On Mon, Nov 07, 2016 at 01:59:45PM +0000, Chris Wilson wrote: > The scheduler needs to know the dependencies of each request for the > lifetime of the request, as it may choose to reschedule the requests at > any time and must ensure the dependency tree is not broken. This is in > additional to using the fence to only allow execution after all > dependencies have been completed. > > One option was to extend the fence to support the bidirectional > dependency tracking required by the scheduler. However the mismatch in > lifetimes between the submit fence and the request essentially meant > that we had to build a completely separate struct (and we could not > simply reuse the existing waitqueue in the fence for one half of the > dependency tracking). The extra dependency tracking simply did not mesh > well with the fence, and keeping it separate both keeps the fence > implementation simpler and allows us to extend the dependency tracking > into a priority tree (whilst maintaining support for reordering the > tree). > > To avoid the additional allocations and list manipulations, the use of > the priotree is disabled when there are no schedulers to use it. > > v2: Create a dedicated slab for i915_dependency. > Rename the lists. Sod. I've squashed the priority sort into this as a rebase calamity. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
