[PATCH 3/4] drm/i915: Declare waits on GPU as io waits, to reduce C-state reduction.

[Eric Anholt <eric@anholt.net>]

Because of this, the C-state governor will consider our process
"performance critical" and avoid dropping CPU power during these
temporary sleeps.  There are two benefits of this: We don't lose our
cache contents (whose value is not well reflected in the metrics of
the governor), and also don't reduce memory bandwidth, which can
reduce GPU performance and increase the time we wait!

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/i915/i915_gem.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8eb8453..8991588 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1988,12 +1988,12 @@ i915_do_wait_request(struct drm_device *dev, uint32_t seqno,
 		ring->waiting_gem_seqno = seqno;
 		ring->user_irq_get(dev, ring);
 		if (interruptible)
-			ret = wait_event_interruptible(ring->irq_queue,
+			ret = io_wait_event_interruptible(ring->irq_queue,
 				i915_seqno_passed(
 					ring->get_seqno(dev, ring), seqno)
 				|| atomic_read(&dev_priv->mm.wedged));
 		else
-			wait_event(ring->irq_queue,
+			io_wait_event(ring->irq_queue,
 				i915_seqno_passed(
 					ring->get_seqno(dev, ring), seqno)
 				|| atomic_read(&dev_priv->mm.wedged));
-- 
1.7.2.3