rcupdate: Replace smp_read_barrier_depends() with lockless_dereference()
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>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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 @@
})
#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 @@
})
#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); \
})