drm/i915: Only hold a process-local lock whilst throttling.

Avoid cause latencies in other clients by not taking the global struct
mutex and moving the per-client request manipulation a local per-client
mutex. For example, this allows a compositor to schedule a page-flip
(through X) whilst an OpenGL application is monopolising the GPU.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 11 insertions, 11 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 048c54bdfd4c..a3aea17c964b 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2162,20 +2162,19 @@ int i915_driver_unload(struct drm_device *dev)
         return 0;
 }
 
-int i915_driver_open(struct drm_device *dev, struct drm_file *file_priv)
+int i915_driver_open(struct drm_device *dev, struct drm_file *file)
 {
-        struct drm_i915_file_private *i915_file_priv;
+        struct drm_i915_file_private *file_priv;
 
         DRM_DEBUG_DRIVER("\n");
-        i915_file_priv = (struct drm_i915_file_private *)
-            kmalloc(sizeof(*i915_file_priv), GFP_KERNEL);
-
-        if (!i915_file_priv)
+        file_priv = kmalloc(sizeof(*file_priv), GFP_KERNEL);
+        if (!file_priv)
                 return -ENOMEM;
 
-        file_priv->driver_priv = i915_file_priv;
+        file->driver_priv = file_priv;
 
-        INIT_LIST_HEAD(&i915_file_priv->mm.request_list);
+        INIT_LIST_HEAD(&file_priv->mm.request_list);
+        mutex_init(&file_priv->mutex);
 
         return 0;
 }
@@ -2218,11 +2217,12 @@ void i915_driver_preclose(struct drm_device * dev, struct drm_file *file_priv)
                 i915_mem_release(dev, file_priv, dev_priv->agp_heap);
 }
 
-void i915_driver_postclose(struct drm_device *dev, struct drm_file *file_priv)
+void i915_driver_postclose(struct drm_device *dev, struct drm_file *file)
 {
-        struct drm_i915_file_private *i915_file_priv = file_priv->driver_priv;
+        struct drm_i915_file_private *file_priv = file->driver_priv;
 
-        kfree(i915_file_priv);
+        mutex_destroy(&file_priv->mutex);
+        kfree(file_priv);
 }
 
 struct drm_ioctl_desc i915_ioctls[] = {