tile: 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: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/1338275765-3217-6-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/tile/kernel/smpboot.c b/arch/tile/kernel/smpboot.c
index 84873fbe8f2769b0bfa22faaed187ae0919c523d..e686c5ac90be36bcf14d33019ac97bb5e46bc4ee 100644 (file)
--- a/arch/tile/kernel/smpboot.c
+++ b/arch/tile/kernel/smpboot.c
@@ -198,17 +198,7 @@ void __cpuinit online_secondary(void)
 
        notify_cpu_starting(smp_processor_id());
 
-       /*
-        * We need to hold call_lock, so there is no inconsistency
-        * between the time smp_call_function() determines number of
-        * IPI recipients, and the time when the determination is made
-        * for which cpus receive the IPI. Holding this
-        * lock helps us to not include this cpu in a currently in progress
-        * smp_call_function().
-        */
-       ipi_call_lock();
        set_cpu_online(smp_processor_id(), 1);
-       ipi_call_unlock();
        __get_cpu_var(cpu_state) = CPU_ONLINE;
 
        /* Set up tile-specific state for this cpu. */