Commit-ID: 3f2947b78151ec938dc06aea4ba0e11e56becdff
Gitweb: https://git.kernel.org/tip/3f2947b78151ec938dc06aea4ba0e11e56becdff
Author: Oleg Nesterov <oleg@xxxxxxxxxx>
AuthorDate: Tue, 23 Apr 2019 18:32:41 +0200
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Tue, 28 May 2019 09:05:23 -0700
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: Oleg Nesterov <oleg@xxxxxxxxxx>
Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
include/linux/percpu-rwsem.h | 8 ++++++--
kernel/cgroup/cgroup.c | 3 +--
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
index 6887636ea169..2809b44cbbee 100644
--- a/include/linux/percpu-rwsem.h
+++ b/include/linux/percpu-rwsem.h
@@ -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 *);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 217cec4e22c6..b112e93388dc 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -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));
|