drm/i915/gt: Kick virtual siblings on timeslice out

If we decide to timeslice out the current virtual request, we will
unsubmit it while it is still busy (ve->context.inflight == sibling[0]).
If the virtual tasklet and then the other sibling tasklets run before we
completely schedule out the active virtual request for the preemption,
those other tasklets will see that the virtul request is still inflight
on sibling[0] and leave it be. Therefore when we finally schedule-out
the virtual request and if we see that we have passed it back to the
virtual engine, reschedule the virtual tasklet so that it may be
resubmitted on any of the siblings.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200519132046.22443-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index d7ef3f8640d228fcc73334ac4362e80b782f2766..7ee89d58258adae921a2ab09f7456f3d16270fa9 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1402,7 +1402,7 @@ static void kick_siblings(struct i915_request *rq, struct intel_context *ce)
        struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
        struct i915_request *next = READ_ONCE(ve->request);
 
-       if (next && next->execution_mask & ~rq->execution_mask)
+       if (next == rq || (next && next->execution_mask & ~rq->execution_mask))
                tasklet_hi_schedule(&ve->base.execlists.tasklet);
 }