From 7c572e1bdf8dea0c84ce8da01a84cdaa26d8e138 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 3 May 2018 20:51:15 +0100 Subject: [PATCH] drm/i915: Keep one request in our ring_list 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 Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180503195115.22309-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_request.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) 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); /* -- 2.11.0