[PATCH] lockdep: locking init debugging improvement

Locking init improvement:

- introduce and use __SPIN_LOCK_UNLOCKED for array initializations,
to pass in the name string of locks, used by debugging

Signed-off-by: Ingo Molnar <[e-mail]>
Signed-off-by: Arjan van de Ven <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/char/random.c

···
 	.poolinfo = &poolinfo_table[0],
 	.name = "input",
 	.limit = 1,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&input_pool.lock),
 	.pool = input_pool_data
 };
 
···
 	.name = "blocking",
 	.limit = 1,
 	.pull = &input_pool,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&blocking_pool.lock),
 	.pool = blocking_pool_data
 };
 
···
 	.poolinfo = &poolinfo_table[1],
 	.name = "nonblocking",
 	.pull = &input_pool,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&nonblocking_pool.lock),
 	.pool = nonblocking_pool_data
 };
 

fs/dcache.c

···
 EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 
  __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
-static seqlock_t rename_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
+static __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
 
 EXPORT_SYMBOL(dcache_lock);
 

include/linux/idr.h

···
 	.id_free	= NULL,					\
 	.layers 	= 0,					\
 	.id_free_cnt	= 0,					\
-	.lock		= SPIN_LOCK_UNLOCKED,			\
+	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),	\
 }
 #define DEFINE_IDR(name)	struct idr name = IDR_INIT(name)
 

include/linux/init_task.h

···
 	.count		= ATOMIC_INIT(1), 		\
 	.fdt		= &init_files.fdtab, 		\
 	.fdtab		= INIT_FDTABLE,			\
-	.file_lock	= SPIN_LOCK_UNLOCKED, 		\
+	.file_lock	= __SPIN_LOCK_UNLOCKED(init_task.file_lock), \
 	.next_fd	= 0, 				\
 	.close_on_exec_init = { { 0, } }, 		\
 	.open_fds_init	= { { 0, } }, 			\
···
 	.user_id	= 0,				\
 	.next		= NULL,				\
 	.wait		= __WAIT_QUEUE_HEAD_INITIALIZER(name.wait), \
-	.ctx_lock	= SPIN_LOCK_UNLOCKED,		\
+	.ctx_lock	= __SPIN_LOCK_UNLOCKED(name.ctx_lock), \
 	.reqs_active	= 0U,				\
 	.max_reqs	= ~0U,				\
 }
···
 	.mm_users	= ATOMIC_INIT(2), 			\
 	.mm_count	= ATOMIC_INIT(1), 			\
 	.mmap_sem	= __RWSEM_INITIALIZER(name.mmap_sem),	\
-	.page_table_lock =  SPIN_LOCK_UNLOCKED, 		\
+	.page_table_lock =  __SPIN_LOCK_UNLOCKED(name.page_table_lock),	\
 	.mmlist		= LIST_HEAD_INIT(name.mmlist),		\
 	.cpu_vm_mask	= CPU_MASK_ALL,				\
 }
···
 #define INIT_SIGHAND(sighand) {						\
 	.count		= ATOMIC_INIT(1), 				\
 	.action		= { { { .sa_handler = NULL, } }, },		\
-	.siglock	= SPIN_LOCK_UNLOCKED, 				\
+	.siglock	= __SPIN_LOCK_UNLOCKED(sighand.siglock),	\
 }
 
 extern struct group_info init_groups;
···
 		.list = LIST_HEAD_INIT(tsk.pending.list),		\
 		.signal = {{0}}},					\
 	.blocked	= {{0}},					\
-	.alloc_lock	= SPIN_LOCK_UNLOCKED,				\
+	.alloc_lock	= __SPIN_LOCK_UNLOCKED(tsk.alloc_lock),		\
 	.journal_info	= NULL,						\
 	.cpu_timers	= INIT_CPU_TIMERS(tsk.cpu_timers),		\
 	.fs_excl	= ATOMIC_INIT(0),				\

include/linux/notifier.h

···
 	} while (0)
 
 #define ATOMIC_NOTIFIER_INIT(name) {				\
-		.lock = SPIN_LOCK_UNLOCKED,			\
+		.lock = __SPIN_LOCK_UNLOCKED(name.lock),	\
 		.head = NULL }
 #define BLOCKING_NOTIFIER_INIT(name) {				\
 		.rwsem = __RWSEM_INITIALIZER((name).rwsem),	\

include/linux/seqlock.h

···
  * These macros triggered gcc-3.x compile-time problems.  We think these are
  * OK now.  Be cautious.
  */
-#define SEQLOCK_UNLOCKED { 0, SPIN_LOCK_UNLOCKED }
-#define seqlock_init(x)	do { *(x) = (seqlock_t) SEQLOCK_UNLOCKED; } while (0)
+#define __SEQLOCK_UNLOCKED(lockname) \
+		 { 0, __SPIN_LOCK_UNLOCKED(lockname) }
 
+#define SEQLOCK_UNLOCKED \
+		 __SEQLOCK_UNLOCKED(old_style_seqlock_init)
+
+#define seqlock_init(x) \
+		do { *(x) = (seqlock_t) __SEQLOCK_UNLOCKED(x); } while (0)
+
+#define DEFINE_SEQLOCK(x) \
+		seqlock_t x = __SEQLOCK_UNLOCKED(x)
 
 /* Lock out other writers and update the count.
  * Acts like a normal spin_lock/unlock.

include/linux/spinlock_types.h

···
 #define SPINLOCK_OWNER_INIT	((void *)-1L)
 
 #ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_LOCK_UNLOCKED						\
+# define __SPIN_LOCK_UNLOCKED(lockname)					\
 	(spinlock_t)	{	.raw_lock = __RAW_SPIN_LOCK_UNLOCKED,	\
 				.magic = SPINLOCK_MAGIC,		\
 				.owner = SPINLOCK_OWNER_INIT,		\
 				.owner_cpu = -1 }
-#define RW_LOCK_UNLOCKED						\
+#define __RW_LOCK_UNLOCKED(lockname)					\
 	(rwlock_t)	{	.raw_lock = __RAW_RW_LOCK_UNLOCKED,	\
 				.magic = RWLOCK_MAGIC,			\
 				.owner = SPINLOCK_OWNER_INIT,		\
 				.owner_cpu = -1 }
 #else
-# define SPIN_LOCK_UNLOCKED \
+# define __SPIN_LOCK_UNLOCKED(lockname) \
 	(spinlock_t)	{	.raw_lock = __RAW_SPIN_LOCK_UNLOCKED }
-#define RW_LOCK_UNLOCKED \
+#define __RW_LOCK_UNLOCKED(lockname) \
 	(rwlock_t)	{	.raw_lock = __RAW_RW_LOCK_UNLOCKED }
 #endif
 
-#define DEFINE_SPINLOCK(x)	spinlock_t x = SPIN_LOCK_UNLOCKED
-#define DEFINE_RWLOCK(x)	rwlock_t x = RW_LOCK_UNLOCKED
+#define SPIN_LOCK_UNLOCKED	__SPIN_LOCK_UNLOCKED(old_style_spin_init)
+#define RW_LOCK_UNLOCKED	__RW_LOCK_UNLOCKED(old_style_rw_init)
+
+#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+#define DEFINE_RWLOCK(x)	rwlock_t x = __RW_LOCK_UNLOCKED(x)
 
 #endif /* __LINUX_SPINLOCK_TYPES_H */

include/linux/wait.h

···
 	wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
 
 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {				\
-	.lock		= SPIN_LOCK_UNLOCKED,				\
+	.lock		= __SPIN_LOCK_UNLOCKED(name.lock),		\
 	.task_list	= { &(name).task_list, &(name).task_list } }
 
 #define DECLARE_WAIT_QUEUE_HEAD(name) \

kernel/rcupdate.c

···
 static struct rcu_ctrlblk rcu_ctrlblk = {
 	.cur = -300,
 	.completed = -300,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&rcu_ctrlblk.lock),
 	.cpumask = CPU_MASK_NONE,
 };
 static struct rcu_ctrlblk rcu_bh_ctrlblk = {
 	.cur = -300,
 	.completed = -300,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&rcu_bh_ctrlblk.lock),
 	.cpumask = CPU_MASK_NONE,
 };
 

kernel/timer.c

···
  * playing with xtime and avenrun.
  */
 #ifndef ARCH_HAVE_XTIME_LOCK
-seqlock_t xtime_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
 
 EXPORT_SYMBOL(xtime_lock);
 #endif

mm/swap_state.c

···
 
 struct address_space swapper_space = {
 	.page_tree	= RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),
-	.tree_lock	= RW_LOCK_UNLOCKED,
+	.tree_lock	= __RW_LOCK_UNLOCKED(swapper_space.tree_lock),
 	.a_ops		= &swap_aops,
 	.i_mmap_nonlinear = LIST_HEAD_INIT(swapper_space.i_mmap_nonlinear),
 	.backing_dev_info = &swap_backing_dev_info,

net/ipv4/tcp_ipv4.c

···
 void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
 
 struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
-	.lhash_lock	= RW_LOCK_UNLOCKED,
+	.lhash_lock	= __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
 	.lhash_users	= ATOMIC_INIT(0),
 	.lhash_wait	= __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
 };

net/ipv4/tcp_minisocks.c

···
 struct inet_timewait_death_row tcp_death_row = {
 	.sysctl_max_tw_buckets = NR_FILE * 2,
 	.period		= TCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
-	.death_lock	= SPIN_LOCK_UNLOCKED,
+	.death_lock	= __SPIN_LOCK_UNLOCKED(tcp_death_row.death_lock),
 	.hashinfo	= &tcp_hashinfo,
 	.tw_timer	= TIMER_INITIALIZER(inet_twdr_hangman, 0,
 					    (unsigned long)&tcp_death_row),