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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-05-26 22:14:36 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-09-28 21:36:42 -0700
commit2c42818e962e2858334bf45bfc56662b3752df34 (patch)
tree192364123c9aeeab282c53168e51eddece9d8be4 /include/linux
parentf039d1f1884b2fe9c13d28f59d8330f0b0518fc4 (diff)
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rcu: Abstract common code for RCU grace-period-wait primitives
Pull the code that waits for an RCU grace period into a single function, which is then called by synchronize_rcu() and friends in the case of TREE_RCU and TREE_PREEMPT_RCU, and from rcu_barrier() and friends in the case of TINY_RCU and TINY_PREEMPT_RCU. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/rcupdate.h130
-rw-r--r--include/linux/rcutiny.h16
-rw-r--r--include/linux/rcutree.h2
3 files changed, 90 insertions, 58 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 87bd390df73f..ae5327de41aa 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -66,11 +66,73 @@ static inline void rcutorture_record_progress(unsigned long vernum)
#define ULONG_CMP_LT(a, b) (ULONG_MAX / 2 < (a) - (b))
/* Exported common interfaces */
+
+#ifdef CONFIG_PREEMPT_RCU
+
+/**
+ * call_rcu() - Queue an RCU callback for invocation after a grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all pre-existing RCU read-side
+ * critical sections have completed. However, the callback function
+ * might well execute concurrently with RCU read-side critical sections
+ * that started after call_rcu() was invoked. RCU read-side critical
+ * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
+ * and may be nested.
+ */
+extern void call_rcu(struct rcu_head *head,
+ void (*func)(struct rcu_head *head));
+
+#else /* #ifdef CONFIG_PREEMPT_RCU */
+
+/* In classic RCU, call_rcu() is just call_rcu_sched(). */
+#define call_rcu call_rcu_sched
+
+#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+
+/**
+ * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_bh() assumes
+ * that the read-side critical sections end on completion of a softirq
+ * handler. This means that read-side critical sections in process
+ * context must not be interrupted by softirqs. This interface is to be
+ * used when most of the read-side critical sections are in softirq context.
+ * RCU read-side critical sections are delimited by :
+ * - rcu_read_lock() and rcu_read_unlock(), if in interrupt context.
+ * OR
+ * - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context.
+ * These may be nested.
+ */
+extern void call_rcu_bh(struct rcu_head *head,
+ void (*func)(struct rcu_head *head));
+
+/**
+ * call_rcu_sched() - Queue an RCU for invocation after sched grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_sched() assumes
+ * that the read-side critical sections end on enabling of preemption
+ * or on voluntary preemption.
+ * RCU read-side critical sections are delimited by :
+ * - rcu_read_lock_sched() and rcu_read_unlock_sched(),
+ * OR
+ * anything that disables preemption.
+ * These may be nested.
+ */
extern void call_rcu_sched(struct rcu_head *head,
void (*func)(struct rcu_head *rcu));
+
extern void synchronize_sched(void);
-extern void rcu_barrier_bh(void);
-extern void rcu_barrier_sched(void);
static inline void __rcu_read_lock_bh(void)
{
@@ -143,6 +205,15 @@ static inline void rcu_exit_nohz(void)
#endif /* #else #ifdef CONFIG_NO_HZ */
+/*
+ * Infrastructure to implement the synchronize_() primitives in
+ * TREE_RCU and rcu_barrier_() primitives in TINY_RCU.
+ */
+
+typedef void call_rcu_func_t(struct rcu_head *head,
+ void (*func)(struct rcu_head *head));
+void wait_rcu_gp(call_rcu_func_t crf);
+
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
#include <linux/rcutree.h>
#elif defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
@@ -723,61 +794,6 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
#define RCU_INIT_POINTER(p, v) \
p = (typeof(*v) __force __rcu *)(v)
-/* Infrastructure to implement the synchronize_() primitives. */
-
-struct rcu_synchronize {
- struct rcu_head head;
- struct completion completion;
-};
-
-extern void wakeme_after_rcu(struct rcu_head *head);
-
-#ifdef CONFIG_PREEMPT_RCU
-
-/**
- * call_rcu() - Queue an RCU callback for invocation after a grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual callback function to be invoked after the grace period
- *
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all pre-existing RCU read-side
- * critical sections have completed. However, the callback function
- * might well execute concurrently with RCU read-side critical sections
- * that started after call_rcu() was invoked. RCU read-side critical
- * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
- * and may be nested.
- */
-extern void call_rcu(struct rcu_head *head,
- void (*func)(struct rcu_head *head));
-
-#else /* #ifdef CONFIG_PREEMPT_RCU */
-
-/* In classic RCU, call_rcu() is just call_rcu_sched(). */
-#define call_rcu call_rcu_sched
-
-#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
-
-/**
- * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual callback function to be invoked after the grace period
- *
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. call_rcu_bh() assumes
- * that the read-side critical sections end on completion of a softirq
- * handler. This means that read-side critical sections in process
- * context must not be interrupted by softirqs. This interface is to be
- * used when most of the read-side critical sections are in softirq context.
- * RCU read-side critical sections are delimited by :
- * - rcu_read_lock() and rcu_read_unlock(), if in interrupt context.
- * OR
- * - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context.
- * These may be nested.
- */
-extern void call_rcu_bh(struct rcu_head *head,
- void (*func)(struct rcu_head *head));
-
/*
* debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
* by call_rcu() and rcu callback execution, and are therefore not part of the
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 52b3e0281fd0..4eab233a00cd 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -31,6 +31,16 @@ static inline void rcu_init(void)
{
}
+static inline void rcu_barrier_bh(void)
+{
+ wait_rcu_gp(call_rcu_bh);
+}
+
+static inline void rcu_barrier_sched(void)
+{
+ wait_rcu_gp(call_rcu_sched);
+}
+
#ifdef CONFIG_TINY_RCU
static inline void synchronize_rcu_expedited(void)
@@ -45,9 +55,13 @@ static inline void rcu_barrier(void)
#else /* #ifdef CONFIG_TINY_RCU */
-void rcu_barrier(void);
void synchronize_rcu_expedited(void);
+static inline void rcu_barrier(void)
+{
+ wait_rcu_gp(call_rcu);
+}
+
#endif /* #else #ifdef CONFIG_TINY_RCU */
static inline void synchronize_rcu_bh(void)
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index e65d06634dd8..67458468f1a8 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -67,6 +67,8 @@ static inline void synchronize_rcu_bh_expedited(void)
}
extern void rcu_barrier(void);
+extern void rcu_barrier_bh(void);
+extern void rcu_barrier_sched(void);
extern unsigned long rcutorture_testseq;
extern unsigned long rcutorture_vernum;