From: Rob Clark robdclark@chromium.org
Move grabbing the bo lock into shrinker, with a msm_gem_trylock() to skip over bo's that are already locked. This gets rid of the nested lock classes.
Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/msm_gem.c | 24 +++++---------------- drivers/gpu/drm/msm/msm_gem.h | 29 ++++++++++---------------- drivers/gpu/drm/msm/msm_gem_shrinker.c | 27 +++++++++++++++++------- 3 files changed, 35 insertions(+), 45 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index e0d8d739b068..1195847714ba 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -17,8 +17,6 @@ #include "msm_gpu.h" #include "msm_mmu.h"
-static void msm_gem_vunmap_locked(struct drm_gem_object *obj); -
static dma_addr_t physaddr(struct drm_gem_object *obj) { @@ -693,20 +691,19 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv) return (madv != __MSM_MADV_PURGED); }
-void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass) +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(!msm_gem_is_locked(obj)); WARN_ON(!is_purgeable(msm_obj)); WARN_ON(obj->import_attach);
- mutex_lock_nested(&msm_obj->lock, subclass); - put_iova(obj);
- msm_gem_vunmap_locked(obj); + msm_gem_vunmap(obj);
put_pages(obj);
@@ -724,11 +721,9 @@ void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass)
invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1); - - msm_gem_unlock(obj); }
-static void msm_gem_vunmap_locked(struct drm_gem_object *obj) +void msm_gem_vunmap(struct drm_gem_object *obj) { struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -741,15 +736,6 @@ static void msm_gem_vunmap_locked(struct drm_gem_object *obj) msm_obj->vaddr = NULL; }
-void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass) -{ - struct msm_gem_object *msm_obj = to_msm_bo(obj); - - mutex_lock_nested(&msm_obj->lock, subclass); - msm_gem_vunmap_locked(obj); - msm_gem_unlock(obj); -} - /* must be called before _move_to_active().. */ int msm_gem_sync_object(struct drm_gem_object *obj, struct msm_fence_context *fctx, bool exclusive) @@ -986,7 +972,7 @@ static void free_object(struct msm_gem_object *msm_obj)
drm_prime_gem_destroy(obj, msm_obj->sgt); } else { - msm_gem_vunmap_locked(obj); + msm_gem_vunmap(obj); put_pages(obj); }
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index d55d5401a2d2..c5232b8da794 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -162,6 +162,13 @@ msm_gem_lock(struct drm_gem_object *obj) mutex_lock(&msm_obj->lock); }
+static inline bool __must_check +msm_gem_trylock(struct drm_gem_object *obj) +{ + struct msm_gem_object *msm_obj = to_msm_bo(obj); + return mutex_trylock_recursive(&msm_obj->lock) == MUTEX_TRYLOCK_SUCCESS; +} + static inline int msm_gem_lock_interruptible(struct drm_gem_object *obj) { @@ -190,6 +197,7 @@ static inline bool is_active(struct msm_gem_object *msm_obj)
static inline bool is_purgeable(struct msm_gem_object *msm_obj) { + WARN_ON(!msm_gem_is_locked(&msm_obj->base)); WARN_ON(!mutex_is_locked(&msm_obj->base.dev->struct_mutex)); return (msm_obj->madv == MSM_MADV_DONTNEED) && msm_obj->sgt && !msm_obj->base.dma_buf && !msm_obj->base.import_attach; @@ -197,27 +205,12 @@ static inline bool is_purgeable(struct msm_gem_object *msm_obj)
static inline bool is_vunmapable(struct msm_gem_object *msm_obj) { + WARN_ON(!msm_gem_is_locked(&msm_obj->base)); return (msm_obj->vmap_count == 0) && msm_obj->vaddr; }
-/* The shrinker can be triggered while we hold objA->lock, and need - * to grab objB->lock to purge it. Lockdep just sees these as a single - * class of lock, so we use subclasses to teach it the difference. - * - * OBJ_LOCK_NORMAL is implicit (ie. normal mutex_lock() call), and - * OBJ_LOCK_SHRINKER is used by shrinker. - * - * It is *essential* that we never go down paths that could trigger the - * shrinker for a purgable object. This is ensured by checking that - * msm_obj->madv == MSM_MADV_WILLNEED. - */ -enum msm_gem_lock { - OBJ_LOCK_NORMAL, - OBJ_LOCK_SHRINKER, -}; - -void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass); -void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass); +void msm_gem_purge(struct drm_gem_object *obj); +void msm_gem_vunmap(struct drm_gem_object *obj); void msm_gem_free_work(struct work_struct *work);
/* Created per submit-ioctl, to track bo's and cmdstream bufs, etc, diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c index 482576d7a39a..2dc0ffa925b4 100644 --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c @@ -52,8 +52,11 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) return 0;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) { + if (!msm_gem_trylock(&msm_obj->base)) + continue; if (is_purgeable(msm_obj)) count += msm_obj->base.size >> PAGE_SHIFT; + msm_gem_unlock(&msm_obj->base); }
if (unlock) @@ -78,10 +81,13 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) { if (freed >= sc->nr_to_scan) break; + if (!msm_gem_trylock(&msm_obj->base)) + continue; if (is_purgeable(msm_obj)) { - msm_gem_purge(&msm_obj->base, OBJ_LOCK_SHRINKER); + msm_gem_purge(&msm_obj->base); freed += msm_obj->base.size >> PAGE_SHIFT; } + msm_gem_unlock(&msm_obj->base); }
if (unlock) @@ -107,15 +113,20 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr) return NOTIFY_DONE;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) { + if (!msm_gem_trylock(&msm_obj->base)) + continue; if (is_vunmapable(msm_obj)) { - msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER); - /* since we don't know any better, lets bail after a few - * and if necessary the shrinker will be invoked again. - * Seems better than unmapping *everything* - */ - if (++unmapped >= 15) - break; + msm_gem_vunmap(&msm_obj->base); + unmapped++; } + msm_gem_unlock(&msm_obj->base); + + /* since we don't know any better, lets bail after a few + * and if necessary the shrinker will be invoked again. + * Seems better than unmapping *everything* + */ + if (++unmapped >= 15) + break; }
if (unlock)