drm/i915/shrinker: Refactor common uninterruptible locking

Both the oom and vmap notifier callbacks have a loop to acquire the
struct_mutex and set the device as uninterruptible, within a certain
time. Refactor the common code into a pair of functions.

Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459848145-24042-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index be7501a..3994379 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -289,35 +289,56 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
        return freed;
 }
 
+struct shrinker_lock_uninterruptible {
+       bool was_interruptible;
+       bool unlock;
+};
+
+static bool
+i915_gem_shrinker_lock_uninterruptible(struct drm_i915_private *dev_priv,
+                                      struct shrinker_lock_uninterruptible *slu,
+                                      int timeout_ms)
+{
+       unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;
+
+       while (!i915_gem_shrinker_lock(dev_priv->dev, &slu->unlock)) {
+               schedule_timeout_killable(1);
+               if (fatal_signal_pending(current))
+                       return false;
+               if (--timeout == 0) {
+                       pr_err("Unable to lock GPU to purge memory.\n");
+                       return false;
+               }
+       }
+
+       slu->was_interruptible = dev_priv->mm.interruptible;
+       dev_priv->mm.interruptible = false;
+       return true;
+}
+
+static void
+i915_gem_shrinker_unlock_uninterruptible(struct drm_i915_private *dev_priv,
+                                        struct shrinker_lock_uninterruptible *slu)
+{
+       dev_priv->mm.interruptible = slu->was_interruptible;
+       if (slu->unlock)
+               mutex_unlock(&dev_priv->dev->struct_mutex);
+}
+
 static int
 i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
 {
        struct drm_i915_private *dev_priv =
                container_of(nb, struct drm_i915_private, mm.oom_notifier);
-       struct drm_device *dev = dev_priv->dev;
+       struct shrinker_lock_uninterruptible slu;
        struct drm_i915_gem_object *obj;
-       unsigned long timeout = msecs_to_jiffies(5000) + 1;
        unsigned long pinned, bound, unbound, freed_pages;
-       bool was_interruptible;
-       bool unlock;
 
-       while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
-               schedule_timeout_killable(1);
-               if (fatal_signal_pending(current))
-                       return NOTIFY_DONE;
-       }
-       if (timeout == 0) {
-               pr_err("Unable to purge GPU memory due lock contention.\n");
+       if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
                return NOTIFY_DONE;
-       }
-
-       was_interruptible = dev_priv->mm.interruptible;
-       dev_priv->mm.interruptible = false;
 
        freed_pages = i915_gem_shrink_all(dev_priv);
 
-       dev_priv->mm.interruptible = was_interruptible;
-
        /* Because we may be allocating inside our own driver, we cannot
         * assert that there are no objects with pinned pages that are not
         * being pointed to by hardware.
@@ -342,8 +363,7 @@ i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
                        bound += obj->base.size;
        }
 
-       if (unlock)
-               mutex_unlock(&dev->struct_mutex);
+       i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
 
        if (freed_pages || unbound || bound)
                pr_info("Purging GPU memory, %lu bytes freed, %lu bytes still pinned.\n",
@@ -362,30 +382,15 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr
 {
        struct drm_i915_private *dev_priv =
                container_of(nb, struct drm_i915_private, mm.vmap_notifier);
-       struct drm_device *dev = dev_priv->dev;
-       unsigned long timeout = msecs_to_jiffies(5000) + 1;
+       struct shrinker_lock_uninterruptible slu;
        unsigned long freed_pages;
-       bool was_interruptible;
-       bool unlock;
 
-       while (!i915_gem_shrinker_lock(dev, &unlock) && --timeout) {
-               schedule_timeout_killable(1);
-               if (fatal_signal_pending(current))
-                       return NOTIFY_DONE;
-       }
-       if (timeout == 0) {
-               pr_err("Unable to purge GPU vmaps due to lock contention.\n");
+       if (!i915_gem_shrinker_lock_uninterruptible(dev_priv, &slu, 5000))
                return NOTIFY_DONE;
-       }
-
-       was_interruptible = dev_priv->mm.interruptible;
-       dev_priv->mm.interruptible = false;
 
        freed_pages = i915_gem_shrink_all(dev_priv);
 
-       dev_priv->mm.interruptible = was_interruptible;
-       if (unlock)
-               mutex_unlock(&dev->struct_mutex);
+       i915_gem_shrinker_unlock_uninterruptible(dev_priv, &slu);
 
        *(unsigned long *)ptr += freed_pages;
        return NOTIFY_DONE;