[PATCH] [20/34] i386: avoid checking for cpu gone when CONFIG_HOTPLUG_CPU not defined

[Andi Kleen]

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

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@xxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Gautham R Shenoy <ego@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

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

Index: linux/arch/i386/kernel/smp.c
===================================================================
--- linux.orig/arch/i386/kernel/smp.c
+++ linux/arch/i386/kernel/smp.c
@@ -359,10 +359,12 @@ 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
-
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