drm/i915/execlists: Mark up priority boost on preemption

Record the priority boost we giving to the preempted client or else we may end up in a situation where the priority queue no longer matches the request priority order and so we can end up in an infinite loop of preempting the same pair of requests. Fixes: e9eaf82 ("drm/i915: Priority boost for waiting clients") Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Reviewed-by: Tvrtko Ursulin <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] (cherry picked from commit 6e062b6) Signed-off-by: Jani Nikula <[email protected]>
CarlFK · Jan 24, 2019 · 2b24408 · 2b24408
1 parent 49a5785
commit 2b24408
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
@@ -303,6 +303,7 @@ static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
 	 */
 	if (!(prio & I915_PRIORITY_NEWCLIENT)) {
 		prio |= I915_PRIORITY_NEWCLIENT;
+		active->sched.attr.priority = prio;
 		list_move_tail(&active->sched.link,
 			       i915_sched_lookup_priolist(engine, prio));
 	}
@@ -645,6 +646,9 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 		int i;
 
 		priolist_for_each_request_consume(rq, rn, p, i) {
+			GEM_BUG_ON(last &&
+				   need_preempt(engine, last, rq_prio(rq)));
+
 			/*
 			 * Can we combine this request with the current port?
 			 * It has to be the same context/ringbuffer and not