Hanging problem...

Jim Paradis (paradis@amt.tay1.dec.com)
Sat, 28 Oct 1995 01:49:26 -0500 (EDT)


Well, folks, I've been hard at work on BLADE 0.3 the past few days.
I've been using a NoName system as my development platform, with a
SCSI root disk and an IDE development area.

I've been getting mysterious hangs whenever I bang *hard* on the disk
(e.g. when I take 30+Mb of stuff and crunch it down into 8 floppy
images...). This is, to say the least, annoying.

I've seen this mainly on the IDE disk (e.g. moving stuff to the SCSI
disk often alleviates the problem), but I coulda sworn I saw it once or
twice when I've been just banging on the SCSI disk.

The system doesn't *completely* hang; I can do things that don't use
the affected drive. Anything that does (including a sync) hangs forever.

Hitting SHIFT+SCROLLOCK when this happens reveals that in every case
there is exactly *one* buffer that's locked... so I think there's either
a deadlock or some code path that's not releasing a buffer when it
should... I'm not sure this is an Alpha-specific problem either...

I backtracked through David M-T's wonderful collection of prebuilt
kernels; the problem doesn't appear in 1.3.27 but does appear in 1.3.31
and later (I've tried all the way through .36). I suppose I could
look at the diffs, but I was wondering if anyone had any ideas off
the top of their head...

Thanks!

-- 
Jim Paradis (paradis@amt.tay1.dec.com)        "It's not procrastination, 
Digital Equipment Corporation		       it's my new Just-In-Time 
(508)952-4047				       Workload Management System!"