From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 24 May 2017 08:15:19 +0000 (+0200)
Subject: x86/mtrr: Remove get_online_cpus() from mtrr_save_state()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=547efeadd42a3c75e41e33c0637cba100fc18289;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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 2bce84d91c2b..c5bb63be4ba1 100644
--- 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)