On 17.07.2014 21:00, Marek Olšák wrote:
On Thu, Jul 17, 2014 at 12:01 PM, Michel Dänzer michel@daenzer.net wrote:
From: Michel Dänzer michel.daenzer@amd.com
This is hopefully safe: The kernel makes sure writes to these mappings finish before the GPU might start reading from them, and the GPU caches are invalidated at the start of a command stream.
The resource flags actually tell you what you can do. If the COHERENT flag is set, the mapping must be cached.
Why is that required? As I explain above, we should satisfy the requirements of the ARB_buffer_storage extension AFAICT.
As pointed out by you and Grigori in other posts, I should probably just drop the special treatment of persistent mappings though, so the placement and flags are derived from the buffer usage.