Re: [PATCH RFC v2 5/8] workqueue: add workqueue_set_affn_scope()

[Tejun Heo <tj@kernel.org>]

On Wed, Sep 02, 2026 at 03:28:50PM -0400, Chuck Lever wrote:
> An unbound workqueue's affinity scope can be changed only through
> sysfs. A module whose workqueue contends on the pool lock at the
> default scope has no in-kernel way to select a finer one, because
> alloc_workqueue_attrs() and apply_workqueue_attrs() are not
> exported. Exporting them would also invite a caller to apply freshly

BTW, please feel free to export them.

> +int workqueue_set_affn_scope(struct workqueue_struct *wq,
> +			     enum wq_affn_scope affn_scope)

No need for the line break.

> +{
> +	struct workqueue_attrs *attrs;
> +	int ret = -ENOMEM;
> +
> +	if ((unsigned int)affn_scope >= WQ_AFFN_NR_TYPES)
> +		return -EINVAL;
> +
> +	mutex_lock(&wq_pool_mutex);
> +	attrs = alloc_workqueue_attrs();

Maybe alloc outside mutex and use alloc and mutex guards?

Thanks.

-- 
tejun