Commit fbb3d4c1 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Tejun Heo
Browse files

workqueue: Simplify wq_calc_pod_cpumask() with wq_online_cpumask 



Avoid relying on cpu_online_mask for wqattrs changes so that
cpus_read_lock() can be removed from apply_wqattrs_lock().

And with wq_online_cpumask, attrs->__pod_cpumask doesn't need to be
reused as a temporary storage to calculate if the pod have any online
CPUs @attrs wants since @cpu_going_down is not in the wq_online_cpumask.

Signed-off-by: default avatarLai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 8d84baf7

kernel/workqueue.c

+3 −9
Original line number Diff line number Diff line
@@ -5146,20 +5146,14 @@ static void wq_calc_pod_cpumask(struct workqueue_attrs *attrs, int cpu, 
	const struct wq_pod_type *pt = wqattrs_pod_type(attrs);

	int pod = pt->cpu_pod[cpu];



	/* does @pod have any online CPUs @attrs wants? */

	/* calculate possible CPUs in @pod that @attrs wants */

	cpumask_and(attrs->__pod_cpumask, pt->pod_cpus[pod], attrs->cpumask);

	cpumask_and(attrs->__pod_cpumask, attrs->__pod_cpumask, cpu_online_mask);

	if (cpu_going_down >= 0)

		cpumask_clear_cpu(cpu_going_down, attrs->__pod_cpumask);



	if (cpumask_empty(attrs->__pod_cpumask)) {

	/* does @pod have any online CPUs @attrs wants? */

	if (!cpumask_intersects(attrs->__pod_cpumask, wq_online_cpumask)) {

		cpumask_copy(attrs->__pod_cpumask, attrs->cpumask);

		return;

	}



	/* yeap, return possible CPUs in @pod that @attrs wants */

	cpumask_and(attrs->__pod_cpumask, attrs->cpumask, pt->pod_cpus[pod]);



	if (cpumask_empty(attrs->__pod_cpumask))

		pr_warn_once("WARNING: workqueue cpumask: online intersect > "

				"possible intersect\n");