Re: [RFC RESEND PATCH v2] scsi: iscsi: register sysfs for iscsi workqueue

["Martin K. Petersen" <martin.petersen@oracle.com>]

Chris/Lee: Please review!

> Motivation:
> This patch enable setting cpu affinity through "cpumask" for iscsi workqueues
> (iscsi_q_xx and iscsi_eh), so as to get performance isolation.
>
> The max number of active worker was changed form 1 to 2, because "cpumask" of
> ordered workqueue isn't allowed to change.
>
> Notes:
> - Having 2 workers break the current ordering guarantees, please let me know
>   if anyone depends on this.
>
> - __WQ_LEGACY have to be left because of
> 23d11a5(workqueue: skip flush dependency checks for legacy workqueues)
>
> Signed-off-by: Bob Liu <bob.liu@oracle.com>
> ---
>  drivers/scsi/libiscsi.c             | 4 +++-
>  drivers/scsi/scsi_transport_iscsi.c | 4 +++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
> index 70b99c0..adf9bb4 100644
> --- a/drivers/scsi/libiscsi.c
> +++ b/drivers/scsi/libiscsi.c
> @@ -2627,7 +2627,9 @@ struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
>  	if (xmit_can_sleep) {
>  		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
>  			"iscsi_q_%d", shost->host_no);
> -		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
> +		ihost->workq = alloc_workqueue("%s",
> +			WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
> +			2, ihost->workq_name);
>  		if (!ihost->workq)
>  			goto free_host;
>  	}
> diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
> index dfc726f..bdbc4a2 100644
> --- a/drivers/scsi/scsi_transport_iscsi.c
> +++ b/drivers/scsi/scsi_transport_iscsi.c
> @@ -4602,7 +4602,9 @@ static __init int iscsi_transport_init(void)
>  		goto unregister_flashnode_bus;
>  	}
>  
> -	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
> +	iscsi_eh_timer_workq = alloc_workqueue("%s",
> +			WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
> +			2, "iscsi_eh");
>  	if (!iscsi_eh_timer_workq) {
>  		err = -ENOMEM;
>  		goto release_nls;

-- 
Martin K. Petersen	Oracle Linux Engineering