[plug] kill them dead

[Ian Kent]

On Sat, 2006-10-14 at 17:39 +0800, Gavin Chester wrote:
> On Sat, 2006-10-14 at 11:45 +0800, Arie Hol wrote:
> 
> -snip-
> 
> > It may not be the fault of Linux....
> > 
> > There could be a problem with the optical drive - or the drive may have a 
> > problem with certain types of media.
> > 
> > When you have the problem - are you trying to read commercially produced 
> > discs or burnt copies ??????????           :-)
> 
> The first one :-)  K9copy sort of freezes with certain discs and the
> drive just spins and spins and ignores all kill and eject commands and
> is unavailable for other processes - as you would expect.  Once I can
> kill k9copy by some means then the drive is freed up again.  I was
> approaching this from the other angle: software at fault rather than
> media or drive.  You may have a point, but the original topic still
> remains: how to kill it dead and wrest back control of the drive.

You can't kill a process that is in an uninterruptable sleep. There are
times when drivers "must" not be interrupted during a task and so they
set this process flag when sleeping, waiting for the operation. In some
circumstances it can be really hard to do this any other way, for
example due to restrictions on what can be done in interrupt context in
the kernel.

Historically NFS is kinda notorious for this on all *nixs.

Ian