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: [thiscpuops upgrade 05/10] x86: Use this_cpu_inc_return for nmi counter
Date: Tue, 23 Nov 2010 17:51:44 -0600 [thread overview]
Message-ID: <20101123235158.826005750@linux.com> (raw)
In-Reply-To: 20101123235139.908255844@linux.com
[-- Attachment #1: this_cpu_add_nmi --]
[-- Type: text/plain, Size: 859 bytes --]
this_cpu_inc_return() saves us a memory access there.
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:[~2010-11-23 23:53 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-23 23:51 [thiscpuops upgrade 00/10] Upgrade of this_cpu_ops Christoph Lameter
2010-11-23 23:51 ` [thiscpuops upgrade 01/10] percpucounter: Optimize __percpu_counter_add a bit through the use of this_cpu() options Christoph Lameter
2010-11-24 7:07 ` Pekka Enberg
2010-11-26 15:43 ` Tejun Heo
2010-11-23 23:51 ` [thiscpuops upgrade 02/10] vmstat: Optimize zone counter modifications through the use of this cpu operations Christoph Lameter
2010-11-26 16:25 ` Tejun Heo
2010-11-23 23:51 ` [thiscpuops upgrade 03/10] percpu: Generic support for this_cpu_add,sub,dec,inc_return Christoph Lameter
2010-11-26 16:31 ` Tejun Heo
2010-11-26 16:37 ` Christoph Lameter
2010-11-26 16:39 ` Tejun Heo
2010-11-23 23:51 ` [thiscpuops upgrade 04/10] x86: Support " Christoph Lameter
2010-11-26 16:33 ` Tejun Heo
2010-11-23 23:51 ` Christoph Lameter [this message]
2010-11-26 16:35 ` [thiscpuops upgrade 05/10] x86: Use this_cpu_inc_return for nmi counter Tejun Heo
2010-11-26 17:02 ` Christoph Lameter
2010-11-26 17:05 ` Tejun Heo
2010-11-23 23:51 ` [thiscpuops upgrade 06/10] vmstat: Use this_cpu_inc_return for vm statistics Christoph Lameter
2010-11-23 23:51 ` [thiscpuops upgrade 07/10] highmem: Use this_cpu_xx_return() operations Christoph Lameter
2010-11-23 23:51 ` [thiscpuops upgrade 08/10] percpu: generic this_cpu_cmpxchg() and this_cpu_cmpxchg_double support Christoph Lameter
2010-11-26 16:51 ` Tejun Heo
2010-11-26 16:56 ` Eric Dumazet
2010-11-26 16:58 ` Tejun Heo
2010-11-26 17:01 ` Eric Dumazet
2010-11-26 17:07 ` Tejun Heo
2010-11-26 17:16 ` Eric Dumazet
2010-11-23 23:51 ` [thiscpuops upgrade 09/10] x86: this_cpu_cmpxchg and this_cpu_cmpxchg_double operations Christoph Lameter
2010-11-24 0:41 ` Eric Dumazet
2010-11-24 3:11 ` Christoph Lameter
2010-11-24 7:05 ` Pekka Enberg
2010-11-24 0:44 ` Mathieu Desnoyers
2010-11-23 23:51 ` [thiscpuops upgrade 10/10] Lockless (and preemptless) fastpaths for slub Christoph Lameter
2010-11-24 0:22 ` Eric Dumazet
2010-11-24 3:13 ` Christoph Lameter
2010-11-24 4:37 ` Christoph Lameter
2010-11-24 1:02 ` Mathieu Desnoyers
2010-11-24 1:05 ` Mathieu Desnoyers
2010-11-24 3:09 ` Christoph Lameter
2010-11-24 7:16 ` Pekka Enberg
2010-11-24 16:17 ` Christoph Lameter
2010-11-24 16:37 ` Pekka Enberg
2010-11-24 16:45 ` Christoph Lameter
2010-11-24 16:47 ` Pekka Enberg
2010-11-24 16:55 ` Christoph Lameter
2010-11-24 19:37 ` Jeremy Fitzhardinge
2010-11-24 19:53 ` Christoph Lameter
2010-11-24 20:01 ` Jeremy Fitzhardinge
2010-11-24 19:56 ` Mathieu Desnoyers
2010-11-24 8:15 ` Peter Zijlstra
2010-11-24 16:14 ` Christoph Lameter
2010-11-24 17:26 ` Peter Zijlstra
2010-11-24 18:08 ` Christoph Lameter
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