSS WCHAN  STAT TTY        TIME COMMAND
1     0  1539     1  15   0     0    0 scsi_w D    ?          0:00 [knodemgrd_1]
# cat /proc/1539/wchan
scsi_wait_req

Patrick Mansfield wrote on 2005-07-27:
> Seeing sysrq-t stack traces might help debugging.

The knodemgrd is not traced by sysrq-t, and no userspace task is
hanging.

Thanks for the hints so far, I will hopefully be back with better
debug info later.
-- 
Stefan Richter
-=====-=-=-= -=== ====-
http://arcgraph.de/sr/