Re: kernel panic (2.5.67-ac1)

[Patrick Mansfield <patmans@us.ibm.com>]

On Mon, Apr 14, 2003 at 12:25:48PM -0700, Christian Staudenmayer wrote:
> hello,
> 
> (i've posted a similar message before but i've been told to add the whole error
> message, so here it is. sorry about that, but typing screenfulls of hex numbers
> makes me feel like a geek but it also makes my head hurt ;)
> 
> the 2.5.67 kernel boots fine here, but the -ac1 patch to it ends up in 
> a kernel panic.
> here are the last 25 lines of the error, i don't know if there is more above of it,
> scrolling up didn't work... (btw there can be typos in it ;)

This stack looks very much like the problem with scsi queue plugging
behaviour and the removal of blk_empty_queue. It is not always hit, there
could easily be something in ac that changed the timing.

[If so] this is not a problem in the ac kernel, even though you only hit
it after adding the ac patch.

James B sent in a fix, it's included in the current bk tree, the changelog
says:

  fix scsi queue plugging behaviour
  
  Following recent changes removing blk_queue_empty(), we were
  incorrectly plugging the queue some times (most often as part of
  the SCSI scan process).  This was causing a non-deterministic panic
  in the scan code because a destroyed queue was sometimes being
  unplugged and run.

Or see this for log and patch:

http://linux.bkbits.net:8080/linux-2.5/cset@1.971.103.27?nav=index.html|ChangeSet@-2d

The patch won't apply cleanly on top of 2.5.67.

-- Patrick Mansfield