[PATCH 3/3] x86: Use this_cpu_inc_return for nmi counter

From: Tejun Heo
Date: Sat Dec 18 2010 - 10:30:55 EST


this_cpu_inc_return() saves us a memory access there.

Reviewed-by: Tejun Heo <tj@xxxxxxxxxx>
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Acked-by: H. Peter Anvin <hpa@xxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
---
arch/x86/kernel/apic/nmi.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index b387dce..37769cc 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..
*/
--
1.7.1

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