diff options
| -rw-r--r-- | linux-core/i915_gem.c | 49 | ||||
| -rw-r--r-- | shared-core/i915_drv.h | 3 |
2 files changed, 30 insertions, 22 deletions
diff --git a/linux-core/i915_gem.c b/linux-core/i915_gem.c index 94e2e477..641ca8a3 100644 --- a/linux-core/i915_gem.c +++ b/linux-core/i915_gem.c @@ -154,6 +154,7 @@ i915_add_request(struct drm_device *dev) DRM_DEBUG("%d\n", seqno); request->seqno = seqno; + request->emitted_jiffies = jiffies; list_add_tail(&request->list, &dev_priv->mm.request_list); return seqno; @@ -966,34 +967,38 @@ i915_dispatch_gem_execbuffer(struct drm_device *dev, return 0; } -/* - * Kludge -- wait for almost all rendering to complete - * before queuing more. This uses interrupts, so the wakeup - * occurs without any delay. +/* Throttle our rendering by waiting until the ring has completed our requests + * emitted over 20 msec ago. + * + * This should get us reasonable parallelism between CPU and GPU but also + * relatively low latency when blocking on a particular request to finish. */ static int -i915_gem_wait_space(struct drm_device *dev) +i915_gem_ring_throttle(struct drm_device *dev) { drm_i915_private_t *dev_priv = dev->dev_private; - drm_i915_ring_buffer_t *ring = &(dev_priv->ring); - struct drm_i915_gem_object *obj_priv, *last_priv = NULL; int ret = 0; mutex_lock(&dev->struct_mutex); - while (ring->space + 1024 < dev_priv->ring.Size && - !list_empty(&dev_priv->mm.active_list)) { - obj_priv = list_first_entry(&dev_priv->mm.active_list, - struct drm_i915_gem_object, - list); - if (obj_priv == last_priv) - break; - drm_gem_object_reference(obj_priv->obj); - ret = i915_gem_object_wait_rendering(obj_priv->obj); - drm_gem_object_unreference(obj_priv->obj); - if (ret) - break; - last_priv = obj_priv; - i915_kernel_lost_context(dev); + while (!list_empty(&dev_priv->mm.request_list)) { + struct drm_i915_gem_request *request; + + request = list_first_entry(&dev_priv->mm.request_list, + struct drm_i915_gem_request, + list); + + /* Break out if we're close enough. */ + if (jiffies_to_msecs(jiffies - request->emitted_jiffies) < 20) { + mutex_unlock(&dev->struct_mutex); + return 0; + } + + /* Wait on the last request if not. */ + ret = i915_wait_request(dev, request->seqno); + if (ret != 0) { + mutex_unlock(&dev->struct_mutex); + return ret; + } } mutex_unlock(&dev->struct_mutex); return ret; @@ -1019,7 +1024,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data, #endif i915_kernel_lost_context(dev); - ret = i915_gem_wait_space(dev); + ret = i915_gem_ring_throttle(dev); if (ret) return ret; diff --git a/shared-core/i915_drv.h b/shared-core/i915_drv.h index ef41b433..e3f280d5 100644 --- a/shared-core/i915_drv.h +++ b/shared-core/i915_drv.h @@ -331,6 +331,9 @@ struct drm_i915_gem_request { /** GEM sequence number associated with this request. */ uint32_t seqno; + /** Time at which this request was emitted, in jiffies. */ + unsigned long emitted_jiffies; + struct list_head list; }; |