[Intel-gfx] [PATCH 3/3] drm/i915: Use insert_page for pwrite_fast

[Tvrtko Ursulin]

On 05/11/15 12:42, Chris Wilson wrote:
> On Thu, Nov 05, 2015 at 12:37:46PM +0000, Tvrtko Ursulin wrote:
>>
>> On 05/11/15 11:45, ankitprasad.r.sharma at intel.com wrote:
>>> From: Ankitprasad Sharma <ankitprasad.r.sharma at intel.com>
>>>
>>> In pwrite_fast, map an object page by page if obj_ggtt_pin fails. First,
>>> we try a nonblocking pin for the whole object (since that is fastest if
>>> reused), then failing that we try to grab one page in the mappable
>>> aperture. It also allows us to handle objects larger than the mappable
>>> aperture (e.g. if we need to pwrite with vGPU restricting the aperture
>>> to a measely 8MiB or something like that).
>>
>> Aperture in aperture, reminds me of those "Yo dawg I've heard you
>> like X so I've put X in your X so you can Y while you Y" jokes. :D
>>
>> Would using the partial view code be interesting for this? Might be
>> faster due to larger chunks possible, or slower due more expensive
>> set up time, I don't know.
>
> It's the wrong abstraction.

Looks the same to me, only difference is the size.

Why not just to the page aperture then for simplicity? If there is any 
performance gain from trying the full VMA first then why there wouldn't 
be some to try with the partial VMA?

Regards,

Tvrtko