On 26/04/2017 09:06, Chris Wilson wrote:
If we are enabling the breadcrumbs signaling prior to submitting the request, we know that we cannot have missed the interrupt and can therefore skip immediately waking the signaler to check.This reduces a significant chunk of the __i915_gem_request_submit() overhead for inter-engine synchronisation, for example in gem_exec_whisper. Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com> --- drivers/gpu/drm/i915/i915_gem_request.c | 4 ++-- drivers/gpu/drm/i915/i915_guc_submission.c | 2 +- drivers/gpu/drm/i915/intel_breadcrumbs.c | 7 ++++--- drivers/gpu/drm/i915/intel_ringbuffer.h | 3 ++- 4 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 8bbec19e267a..7b9a509f00f3 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -61,7 +61,7 @@ static bool i915_fence_enable_signaling(struct dma_fence *fence) if (i915_fence_signaled(fence)) return false; - intel_engine_enable_signaling(to_request(fence)); + intel_engine_enable_signaling(to_request(fence), true); return true; } @@ -448,7 +448,7 @@ void __i915_gem_request_submit(struct drm_i915_gem_request *request) spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING); request->global_seqno = seqno; if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) - intel_engine_enable_signaling(request); + intel_engine_enable_signaling(request, false); spin_unlock(&request->lock); engine->emit_breadcrumb(request, diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index a4eca6ac449b..7ccb22709efb 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -649,7 +649,7 @@ static void nested_enable_signaling(struct drm_i915_gem_request *rq) trace_dma_fence_enable_signal(&rq->fence); spin_lock_nested(&rq->lock, SINGLE_DEPTH_NESTING); - intel_engine_enable_signaling(rq); + intel_engine_enable_signaling(rq, true); spin_unlock(&rq->lock); } diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c index 0839f928bc57..8f52fd5f6102 100644 --- a/drivers/gpu/drm/i915/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c @@ -683,12 +683,13 @@ static int intel_breadcrumbs_signaler(void *arg) return 0; } -void intel_engine_enable_signaling(struct drm_i915_gem_request *request) +void intel_engine_enable_signaling(struct drm_i915_gem_request *request, + bool wakeup) { struct intel_engine_cs *engine = request->engine; struct intel_breadcrumbs *b = &engine->breadcrumbs; struct rb_node *parent, **p; - bool first, wakeup; + bool first; u32 seqno; /* Note that we may be called from an interrupt handler on another @@ -721,7 +722,7 @@ void intel_engine_enable_signaling(struct drm_i915_gem_request *request) * If we are the oldest waiter, enable the irq (after which we * must double check that the seqno did not complete). */ - wakeup = __intel_engine_add_wait(engine, &request->signaling.wait); + wakeup &= __intel_engine_add_wait(engine, &request->signaling.wait); /* Now insert ourselves into the retirement ordered list of signals * on this engine. We track the oldest seqno as that will be the diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 3f7d5666bcf6..de5b968f508a 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -672,7 +672,8 @@ bool intel_engine_add_wait(struct intel_engine_cs *engine, struct intel_wait *wait); void intel_engine_remove_wait(struct intel_engine_cs *engine, struct intel_wait *wait); -void intel_engine_enable_signaling(struct drm_i915_gem_request *request); +void intel_engine_enable_signaling(struct drm_i915_gem_request *request, + bool wakeup); void intel_engine_cancel_signaling(struct drm_i915_gem_request *request); static inline bool intel_engine_has_waiter(const struct intel_engine_cs *engine)
Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com> Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
