[patch V2 12/24] s390/kernel: Use stop_machine_cpuslocked()

Thomas Gleixner
2017-04-18T19:51:02Z

[-- Attachment #1: s390-kernel-Use_stop_machine_locked.patch --]
[-- Type: text/plain, Size: 1062 bytes --]

stp_work_fn() holds get_online_cpus() while invoking stop_machine().

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org

---
arch/s390/kernel/time.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -636,7 +636,7 @@ static void stp_work_fn(struct work_stru
memset(&stp_sync, 0, sizeof(stp_sync));
get_online_cpus();
atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
- stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask);
+ stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
put_online_cpus();

if (!check_sync_clock())