From 16e3081191837a6a04733de5cd5d1d1b303140d4 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 13 Sep 2009 09:15:11 -0700 Subject: rcu: Fix synchronize_rcu() for TREE_PREEMPT_RCU The redirection of synchronize_sched() to synchronize_rcu() was appropriate for TREE_RCU, but not for TREE_PREEMPT_RCU. Fix this by creating an underlying synchronize_sched(). TREE_RCU then redirects synchronize_rcu() to synchronize_sched(), while TREE_PREEMPT_RCU has its own version of synchronize_rcu(). Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12528585111916-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/rcupdate.h | 23 +++++------------------ include/linux/rcutree.h | 4 ++-- 2 files changed, 7 insertions(+), 20 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 95e0615f4d75..39dce83c4865 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -52,8 +52,13 @@ struct rcu_head { }; /* Exported common interfaces */ +#ifdef CONFIG_TREE_PREEMPT_RCU extern void synchronize_rcu(void); +#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ +#define synchronize_rcu synchronize_sched +#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */ extern void synchronize_rcu_bh(void); +extern void synchronize_sched(void); extern void rcu_barrier(void); extern void rcu_barrier_bh(void); extern void rcu_barrier_sched(void); @@ -261,24 +266,6 @@ struct rcu_synchronize { extern void wakeme_after_rcu(struct rcu_head *head); -/** - * synchronize_sched - block until all CPUs have exited any non-preemptive - * kernel code sequences. - * - * This means that all preempt_disable code sequences, including NMI and - * hardware-interrupt handlers, in progress on entry will have completed - * before this primitive returns. However, this does not guarantee that - * softirq handlers will have completed, since in some kernels, these - * handlers can run in process context, and can block. - * - * This primitive provides the guarantees made by the (now removed) - * synchronize_kernel() API. In contrast, synchronize_rcu() only - * guarantees that rcu_read_lock() sections will have completed. - * In "classic RCU", these two guarantees happen to be one and - * the same, but can differ in realtime RCU implementations. - */ -#define synchronize_sched() __synchronize_sched() - /** * call_rcu - Queue an RCU callback for invocation after a grace period. * @head: structure to be used for queueing the RCU updates. diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index a89307717825..00d08c0cbcc1 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -53,6 +53,8 @@ static inline void __rcu_read_unlock(void) preempt_enable(); } +#define __synchronize_sched() synchronize_rcu() + static inline void exit_rcu(void) { } @@ -68,8 +70,6 @@ static inline void __rcu_read_unlock_bh(void) local_bh_enable(); } -#define __synchronize_sched() synchronize_rcu() - extern void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); -- cgit v1.2.2