S390: Smp: remove call to ipi_call_lock()/ipi_call_unlock()

ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock
protects only the call_function data structure itself, but it's
completely unrelated to cpu_online_mask. The mask to which the IPIs
are sent is calculated before call_function.lock is taken in
smp_call_function_many(), so the locking around set_cpu_online() is
pointless and can be removed.

[ tglx: Massaged changelog ]

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: ralf@linux-mips.org
Cc: sshtylyov@mvista.com
Cc: david.daney@cavium.com
Cc: nikunj@linux.vnet.ibm.com
Cc: paulmck@linux.vnet.ibm.com
Cc: axboe@kernel.dk
Cc: peterz@infradead.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/1338275765-3217-5-git-send-email-yong.zhang0@gmail.com
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 15cca26ccb6c4ff1cbde51c60259a7ec95471718..8dca9c248ac793ea292ad4683e0057af5e9470d8 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -717,9 +717,7 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)
        init_cpu_vtimer();
        pfault_init();
        notify_cpu_starting(smp_processor_id());
-       ipi_call_lock();
        set_cpu_online(smp_processor_id(), true);
-       ipi_call_unlock();
        local_irq_enable();
        /* cpu_idle will call schedule for us */
        cpu_idle();