On 11/10/16 09:04 PM, Christian König wrote: > Am 11.10.2016 um 05:58 schrieb Michel Dänzer: >> On 07/10/16 09:34 PM, Mike Lothian wrote: >>> This has discussion has gone a little quiet >>> >>> Was there any agreement about what needed doing to get this working >>> for i965/amdgpu? >> Christian, do you see anything which could prevent the solution I >> outlined from working? > > I thought about that approach as well, but unfortunately it also has a > couple of downsides. Especially keeping the exclusive fence set while we > actually don't need it isn't really clean either. I was wondering if it's possible to have a singleton pseudo exclusive fence which is used for all BOs. That might keep the overhead acceptably low. > I'm currently a bit busy with other tasks and so put Nayan on a road to > get a bit into the kernel driver (he asked for that anyway). > > Implementing the simple workaround to sync when we export the DMA-buf > should be something like 20 lines of code and fortunately Nayan has an > I+A system and so can actually test it. > > If it turns out to be more problematic or somebody really starts to need > it I'm going to hack on that myself a bit more. If you mean only syncing when a DMA-buf is exported, that's not enough, as I explained before. The BOs being shared are long-lived, and synchronization between GPUs is required for every command stream submission. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer
