diff options
| author | Thomas Hellstrom <thellstrom@vmware.com> | 2012-11-21 14:53:21 +0000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-11-28 18:37:59 +1000 |
| commit | 82fe50bcc87e508e85250c87b745296a36a07897 (patch) | |
| tree | 6fd205d9d0a92391e9bf5cf31a442a54992fe0b5 /drivers/gpu/drm/ttm | |
| parent | 5293908afa04b651cc8a7e85ba0938b71f97c2f8 (diff) | |
drm/ttm: Optimize vm locking using kref_get_unless_zero v3
Removes the need for a write lock each time we call ttm_bo_unref().
v2: Remove an unused variable.
v3: Really remove the unused variable.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/ttm')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo.c | 5 | ||||
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo_vm.c | 4 |
2 files changed, 3 insertions, 6 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 7426fe59108..2c54c3d414b 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); @@ -707,18 +708,14 @@ 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) { struct ttm_buffer_object *bo = *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 3ba72dbdc4b..74705f329d9 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)) { |