Re: video doesn't return to console on X shutdown

["Peter H. Coffin" <hellsop_(_at_)_ninehells_(_dot_)_com>]

On Mon, Sep 27, 2004 at 06:59:03PM +0200, Jonathan Thornburg wrote:
> Watching the screen during step 6, I see each X window (including ones
> that are icons at the time start of step 6) open and its screen image
> refresh, before that window disappears (presumably as its process is killed).
> 
> Now the problem:
> If, at the start of step 6, I have lots of X windows around whose
> programs have been inactive for a while (minutes or more)
> 	[typical window set would be
> 	* 4 xterms open
> 	* 12 xterms iconified
> 	* 5 ghostscript/gv windows iconified
> 	* xbatt
> 	* xmeter
> 	* xclock]
> *and* I have run other large-memory programs during that
> "inactive for a while" period
> 	["large-memory" means "enough to make the system page",
> 	eg these days I'm debugging a black-hole-collision
> 	simulation whose current test case takes 400+MB memory]
> so (I believe) the inactive stuff has been swapped out,
> *then*
> the video never switches back to the console in step 7.
> Instead, the screen continues to show the last window or two from
> the "every window opens and refreshes during twm/X shutdown" sequence.
> This screen image never changes until I power-cycle.
> At this point
> * ctrl-alt-del will do what appears to be a clean shutdown
>   (or at least fsck says all the filesystems ar clean),
>   though without the usual shutdown output (step 9 above).
> * No other keyboard input seems to have any effect.
>   In particular, ctrl-alt-f[1234] does NOT get me a virtual console.
>   (Or at least if it does, there's no video to see it. :(
> 
> So, questions...
> * Does anyone recognize this set of symptoms as a known bug?

Not one offhand. It looks like something that's running under X isn't
quitting.

> * Are there any practical workarounds known (to get back the console video)
>   other than manually closing windows before shutting down X?

Does that work? Manually closing everything, that is... If so, it's a
matter of finding which APPLICATION is misbehaving when you're pulling X
out from under it, rather than an OS/X-Window issue.

-- 
Cunningham's First Law:
Any sufficiently complex deterministic system will exhibit
non-deterministic behaviour.