[Nouveau] CCACHE and VFETCH FAULTs causing lockups

[Ben Skeggs]

On Tue, 2011-03-01 at 21:08 +0000, Maarten Maathuis wrote:

> Those come after 15-30 minutes of running warzone2100, i haven't
> played any games for a while, so no idea how long this has been going
> on.
> I also got a TRAP_CCACHE on channel 2 a little while ago, it takes
> much longer to trigger (a few hours). I'm using todays "nouveau
> kernel" git.
You're not the first person to have reported this fwiw, personally, I
haven't seen it yet..

> 
> I'm guessing something is being unmapped too early or without reason,
> or some cache is stale. But it isn't obvious what exactly it is.
> 
> Because i don't remember having these lockups before I'm inclined to
> guess that this commit is involved
> http://cgit.freedesktop.org/nouveau/linux-2.6/commit/?id=6330d8f5ecc4a19fd2ad3c7fa128b2f4c2ce3360
> 
> Any ideas?
Not really.  If this commit *is* the cause, the problem is still
somewhere else.  That commit just makes sure PTEs are marked invalid, so
if it's causing your faults, then previously the GPU would still have
been reading/writing invalid data.

Plus, I expect you should probably have seen a VM fault..

Ben.
> 
> Maarten.
>