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Commit 55c6659a authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Paul E. McKenney
Browse files

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: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated for __DELAYED_WORK_INITIALIZER() added argument,
	   fixed whitespace issue. ]
parent f2ebfbc9

include/linux/srcu.h

+30 −0
Original line number Diff line number Diff line
@@ -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