[PATCH 20/42] drm/i915/gt: Specify a deadline for the heartbeat

[Chris Wilson]

As we know when we expect the heartbeat to be checked for completion,
pass this information along as its deadline. We still do not complain if
the deadline is missed, at least until we have tried a few times, but it
will allow for quicker hang detection on systems where deadlines are
adhered to.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
index 0133d05ef954..945735d6f992 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
@@ -65,6 +65,16 @@ static void heartbeat_commit(struct i915_request *rq,
 	__i915_request_queue(rq, attr);
 }
 
+static void set_heartbeat_deadline(struct intel_engine_cs *engine,
+				   struct i915_request *rq)
+{
+	unsigned long interval;
+
+	interval = READ_ONCE(engine->props.heartbeat_interval_ms);
+	if (interval)
+		i915_request_set_deadline(rq, ktime_get() + (interval << 20));
+}
+
 static void show_heartbeat(const struct i915_request *rq,
 			   struct intel_engine_cs *engine)
 {
@@ -114,8 +124,7 @@ static void heartbeat(struct work_struct *wrk)
 			 * but all other contexts, including the kernel
 			 * context are stuck waiting for the signal.
 			 */
-		} else if (intel_engine_has_scheduler(engine) &&
-			   rq->sched.attr.priority < I915_PRIORITY_BARRIER) {
+		} else if (rq->sched.attr.priority < I915_PRIORITY_BARRIER) {
 			/*
 			 * Gradually raise the priority of the heartbeat to
 			 * give high priority work [which presumably desires
@@ -129,6 +138,8 @@ static void heartbeat(struct work_struct *wrk)
 				attr.priority = I915_PRIORITY_BARRIER;
 
 			local_bh_disable();
+			if (attr.priority == I915_PRIORITY_BARRIER)
+				i915_request_set_deadline(rq, 0);
 			i915_request_set_priority(rq, attr.priority);
 			local_bh_enable();
 		} else {
@@ -161,6 +172,7 @@ static void heartbeat(struct work_struct *wrk)
 	if (IS_ERR(rq))
 		goto unlock;
 
+	set_heartbeat_deadline(engine, rq);
 	heartbeat_commit(rq, &attr);
 
 unlock:
-- 
2.20.1