On 2020-07-22 16:23, Christian König wrote:
Am 22.07.20 um 16:07 schrieb Daniel Vetter:
On Wed, Jul 22, 2020 at 3:12 PM Thomas Hellström (Intel) thomas_os@shipmail.org wrote:
On 2020-07-22 14:41, Daniel Vetter wrote:
I'm pretty sure there's more bugs, I just haven't heard from them yet. Also due to the opt-in nature of dma-fence we can limit the scope of what we fix fairly naturally, just don't put them where no one cares :-) Of course that also hides general locking issues in dma_fence signalling code, but well *shrug*.
Hmm, yes. Another potential big problem would be drivers that want to use gpu page faults in the dma-fence critical sections with the batch-based programming model.
Yeah that's a massive can of worms. But luckily there's no such driver merged in upstream, so hopefully we can think about all the constraints and how to best annotate&enforce this before we land any code and have big regrets.
Do you want a bad news? I once made a prototype for that when Vega10 came out.
But we abandoned this approach for the the batch based approach because of the horrible performance.
In context of the previous discussion I'd consider the fact that it's not performant in the batch-based model good news :)
Thomas
KFD is going to see that, but this is only with user queues and no dma_fence involved whatsoever.
Christian.
-Daniel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx