Quoting Tvrtko Ursulin (2019-09-20 16:12:23) > > On 20/09/2019 15:57, Chris Wilson wrote: > > Quoting Chris Wilson (2019-09-20 09:36:24) > >> Force bonded requests to run on distinct engines so that they cannot be > >> shuffled onto the same engine where timeslicing will reverse the order. > >> A bonded request will often wait on a semaphore signaled by its master, > >> creating an implicit dependency -- if we ignore that implicit dependency > >> and allow the bonded request to run on the same engine and before its > >> master, we will cause a GPU hang. > > > > Thinking more, it should not directly cause a GPU hang, as the stuck request > > should be timesliced away, and each preemption should be enough to keep > > hangcheck at bay (though we have evidence it may not). So at best it runs > > at half-speed, at worst a third (if my model is correct). > > But I think it is still correct to do since we don't have the coupling > information on re-submit. Hm.. but don't we need to prevent slave from > changing engines as well? Yes, it still looks like a sensible enough patch (even if I am biased because I think it is cute), especially in light of how we only run the bond_execute once and do not reconfigure the execution_mask on unsubmit. Still working on the test cases to exercise timeslicing + submit/bonding. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
