diff mbox

[CI,2/2] drm/i915: Keep one request in our ring_list

Message ID 20180503195115.22309-2-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Wilson May 3, 2018, 7:51 p.m. UTC 
Don't pre-emptively retire the oldest request in our ring's list if it
is the only request. We keep various bits of state alive using the
active reference from the request and would rather transfer that state
over to a new request rather than the more involved process of retiring
and reacquiring it.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/i915_request.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 63bb61089be5..d68739b94dac 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -695,9 +695,9 @@  i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 		goto err_unreserve;
 
 	/* Move our oldest request to the slab-cache (if not in use!) */
-	rq = list_first_entry_or_null(&ring->request_list,
-				      typeof(*rq), ring_link);
-	if (rq && i915_request_completed(rq))
+	rq = list_first_entry(&ring->request_list, typeof(*rq), ring_link);
+	if (!list_is_last(&rq->ring_link, &ring->request_list) &&
+	    i915_request_completed(rq))
 		i915_request_retire(rq);
 
 	/*