From: Tejun Heo <tj@kernel.org>
Date: Sat, 18 Dec 2010 15:30:48 +0000 (+0100)
Subject: x86: Use this_cpu_inc_return for nmi counter
X-Git-Tag: firefly_0821_release~7613^2~3101^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c1955b5f3a95717ce1f5235f6e9968da068e3183;p=firefly-linux-kernel-4.4.55.git

x86: Use this_cpu_inc_return for nmi counter

this_cpu_inc_return() saves us a memory access there.

Reviewed-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index b387dce0b409..37769cc4fe55 100644
--- a/arch/x86/kernel/apic/nmi.c
+++ b/arch/x86/kernel/apic/nmi.c
@@ -432,8 +432,7 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
 		 * Ayiee, looks like this CPU is stuck ...
 		 * wait a few IRQs (5 seconds) before doing the oops ...
 		 */
-		__this_cpu_inc(alert_counter);
-		if (__this_cpu_read(alert_counter) == 5 * nmi_hz)
+		if (__this_cpu_inc_return(alert_counter) == 5 * nmi_hz)
 			/*
 			 * die_nmi will return ONLY if NOTIFY_STOP happens..
 			 */