Re: [PATCH] Revert "drm/i915: Allocate context objects from stolen"

Chris Wilson
2015-06-29T20:05:45Z

On Mon, Jun 29, 2015 at 08:53:12PM +0100, Chris Wilson wrote:
> On Mon, Jun 29, 2015 at 08:28:35PM +0300, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@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)

I can get a patch to do the migration ready tomorrow, though it will
certainly be quite a few interesting patches.

What's the timeframe for a fix/revert here? (i.e. did this get merged
for 4.2 or was it 4.3?)