On 17.04.20 13:15, Bob Liu wrote:
> Then users can set cpu affinity through "cpumask" for iscsi workqueues, so
> as to get performance isolation.
>
> This patch changes the max number of active worker form 1 to 2,
> since ordered workqueue wont' be allowed to change "cpumask".
>
Won't having 2 workers break the current ordering guarantees?
Did you check that no-one depends on this?
> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
> ---
> 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);
>From looking at the documentation, __WQ_LEGACY doesn't seem to belong here.
> 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;
>
