Commit 3f2947b7 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Paul E. McKenney
Browse files

locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem 



Turn DEFINE_STATIC_PERCPU_RWSEM() into __DEFINE_PERCPU_RWSEM() with the
additional "is_static" argument to introduce DEFINE_PERCPU_RWSEM().

Change cgroup.c to use DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem).

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent 2bf1acc2

include/linux/percpu-rwsem.h

+6 −2
Original line number Diff line number Diff line
@@ -17,14 +17,18 @@ struct percpu_rw_semaphore { 
	int			readers_block;

};



#define DEFINE_STATIC_PERCPU_RWSEM(name)				\

#define __DEFINE_PERCPU_RWSEM(name, is_static)				\

static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\

static struct percpu_rw_semaphore name = {				\

is_static struct percpu_rw_semaphore name = {				\

	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\

	.read_count = &__percpu_rwsem_rc_##name,			\

	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\

	.writer = __RCUWAIT_INITIALIZER(name.writer),			\

}

#define DEFINE_PERCPU_RWSEM(name)		\

	__DEFINE_PERCPU_RWSEM(name, /* not static */)

#define DEFINE_STATIC_PERCPU_RWSEM(name)	\

	__DEFINE_PERCPU_RWSEM(name, static)



extern int __percpu_down_read(struct percpu_rw_semaphore *, int);

extern void __percpu_up_read(struct percpu_rw_semaphore *);

kernel/cgroup/cgroup.c

+1 −2
Original line number Diff line number Diff line
@@ -101,7 +101,7 @@ static DEFINE_SPINLOCK(cgroup_idr_lock); 
 */

static DEFINE_SPINLOCK(cgroup_file_kn_lock);



struct percpu_rw_semaphore cgroup_threadgroup_rwsem;

DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem);



#define cgroup_assert_mutex_or_rcu_locked()				\

	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
@@ -5616,7 +5616,6 @@ int __init cgroup_init(void) 
	int ssid;



	BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16);

	BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));

	BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));

	BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files));

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