Commit cf11c1f8 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Drop struct_mutex in shrinker path 



Now that the inactive_list is protected by mm_lock, and everything
else on per-obj basis is protected by obj->resv, we no longer depend
on struct_mutex.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Reviewed-by: default avatarKristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent f92f026a

drivers/gpu/drm/msm/msm_gem.c

+0 −1
Original line number Diff line number Diff line
@@ -687,7 +687,6 @@ void msm_gem_purge(struct drm_gem_object *obj) 
	struct drm_device *dev = obj->dev;

	struct msm_gem_object *msm_obj = to_msm_bo(obj);



	WARN_ON(!mutex_is_locked(&dev->struct_mutex));

	WARN_ON(!is_purgeable(msm_obj));

	WARN_ON(obj->import_attach);

drivers/gpu/drm/msm/msm_gem_shrinker.c

+0 −54
Original line number Diff line number Diff line
@@ -8,48 +8,13 @@ 
#include "msm_gem.h"

#include "msm_gpu_trace.h"



static bool msm_gem_shrinker_lock(struct drm_device *dev, bool *unlock)

{

	/* NOTE: we are *closer* to being able to get rid of

	 * mutex_trylock_recursive().. the msm_gem code itself does

	 * not need struct_mutex, although codepaths that can trigger

	 * shrinker are still called in code-paths that hold the

	 * struct_mutex.

	 *

	 * Also, msm_obj->madv is protected by struct_mutex.

	 *

	 * The next step is probably split out a seperate lock for

	 * protecting inactive_list, so that shrinker does not need

	 * struct_mutex.

	 */

	switch (mutex_trylock_recursive(&dev->struct_mutex)) {

	case MUTEX_TRYLOCK_FAILED:

		return false;



	case MUTEX_TRYLOCK_SUCCESS:

		*unlock = true;

		return true;



	case MUTEX_TRYLOCK_RECURSIVE:

		*unlock = false;

		return true;

	}



	BUG();

}



static unsigned long

msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)

{

	struct msm_drm_private *priv =

		container_of(shrinker, struct msm_drm_private, shrinker);

	struct drm_device *dev = priv->dev;

	struct msm_gem_object *msm_obj;

	unsigned long count = 0;

	bool unlock;



	if (!msm_gem_shrinker_lock(dev, &unlock))

		return 0;



	mutex_lock(&priv->mm_lock);
@@ -63,9 +28,6 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) 


	mutex_unlock(&priv->mm_lock);



	if (unlock)

		mutex_unlock(&dev->struct_mutex);



	return count;

}
@@ -74,13 +36,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) 
{

	struct msm_drm_private *priv =

		container_of(shrinker, struct msm_drm_private, shrinker);

	struct drm_device *dev = priv->dev;

	struct msm_gem_object *msm_obj;

	unsigned long freed = 0;

	bool unlock;



	if (!msm_gem_shrinker_lock(dev, &unlock))

		return SHRINK_STOP;



	mutex_lock(&priv->mm_lock);
@@ -98,9 +55,6 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) 


	mutex_unlock(&priv->mm_lock);



	if (unlock)

		mutex_unlock(&dev->struct_mutex);



	if (freed > 0)

		trace_msm_gem_purge(freed << PAGE_SHIFT);
@@ -112,13 +66,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr) 
{

	struct msm_drm_private *priv =

		container_of(nb, struct msm_drm_private, vmap_notifier);

	struct drm_device *dev = priv->dev;

	struct msm_gem_object *msm_obj;

	unsigned unmapped = 0;

	bool unlock;



	if (!msm_gem_shrinker_lock(dev, &unlock))

		return NOTIFY_DONE;



	mutex_lock(&priv->mm_lock);
@@ -141,9 +90,6 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr) 


	mutex_unlock(&priv->mm_lock);



	if (unlock)

		mutex_unlock(&dev->struct_mutex);



	*(unsigned long *)ptr += unmapped;



	if (unmapped > 0)

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