From 71bdf35a76eec98f331eb217dda7d58cb66e4311 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 25 Feb 2014 14:34:50 +0000 Subject: [PATCH 2/3] drm/i915: Refactor common lock handling between shrinker count/scan We can share a few lines of tricky lock handling we need to use for both shrinker routines and in the process fix the return value for count() when reporting a deadlock. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/i915_gem.c | 42 ++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 285f7d4..ffaf5cc 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4886,6 +4886,22 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task) #endif } +static bool i915_gem_shrinker_lock(struct drm_device *dev, bool *unlock) +{ + if (!mutex_trylock(&dev->struct_mutex)) { + if (!mutex_is_locked_by(&dev->struct_mutex, current)) + return false; + + if (to_i915(dev)->mm.shrinker_no_lock_stealing) + return false; + + *unlock = false; + } else + *unlock = true; + + return true; +} + static int num_vma_bound(struct drm_i915_gem_object *obj) { struct i915_vma *vma; @@ -4905,18 +4921,11 @@ i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) container_of(shrinker, struct drm_i915_private, mm.shrinker); struct drm_device *dev = dev_priv->dev; struct drm_i915_gem_object *obj; - bool unlock = true; unsigned long count; + bool unlock; - if (!mutex_trylock(&dev->struct_mutex)) { - if (!mutex_is_locked_by(&dev->struct_mutex, current)) - return 0; - - if (dev_priv->mm.shrinker_no_lock_stealing) - return 0; - - unlock = false; - } + if (!i915_gem_shrinker_lock(dev, &unlock)) + return 0; count = 0; list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) @@ -5004,17 +5013,10 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) container_of(shrinker, struct drm_i915_private, mm.shrinker); struct drm_device *dev = dev_priv->dev; unsigned long freed; - bool unlock = true; + bool unlock; - if (!mutex_trylock(&dev->struct_mutex)) { - if (!mutex_is_locked_by(&dev->struct_mutex, current)) - return SHRINK_STOP; - - if (dev_priv->mm.shrinker_no_lock_stealing) - return SHRINK_STOP; - - unlock = false; - } + if (!i915_gem_shrinker_lock(dev, &unlock)) + return SHRINK_STOP; freed = i915_gem_purge(dev_priv, sc->nr_to_scan); if (freed < sc->nr_to_scan) -- 1.7.9.5