workqueue: workqueue_cpu_callback() should be cpu_notifier instead of hotcpu_notifier

Commit 6ee0578b (workqueue: mark init_workqueues as early_initcall)
made workqueue SMP initialization depend on workqueue_cpu_callback(),
which however was registered as hotcpu_notifier() and didn't get
called if CONFIG_HOTPLUG_CPU is not set.  This made gcwqs on non-boot
CPUs not create their initial workers leading to boot failures.  Fix
it by making it a cpu_notifier.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-bisected-by: walt <w41ter@gmail.com>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index da6c482..2994a0e 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3527,7 +3527,7 @@ static int __init init_workqueues(void)
        unsigned int cpu;
        int i;
 
-       hotcpu_notifier(workqueue_cpu_callback, CPU_PRI_WORKQUEUE);
+       cpu_notifier(workqueue_cpu_callback, CPU_PRI_WORKQUEUE);
 
        /* initialize gcwqs */
        for_each_gcwq_cpu(cpu) {