[Intel-gfx] [PATCH 178/190] drm/i915: Do an inline flush-active before dropping the mutex when waiting

[Chris Wilson]

In a nonblocking wait, we gather up all the outstanding requests and
then drop the mutex. However if all those requests have already
completed we do not need to wait upon them and can exit early without
having to drop and reacquire the struct_mutex.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a7cad2c7c034..d452499ae5a9 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1226,7 +1226,10 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 		if (req == NULL)
 			return 0;
 
-		requests[n++] = i915_gem_request_get(req);
+		if (i915_gem_request_completed(req))
+			i915_gem_request_retire_upto(req);
+		else
+			requests[n++] = i915_gem_request_get(req);
 	} else {
 		for (i = 0; i < I915_NUM_RINGS; i++) {
 			struct drm_i915_gem_request *req;
@@ -1235,10 +1238,16 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
 			if (req == NULL)
 				continue;
 
-			requests[n++] = i915_gem_request_get(req);
+			if (i915_gem_request_completed(req))
+				i915_gem_request_retire_upto(req);
+			else
+				requests[n++] = i915_gem_request_get(req);
 		}
 	}
 
+	if (n == 0)
+		return 0;
+
 	mutex_unlock(&dev->struct_mutex);
 	ret = 0;
 	for (i = 0; ret == 0 && i < n; i++)
-- 
2.7.0.rc3