[RFC PATCH 09/12] workqueue: Affine unbound workqueues to housekeeping cpumask

[Frederic Weisbecker <fweisbec@gmail.com>]

Although the unbound workqueue cpumask can be overriden through sysfs,
we also want to affine the workqueues when isolcpus= will be
reimplemented on top of housekeeping.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
---
 include/linux/housekeeping.h | 1 +
 kernel/workqueue.c           | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/housekeeping.h b/include/linux/housekeeping.h
index b1a62544..0959601 100644
--- a/include/linux/housekeeping.h
+++ b/include/linux/housekeeping.h
@@ -10,6 +10,7 @@ enum hk_flags {
 	HK_FLAG_RCU		= (1 << 1),
 	HK_FLAG_MISC		= (1 << 2),
 	HK_FLAG_SCHED		= (1 << 3),
+	HK_FLAG_WORKQUEUE	= (1 << 4),
 };
 
 #ifdef CONFIG_CPU_ISOLATION
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ca937b0..256e3cb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -48,6 +48,7 @@
 #include <linux/nodemask.h>
 #include <linux/moduleparam.h>
 #include <linux/uaccess.h>
+#include <linux/housekeeping.h>
 
 #include "workqueue_internal.h"
 
@@ -5546,7 +5547,7 @@ int __init workqueue_init_early(void)
 	WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
 
 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
-	cpumask_copy(wq_unbound_cpumask, cpu_possible_mask);
+	cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(HK_FLAG_WORKQUEUE));
 
 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
 
-- 
2.7.4