XOrg freeze that affects a lot of people

[Randall Nortman]

On Mon, Mar 21, 2005 at 12:27:27PM +1100, Daniel Stone wrote:
[...]
> Xorg will call into the driver, and the driver will attempt to do stuff.
> 
> But the GPU's wedged, and not responding, so the driver will never
> return (and there's really not much you can do to prevent this, except
> a watchdog, ish).  So Xorg's just waiting on a function call to return.
> 
> But that function call will never return.
[...]

I never do any coding anywhere near the hardware/kernel level (at
least not on Linux), so this might be a stupid idea, but...

How about arranging for a SIGALRM to be sent to the X process every
second or so, and the signal handler could then detect (via some
global "watchdog" variable that's supposed to be incremented at least
once a second) when the driver is hung and do something graceful
(exit, restart, etc.).

Randall