Re: unconfiguring swap at shutdown

[David Holland <dholland-tech%netbsd.org@localhost>]

On Wed, Sep 03, 2008 at 09:37:33AM -0400, der Mouse wrote:
 > > Processes end up unkillable because they're in an uninterruptible
 > > wait.  If you interrupt the uninterruptible wait, there's no recovery
 > > and cleanup code.  So you're pretty much limited to taking the
 > > process out of the process table and dropping it on the floor; but
 > > that doesn't really accomplish anything.
 > 
 > If you're trying to shut down, it does indeed - it gets rid of the
 > process that's holding all those pages on swap.  This "recovery" is
 > basically what happens now if you shut down a system with a process
 > stuck in an unkillable wait, after all; it's just at a different point.

No, only if you go destroy (or at least clean out) the address space,
but if you do that while the process is stuck somewhere and probably
holding locks, you're likely to deadlock.

"drop on the floor" does not mean "go through exit()".

-- 
David A. Holland
dholland%netbsd.org@localhost