srcu: Add DEFINE_SRCU()

In old days, we had two different API sets for dynamic-allocated per-CPU
data and DEFINE_PER_CPU()-defined per_cpu data, and because SRCU used
dynamic-allocated per-CPU data, its srcu_struct structures cannot be
declared statically.  This commit therefore introduces DEFINE_SRCU()
and DEFINE_STATIC_SRCU() to allow statically declared SRCU structures,
using the new static per-CPU interfaces.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated for __DELAYED_WORK_INITIALIZER() added argument,
	   fixed whitespace issue. ]
This commit is contained in:
Lai Jiangshan 2012-10-13 01:14:16 +08:00 committed by Paul E. McKenney
parent f2ebfbc991
commit 55c6659afa

View File

@ -42,6 +42,8 @@ struct rcu_batch {
struct rcu_head *head, **tail;
};
#define RCU_BATCH_INIT(name) { NULL, &(name.head) }
struct srcu_struct {
unsigned completed;
struct srcu_struct_array __percpu *per_cpu_ref;
@ -72,14 +74,42 @@ int __init_srcu_struct(struct srcu_struct *sp, const char *name,
__init_srcu_struct((sp), #sp, &__srcu_key); \
})
#define __SRCU_DEP_MAP_INIT(srcu_name) .dep_map = { .name = #srcu_name },
#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
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), \
.running = false, \
.batch_queue = RCU_BATCH_INIT(name.batch_queue), \
.batch_check0 = RCU_BATCH_INIT(name.batch_check0), \
.batch_check1 = RCU_BATCH_INIT(name.batch_check1), \
.batch_done = RCU_BATCH_INIT(name.batch_done), \
.work = __DELAYED_WORK_INITIALIZER(name.work, process_srcu, 0),\
__SRCU_DEP_MAP_INIT(name) \
}
/*
* define and init a srcu struct at build time.
* dont't call init_srcu_struct() nor cleanup_srcu_struct() on it.
*/
#define DEFINE_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
struct srcu_struct name = __SRCU_STRUCT_INIT(name);
#define DEFINE_STATIC_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
static struct srcu_struct name = __SRCU_STRUCT_INIT(name);
/**
* call_srcu() - Queue a callback for invocation after an SRCU grace period
* @sp: srcu_struct in queue the callback