From: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>

Avoid checking for cpu gone in mm hot path when CONFIG_HOTPLUG_CPU is not
defined.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/i386/kernel/smp.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff -puN arch/i386/kernel/smp.c~i386-avoid-checking-for-cpu-gone-when-config_hotplug_cpu-not-defined arch/i386/kernel/smp.c
--- a/arch/i386/kernel/smp.c~i386-avoid-checking-for-cpu-gone-when-config_hotplug_cpu-not-defined
+++ a/arch/i386/kernel/smp.c
@@ -367,10 +367,12 @@ void native_flush_tlb_others(const cpuma
 	BUG_ON(cpu_isset(smp_processor_id(), cpumask));
 	BUG_ON(!mm);
 
+#ifdef CONFIG_HOTPLUG_CPU
 	/* If a CPU which we ran on has gone down, OK. */
 	cpus_and(cpumask, cpumask, cpu_online_map);
-	if (cpus_empty(cpumask))
+	if (unlikely(cpus_empty(cpumask)))
 		return;
+#endif
 
 	/*
 	 * i'm not happy about this global shared spinlock in the
_