Re: [PATCH v3 05/25] drm/xe: Update xe_bo_put_deferred arguments to include writeback flag

[Francois Dugast <francois.dugast@intel.com>]

On Fri, Feb 27, 2026 at 05:34:41PM -0800, Matthew Brost wrote:
> Update the xe_bo_put_deferred arguments to include a writeback flag,
> which indicates whether the BO was added to the deferred list. This is
> useful when the caller needs to take additional actions after the BO has
> been queued for deferred release.
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_bo.h         | 10 ++++++++--
>  drivers/gpu/drm/xe/xe_drm_client.c |  2 +-
>  drivers/gpu/drm/xe/xe_pt.c         |  2 +-
>  3 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.h b/drivers/gpu/drm/xe/xe_bo.h
> index c914ab719f20..bf284ed47325 100644
> --- a/drivers/gpu/drm/xe/xe_bo.h
> +++ b/drivers/gpu/drm/xe/xe_bo.h
> @@ -348,6 +348,8 @@ void __xe_bo_release_dummy(struct kref *kref);
>   * @bo: The bo to put.
>   * @deferred: List to which to add the buffer object if we cannot put, or
>   * NULL if the function is to put unconditionally.
> + * @added: BO was added to deferred list, written back to caller, can be NULL if
> + * writeback is not needed.

We should add in this comment that if set by the caller then it must be
false, because this function only sets it to true. With that:

    Reviewed-by: Francois Dugast <francois.dugast@intel.com>

>   *
>   * Since the final freeing of an object includes both sleeping and (!)
>   * memory allocation in the dma_resv individualization, it's not ok
> @@ -367,7 +369,8 @@ void __xe_bo_release_dummy(struct kref *kref);
>   * false otherwise.
>   */
>  static inline bool
> -xe_bo_put_deferred(struct xe_bo *bo, struct llist_head *deferred)
> +xe_bo_put_deferred(struct xe_bo *bo, struct llist_head *deferred,
> +		   bool *added)
>  {
>  	if (!deferred) {
>  		xe_bo_put(bo);
> @@ -377,6 +380,9 @@ xe_bo_put_deferred(struct xe_bo *bo, struct llist_head *deferred)
>  	if (!kref_put(&bo->ttm.base.refcount, __xe_bo_release_dummy))
>  		return false;
>  
> +	if (added)
> +		*added = true;
> +
>  	return llist_add(&bo->freed, deferred);
>  }
>  
> @@ -393,7 +399,7 @@ xe_bo_put_async(struct xe_bo *bo)
>  {
>  	struct xe_bo_dev *bo_device = &xe_bo_device(bo)->bo_device;
>  
> -	if (xe_bo_put_deferred(bo, &bo_device->async_list))
> +	if (xe_bo_put_deferred(bo, &bo_device->async_list, NULL))
>  		schedule_work(&bo_device->async_free);
>  }
>  
> diff --git a/drivers/gpu/drm/xe/xe_drm_client.c b/drivers/gpu/drm/xe/xe_drm_client.c
> index 84b66147bf49..45efe7a55427 100644
> --- a/drivers/gpu/drm/xe/xe_drm_client.c
> +++ b/drivers/gpu/drm/xe/xe_drm_client.c
> @@ -246,7 +246,7 @@ static void show_meminfo(struct drm_printer *p, struct drm_file *file)
>  			xe_assert(xef->xe, !list_empty(&bo->client_link));
>  		}
>  
> -		xe_bo_put_deferred(bo, &deferred);
> +		xe_bo_put_deferred(bo, &deferred, NULL);
>  	}
>  	spin_unlock(&client->bos_lock);
>  
> diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> index 99b15d37267f..83dacc91b7b3 100644
> --- a/drivers/gpu/drm/xe/xe_pt.c
> +++ b/drivers/gpu/drm/xe/xe_pt.c
> @@ -212,7 +212,7 @@ void xe_pt_destroy(struct xe_pt *pt, u32 flags, struct llist_head *deferred)
>  
>  	XE_WARN_ON(!list_empty(&pt->bo->ttm.base.gpuva.list));
>  	xe_bo_unpin(pt->bo);
> -	xe_bo_put_deferred(pt->bo, deferred);
> +	xe_bo_put_deferred(pt->bo, deferred, NULL);
>  
>  	if (pt->level > 0 && pt->num_live) {
>  		struct xe_pt_dir *pt_dir = as_xe_pt_dir(pt);
> -- 
> 2.34.1
>