Re: [PATCH v2 3/3] s390: replace use of system_wq with system_dfl_wq

[Mete Durlu <meted@linux.ibm.com>]

On 9/17/25 5:38 PM, Marco Crivellari wrote:
> Currently if a user enqueue a work item using schedule_delayed_work() the
> used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
> WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
> schedule_work() that is using system_wq and queue_work(), that makes use
> again of WORK_CPU_UNBOUND.
> 
> This lack of consistentcy cannot be addressed without refactoring the API.
> 
> system_wq is a per-CPU worqueue (replaced by system_percpu_wq), but the
> current code does not benefit from it. Because of that, system_wq has been
> replaced by system_dfl_wq, the new unbound workqueue.

That sounds right. Thanks!

> The old wq will be kept for a few release cylces.
> 
> Suggested-by: Tejun Heo <tj@kernel.org>
> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
> ---
>   arch/s390/kernel/hiperdispatch.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/kernel/hiperdispatch.c b/arch/s390/kernel/hiperdispatch.c
> index e7b66d046e8d..2507bc3f7757 100644
> --- a/arch/s390/kernel/hiperdispatch.c
> +++ b/arch/s390/kernel/hiperdispatch.c
> @@ -191,7 +191,7 @@ int hd_enable_hiperdispatch(void)
>   		return 0;
>   	if (hd_online_cores <= hd_entitled_cores)
>   		return 0;
> -	mod_delayed_work(system_wq, &hd_capacity_work, HD_DELAY_INTERVAL * hd_delay_factor);
> +	mod_delayed_work(system_dfl_wq, &hd_capacity_work, HD_DELAY_INTERVAL * hd_delay_factor);
>   	hd_update_capacities();
>   	return 1;
>   }


Thank you for making the change from *_percpu_wq to *_dfl_wq.
I am not sure if its too late but you can have my r-b

Reviewed-by: Mete Durlu <meted@linux.ibm.com>