From: Christoph Lameter <cl@linux.com>
To: akpm@linux-foundation.org
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: linux-kernel@vger.kernel.org
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tejun Heo <tj@kernel.org>
Subject: [thisops uV2 05/10] x86: Use this_cpu_inc_return for nmi counter
Date: Fri, 26 Nov 2010 15:09:42 -0600 [thread overview]
Message-ID: <20101126210951.874368925@linux.com> (raw)
In-Reply-To: 20101126210937.383047168@linux.com
[-- Attachment #1: this_cpu_add_nmi --]
[-- Type: text/plain, Size: 898 bytes --]
this_cpu_inc_return() saves us a memory access there.
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
---
arch/x86/kernel/apic/nmi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
Index: linux-2.6/arch/x86/kernel/apic/nmi.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/nmi.c 2010-11-23 16:35:19.000000000 -0600
+++ linux-2.6/arch/x86/kernel/apic/nmi.c 2010-11-23 16:38:29.000000000 -0600
@@ -432,8 +432,7 @@ nmi_watchdog_tick(struct pt_regs *regs,
* 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..
*/
next prev parent reply other threads:[~2010-11-26 21:11 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-26 21:09 [thisops uV2 00/10] Upgrade of this_cpu_ops V2 Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 01/10] percpucounter: Optimize __percpu_counter_add a bit through the use of this_cpu() options Christoph Lameter
2010-11-27 14:42 ` Mathieu Desnoyers
2010-11-26 21:09 ` [thisops uV2 02/10] vmstat: Optimize zone counter modifications through the use of this cpu operations Christoph Lameter
2010-11-27 8:00 ` Pekka Enberg
2010-11-27 14:49 ` Mathieu Desnoyers
2010-11-29 16:16 ` Christoph Lameter
2010-11-29 17:13 ` Christoph Lameter
2010-11-29 19:28 ` Mathieu Desnoyers
2010-11-29 20:07 ` Christoph Lameter
2010-11-29 20:59 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 03/10] percpu: Generic support for this_cpu_add,sub,dec,inc_return Christoph Lameter
2010-11-27 14:58 ` Mathieu Desnoyers
2010-11-29 16:08 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 04/10] x86: Support " Christoph Lameter
2010-11-27 8:06 ` Pekka Enberg
2010-11-29 16:03 ` Christoph Lameter
2010-11-27 15:00 ` Mathieu Desnoyers
2010-11-29 16:31 ` Christoph Lameter
2010-11-29 18:33 ` Mathieu Desnoyers
2010-11-29 18:54 ` Christoph Lameter
2010-11-29 19:22 ` Mathieu Desnoyers
2010-11-29 20:09 ` Christoph Lameter
2010-11-26 21:09 ` Christoph Lameter [this message]
2010-11-27 8:07 ` [thisops uV2 05/10] x86: Use this_cpu_inc_return for nmi counter Pekka Enberg
2010-11-27 15:00 ` Mathieu Desnoyers
2010-11-26 21:09 ` [thisops uV2 06/10] vmstat: Use this_cpu_inc_return for vm statistics Christoph Lameter
2010-11-27 8:09 ` Pekka Enberg
2010-11-29 16:04 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 07/10] highmem: Use this_cpu_xx_return() operations Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 08/10] percpu: generic this_cpu_cmpxchg() and this_cpu_cmpxchg_double support Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 09/10] x86: this_cpu_cmpxchg and this_cpu_cmpxchg_double operations Christoph Lameter
2010-11-27 6:30 ` Eric Dumazet
2010-11-27 15:20 ` Mathieu Desnoyers
2010-11-29 16:11 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 10/10] slub: Lockless fastpaths Christoph Lameter
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