On Thu, Aug 8, 2013 at 1:25 AM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > On Thu, Aug 08, 2013 at 01:18:18AM +0200, Daniel Vetter wrote: >> Afaict the request holds a ref on the context, and that a ref on the hw >> context bo. But the active list itself (thanks to the move_to_active) >> should also hold a ref to the hw context bo, so I don't think we really >> need full request here. The old context might disappear, but no one really >> cares if it disappears a notch too early since the backing storage will >> survive long enough. > > The next request holds a ref to the new context. We care about holding a > ref to the old context until the hw has finished writing to it. That is > the purpose of taking a request here, to bump the old_ctx->bo->active > for the context save. Otherwise the backing storage is liable to disappear > too early (and the hw write to a random location). Hm, I might be especially dense, but doesn't the i915_gem_object_move_to_active(from->obj, ring) call right above the add_request take care of exactly that, whether we have the request added or not? And anyone waiting for that object (e.g. the eviction code) will notice in check_olr that the request is missing, add it and then wait for it? -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
