On Thu, Dec 12, 2013 at 8:34 PM, Thomas Hellstrom thellstrom@vmware.com wrote:
On 12/12/2013 03:36 PM, Thierry Reding wrote:
This is a simple test module that can be used to allocate, export and delete DMA-BUF objects. It can be used to test DMA-BUF sharing in systems that lack a real second driver.
Looks nice. I wonder whether this could be extended to create a "streaming" dma-buf from a user space mapping. That could be used as a generic way to implement streaming (user) buffer objects, rather than to add explicit support for those in, for example, TTM.
Atm there's no way to get gpus to unbind their dma-buf mappings, so their essentially pinned forever from first use on. Userptr won't really make this worse, but imo we should fix this first before expanding the use-cases too much. And getting dma-bufs to integrate better into existing memory mangers like ttm will be a lot of pain. -Daniel