From: Maarten Lankhorst maarten.lankhorst@linux.intel.com
With userptr fixed, there is no need for all separate lockdep classes now, and we can remove all lockdep tricks used. A trylock in the shrinker is all we need now to flatten the locking hierarchy.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com --- drivers/gpu/drm/i915/gem/i915_gem_object.c | 6 +--- drivers/gpu/drm/i915/gem/i915_gem_object.h | 20 ++---------- drivers/gpu/drm/i915/gem/i915_gem_pages.c | 34 ++++++++++---------- drivers/gpu/drm/i915/gem/i915_gem_phys.c | 2 +- drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 10 +++--- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 2 +- 6 files changed, 27 insertions(+), 47 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c index 1393988bd5af..028a556ab1a5 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c @@ -62,7 +62,7 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj, const struct drm_i915_gem_object_ops *ops, struct lock_class_key *key, unsigned flags) { - __mutex_init(&obj->mm.lock, ops->name ?: "obj->mm.lock", key); + mutex_init(&obj->mm.lock);
spin_lock_init(&obj->vma.lock); INIT_LIST_HEAD(&obj->vma.list); @@ -86,10 +86,6 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj, mutex_init(&obj->mm.get_page.lock); INIT_RADIX_TREE(&obj->mm.get_dma_page.radix, GFP_KERNEL | __GFP_NOWARN); mutex_init(&obj->mm.get_dma_page.lock); - - if (IS_ENABLED(CONFIG_LOCKDEP) && i915_gem_object_is_shrinkable(obj)) - i915_gem_shrinker_taints_mutex(to_i915(obj->base.dev), - &obj->mm.lock); }
/** diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h index 33412248f6df..1b85f51c6ddd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h @@ -339,27 +339,10 @@ void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj); int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj);
-enum i915_mm_subclass { /* lockdep subclass for obj->mm.lock/struct_mutex */ - I915_MM_NORMAL = 0, - /* - * Only used by struct_mutex, when called "recursively" from - * direct-reclaim-esque. Safe because there is only every one - * struct_mutex in the entire system. - */ - I915_MM_SHRINKER = 1, - /* - * Used for obj->mm.lock when allocating pages. Safe because the object - * isn't yet on any LRU, and therefore the shrinker can't deadlock on - * it. As soon as the object has pages, obj->mm.lock nests within - * fs_reclaim. - */ - I915_MM_GET_PAGES = 1, -}; - static inline int __must_check i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) { - might_lock_nested(&obj->mm.lock, I915_MM_GET_PAGES); + might_lock(&obj->mm.lock);
if (atomic_inc_not_zero(&obj->mm.pages_pin_count)) return 0; @@ -403,6 +386,7 @@ i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) }
int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj); +int __i915_gem_object_put_pages_locked(struct drm_i915_gem_object *obj); void i915_gem_object_truncate(struct drm_i915_gem_object *obj); void i915_gem_object_writeback(struct drm_i915_gem_object *obj);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c index 60149cad6080..5bcd21a8fc4e 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c @@ -111,7 +111,7 @@ int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj) { int err;
- err = mutex_lock_interruptible_nested(&obj->mm.lock, I915_MM_GET_PAGES); + err = mutex_lock_interruptible(&obj->mm.lock); if (err) return err;
@@ -193,21 +193,13 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj) return pages; }
-int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj) +int __i915_gem_object_put_pages_locked(struct drm_i915_gem_object *obj) { struct sg_table *pages; - int err;
if (i915_gem_object_has_pinned_pages(obj)) return -EBUSY;
- /* May be called by shrinker from within get_pages() (on another bo) */ - mutex_lock(&obj->mm.lock); - if (unlikely(atomic_read(&obj->mm.pages_pin_count))) { - err = -EBUSY; - goto unlock; - } - i915_gem_object_release_mmap_offset(obj);
/* @@ -223,14 +215,22 @@ int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj) * get_pages backends we should be better able to handle the * cancellation of the async task in a more uniform manner. */ - if (!pages) - pages = ERR_PTR(-EINVAL); - - if (!IS_ERR(pages)) + if (!IS_ERR_OR_NULL(pages)) obj->ops->put_pages(obj, pages);
- err = 0; -unlock: + return 0; +} + +int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj) +{ + int err; + + if (i915_gem_object_has_pinned_pages(obj)) + return -EBUSY; + + /* May be called by shrinker from within get_pages() (on another bo) */ + mutex_lock(&obj->mm.lock); + err = __i915_gem_object_put_pages_locked(obj); mutex_unlock(&obj->mm.lock);
return err; @@ -336,7 +336,7 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, !i915_gem_object_type_has(obj, I915_GEM_OBJECT_HAS_IOMEM)) return ERR_PTR(-ENXIO);
- err = mutex_lock_interruptible_nested(&obj->mm.lock, I915_MM_GET_PAGES); + err = mutex_lock_interruptible(&obj->mm.lock); if (err) return ERR_PTR(err);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c index 144e4940eede..0d176bf06405 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c @@ -236,7 +236,7 @@ int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align) if (err) return err;
- err = mutex_lock_interruptible_nested(&obj->mm.lock, I915_MM_GET_PAGES); + err = mutex_lock_interruptible(&obj->mm.lock); if (err) goto err_unlock;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c index dc8f052a0ffe..afc6e5b4dcf1 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c @@ -48,9 +48,9 @@ static bool unsafe_drop_pages(struct drm_i915_gem_object *obj, flags = I915_GEM_OBJECT_UNBIND_TEST;
if (i915_gem_object_unbind(obj, flags) == 0) - __i915_gem_object_put_pages(obj); + return true;
- return !i915_gem_object_has_pages(obj); + return false; }
static void try_to_writeback(struct drm_i915_gem_object *obj, @@ -199,10 +199,10 @@ i915_gem_shrink(struct drm_i915_private *i915,
spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
- if (unsafe_drop_pages(obj, shrink)) { + if (unsafe_drop_pages(obj, shrink) && + mutex_trylock(&obj->mm.lock)) { /* May arrive from get_pages on another bo */ - mutex_lock(&obj->mm.lock); - if (!i915_gem_object_has_pages(obj)) { + if (!__i915_gem_object_put_pages_locked(obj)) { try_to_writeback(obj, shrink); count += obj->base.size >> PAGE_SHIFT; } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 9ea9aa65ade1..0cab9da6669e 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -247,7 +247,7 @@ static int i915_gem_object_userptr_unbind(struct drm_i915_gem_object *obj, bool if (GEM_WARN_ON(i915_gem_object_has_pinned_pages(obj))) return -EBUSY;
- mutex_lock_nested(&obj->mm.lock, I915_MM_GET_PAGES); + mutex_lock(&obj->mm.lock);
pages = __i915_gem_object_unset_pages(obj); if (!IS_ERR_OR_NULL(pages))