Re: [Intel-xe] [PATCH 4/5] drm/xe: Combine destroy_cb and destroy_work in xe_vma into union

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Tue, Jul 11, 2023 at 02:27:47PM -0700, Matthew Brost wrote:
> The callback kicks the worker thus mutually exclusive execution,
> combining saves a bit of space in xe_vma.

could you please open up a bit on why they are multually exclusive?!

> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm_types.h | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
> index 2a8691a48c55..30beae541aca 100644
> --- a/drivers/gpu/drm/xe/xe_vm_types.h
> +++ b/drivers/gpu/drm/xe/xe_vm_types.h
> @@ -51,11 +51,12 @@ struct xe_vma {
>  		struct list_head destroy;
>  	} combined_links;
>  
> -	/** @destroy_cb: callback to destroy VMA when unbind job is done */
> -	struct dma_fence_cb destroy_cb;
> -
> -	/** @destroy_work: worker to destroy this BO */
> -	struct work_struct destroy_work;
> +	union {
> +		/** @destroy_cb: callback to destroy VMA when unbind job is done */
> +		struct dma_fence_cb destroy_cb;
> +		/** @destroy_work: worker to destroy this BO */
> +		struct work_struct destroy_work;
> +	};
>  
>  	/** @userptr: user pointer state */
>  	struct {
> -- 
> 2.34.1
>