workqueue: Move attrs->cpumask out of worker_pool's properties when attrs->affn_strict

Allow more pools can be shared when attrs->affn_strict.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

include/linux/workqueue.h

@@ -185,6 +185,9 @@ struct workqueue_attrs {
 	 * Below fields aren't properties of a worker_pool. They only modify how
 	 * :c:func:`apply_workqueue_attrs` select pools and thus don't
 	 * participate in pool hash calculations or equality comparisons.
+	 *
+	 * If @affn_strict is set, @cpumask isn't a property of a worker_pool
+	 * either.
 	 */
 
 	/**

kernel/workqueue.c

@@ -4625,6 +4625,8 @@ static void wqattrs_clear_for_pool(struct workqueue_attrs *attrs)
 {
 	attrs->affn_scope = WQ_AFFN_NR_TYPES;
 	attrs->ordered = false;
+	if (attrs->affn_strict)
+		cpumask_copy(attrs->cpumask, cpu_possible_mask);
 }
 
 /* hash value of the content of @attr */
@@ -4633,11 +4635,12 @@ static u32 wqattrs_hash(const struct workqueue_attrs *attrs)
 	u32 hash = 0;
 
 	hash = jhash_1word(attrs->nice, hash);
-	hash = jhash(cpumask_bits(attrs->cpumask),
-		     BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long), hash);
+	hash = jhash_1word(attrs->affn_strict, hash);
 	hash = jhash(cpumask_bits(attrs->__pod_cpumask),
 		     BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long), hash);
-	hash = jhash_1word(attrs->affn_strict, hash);
+	if (!attrs->affn_strict)
+		hash = jhash(cpumask_bits(attrs->cpumask),
+			     BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long), hash);
 	return hash;
 }
 
@@ -4647,11 +4650,11 @@ static bool wqattrs_equal(const struct workqueue_attrs *a,
 {
 	if (a->nice != b->nice)
 		return false;
-	if (!cpumask_equal(a->cpumask, b->cpumask))
+	if (a->affn_strict != b->affn_strict)
 		return false;
 	if (!cpumask_equal(a->__pod_cpumask, b->__pod_cpumask))
 		return false;
-	if (a->affn_strict != b->affn_strict)
+	if (!a->affn_strict && !cpumask_equal(a->cpumask, b->cpumask))
 		return false;
 	return true;
 }