[PATCH] drm/radeon: remove visible vram size limit on bo allocation

[Michel Dänzer]

On 18.07.2014 12:26, Alex Deucher wrote:
> On Thu, Jul 17, 2014 at 8:41 PM, Michel Dänzer <michel at daenzer.net> wrote:
>> On 18.07.2014 01:29, Alex Deucher wrote:
>>> @@ -55,10 +55,13 @@ int radeon_gem_object_create(struct radeon_device *rdev, int size,
>>>               alignment = PAGE_SIZE;
>>>       }
>>>
>>> -     /* maximun bo size is the minimun btw visible vram and gtt size */
>>> -     max_size = min(rdev->mc.visible_vram_size, rdev->mc.gtt_size);
>>> +     /* Maximum bo size is the gtt size since we use the gtt to handle
>>> +      * vram to system pool migrations.  We could probably remove this
>>> +      * check altogether with a little additional work.
>>> +      */
>>
>> This comment needs updating: it's not the full GTT size anymore, and how
>> could we remove this check?
> 
> I'll update it.  We could remove it if we added support for breaking
> down vram <-> system transfers into smaller operations.  E.g., if the
> available vram size was twice the size of the available gtt space, we
> could transfer the first half, then update the gart table and transfer
> the second half.

Right, OTOH I suspect it's even less likely that BOs of (almost) the
size of VRAM can actually be used in VRAM, because e.g. scanout buffers
are pinned anywhere in VRAM.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer