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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: [rfc: cpuops adv V1 2/8] --- include/linux/percpu.h | 31 +++---------------------------- 1 file changed, 3 insertions(+), 28 deletions(-)
Date: Thu, 02 Dec 2010 15:53:42 -0600	[thread overview]
Message-ID: <20101202215400.031151691@linux.com> (raw)
In-Reply-To: 20101202215340.562309713@linux.com

[-- Attachment #1: this_cpu_atomic_fallback --]
[-- Type: text/plain, Size: 1922 bytes --]

Index: linux-2.6/include/linux/percpu.h
===================================================================
--- linux-2.6.orig/include/linux/percpu.h	2010-12-02 12:17:14.000000000 -0600
+++ linux-2.6/include/linux/percpu.h	2010-12-02 12:17:30.000000000 -0600
@@ -361,14 +361,7 @@ do {									\
 # define __this_cpu_xchg(pcp, nval)	__pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
 #endif
 
-#define _this_cpu_generic_xchg(pcp, nval)				\
-({	typeof(pcp) ret__;						\
-	preempt_disable();						\
-	ret__ = __this_cpu_read(pcp);					\
-	__this_cpu_write(pcp, nval);					\
-	preempt_enable();						\
-	ret__;								\
-})
+#define _this_cpu_generic_xchg(pcp, nval)	xchg(__this_cpu_ptr(&(pcp)), nval)
 
 #ifndef this_cpu_xchg
 # ifndef this_cpu_xchg_1
@@ -386,15 +379,7 @@ do {									\
 # define this_cpu_xchg(pcp, nval)	__pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
 #endif
 
-#define _this_cpu_generic_cmpxchg(pcp, oval, nval)			\
-({	typeof(pcp) ret__;						\
-	preempt_disable();						\
-	ret__ = __this_cpu_read(pcp);					\
-	if (ret__ == (oval))						\
-		__this_cpu_write(pcp, nval);				\
-	preempt_enable();						\
-	ret__;								\
-})
+#define _this_cpu_generic_cmpxchg(pcp, oval, nval)	cmpxchg(__this_cpu_ptr(&(pcp)), oval, nval);
 
 #ifndef this_cpu_cmpxchg
 # ifndef this_cpu_cmpxchg_1
@@ -892,17 +877,7 @@ do {									\
 # define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
 #endif
 
-#define irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)			\
-({									\
-	typeof(pcp) ret__;						\
-	unsigned long flags;						\
-	local_irq_save(flags);						\
-	ret__ = __this_cpu_read(pcp);					\
-	if (ret__ == (oval))						\
-		__this_cpu_write(pcp, nval);				\
-	local_irq_restore(flags);					\
-	ret__;								\
-})
+#define irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)	cmpxchg(__this_cpu_ptr(&(pcp), oval, nval)
 
 #ifndef irqsafe_cpu_cmpxchg
 # ifndef irqsafe_cpu_cmpxchg_1


  parent reply	other threads:[~2010-12-02 21:54 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-02 21:53 [rfc: cpuops adv V1 0/8] Cmpxchg and xchg support for cpu ops Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 1/8] percpu: generic this_cpu_cmpxchg() and this_cpu_cmpxchg_double support Christoph Lameter
2010-12-02 21:53 ` Christoph Lameter [this message]
2010-12-02 22:06   ` [rfc: cpuops adv V1 2/8] Fallback to atomic xchg, cmpxchg Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 3/8] x86: this_cpu_cmpxchg and this_cpu_cmpxchg_double operations Christoph Lameter
2010-12-06 17:14   ` Avi Kivity
2010-12-06 17:35     ` Christoph Lameter
2010-12-07  9:31       ` Avi Kivity
2010-12-02 21:53 ` [rfc: cpuops adv V1 4/8] irq_work: Use per cpu atomics instead of regular atomics Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 5/8] vmstat: User per cpu atomics to avoid interrupt disable / enable Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 6/8] Lockless (and preemptless) fastpaths for slub Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 7/8] slub: Add PageSlubPartial Christoph Lameter
2010-12-02 21:53 ` [rfc: cpuops adv V1 8/8] slub: [RFC] Partially lockless freepath slowpath Christoph Lameter
2010-12-04 19:29 ` [rfc: cpuops adv V1 0/8] Cmpxchg and xchg support for cpu ops Pekka Enberg
2010-12-04 19:31   ` Tejun Heo
2010-12-06 15:52     ` Christoph Lameter
2010-12-06 15:51   ` Christoph Lameter

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