Re: [PATCH v2 14/14] ublk: cache-align struct ublk_io

[Ming Lei <ming.lei@redhat.com>]

On Fri, Jun 20, 2025 at 09:10:08AM -0600, Caleb Sander Mateos wrote:
> struct ublk_io is already 56 bytes on 64-bit architectures, so round it
> up to a full cache line (typically 64 bytes). This ensures a single
> ublk_io doesn't span multiple cache lines and prevents false sharing if
> consecutive ublk_io's are accessed by different daemon tasks.
> 
> Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
> ---
>  drivers/block/ublk_drv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index ebc56681eb68..740141c63a93 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -186,11 +186,11 @@ struct ublk_io {
>  	unsigned task_registered_buffers;
>  
>  	/* auto-registered buffer, valid if UBLK_IO_FLAG_AUTO_BUF_REG is set */
>  	u16 buf_index;
>  	void *buf_ctx_handle;
> -};
> +} ____cacheline_aligned_in_smp;

Reviewed-by: Ming Lei <ming.lei@redhat.com>

Thanks, 
Ming