From d8be81735aa89413b333de488251f0e64e2be591 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 25 Mar 2017 09:59:38 -0700 Subject: srcu: Create a tiny SRCU In response to automated complaints about modifications to SRCU increasing its size, this commit creates a tiny SRCU that is used in SMP=n && PREEMPT=n builds. Signed-off-by: Paul E. McKenney --- include/linux/srcu.h | 69 ++++++---------------------------------------------- 1 file changed, 8 insertions(+), 61 deletions(-) (limited to 'include/linux/srcu.h') diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 73a1b6296224..907f09b14eda 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -34,28 +34,7 @@ #include #include -struct srcu_array { - unsigned long lock_count[2]; - unsigned long unlock_count[2]; -}; - -struct srcu_struct { - unsigned long completed; - unsigned long srcu_gp_seq; - atomic_t srcu_exp_cnt; - struct srcu_array __percpu *per_cpu_ref; - spinlock_t queue_lock; /* protect ->srcu_cblist */ - struct rcu_segcblist srcu_cblist; - struct delayed_work work; -#ifdef CONFIG_DEBUG_LOCK_ALLOC - struct lockdep_map dep_map; -#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ -}; - -/* Values for -> state variable. */ -#define SRCU_STATE_IDLE 0 -#define SRCU_STATE_SCAN1 1 -#define SRCU_STATE_SCAN2 2 +struct srcu_struct; #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -77,42 +56,13 @@ int init_srcu_struct(struct srcu_struct *sp); #define __SRCU_DEP_MAP_INIT(srcu_name) #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ -void process_srcu(struct work_struct *work); - -#define __SRCU_STRUCT_INIT(name) \ - { \ - .completed = -300, \ - .per_cpu_ref = &name##_srcu_array, \ - .queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \ - .srcu_cblist = RCU_SEGCBLIST_INITIALIZER(name.srcu_cblist),\ - .work = __DELAYED_WORK_INITIALIZER(name.work, process_srcu, 0),\ - __SRCU_DEP_MAP_INIT(name) \ - } - -/* - * Define and initialize a srcu struct at build time. - * Do -not- call init_srcu_struct() nor cleanup_srcu_struct() on it. - * - * Note that although DEFINE_STATIC_SRCU() hides the name from other - * files, the per-CPU variable rules nevertheless require that the - * chosen name be globally unique. These rules also prohibit use of - * DEFINE_STATIC_SRCU() within a function. If these rules are too - * restrictive, declare the srcu_struct manually. For example, in - * each file: - * - * static struct srcu_struct my_srcu; - * - * Then, before the first use of each my_srcu, manually initialize it: - * - * init_srcu_struct(&my_srcu); - * - * See include/linux/percpu-defs.h for the rules on per-CPU variables. - */ -#define __DEFINE_SRCU(name, is_static) \ - static DEFINE_PER_CPU(struct srcu_array, name##_srcu_array);\ - is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name) -#define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) -#define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) +#ifdef CONFIG_TINY_SRCU +#include +#elif defined(CONFIG_TREE_SRCU) +#include +#else +#error "Unknown SRCU implementation specified to kernel configuration" +#endif /** * call_srcu() - Queue a callback for invocation after an SRCU grace period @@ -138,9 +88,6 @@ void cleanup_srcu_struct(struct srcu_struct *sp); int __srcu_read_lock(struct srcu_struct *sp) __acquires(sp); void __srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp); void synchronize_srcu(struct srcu_struct *sp); -void synchronize_srcu_expedited(struct srcu_struct *sp); -unsigned long srcu_batches_completed(struct srcu_struct *sp); -void srcu_barrier(struct srcu_struct *sp); #ifdef CONFIG_DEBUG_LOCK_ALLOC -- cgit v1.2.3