[Intel-gfx] [PATCH 13/16] drm/i915: Free RPS boosts for all laggards

[Chris Wilson]

If the client stalls on a congested request, chosen to be 20ms old to
match throttling, allow the client a free RPS boost.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c  |  2 +-
 drivers/gpu/drm/i915/intel_drv.h |  3 ++-
 drivers/gpu/drm/i915/intel_pm.c  | 19 +++++++++++++++----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 43ac75834e61..83bccb9f62d6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1247,7 +1247,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req,
 		jiffies + nsecs_to_jiffies_timeout((u64)*timeout) : 0;
 
 	if (INTEL_INFO(dev_priv)->gen >= 6)
-		gen6_rps_boost(dev_priv, rps);
+		gen6_rps_boost(dev_priv, rps, req->emitted_jiffies);
 
 	/* Record current time in case interrupted by signal, or wedged */
 	trace_i915_gem_request_wait_begin(req);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9eb0a911343a..34cfa61f3321 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1361,7 +1361,8 @@ void gen6_rps_busy(struct drm_i915_private *dev_priv);
 void gen6_rps_reset_ei(struct drm_i915_private *dev_priv);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);
 void gen6_rps_boost(struct drm_i915_private *dev_priv,
-		    struct intel_rps_client *rps);
+		    struct intel_rps_client *rps,
+		    unsigned long submitted);
 void intel_queue_rps_boost_for_request(struct drm_device *dev,
 				       struct drm_i915_gem_request *rq);
 void ilk_wm_get_hw_state(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index dcc52f928650..850e02e1c7eb 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4122,10 +4122,17 @@ void gen6_rps_idle(struct drm_i915_private *dev_priv)
 }
 
 void gen6_rps_boost(struct drm_i915_private *dev_priv,
-		    struct intel_rps_client *rps)
+		    struct intel_rps_client *rps,
+		    unsigned long submitted)
 {
 	u32 val;
 
+	/* Force a RPS boost (and don't count it against the client) if
+	 * the GPU is severely congested.
+	 */
+	if (rps && time_after(jiffies, submitted + msecs_to_jiffies(20)))
+		rps = NULL;
+
 	mutex_lock(&dev_priv->rps.hw_lock);
 	val = dev_priv->rps.max_freq_softlimit;
 	if (dev_priv->rps.enabled &&
@@ -6825,11 +6832,12 @@ struct request_boost {
 static void __intel_rps_boost_work(struct work_struct *work)
 {
 	struct request_boost *boost = container_of(work, struct request_boost, work);
+	struct drm_i915_gem_request *rq = boost->rq;
 
-	if (!i915_gem_request_completed(boost->rq, true))
-		gen6_rps_boost(to_i915(boost->rq->ring->dev), NULL);
+	if (!i915_gem_request_completed(rq, true))
+		gen6_rps_boost(to_i915(rq->ring->dev), 0, rq->emitted_jiffies);
 
-	i915_gem_request_unreference__unlocked(boost->rq);
+	i915_gem_request_unreference__unlocked(rq);
 	kfree(boost);
 }
 
@@ -6841,6 +6849,9 @@ void intel_queue_rps_boost_for_request(struct drm_device *dev,
 	if (rq == NULL || INTEL_INFO(dev)->gen < 6)
 		return;
 
+	if (i915_gem_request_completed(rq, true))
+		return;
+
 	boost = kmalloc(sizeof(*boost), GFP_ATOMIC);
 	if (boost == NULL)
 		return;
-- 
2.1.4