Re: [PATCH 1/1] scsi: target: Move LUN stats to per CPU

[Bart Van Assche <bvanassche@acm.org>]

On 7/23/25 5:45 PM, Mike Christie wrote:
> diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
> index c4d9116904aa..e73fb224625d 100644
> --- a/include/target/target_core_base.h
> +++ b/include/target/target_core_base.h
> @@ -744,9 +744,9 @@ struct se_port_stat_grps {
>   };
>   
>   struct scsi_port_stats {
> -	atomic_long_t	cmd_pdus;
> -	atomic_long_t	tx_data_octets;
> -	atomic_long_t	rx_data_octets;
> +	u32			cmd_pdus;
> +	u32			tx_data_octets;
> +	u32			rx_data_octets;
>   };
>   
>   struct se_lun {
> @@ -773,7 +773,7 @@ struct se_lun {
>   	spinlock_t		lun_tg_pt_gp_lock;
>   
>   	struct se_portal_group	*lun_tpg;
> -	struct scsi_port_stats	lun_stats;
> +	struct scsi_port_stats	__percpu *lun_stats;
>   	struct config_group	lun_group;
>   	struct se_port_stat_grps port_stat_grps;
>   	struct completion	lun_shutdown_comp;

Is this perhaps an open-coded implementation of struct percpu_counter? 
Why hasn't struct percpu_counter been used? I think this should be
explained in the patch description.

Thanks,

Bart.