| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Wed, 24 May 2017 10:15:26 +0200 |
| Subject: [PATCH 15/32] s390/kernel: Use stop_machine_cpuslocked() |
| |
| 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. Convert |
| *_online_cpus() to the new interfaces while at it. |
| |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Acked-by: Ingo Molnar <mingo@kernel.org> |
| Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> |
| Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> |
| Cc: linux-s390@vger.kernel.org |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Steven Rostedt <rostedt@goodmis.org> |
| Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> |
| Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> |
| Link: http://lkml.kernel.org/r/20170524081548.250203087@linutronix.de |
| --- |
| arch/s390/kernel/time.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| --- a/arch/s390/kernel/time.c |
| +++ b/arch/s390/kernel/time.c |
| @@ -634,10 +634,10 @@ static void stp_work_fn(struct work_stru |
| goto out_unlock; |
| |
| memset(&stp_sync, 0, sizeof(stp_sync)); |
| - get_online_cpus(); |
| + cpus_read_lock(); |
| atomic_set(&stp_sync.cpus, num_online_cpus() - 1); |
| - stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask); |
| - put_online_cpus(); |
| + stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask); |
| + cpus_read_unlock(); |
| |
| if (!check_sync_clock()) |
| /* |
