From 17b51ad8e5c051032d8e1d698e7dfd01d9133a92 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 18 Sep 2017 17:27:33 +0100 Subject: [PATCH] drm/i915: Only wake the waiter from the interrupt if passed As we now check if the seqno is complete in order to signal the fence, we can also decide not to wake up the first_waiter until it is ready (since it is waiting on the same seqno). The only caveat is that if we need the engine->irq_seqno_barrier to enforce some coherency between an interrupt and the seqno read, we have to always wake the waiter in order to perform that heavyweight barrier. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20170918162734.21294-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_irq.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index c23efc4394ce..2190e42ba310 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1038,6 +1038,8 @@ static void notify_ring(struct intel_engine_cs *engine) spin_lock(&engine->breadcrumbs.irq_lock); wait = engine->breadcrumbs.irq_wait; if (wait) { + bool wakeup = engine->irq_seqno_barrier; + /* We use a callback from the dma-fence to submit * requests after waiting on our own requests. To * ensure minimum delay in queuing the next request to @@ -1050,12 +1052,15 @@ static void notify_ring(struct intel_engine_cs *engine) * and many waiters. */ if (i915_seqno_passed(intel_engine_get_seqno(engine), - wait->seqno) && - !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, - &wait->request->fence.flags)) - rq = i915_gem_request_get(wait->request); + wait->seqno)) { + wakeup = true; + if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, + &wait->request->fence.flags)) + rq = i915_gem_request_get(wait->request); + } - wake_up_process(wait->tsk); + if (wakeup) + wake_up_process(wait->tsk); } else { __intel_engine_disarm_breadcrumbs(engine); } -- 2.45.2