rcu: Move __rcu_read_unlock()'s barrier() within if-statement
We only need to constrain the compiler if we are actually exiting the top-level RCU read-side critical section. This commit therefore moves the first barrier() cal in __rcu_read_unlock() to inside the "if" statement, thus avoiding needless register flushes for inner rcu_read_unlock() calls. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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committed by
Paul E. McKenney

parent
6846c0c540
commit
6206ab9bab
@@ -134,16 +134,6 @@ extern void call_rcu_sched(struct rcu_head *head,
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extern void synchronize_sched(void);
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static inline void __rcu_read_lock_bh(void)
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{
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local_bh_disable();
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}
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static inline void __rcu_read_unlock_bh(void)
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{
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local_bh_enable();
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}
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#ifdef CONFIG_PREEMPT_RCU
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extern void __rcu_read_lock(void);
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@@ -686,7 +676,7 @@ static inline void rcu_read_unlock(void)
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*/
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static inline void rcu_read_lock_bh(void)
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{
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__rcu_read_lock_bh();
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local_bh_disable();
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__acquire(RCU_BH);
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rcu_read_acquire_bh();
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}
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@@ -700,7 +690,7 @@ static inline void rcu_read_unlock_bh(void)
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{
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rcu_read_release_bh();
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__release(RCU_BH);
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__rcu_read_unlock_bh();
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local_bh_enable();
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}
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/**
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