Removes the need for a write lock each time we call ttm_bo_unref().
Signed-off-by: Thomas Hellstrom thellstrom@vmware.com --- drivers/gpu/drm/ttm/ttm_bo.c | 4 +--- drivers/gpu/drm/ttm/ttm_bo_vm.c | 4 ++-- 2 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 7426fe5..2dd0238 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -696,6 +696,7 @@ static void ttm_bo_release(struct kref *kref) struct ttm_bo_device *bdev = bo->bdev; struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
+ write_lock(&bdev->vm_lock); if (likely(bo->vm_node != NULL)) { rb_erase(&bo->vm_rb, &bdev->addr_space_rb); drm_mm_put_block(bo->vm_node); @@ -707,7 +708,6 @@ static void ttm_bo_release(struct kref *kref) ttm_mem_io_unlock(man); ttm_bo_cleanup_refs_or_queue(bo); kref_put(&bo->list_kref, ttm_bo_release_list); - write_lock(&bdev->vm_lock); }
void ttm_bo_unref(struct ttm_buffer_object **p_bo) @@ -716,9 +716,7 @@ void ttm_bo_unref(struct ttm_buffer_object **p_bo) struct ttm_bo_device *bdev = bo->bdev;
*p_bo = NULL; - write_lock(&bdev->vm_lock); kref_put(&bo->kref, ttm_bo_release); - write_unlock(&bdev->vm_lock); } EXPORT_SYMBOL(ttm_bo_unref);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 3ba72db..74705f3 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -259,8 +259,8 @@ int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma, read_lock(&bdev->vm_lock); bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff, (vma->vm_end - vma->vm_start) >> PAGE_SHIFT); - if (likely(bo != NULL)) - ttm_bo_reference(bo); + if (likely(bo != NULL) && !kref_get_unless_zero(&bo->kref)) + bo = NULL; read_unlock(&bdev->vm_lock);
if (unlikely(bo == NULL)) {