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From: Pranith Kumar <bobby.prani@gmail.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Josh Triplett <josh@joshtriplett.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <laijs@cn.fujitsu.com>,
	linux-kernel@vger.kernel.org (open list:READ-COPY UPDATE...)
Subject: [PATCH 08/16] rcupdate: Replace smp_read_barrier_depends() with lockless_dereference()
Date: Thu, 13 Nov 2014 14:24:14 -0500	[thread overview]
Message-ID: <1415906662-4576-9-git-send-email-bobby.prani@gmail.com> (raw)
In-Reply-To: <1415906662-4576-1-git-send-email-bobby.prani@gmail.com>

Recently lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the change.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
---
 include/linux/rcupdate.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index ed4f593..386ba28 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -582,11 +582,11 @@ static inline void rcu_preempt_sleep_check(void)
 })
 #define __rcu_dereference_check(p, c, space) \
 ({ \
-	typeof(*p) *_________p1 = (typeof(*p) *__force)ACCESS_ONCE(p); \
+	/* Dependency order vs. p above. */ \
+	typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \
 	rcu_lockdep_assert(c, "suspicious rcu_dereference_check() usage"); \
 	rcu_dereference_sparse(p, space); \
-	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
-	((typeof(*p) __force __kernel *)(_________p1)); \
+	((typeof(*p) __force __kernel *)(________p1)); \
 })
 #define __rcu_dereference_protected(p, c, space) \
 ({ \
@@ -603,10 +603,10 @@ static inline void rcu_preempt_sleep_check(void)
 })
 #define __rcu_dereference_index_check(p, c) \
 ({ \
-	typeof(p) _________p1 = ACCESS_ONCE(p); \
+	/* Dependency order vs. p above. */ \
+	typeof(p) _________p1 = lockless_dereference(p); \
 	rcu_lockdep_assert(c, \
 			   "suspicious rcu_dereference_index_check() usage"); \
-	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
 	(_________p1); \
 })
 
-- 
1.9.1


  parent reply	other threads:[~2014-11-13 19:28 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-13 19:24 [RFC PATCH 00/16] Replace smp_read_barrier_depends() with lockless_derefrence() Pranith Kumar
2014-11-13 19:24 ` [PATCH 01/16] crypto: caam - Remove unnecessary smp_read_barrier_depends() Pranith Kumar
2014-11-13 20:10   ` Paul E. McKenney
     [not found]     ` <546527D0.9040806@gmail.com>
2014-11-14  0:58       ` Kim Phillips
2014-11-13 19:24 ` [PATCH 02/16] doc: memory-barriers.txt: Document use of lockless_dereference() Pranith Kumar
2014-11-13 20:11   ` Paul E. McKenney
2014-11-13 19:24 ` [PATCH 03/16] drivers: dma: Replace smp_read_barrier_depends() with lockless_dereference() Pranith Kumar
2014-11-13 19:24 ` [PATCH 04/16] dcache: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 05/16] overlayfs: " Pranith Kumar
2014-11-17 10:35   ` Miklos Szeredi
2014-11-13 19:24 ` [PATCH 06/16] assoc_array: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 07/16] hyperv: " Pranith Kumar
2014-11-13 19:24 ` Pranith Kumar [this message]
2014-11-18 17:16   ` [PATCH 08/16] rcupdate: " Paul E. McKenney
2014-11-18 19:38     ` Pranith Kumar
2014-11-13 19:24 ` [PATCH 09/16] percpu: " Pranith Kumar
2014-11-14 13:14   ` Tejun Heo
2014-11-14 16:02     ` Pranith Kumar
2014-11-17  4:43     ` Paul E. McKenney
2014-11-13 19:24 ` [PATCH 10/16] perf: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 11/16] seccomp: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 12/16] task_work: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 13/16] ksm: " Pranith Kumar
2014-11-30 22:34   ` Hugh Dickins
2014-11-13 19:24 ` [PATCH 14/16] slab: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 15/16] netfilter: " Pranith Kumar
2014-11-13 19:24 ` [PATCH 16/16] rxrpc: " Pranith Kumar
2014-11-13 20:07 ` [RFC PATCH 00/16] Replace smp_read_barrier_depends() with lockless_derefrence() Paul E. McKenney
2014-11-13 20:11 ` [PATCH 06/16] assoc_array: Replace smp_read_barrier_depends() with lockless_dereference() David Howells
2014-11-13 20:17 ` [PATCH 16/16] rxrpc: " David Howells
2014-11-13 20:47 ` David Howells
2014-11-13 21:55   ` Pranith Kumar
2014-11-13 23:07   ` David Howells

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