[Intel-gfx] [PATCH] Revert "drm/i915: Allocate context objects from stolen"

[Chris Wilson]

On Mon, Jun 29, 2015 at 08:28:35PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Stolen gets trashed during hibernation, so storing contexts there
> is not a very good idea. On my IVB machines this leads to a totally
> dead GPU on resume. A reboot is required to resurrect it. So let's
> not store contexts where they will get trampled.

We need to disable use of stolen entirely then. Fortunately ring buffers
are idle (and so trashable), but all plans for actually using stolen are
off the cards then (e.g. the create2 request to allocate from stolen).

I think it is fairer to say that stolen memory is not restored, and to
do so for hibernation of non-volatile objects would require allocation
of ordinary buffers. Ack on the patch in the short term, does a long
term plan of migrating I915_MADV_WILLNEED stolen objects to normal
memory on hibernation sound acceptable? (I don't like how it makes
hibernation special in terms of shutdown/suspend, but meh)

Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre