X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frcupdate.c;h=9b7fd4723878da6c3b5d2526cd0bc15550cce9a9;hb=628ff7c1d8d8466a5ad8078bd0206a130f8b8a51;hp=ad63af8b25218f562729d868293285ce3433cff8;hpb=5f86515158ca86182c1dbecd546f1848121ba135;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index ad63af8..9b7fd47 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -19,7 +19,7 @@ * * Authors: Dipankar Sarma * Manfred Spraul - * + * * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: @@ -27,7 +27,7 @@ * 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 @@ -45,16 +45,12 @@ #include #include -enum rcu_barrier { - RCU_BARRIER_STD, - RCU_BARRIER_BH, - RCU_BARRIER_SCHED, -}; - -static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL}; -static atomic_t rcu_barrier_cpu_count; -static DEFINE_MUTEX(rcu_barrier_mutex); -static struct completion rcu_barrier_completion; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +static struct lock_class_key rcu_lock_key; +struct lockdep_map rcu_lock_map = + STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key); +EXPORT_SYMBOL_GPL(rcu_lock_map); +#endif /* * Awaken the corresponding synchronize_rcu() instance now that a @@ -67,104 +63,3 @@ void wakeme_after_rcu(struct rcu_head *head) rcu = container_of(head, struct rcu_synchronize, head); complete(&rcu->completion); } - -/** - * synchronize_rcu - wait until a grace period has elapsed. - * - * Control will return to the caller some time after a full grace - * period has elapsed, in other words after all currently executing RCU - * read-side critical sections have completed. RCU read-side critical - * sections are delimited by rcu_read_lock() and rcu_read_unlock(), - * and may be nested. - */ -void synchronize_rcu(void); /* Makes kernel-doc tools happy */ -synchronize_rcu_xxx(synchronize_rcu, call_rcu) -EXPORT_SYMBOL_GPL(synchronize_rcu); - -static void rcu_barrier_callback(struct rcu_head *notused) -{ - if (atomic_dec_and_test(&rcu_barrier_cpu_count)) - complete(&rcu_barrier_completion); -} - -/* - * Called with preemption disabled, and from cross-cpu IRQ context. - */ -static void rcu_barrier_func(void *type) -{ - int cpu = smp_processor_id(); - struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu); - - atomic_inc(&rcu_barrier_cpu_count); - switch ((enum rcu_barrier)type) { - case RCU_BARRIER_STD: - call_rcu(head, rcu_barrier_callback); - break; - case RCU_BARRIER_BH: - call_rcu_bh(head, rcu_barrier_callback); - break; - case RCU_BARRIER_SCHED: - call_rcu_sched(head, rcu_barrier_callback); - break; - } -} - -/* - * Orchestrate the specified type of RCU barrier, waiting for all - * RCU callbacks of the specified type to complete. - */ -static void _rcu_barrier(enum rcu_barrier type) -{ - BUG_ON(in_interrupt()); - /* Take cpucontrol mutex to protect against CPU hotplug */ - mutex_lock(&rcu_barrier_mutex); - init_completion(&rcu_barrier_completion); - /* - * Initialize rcu_barrier_cpu_count to 1, then invoke - * rcu_barrier_func() on each CPU, so that each CPU also has - * incremented rcu_barrier_cpu_count. Only then is it safe to - * decrement rcu_barrier_cpu_count -- otherwise the first CPU - * might complete its grace period before all of the other CPUs - * did their increment, causing this function to return too - * early. - */ - atomic_set(&rcu_barrier_cpu_count, 1); - on_each_cpu(rcu_barrier_func, (void *)type, 1); - if (atomic_dec_and_test(&rcu_barrier_cpu_count)) - complete(&rcu_barrier_completion); - wait_for_completion(&rcu_barrier_completion); - mutex_unlock(&rcu_barrier_mutex); -} - -/** - * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete. - */ -void rcu_barrier(void) -{ - _rcu_barrier(RCU_BARRIER_STD); -} -EXPORT_SYMBOL_GPL(rcu_barrier); - -/** - * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete. - */ -void rcu_barrier_bh(void) -{ - _rcu_barrier(RCU_BARRIER_BH); -} -EXPORT_SYMBOL_GPL(rcu_barrier_bh); - -/** - * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks. - */ -void rcu_barrier_sched(void) -{ - _rcu_barrier(RCU_BARRIER_SCHED); -} -EXPORT_SYMBOL_GPL(rcu_barrier_sched); - -void __init rcu_init(void) -{ - __rcu_init(); -} -