Am 21.07.20 um 09:41 schrieb Daniel Vetter:
On Mon, Jul 20, 2020 at 01:15:17PM +0200, Thomas Hellström (Intel) wrote:
Hi,
On 7/9/20 2:33 PM, Daniel Vetter wrote:
Comes up every few years, gets somewhat tedious to discuss, let's write this down once and for all.
What I'm not sure about is whether the text should be more explicit in flat out mandating the amdkfd eviction fences for long running compute workloads or workloads where userspace fencing is allowed.
Although (in my humble opinion) it might be possible to completely untangle kernel-introduced fences for resource management and dma-fences used for completion- and dependency tracking and lift a lot of restrictions for the dma-fences, including prohibiting infinite ones, I think this makes sense describing the current state.
Yeah I think a future patch needs to type up how we want to make that happen (for some cross driver consistency) and what needs to be considered. Some of the necessary parts are already there (with like the preemption fences amdkfd has as an example), but I think some clear docs on what's required from both hw, drivers and userspace would be really good.
I'm currently writing that up, but probably still need a few days for this.
Christian.
Reviewed-by: Thomas Hellstrom thomas.hellstrom@intel.com
Thanks for taking a look, first 3 patches here with annotations and docs merged to drm-misc-next. I'll ask Maarten/Dave whether another pull is ok for 5.9 so that everyone can use this asap. -Daniel