2.4.19 hard lock problem

2.4.19 hard lock problem

[Bryan Whitehead]

I have a kernel that hard locks when doing fast NFS and scsi.
the last message from the kernel is:
kernel: (scsi0:A:0:0): Locking max tag count at 64

scsi driver is aic7xxx, nfs is client using tcp and v3. HIGHMEM is on,
when using a kernel configured the same exact way with HIGHMEM off there
is no locking up.

The kernel is not a plain kernel, it's a vendor kernel from Mandrake.
But they don't seem to know what's up. If I need to hand build a kernel
from you guys to help debug, let me know!! :)

further info:
At the consol (no X is running and it's not tainted) I can use the sysrq
keys but they will just further hard lock the kernel so it won't even
respond to the keyboard. I can't get a process list, syncing the disks,
or if I try to get memory stats all result in the kernel being totally
deadlocked.

if you have any other sysrq combo's or any other idea's to try, please 
le mw know! I'm willing to patch, rebuild, patch again till a fix is found.


-- 
Bryan Whitehead
SysAdmin - JPL - Interferometry Systems and Technology
Phone: 818 354 2903
driver@jpl.nasa.gov