From 9736387a9f17a521a8aff3bc64814f335a6f09e8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 14 Jan 2021 13:56:12 +0000 Subject: [PATCH] drm/i915: Reduce test_and_set_bit to set_bit in i915_request_submit() Avoid the full blown memory barrier of test_and_set_bit() by noting the completed request and removing it from the lists. Signed-off-by: Chris Wilson Reviewed-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20210114135612.13210-5-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_request.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 973ecea..22e39d9 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -551,8 +551,10 @@ bool __i915_request_submit(struct i915_request *request) * dropped upon retiring. (Otherwise if resubmit a *retired* * request, this would be a horrible use-after-free.) */ - if (__i915_request_is_complete(request)) - goto xfer; + if (__i915_request_is_complete(request)) { + list_del_init(&request->sched.link); + goto active; + } if (unlikely(intel_context_is_banned(request->context))) i915_request_set_error_once(request, -EIO); @@ -587,11 +589,11 @@ bool __i915_request_submit(struct i915_request *request) engine->serial++; result = true; -xfer: - if (!test_and_set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags)) { - list_move_tail(&request->sched.link, &engine->active.requests); - clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); - } + GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags)); + list_move_tail(&request->sched.link, &engine->active.requests); +active: + clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); + set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags); /* * XXX Rollback bonded-execution on __i915_request_unsubmit()? -- 2.7.4