drm/i915: Don't accumulate hangcheck score on forward progress

If the actual head has progressed forward inside a batch (request),
don't accumulate hangcheck score.

As the hangcheck score in increased only by acthd jumping backwards,
the result is that we only declare an active batch as stuck if it is
trapped inside a loop. Or that the looping will dominate the batch
progression so that it overcomes the bonus that forward progress gives.

v2: Improved commit message (Chris Wilson)

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
[danvet: s/active_loop/active (loop)/ as requested by Chris.]
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 0c945e91d5429725756f64859bd808e8e0faaba1..7c478e6cedaec2195519f9fe6cf4c708a663ea1c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -229,6 +229,8 @@ static const char *hangcheck_action_to_str(enum intel_ring_hangcheck_action a)
                return "wait";
        case HANGCHECK_ACTIVE:
                return "active";
+       case HANGCHECK_ACTIVE_LOOP:
+               return "active (loop)";
        case HANGCHECK_KICK:
                return "kick";
        case HANGCHECK_HUNG:

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 6ef9d6fabf80431a60747a1db9598167e48d7905..390ccc2a3096670d636af14a0164dd237a43d66c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3189,8 +3189,14 @@ ring_stuck(struct intel_engine_cs *ring, u64 acthd)
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 tmp;
 
-       if (ring->hangcheck.acthd != acthd)
-               return HANGCHECK_ACTIVE;
+       if (acthd != ring->hangcheck.acthd) {
+               if (acthd > ring->hangcheck.max_acthd) {
+                       ring->hangcheck.max_acthd = acthd;
+                       return HANGCHECK_ACTIVE;
+               }
+
+               return HANGCHECK_ACTIVE_LOOP;
+       }
 
        if (IS_GEN2(dev))
                return HANGCHECK_HUNG;
@@ -3301,8 +3307,9 @@ static void i915_hangcheck_elapsed(unsigned long data)
                                switch (ring->hangcheck.action) {
                                case HANGCHECK_IDLE:
                                case HANGCHECK_WAIT:
-                                       break;
                                case HANGCHECK_ACTIVE:
+                                       break;
+                               case HANGCHECK_ACTIVE_LOOP:
                                        ring->hangcheck.score += BUSY;
                                        break;
                                case HANGCHECK_KICK:
@@ -3322,6 +3329,8 @@ static void i915_hangcheck_elapsed(unsigned long data)
                         */
                        if (ring->hangcheck.score > 0)
                                ring->hangcheck.score--;
+
+                       ring->hangcheck.acthd = ring->hangcheck.max_acthd = 0;
                }
 
                ring->hangcheck.seqno = seqno;

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index ed5941078f9217b8b0434df855e0e1d4d50025cd..70525d0c2c74650ef780a69c797c59316cedd371 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -70,6 +70,7 @@ enum intel_ring_hangcheck_action {
        HANGCHECK_IDLE = 0,
        HANGCHECK_WAIT,
        HANGCHECK_ACTIVE,
+       HANGCHECK_ACTIVE_LOOP,
        HANGCHECK_KICK,
        HANGCHECK_HUNG,
 };
@@ -78,6 +79,7 @@ enum intel_ring_hangcheck_action {
 
 struct intel_ring_hangcheck {
        u64 acthd;
+       u64 max_acthd;
        u32 seqno;
        int score;
        enum intel_ring_hangcheck_action action;