workqueue: Initialize wq_isolated_cpumask in workqueue_init_early()

[ Upstream commit 261dce3d64021e7ec828a17b4975ce9182e54ceb ]

Now when isolcpus is enabled via the cmdline, wq_isolated_cpumask does
not include these isolated CPUs, even wq_unbound_cpumask has already
excluded them. It is only when we successfully configure an isolate cpuset
partition that wq_isolated_cpumask gets overwritten by
workqueue_unbound_exclude_cpumask(), including both the cmdline-specified
isolated CPUs and the isolated CPUs within the cpuset partitions.

Fix this issue by initializing wq_isolated_cpumask properly in
workqueue_init_early().

Fixes: fe28f63 ("workqueue: Add workqueue_unbound_exclude_cpumask() to exclude CPUs from wq_unbound_cpumask")
Signed-off-by: Chuyi Zhou <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 8873080b885145c18e8a4ef2affb858068cdc19d)

Author: kchuyizhou

kernel/workqueue.c

@@ -7731,7 +7731,8 @@ void __init workqueue_init_early(void)
 		restrict_unbound_cpumask("workqueue.unbound_cpus", &wq_cmdline_cpumask);
 
 	cpumask_copy(wq_requested_unbound_cpumask, wq_unbound_cpumask);
-
+	cpumask_andnot(wq_isolated_cpumask, cpu_possible_mask,
+						housekeeping_cpumask(HK_TYPE_DOMAIN));
 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
 
 	unbound_wq_update_pwq_attrs_buf = alloc_workqueue_attrs();