Quoting Mika Kuoppala (2020-05-08 16:37:15) > Chris Wilson <ch...@chris-wilson.co.uk> writes: > > > The downside of using semaphores is that we lose metadata passing > > along the signaling chain. This is particularly nasty when we > > need to pass along a fatal error such as EFAULT or EDEADLK. For > > fatal errors we want to scrub the request before it is executed, > > which means that we cannot preload the request onto HW and have > > it wait upon a semaphore. > > b is waiting on a, a fails and we want to release b with error?
Yes. B is submitted before A, and if B is relying on A to setup GPU page tables or other interesting things, we can't let B run if A dies. For the EDEADLK if B is waiting on A, but then A is submitted with a wait on B -- we have to untangle that mess. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
