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 <chris@chris-wilson.co.uk>
Reviewed-by: Robert Beckett <robert.beckett@intel.com>
Reviewed-by: Rafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Chris Wilson 2014-03-25 13:23:05 +00:00 committed by Daniel Vetter
parent ceabbba524
commit b453c4dbc3

View File

@ -5001,6 +5001,22 @@ 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;
@ -5020,18 +5036,11 @@ 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)
@ -5119,17 +5128,10 @@ 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)