Deprecation of AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED

[Michel Dänzer]

On 30/06/17 03:59 PM, Christian König wrote:
> Am 30.06.2017 um 08:51 schrieb Michel Dänzer:
>> We can deal with that internally in the kernel, while fixing the
>> existing flag for userspace.
> 
> And as I said, NAK to that approach. I'm not going to add a
> CPU_ACCESS_REALLY_REQUIRED flag in the kernel just because mesa has
> messed up it's use case.
> 
> We could agree on filtering that flag from userspace when BOs are
> created and/or map it to a CREATE_CPU_ACCESS_HINT flag.

Then I propose the following:

One patch:

Convert AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED to a kernel internal flag
AMDGPU_GEM_CPU_ACCESS_HINT in amdgpu_gem_create_ioctl, which is
initially treated the same way as AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED.

Another patch:

Change the treatment of AMDGPU_GEM_CPU_ACCESS_HINT according to John's
patch 4 in the latest series, or a variation of that as discussed on IRC.


If any regressions are reported, we will be able to differentiate
whether they are due to the addition of the new flag itself or due to
the change in its handling.


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