On Fri, Mar 20, 2015 at 02:45:04PM +0000, Chris Wilson wrote: > On Fri, Mar 20, 2015 at 03:32:52PM +0100, Daniel Vetter wrote: > > But if we do that short-circuiting in ring_idle the all the requests > > _should_ be completed. Which meanse retire_request_ring should move all > > buffers to the inactive list, even when we do that before retiring > > requests. > > We test for the requests to be retired after we test for the buffers to > be retired. It is very easy then for us to have active buffers as the > seqno advanced after the buffer retirement and before the requests. That > is (one of) the reasons why we previously sampled seqno only once when > retiring buffers + requests. Yeah I get that part of the race. But before we retire anything in these callsites we call gpu_idle. And that waits for everything to complete, except whent there are not outstanding requests (i.e. ->request_list is empyt). So either - ->request_list is empty in ring_idle, which means all requests should have completed. Even if there are some lingering active buffers still around we should clean them up. - ->request_list is not empty, in which case we do a full wait for the most recent request. Again all requests should have completed and we should be able to clean out both request and active lists. I do see how we can get out of the retire_request functions with requests empty but still active buffers around. But I don't understand how that's possible with a gpu_idle in front. And thus far all traces are from places where we do call gpu_idle first. Or am I missing something? -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
