[Intel-gfx] [RFC 3/6] drm/i915: Keep a count of requests submitted from userspace

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Keep a count of requests submitted from userspace and not yet runnable due
unresolved dependencies.

v2: Rename and move under the container struct. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_request.c | 3 +++
 drivers/gpu/drm/i915/intel_engine_cs.c  | 3 ++-
 drivers/gpu/drm/i915/intel_ringbuffer.h | 8 ++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 8da350bacff1..125a598b886c 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -599,6 +599,7 @@ submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 		rcu_read_lock();
 		request->engine->submit_request(request);
 		rcu_read_unlock();
+		atomic_dec(&request->engine->request_stats.queued);
 		break;
 
 	case FENCE_FREE:
@@ -1067,6 +1068,8 @@ void __i915_add_request(struct drm_i915_gem_request *request, bool flush_caches)
 	if (engine->schedule)
 		engine->schedule(request, request->ctx->priority);
 
+	atomic_inc(&engine->request_stats.queued);
+
 	local_bh_disable();
 	i915_sw_fence_commit(&request->submit);
 	local_bh_enable(); /* Kick the execlists tasklet if just scheduled */
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 8377a77cfbe7..46b2a92cb7a2 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1731,12 +1731,13 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 	if (i915_terminally_wedged(&engine->i915->gpu_error))
 		drm_printf(m, "*** WEDGED ***\n");
 
-	drm_printf(m, "\tcurrent seqno %x, last %x, hangcheck %x [%d ms], inflight %d, runnable %u\n",
+	drm_printf(m, "\tcurrent seqno %x, last %x, hangcheck %x [%d ms], inflight %d, queued %u, runnable %u\n",
 		   intel_engine_get_seqno(engine),
 		   intel_engine_last_submit(engine),
 		   engine->hangcheck.seqno,
 		   jiffies_to_msecs(jiffies - engine->hangcheck.action_timestamp),
 		   engine->timeline->inflight_seqnos,
+		   atomic_read(&engine->request_stats.queued),
 		   engine->request_stats.runnable);
 	drm_printf(m, "\tReset count: %d (global %d)\n",
 		   i915_reset_engine_count(error, engine),
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index d7ee7831288d..4519788cc5a1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -304,6 +304,14 @@ struct intel_engine_cs {
 	struct intel_timeline *timeline;
 
 	struct {
+		/**
+		 * @queued: Number of submitted requests with dependencies.
+		 *
+		 * Count of requests waiting for dependencies before they can be
+		 * submitted to the backend.
+		 */
+		atomic_t queued;
+
 		/**
 		 * @runnable: Number of runnable requests sent to the backend.
 		 *
-- 
2.14.1