drm/i915: Slaughter the thundering i915_wait_request herd

[deliverable/linux.git] / drivers / gpu / drm / i915 / i915_gpu_error.c

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 34ff2459ceea3aab4147b75b0d3a36723444d99c..250f0b8180990369b85a77c9aace12dd2fcac2f0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -463,6 +463,18 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
                        }
                }
 
+               if (error->ring[i].num_waiters) {
+                       err_printf(m, "%s --- %d waiters\n",
+                                  dev_priv->engine[i].name,
+                                  error->ring[i].num_waiters);
+                       for (j = 0; j < error->ring[i].num_waiters; j++) {
+                               err_printf(m, " seqno 0x%08x for %s [%d]\n",
+                                          error->ring[i].waiters[j].seqno,
+                                          error->ring[i].waiters[j].comm,
+                                          error->ring[i].waiters[j].pid);
+                       }
+               }
+
                if ((obj = error->ring[i].ringbuffer)) {
                        err_printf(m, "%s --- ringbuffer = 0x%08x\n",
                                   dev_priv->engine[i].name,
@@ -605,8 +617,9 @@ static void i915_error_state_free(struct kref *error_ref)
                i915_error_object_free(error->ring[i].ringbuffer);
                i915_error_object_free(error->ring[i].hws_page);
                i915_error_object_free(error->ring[i].ctx);
-               kfree(error->ring[i].requests);
                i915_error_object_free(error->ring[i].wa_ctx);
+               kfree(error->ring[i].requests);
+               kfree(error->ring[i].waiters);
        }
 
        i915_error_object_free(error->semaphore_obj);
@@ -892,6 +905,48 @@ static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
        }
 }
 
+static void engine_record_waiters(struct intel_engine_cs *engine,
+                                 struct drm_i915_error_ring *ering)
+{
+       struct intel_breadcrumbs *b = &engine->breadcrumbs;
+       struct drm_i915_error_waiter *waiter;
+       struct rb_node *rb;
+       int count;
+
+       ering->num_waiters = 0;
+       ering->waiters = NULL;
+
+       spin_lock(&b->lock);
+       count = 0;
+       for (rb = rb_first(&b->waiters); rb != NULL; rb = rb_next(rb))
+               count++;
+       spin_unlock(&b->lock);
+
+       waiter = NULL;
+       if (count)
+               waiter = kmalloc_array(count,
+                                      sizeof(struct drm_i915_error_waiter),
+                                      GFP_ATOMIC);
+       if (!waiter)
+               return;
+
+       ering->waiters = waiter;
+
+       spin_lock(&b->lock);
+       for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
+               struct intel_wait *w = container_of(rb, typeof(*w), node);
+
+               strcpy(waiter->comm, w->tsk->comm);
+               waiter->pid = w->tsk->pid;
+               waiter->seqno = w->seqno;
+               waiter++;
+
+               if (++ering->num_waiters == count)
+                       break;
+       }
+       spin_unlock(&b->lock);
+}
+
 static void i915_record_ring_state(struct drm_i915_private *dev_priv,
                                   struct drm_i915_error_state *error,
                                   struct intel_engine_cs *engine,
@@ -926,7 +981,7 @@ static void i915_record_ring_state(struct drm_i915_private *dev_priv,
                ering->instdone = I915_READ(GEN2_INSTDONE);
        }
 
-       ering->waiting = waitqueue_active(&engine->irq_queue);
+       ering->waiting = intel_engine_has_waiter(engine);
        ering->instpm = I915_READ(RING_INSTPM(engine->mmio_base));
        ering->acthd = intel_ring_get_active_head(engine);
        ering->seqno = engine->get_seqno(engine);
@@ -1032,6 +1087,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
                error->ring[i].valid = true;
 
                i915_record_ring_state(dev_priv, error, engine, &error->ring[i]);
+               engine_record_waiters(engine, &error->ring[i]);
 
                request = i915_gem_find_active_request(engine);
                if (request) {