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| author | Ingo Molnar <mingo@kernel.org> | 2015-08-25 09:44:49 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-08-25 09:44:49 +0200 |
| commit | f612a7b1a7f1b5139f228724ce340aac24720591 (patch) | |
| tree | d75f83de54578908af0484d25bcfcb8e650e1cf2 /kernel | |
| parent | 9b9412dc7008f360c8e8ed10a654d3c8719f69d8 (diff) | |
| parent | 12d560f4ea87030667438a169912380be00cea4b (diff) | |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU cleanup from Paul E. McKenney:
"Privatize smp_mb__after_unlock_lock(). This commit moves the
definition of smp_mb__after_unlock_lock() to kernel/rcu/tree.h,
in recognition of the fact that RCU is the only thing using
this, that nothing else is likely to use it, and that it is
likely to go away completely."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 0412030ca882..2e991f8361e4 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -653,3 +653,15 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll) #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ } #endif /* #ifdef CONFIG_RCU_TRACE */ + +/* + * Place this after a lock-acquisition primitive to guarantee that + * an UNLOCK+LOCK pair act as a full barrier. This guarantee applies + * if the UNLOCK and LOCK are executed by the same CPU or if the + * UNLOCK and LOCK operate on the same lock variable. + */ +#ifdef CONFIG_PPC +#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */ +#else /* #ifdef CONFIG_PPC */ +#define smp_mb__after_unlock_lock() do { } while (0) +#endif /* #else #ifdef CONFIG_PPC */ |