x86/mtrr: Remove get_online_cpus() from mtrr_save_state()

mtrr_save_state() is invoked from native_cpu_up() which is in the context
of a CPU hotplug operation and therefor calling get_online_cpus() is
pointless.

While this works in the current get_online_cpus() implementation it
prevents from converting the hotplug locking to percpu rwsems.

Remove it.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.651378834@linutronix.de

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 2bce84d91c2b6adba00a678a683843b2e47b485a..c5bb63be4ba1e6a2df1203fe73079faad9fc62e7 100644 (file)
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -807,10 +807,8 @@ void mtrr_save_state(void)
        if (!mtrr_enabled())
                return;
 
-       get_online_cpus();
        first_cpu = cpumask_first(cpu_online_mask);
        smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);
-       put_online_cpus();
 }
 
 void set_mtrr_aps_delayed_init(void)