[Mesa-dev] [PATCH 1/2] gallium: Add PIPE_CAP_USER_MEMORY_PAGE_SIZE for page size of user pointers

Michel Dänzer michel at daenzer.net
Thu Aug 17 02:51:22 UTC 2017

On 17/08/17 11:48 AM, Alex Deucher wrote:
> On Wed, Aug 16, 2017 at 10:39 PM, Michel Dänzer <michel at daenzer.net> wrote:
>> On 17/08/17 10:52 AM, Aaron Watry wrote:
>>> PIPE_CAP_RESOURCE_FROM_USER_MEMORY says that size must be page aligned,
>>> but doesn't necessarily say anything about the size of those pages.
>> Is there any case known so far where it's not the CPU page size?
> It's always the CPU page size.  The limitation is not a hw limitation,
> it's a sw limitation with the way the kernel handles creating BOs from
> user memory.

Right, I suspect "page" in the PIPE_CAP_RESOURCE_FROM_USER_MEMORY
documentation was always intended as "CPU page". Maybe that just needs
to be clarified.

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

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