/*
- * Read-Copy Update mechanism for mutual exclusion
+ * Read-Copy Update mechanism for mutual exclusion
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Copyright IBM Corporation, 2001
*
* Author: Dipankar Sarma <dipankar@in.ibm.com>
- *
+ *
* Based on the original work by Paul McKenney <paulmck@us.ibm.com>
* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
* Papers:
* http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
*
* For detailed explanation of Read-Copy Update mechanism see -
- * http://lse.sourceforge.net/locking/rcupdate.html
+ * http://lse.sourceforge.net/locking/rcupdate.html
*
*/
#include <linux/cache.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
-#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/lockdep.h>
void (*func)(struct rcu_head *head);
};
-#if defined(CONFIG_CLASSIC_RCU)
-#include <linux/rcuclassic.h>
-#elif defined(CONFIG_TREE_RCU)
+/* Exported common interfaces */
+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);
+extern void synchronize_sched_expedited(void);
+extern int sched_expedited_torture_stats(char *page);
+
+/* Internal to kernel */
+extern void rcu_init(void);
+
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
#include <linux/rcutree.h>
-#elif defined(CONFIG_PREEMPT_RCU)
-#include <linux/rcupreempt.h>
+#elif defined(CONFIG_TINY_RCU)
+#include <linux/rcutiny.h>
#else
#error "Unknown RCU implementation specified to kernel configuration"
-#endif /* #else #if defined(CONFIG_CLASSIC_RCU) */
+#endif
-#define RCU_HEAD_INIT { .next = NULL, .func = NULL }
+#define RCU_HEAD_INIT { .next = NULL, .func = NULL }
#define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT
#define INIT_RCU_HEAD(ptr) do { \
(ptr)->next = NULL; (ptr)->func = NULL; \
} while (0)
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern struct lockdep_map rcu_lock_map;
+# define rcu_read_acquire() \
+ lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_)
+# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_)
+#else
+# define rcu_read_acquire() do { } while (0)
+# define rcu_read_release() do { } while (0)
+#endif
+
/**
* rcu_read_lock - mark the beginning of an RCU read-side critical section.
*
*
* It is illegal to block while in an RCU read-side critical section.
*/
-#define rcu_read_lock() __rcu_read_lock()
-
-/**
- * rcu_read_unlock - marks the end of an RCU read-side critical section.
- *
- * See rcu_read_lock() for more information.
- */
+static inline void rcu_read_lock(void)
+{
+ __rcu_read_lock();
+ __acquire(RCU);
+ rcu_read_acquire();
+}
/*
* So where is rcu_write_lock()? It does not exist, as there is no
* used as well. RCU does not care how the writers keep out of each
* others' way, as long as they do so.
*/
-#define rcu_read_unlock() __rcu_read_unlock()
+
+/**
+ * rcu_read_unlock - marks the end of an RCU read-side critical section.
+ *
+ * See rcu_read_lock() for more information.
+ */
+static inline void rcu_read_unlock(void)
+{
+ rcu_read_release();
+ __release(RCU);
+ __rcu_read_unlock();
+}
/**
* rcu_read_lock_bh - mark the beginning of a softirq-only RCU critical section
* can use just rcu_read_lock().
*
*/
-#define rcu_read_lock_bh() __rcu_read_lock_bh()
+static inline void rcu_read_lock_bh(void)
+{
+ __rcu_read_lock_bh();
+ __acquire(RCU_BH);
+ rcu_read_acquire();
+}
/*
* rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section
*
* See rcu_read_lock_bh() for more information.
*/
-#define rcu_read_unlock_bh() __rcu_read_unlock_bh()
+static inline void rcu_read_unlock_bh(void)
+{
+ rcu_read_release();
+ __release(RCU_BH);
+ __rcu_read_unlock_bh();
+}
/**
* rcu_read_lock_sched - mark the beginning of a RCU-classic critical section
* - call_rcu_sched() and rcu_barrier_sched()
* on the write-side to insure proper synchronization.
*/
-#define rcu_read_lock_sched() preempt_disable()
+static inline void rcu_read_lock_sched(void)
+{
+ preempt_disable();
+ __acquire(RCU_SCHED);
+ rcu_read_acquire();
+}
+
+/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
+static inline notrace void rcu_read_lock_sched_notrace(void)
+{
+ preempt_disable_notrace();
+ __acquire(RCU_SCHED);
+}
/*
* rcu_read_unlock_sched - marks the end of a RCU-classic critical section
*
* See rcu_read_lock_sched for more information.
*/
-#define rcu_read_unlock_sched() preempt_enable()
+static inline void rcu_read_unlock_sched(void)
+{
+ rcu_read_release();
+ __release(RCU_SCHED);
+ preempt_enable();
+}
+/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
+static inline notrace void rcu_read_unlock_sched_notrace(void)
+{
+ __release(RCU_SCHED);
+ preempt_enable_notrace();
+}
/**
extern void wakeme_after_rcu(struct rcu_head *head);
-#define synchronize_rcu_xxx(name, func) \
-void name(void) \
-{ \
- struct rcu_synchronize rcu; \
- \
- init_completion(&rcu.completion); \
- /* Will wake me after RCU finished. */ \
- func(&rcu.head, wakeme_after_rcu); \
- /* Wait for it. */ \
- wait_for_completion(&rcu.completion); \
-}
-
-/**
- * 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.
extern void call_rcu_bh(struct rcu_head *head,
void (*func)(struct rcu_head *head));
-/* Exported common interfaces */
-extern void synchronize_rcu(void);
-extern void rcu_barrier(void);
-extern void rcu_barrier_bh(void);
-extern void rcu_barrier_sched(void);
-
-/* Internal to kernel */
-extern void rcu_init(void);
-extern int rcu_needs_cpu(int cpu);
-
#endif /* __LINUX_RCUPDATE_H */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff