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Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Browse source 
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rtmutex: tester: Remove the remaining BKL leftovers
  lockdep/timers: Explain in detail the locking problems del_timer_sync() may cause
  rtmutex: Simplify PI algorithm and make highest prio task get lock
  rwsem: Remove redundant asmregparm annotation
  rwsem: Move duplicate function prototypes to linux/rwsem.h
  rwsem: Unify the duplicate rwsem_is_locked() inlines
  rwsem: Move duplicate init macros and functions to linux/rwsem.h
  rwsem: Move duplicate struct rwsem declaration to linux/rwsem.h
  x86: Cleanup rwsem_count_t typedef
  rwsem: Cleanup includes
  locking: Remove deprecated lock initializers
  cred: Replace deprecated spinlock initialization
  kthread: Replace deprecated spinlock initialization
  xtensa: Replace deprecated spinlock initialization
  um: Replace deprecated spinlock initialization
  sparc: Replace deprecated spinlock initialization
  mips: Replace deprecated spinlock initialization
  cris: Replace deprecated spinlock initialization
  alpha: Replace deprecated spinlock initialization
  rtmutex-tester: Remove BKL tests
This commit is contained in:
Linus Torvalds 2011-03-15 18:28:30 -07:00
commit 0586bed3e8
40 changed files with 228 additions and 816 deletions
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24
Documentation/spinlocks.txt
View file

@ -86,7 +86,7 @@ to change the variables it has to get an exclusive write lock.
The routines look the same as above:
rwlock_t xxx_lock = RW_LOCK_UNLOCKED;
rwlock_t xxx_lock = __RW_LOCK_UNLOCKED(xxx_lock);
unsigned long flags;
@ -196,25 +196,3 @@ appropriate:
For static initialization, use DEFINE_SPINLOCK() / DEFINE_RWLOCK() or
__SPIN_LOCK_UNLOCKED() / __RW_LOCK_UNLOCKED() as appropriate.
SPIN_LOCK_UNLOCKED and RW_LOCK_UNLOCKED are deprecated. These interfere
with lockdep state tracking.
Most of the time, you can simply turn:
static spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED;
into:
static DEFINE_SPINLOCK(xxx_lock);
Static structure member variables go from:
struct foo bar {
.lock = SPIN_LOCK_UNLOCKED;
};
to:
struct foo bar {
.lock = __SPIN_LOCK_UNLOCKED(bar.lock);
};
Declaration of static rw_locks undergo a similar transformation.

36
arch/alpha/include/asm/rwsem.h
View file

@ -13,44 +13,13 @@
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/spinlock.h>
struct rwsem_waiter;
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
/*
* the semaphore definition
*/
struct rw_semaphore {
long count;
#define RWSEM_UNLOCKED_VALUE 0x0000000000000000L
#define RWSEM_ACTIVE_BIAS 0x0000000000000001L
#define RWSEM_ACTIVE_MASK 0x00000000ffffffffL
#define RWSEM_WAITING_BIAS (-0x0000000100000000L)
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
spinlock_t wait_lock;
struct list_head wait_list;
};
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
LIST_HEAD_INIT((name).wait_list) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
static inline void init_rwsem(struct rw_semaphore *sem)
{
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
static inline void __down_read(struct rw_semaphore *sem)
{
@ -250,10 +219,5 @@ static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem)
#endif
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* __KERNEL__ */
#endif /* _ALPHA_RWSEM_H */

4
arch/cris/arch-v32/kernel/smp.c
View file

@ -26,7 +26,9 @@
#define FLUSH_ALL (void*)0xffffffff
/* Vector of locks used for various atomic operations */
spinlock_t cris_atomic_locks[] = { [0 ... LOCK_COUNT - 1] = SPIN_LOCK_UNLOCKED};
spinlock_t cris_atomic_locks[] = {
[0 ... LOCK_COUNT - 1] = __SPIN_LOCK_UNLOCKED(cris_atomic_locks)
};
/* CPU masks */
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;

37
arch/ia64/include/asm/rwsem.h
View file

@ -25,20 +25,8 @@
#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
#endif
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/intrinsics.h>
/*
* the semaphore definition
*/
struct rw_semaphore {
signed long count;
spinlock_t wait_lock;
struct list_head wait_list;
};
#define RWSEM_UNLOCKED_VALUE __IA64_UL_CONST(0x0000000000000000)
#define RWSEM_ACTIVE_BIAS (1L)
#define RWSEM_ACTIVE_MASK (0xffffffffL)
@ -46,26 +34,6 @@ struct rw_semaphore {
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
static inline void
init_rwsem (struct rw_semaphore *sem)
{
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
/*
* lock for reading
*/
@ -174,9 +142,4 @@ __downgrade_write (struct rw_semaphore *sem)
#define rwsem_atomic_add(delta, sem) atomic64_add(delta, (atomic64_t *)(&(sem)->count))
#define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* _ASM_IA64_RWSEM_H */

51
arch/powerpc/include/asm/rwsem.h
View file

@ -13,11 +13,6 @@
* by Paul Mackerras <paulus@samba.org>.
*/
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <asm/system.h>
/*
* the semaphore definition
*/
@ -33,47 +28,6 @@
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
struct rw_semaphore {
long count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ \
RWSEM_UNLOCKED_VALUE, \
__SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) \
__RWSEM_DEP_MAP_INIT(name) \
}
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
/*
* lock for reading
*/
@ -174,10 +128,5 @@ static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return sem->count != 0;
}
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_RWSEM_H */

63
arch/s390/include/asm/rwsem.h
View file

@ -43,29 +43,6 @@
#ifdef __KERNEL__
#include <linux/list.h>
#include <linux/spinlock.h>
struct rwsem_waiter;
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_downgrade_write(struct rw_semaphore *);
/*
* the semaphore definition
*/
struct rw_semaphore {
signed long count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
#ifndef __s390x__
#define RWSEM_UNLOCKED_VALUE 0x00000000
#define RWSEM_ACTIVE_BIAS 0x00000001
@ -80,41 +57,6 @@ struct rw_semaphore {
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
/*
* initialisation
*/
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait.lock), \
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
static inline void init_rwsem(struct rw_semaphore *sem)
{
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
/*
* lock for reading
*/
@ -377,10 +319,5 @@ static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
return new;
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* __KERNEL__ */
#endif /* _S390_RWSEM_H */

56
arch/sh/include/asm/rwsem.h
View file

@ -11,64 +11,13 @@
#endif
#ifdef __KERNEL__
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <asm/system.h>
/*
* the semaphore definition
*/
struct rw_semaphore {
long count;
#define RWSEM_UNLOCKED_VALUE 0x00000000
#define RWSEM_ACTIVE_BIAS 0x00000001
#define RWSEM_ACTIVE_MASK 0x0000ffff
#define RWSEM_WAITING_BIAS (-0x00010000)
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) \
__RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
static inline void init_rwsem(struct rw_semaphore *sem)
{
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
/*
* lock for reading
@ -179,10 +128,5 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
return atomic_add_return(delta, (atomic_t *)(&sem->count));
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* __KERNEL__ */
#endif /* _ASM_SH_RWSEM_H */

46
arch/sparc/include/asm/rwsem.h
View file

@ -13,53 +13,12 @@
#ifdef __KERNEL__
#include <linux/list.h>
#include <linux/spinlock.h>
struct rwsem_waiter;
struct rw_semaphore {
signed long count;
#define RWSEM_UNLOCKED_VALUE 0x00000000L
#define RWSEM_ACTIVE_BIAS 0x00000001L
#define RWSEM_ACTIVE_MASK 0xffffffffL
#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1)
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
/*
* lock for reading
@ -160,11 +119,6 @@ static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
return atomic64_add_return(delta, (atomic64_t *)(&sem->count));
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* __KERNEL__ */
#endif /* _SPARC64_RWSEM_H */

2
arch/sparc/lib/atomic32.c
View file

@ -16,7 +16,7 @@
#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
[0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED
[0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash)
};
#else /* SMP */

2
arch/um/drivers/ubd_kern.c
View file

@ -185,7 +185,7 @@ struct ubd {
.no_cow = 0, \
.shared = 0, \
.cow = DEFAULT_COW, \
.lock = SPIN_LOCK_UNLOCKED, \
.lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \
.request = NULL, \
.start_sg = 0, \
.end_sg = 0, \

80
arch/x86/include/asm/rwsem.h
View file

@ -37,26 +37,9 @@
#endif
#ifdef __KERNEL__
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/lockdep.h>
#include <asm/asm.h>
struct rwsem_waiter;
extern asmregparm struct rw_semaphore *
rwsem_down_read_failed(struct rw_semaphore *sem);
extern asmregparm struct rw_semaphore *
rwsem_down_write_failed(struct rw_semaphore *sem);
extern asmregparm struct rw_semaphore *
rwsem_wake(struct rw_semaphore *);
extern asmregparm struct rw_semaphore *
rwsem_downgrade_wake(struct rw_semaphore *sem);
/*
* the semaphore definition
*
* The bias values and the counter type limits the number of
* potential readers/writers to 32767 for 32 bits and 2147483647
* for 64 bits.
@ -74,43 +57,6 @@ extern asmregparm struct rw_semaphore *
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
typedef signed long rwsem_count_t;
struct rw_semaphore {
rwsem_count_t count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ \
RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) \
}
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
/*
* lock for reading
*/
@ -133,7 +79,7 @@ static inline void __down_read(struct rw_semaphore *sem)
*/
static inline int __down_read_trylock(struct rw_semaphore *sem)
{
rwsem_count_t result, tmp;
long result, tmp;
asm volatile("# beginning __down_read_trylock\n\t"
" mov %0,%1\n\t"
"1:\n\t"
@ -155,7 +101,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
*/
static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
{
rwsem_count_t tmp;
long tmp;
asm volatile("# beginning down_write\n\t"
LOCK_PREFIX " xadd %1,(%2)\n\t"
/* adds 0xffff0001, returns the old value */
@ -180,9 +126,8 @@ static inline void __down_write(struct rw_semaphore *sem)
*/
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
rwsem_count_t ret = cmpxchg(&sem->count,
RWSEM_UNLOCKED_VALUE,
RWSEM_ACTIVE_WRITE_BIAS);
long ret = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
RWSEM_ACTIVE_WRITE_BIAS);
if (ret == RWSEM_UNLOCKED_VALUE)
return 1;
return 0;
@ -193,7 +138,7 @@ static inline int __down_write_trylock(struct rw_semaphore *sem)
*/
static inline void __up_read(struct rw_semaphore *sem)
{
rwsem_count_t tmp;
long tmp;
asm volatile("# beginning __up_read\n\t"
LOCK_PREFIX " xadd %1,(%2)\n\t"
/* subtracts 1, returns the old value */
@ -211,7 +156,7 @@ static inline void __up_read(struct rw_semaphore *sem)
*/
static inline void __up_write(struct rw_semaphore *sem)
{
rwsem_count_t tmp;
long tmp;
asm volatile("# beginning __up_write\n\t"
LOCK_PREFIX " xadd %1,(%2)\n\t"
/* subtracts 0xffff0001, returns the old value */
@ -247,8 +192,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
/*
* implement atomic add functionality
*/
static inline void rwsem_atomic_add(rwsem_count_t delta,
struct rw_semaphore *sem)
static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
{
asm volatile(LOCK_PREFIX _ASM_ADD "%1,%0"
: "+m" (sem->count)
@ -258,10 +202,9 @@ static inline void rwsem_atomic_add(rwsem_count_t delta,
/*
* implement exchange and add functionality
*/
static inline rwsem_count_t rwsem_atomic_update(rwsem_count_t delta,
struct rw_semaphore *sem)
static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
{
rwsem_count_t tmp = delta;
long tmp = delta;
asm volatile(LOCK_PREFIX "xadd %0,%1"
: "+r" (tmp), "+m" (sem->count)
@ -270,10 +213,5 @@ static inline rwsem_count_t rwsem_atomic_update(rwsem_count_t delta,
return tmp + delta;
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* __KERNEL__ */
#endif /* _ASM_X86_RWSEM_H */

37
arch/xtensa/include/asm/rwsem.h
View file

@ -17,44 +17,12 @@
#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
#endif
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <asm/system.h>
/*
* the semaphore definition
*/
struct rw_semaphore {
signed long count;
#define RWSEM_UNLOCKED_VALUE 0x00000000
#define RWSEM_ACTIVE_BIAS 0x00000001
#define RWSEM_ACTIVE_MASK 0x0000ffff
#define RWSEM_WAITING_BIAS (-0x00010000)
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
spinlock_t wait_lock;
struct list_head wait_list;
};
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
LIST_HEAD_INIT((name).wait_list) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
static inline void init_rwsem(struct rw_semaphore *sem)
{
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
/*
* lock for reading
@ -160,9 +128,4 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
return atomic_add_return(delta, (atomic_t *)(&sem->count));
}
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
}
#endif /* _XTENSA_RWSEM_H */

2
include/linux/kthread.h
View file

@ -64,7 +64,7 @@ struct kthread_work {
};
#define KTHREAD_WORKER_INIT(worker) { \
.lock = SPIN_LOCK_UNLOCKED, \
.lock = __SPIN_LOCK_UNLOCKED((worker).lock), \
.work_list = LIST_HEAD_INIT((worker).work_list), \
}

8
include/linux/rwlock_types.h
View file

@ -43,14 +43,6 @@ typedef struct {
RW_DEP_MAP_INIT(lockname) }
#endif
/*
* RW_LOCK_UNLOCKED defeat lockdep state tracking and is hence
* deprecated.
*
* Please use DEFINE_RWLOCK() or __RW_LOCK_UNLOCKED() as appropriate.
*/
#define RW_LOCK_UNLOCKED __RW_LOCK_UNLOCKED(old_style_rw_init)
#define DEFINE_RWLOCK(x) rwlock_t x = __RW_LOCK_UNLOCKED(x)
#endif /* __LINUX_RWLOCK_TYPES_H */

31
include/linux/rwsem-spinlock.h
View file

@ -12,15 +12,7 @@
#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
#endif
#include <linux/spinlock.h>
#include <linux/list.h>
#ifdef __KERNEL__
#include <linux/types.h>
struct rwsem_waiter;
/*
* the rw-semaphore definition
* - if activity is 0 then there are no active readers or writers
@ -37,28 +29,7 @@ struct rw_semaphore {
#endif
};
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ 0, __SPIN_LOCK_UNLOCKED(name.wait_lock), LIST_HEAD_INIT((name).wait_list) \
__RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
#define RWSEM_UNLOCKED_VALUE 0x00000000
extern void __down_read(struct rw_semaphore *sem);
extern int __down_read_trylock(struct rw_semaphore *sem);

53
include/linux/rwsem.h
View file

@ -11,6 +11,9 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/atomic.h>
@ -19,8 +22,56 @@ struct rw_semaphore;
#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
#include <linux/rwsem-spinlock.h> /* use a generic implementation */
#else
#include <asm/rwsem.h> /* use an arch-specific implementation */
/* All arch specific implementations share the same struct */
struct rw_semaphore {
long count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
};
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
/* Include the arch specific part */
#include <asm/rwsem.h>
/* In all implementations count != 0 means locked */
static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return sem->count != 0;
}
#endif
/* Common initializer macros and functions */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
#else
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED(name.wait_lock), \
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
struct lock_class_key *key);
#define init_rwsem(sem) \
do { \
static struct lock_class_key __key; \
\
__init_rwsem((sem), #sem, &__key); \
} while (0)
/*
* lock for reading

8
include/linux/spinlock_types.h
View file

@ -81,14 +81,6 @@ typedef struct spinlock {
#define __SPIN_LOCK_UNLOCKED(lockname) \
(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
/*
* SPIN_LOCK_UNLOCKED defeats lockdep state tracking and is hence
* deprecated.
* Please use DEFINE_SPINLOCK() or __SPIN_LOCK_UNLOCKED() as
* appropriate.
*/
#define SPIN_LOCK_UNLOCKED __SPIN_LOCK_UNLOCKED(old_style_spin_init)
#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
#include <linux/rwlock_types.h>

2
kernel/cred.c
View file

@ -35,7 +35,7 @@ static struct kmem_cache *cred_jar;
static struct thread_group_cred init_tgcred = {
.usage = ATOMIC_INIT(2),
.tgid = 0,
.lock = SPIN_LOCK_UNLOCKED,
.lock = __SPIN_LOCK_UNLOCKED(init_cred.tgcred.lock),
};
#endif

22
kernel/futex.c
View file

@ -1555,10 +1555,10 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
/*
* We are here either because we stole the rtmutex from the
* pending owner or we are the pending owner which failed to
* get the rtmutex. We have to replace the pending owner TID
* in the user space variable. This must be atomic as we have
* to preserve the owner died bit here.
* previous highest priority waiter or we are the highest priority
* waiter but failed to get the rtmutex the first time.
* We have to replace the newowner TID in the user space variable.
* This must be atomic as we have to preserve the owner died bit here.
*
* Note: We write the user space value _before_ changing the pi_state
* because we can fault here. Imagine swapped out pages or a fork
@ -1605,8 +1605,8 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
/*
* To handle the page fault we need to drop the hash bucket
* lock here. That gives the other task (either the pending
* owner itself or the task which stole the rtmutex) the
* lock here. That gives the other task (either the highest priority
* waiter itself or the task which stole the rtmutex) the
* chance to try the fixup of the pi_state. So once we are
* back from handling the fault we need to check the pi_state
* after reacquiring the hash bucket lock and before trying to
@ -1682,18 +1682,20 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
/*
* pi_state is incorrect, some other task did a lock steal and
* we returned due to timeout or signal without taking the
* rt_mutex. Too late. We can access the rt_mutex_owner without
* locking, as the other task is now blocked on the hash bucket
* lock. Fix the state up.
* rt_mutex. Too late.
*/
raw_spin_lock(&q->pi_state->pi_mutex.wait_lock);
owner = rt_mutex_owner(&q->pi_state->pi_mutex);
if (!owner)
owner = rt_mutex_next_owner(&q->pi_state->pi_mutex);
raw_spin_unlock(&q->pi_state->pi_mutex.wait_lock);
ret = fixup_pi_state_owner(uaddr, q, owner);
goto out;
}
/*
* Paranoia check. If we did not take the lock, then we should not be
* the owner, nor the pending owner, of the rt_mutex.
* the owner of the rt_mutex.
*/
if (rt_mutex_owner(&q->pi_state->pi_mutex) == current)
printk(KERN_ERR "fixup_owner: ret = %d pi-mutex: %p "

1
kernel/rtmutex-debug.c
View file

@ -215,7 +215,6 @@ void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
put_pid(waiter->deadlock_task_pid);
TRACE_WARN_ON(!plist_node_empty(&waiter->list_entry));
TRACE_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
TRACE_WARN_ON(waiter->task);
memset(waiter, 0x22, sizeof(*waiter));
}

40
kernel/rtmutex-tester.c
View file

@ -9,7 +9,6 @@
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
@ -27,7 +26,6 @@ struct test_thread_data {
int opcode;
int opdata;
int mutexes[MAX_RT_TEST_MUTEXES];
int bkl;
int event;
struct sys_device sysdev;
};
@ -46,9 +44,8 @@ enum test_opcodes {
RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */
RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */
RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */
RTTEST_LOCKBKL, /* 9 Lock BKL */
RTTEST_UNLOCKBKL, /* 10 Unlock BKL */
RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */
/* 9, 10 - reserved for BKL commemoration */
RTTEST_SIGNAL = 11, /* 11 Signal other test thread, data = thread id */
RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
RTTEST_RESET = 99, /* 99 Reset all pending operations */
};
@ -74,13 +71,6 @@ static int handle_op(struct test_thread_data *td, int lockwakeup)
td->mutexes[i] = 0;
}
}
if (!lockwakeup && td->bkl == 4) {
#ifdef CONFIG_LOCK_KERNEL
unlock_kernel();
#endif
td->bkl = 0;
}
return 0;
case RTTEST_RESETEVENT:
@ -131,25 +121,6 @@ static int handle_op(struct test_thread_data *td, int lockwakeup)
td->mutexes[id] = 0;
return 0;
case RTTEST_LOCKBKL:
if (td->bkl)
return 0;
td->bkl = 1;
#ifdef CONFIG_LOCK_KERNEL
lock_kernel();
#endif
td->bkl = 4;
return 0;
case RTTEST_UNLOCKBKL:
if (td->bkl != 4)
break;
#ifdef CONFIG_LOCK_KERNEL
unlock_kernel();
#endif
td->bkl = 0;
return 0;
default:
break;
}
@ -196,7 +167,6 @@ void schedule_rt_mutex_test(struct rt_mutex *mutex)
td->event = atomic_add_return(1, &rttest_event);
break;
case RTTEST_LOCKBKL:
default:
break;
}
@ -229,8 +199,6 @@ void schedule_rt_mutex_test(struct rt_mutex *mutex)
td->event = atomic_add_return(1, &rttest_event);
return;
case RTTEST_LOCKBKL:
return;
default:
return;
}
@ -380,11 +348,11 @@ static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute
spin_lock(&rttest_lock);
curr += sprintf(curr,
"O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
"O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, M:",
td->opcode, td->event, tsk->state,
(MAX_RT_PRIO - 1) - tsk->prio,
(MAX_RT_PRIO - 1) - tsk->normal_prio,
tsk->pi_blocked_on, td->bkl);
tsk->pi_blocked_on);
for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
curr += sprintf(curr, "%d", td->mutexes[i]);

318
kernel/rtmutex.c
View file

@ -20,41 +20,34 @@
/*
* lock->owner state tracking:
*
* lock->owner holds the task_struct pointer of the owner. Bit 0 and 1
* are used to keep track of the "owner is pending" and "lock has
* waiters" state.
* lock->owner holds the task_struct pointer of the owner. Bit 0
* is used to keep track of the "lock has waiters" state.
*
* owner bit1 bit0
* NULL 0 0 lock is free (fast acquire possible)
* NULL 0 1 invalid state
* NULL 1 0 Transitional State*
* NULL 1 1 invalid state
* taskpointer 0 0 lock is held (fast release possible)
* taskpointer 0 1 task is pending owner
* taskpointer 1 0 lock is held and has waiters
* taskpointer 1 1 task is pending owner and lock has more waiters
*
* Pending ownership is assigned to the top (highest priority)
* waiter of the lock, when the lock is released. The thread is woken
* up and can now take the lock. Until the lock is taken (bit 0
* cleared) a competing higher priority thread can steal the lock
* which puts the woken up thread back on the waiters list.
* owner bit0
* NULL 0 lock is free (fast acquire possible)
* NULL 1 lock is free and has waiters and the top waiter
* is going to take the lock*
* taskpointer 0 lock is held (fast release possible)
* taskpointer 1 lock is held and has waiters**
*
* The fast atomic compare exchange based acquire and release is only
* possible when bit 0 and 1 of lock->owner are 0.
* possible when bit 0 of lock->owner is 0.
*
* (*) There's a small time where the owner can be NULL and the
* "lock has waiters" bit is set. This can happen when grabbing the lock.
* To prevent a cmpxchg of the owner releasing the lock, we need to set this
* bit before looking at the lock, hence the reason this is a transitional
* state.
* (*) It also can be a transitional state when grabbing the lock
* with ->wait_lock is held. To prevent any fast path cmpxchg to the lock,
* we need to set the bit0 before looking at the lock, and the owner may be
* NULL in this small time, hence this can be a transitional state.
*
* (**) There is a small time when bit 0 is set but there are no
* waiters. This can happen when grabbing the lock in the slow path.
* To prevent a cmpxchg of the owner releasing the lock, we need to
* set this bit before looking at the lock.
*/
static void
rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner,
unsigned long mask)
rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner)
{
unsigned long val = (unsigned long)owner | mask;
unsigned long val = (unsigned long)owner;
if (rt_mutex_has_waiters(lock))
val |= RT_MUTEX_HAS_WAITERS;
@ -203,15 +196,14 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* reached or the state of the chain has changed while we
* dropped the locks.
*/
if (!waiter || !waiter->task)
if (!waiter)
goto out_unlock_pi;
/*
* Check the orig_waiter state. After we dropped the locks,
* the previous owner of the lock might have released the lock
* and made us the pending owner:
* the previous owner of the lock might have released the lock.
*/
if (orig_waiter && !orig_waiter->task)
if (orig_waiter && !rt_mutex_owner(orig_lock))
goto out_unlock_pi;
/*
@ -254,6 +246,17 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
/* Release the task */
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
if (!rt_mutex_owner(lock)) {
/*
* If the requeue above changed the top waiter, then we need
* to wake the new top waiter up to try to get the lock.
*/
if (top_waiter != rt_mutex_top_waiter(lock))
wake_up_process(rt_mutex_top_waiter(lock)->task);
raw_spin_unlock(&lock->wait_lock);
goto out_put_task;
}
put_task_struct(task);
/* Grab the next task */
@ -295,79 +298,17 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
return ret;
}
/*
* Optimization: check if we can steal the lock from the
* assigned pending owner [which might not have taken the
* lock yet]:
*/
static inline int try_to_steal_lock(struct rt_mutex *lock,
struct task_struct *task)
{
struct task_struct *pendowner = rt_mutex_owner(lock);
struct rt_mutex_waiter *next;
unsigned long flags;
if (!rt_mutex_owner_pending(lock))
return 0;
if (pendowner == task)
return 1;
raw_spin_lock_irqsave(&pendowner->pi_lock, flags);
if (task->prio >= pendowner->prio) {
raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
return 0;
}
/*
* Check if a waiter is enqueued on the pending owners
* pi_waiters list. Remove it and readjust pending owners
* priority.
*/
if (likely(!rt_mutex_has_waiters(lock))) {
raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
return 1;
}
/* No chain handling, pending owner is not blocked on anything: */
next = rt_mutex_top_waiter(lock);
plist_del(&next->pi_list_entry, &pendowner->pi_waiters);
__rt_mutex_adjust_prio(pendowner);
raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
/*
* We are going to steal the lock and a waiter was
* enqueued on the pending owners pi_waiters queue. So
* we have to enqueue this waiter into
* task->pi_waiters list. This covers the case,
* where task is boosted because it holds another
* lock and gets unboosted because the booster is
* interrupted, so we would delay a waiter with higher
* priority as task->normal_prio.
*
* Note: in the rare case of a SCHED_OTHER task changing
* its priority and thus stealing the lock, next->task
* might be task:
*/
if (likely(next->task != task)) {
raw_spin_lock_irqsave(&task->pi_lock, flags);
plist_add(&next->pi_list_entry, &task->pi_waiters);
__rt_mutex_adjust_prio(task);
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
return 1;
}
/*
* Try to take an rt-mutex
*
* This fails
* - when the lock has a real owner
* - when a different pending owner exists and has higher priority than current
*
* Must be called with lock->wait_lock held.
*
* @lock: the lock to be acquired.
* @task: the task which wants to acquire the lock
* @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
*/
static int try_to_take_rt_mutex(struct rt_mutex *lock)
static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
struct rt_mutex_waiter *waiter)
{
/*
* We have to be careful here if the atomic speedups are
@ -390,15 +331,52 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock)
*/
mark_rt_mutex_waiters(lock);
if (rt_mutex_owner(lock) && !try_to_steal_lock(lock, current))
if (rt_mutex_owner(lock))
return 0;
/*
* It will get the lock because of one of these conditions:
* 1) there is no waiter
* 2) higher priority than waiters
* 3) it is top waiter
*/
if (rt_mutex_has_waiters(lock)) {
if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
if (!waiter || waiter != rt_mutex_top_waiter(lock))
return 0;
}
}
if (waiter || rt_mutex_has_waiters(lock)) {
unsigned long flags;
struct rt_mutex_waiter *top;
raw_spin_lock_irqsave(&task->pi_lock, flags);
/* remove the queued waiter. */
if (waiter) {
plist_del(&waiter->list_entry, &lock->wait_list);
task->pi_blocked_on = NULL;
}
/*
* We have to enqueue the top waiter(if it exists) into
* task->pi_waiters list.
*/
if (rt_mutex_has_waiters(lock)) {
top = rt_mutex_top_waiter(lock);
top->pi_list_entry.prio = top->list_entry.prio;
plist_add(&top->pi_list_entry, &task->pi_waiters);
}
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
/* We got the lock. */
debug_rt_mutex_lock(lock);
rt_mutex_set_owner(lock, current, 0);
rt_mutex_set_owner(lock, task);
rt_mutex_deadlock_account_lock(lock, current);
rt_mutex_deadlock_account_lock(lock, task);
return 1;
}
@ -436,6 +414,9 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
if (!owner)
return 0;
if (waiter == rt_mutex_top_waiter(lock)) {
raw_spin_lock_irqsave(&owner->pi_lock, flags);
plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
@ -472,21 +453,18 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
/*
* Wake up the next waiter on the lock.
*
* Remove the top waiter from the current tasks waiter list and from
* the lock waiter list. Set it as pending owner. Then wake it up.
* Remove the top waiter from the current tasks waiter list and wake it up.
*
* Called with lock->wait_lock held.
*/
static void wakeup_next_waiter(struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
struct task_struct *pendowner;
unsigned long flags;
raw_spin_lock_irqsave(&current->pi_lock, flags);
waiter = rt_mutex_top_waiter(lock);
plist_del(&waiter->list_entry, &lock->wait_list);
/*
* Remove it from current->pi_waiters. We do not adjust a
@ -495,43 +473,19 @@ static void wakeup_next_waiter(struct rt_mutex *lock)
* lock->wait_lock.
*/
plist_del(&waiter->pi_list_entry, &current->pi_waiters);
pendowner = waiter->task;
waiter->task = NULL;
rt_mutex_set_owner(lock, pendowner, RT_MUTEX_OWNER_PENDING);
rt_mutex_set_owner(lock, NULL);
raw_spin_unlock_irqrestore(&current->pi_lock, flags);
/*
* Clear the pi_blocked_on variable and enqueue a possible
* waiter into the pi_waiters list of the pending owner. This
* prevents that in case the pending owner gets unboosted a
* waiter with higher priority than pending-owner->normal_prio
* is blocked on the unboosted (pending) owner.
*/
raw_spin_lock_irqsave(&pendowner->pi_lock, flags);
WARN_ON(!pendowner->pi_blocked_on);
WARN_ON(pendowner->pi_blocked_on != waiter);
WARN_ON(pendowner->pi_blocked_on->lock != lock);
pendowner->pi_blocked_on = NULL;
if (rt_mutex_has_waiters(lock)) {
struct rt_mutex_waiter *next;
next = rt_mutex_top_waiter(lock);
plist_add(&next->pi_list_entry, &pendowner->pi_waiters);
}
raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
wake_up_process(pendowner);
wake_up_process(waiter->task);
}
/*
* Remove a waiter from a lock
* Remove a waiter from a lock and give up
*
* Must be called with lock->wait_lock held
* Must be called with lock->wait_lock held and
* have just failed to try_to_take_rt_mutex().
*/
static void remove_waiter(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
@ -543,11 +497,13 @@ static void remove_waiter(struct rt_mutex *lock,
raw_spin_lock_irqsave(&current->pi_lock, flags);
plist_del(&waiter->list_entry, &lock->wait_list);
waiter->task = NULL;
current->pi_blocked_on = NULL;
raw_spin_unlock_irqrestore(&current->pi_lock, flags);
if (first && owner != current) {
if (!owner)
return;
if (first) {
raw_spin_lock_irqsave(&owner->pi_lock, flags);
@ -614,21 +570,19 @@ void rt_mutex_adjust_pi(struct task_struct *task)
* or TASK_UNINTERRUPTIBLE)
* @timeout: the pre-initialized and started timer, or NULL for none
* @waiter: the pre-initialized rt_mutex_waiter
* @detect_deadlock: passed to task_blocks_on_rt_mutex
*
* lock->wait_lock must be held by the caller.
*/
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
struct rt_mutex_waiter *waiter,
int detect_deadlock)
struct rt_mutex_waiter *waiter)
{
int ret = 0;
for (;;) {
/* Try to acquire the lock: */
if (try_to_take_rt_mutex(lock))
if (try_to_take_rt_mutex(lock, current, waiter))
break;
/*
@ -645,39 +599,11 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
break;
}
/*
* waiter->task is NULL the first time we come here and
* when we have been woken up by the previous owner
* but the lock got stolen by a higher prio task.
*/
if (!waiter->task) {
ret = task_blocks_on_rt_mutex(lock, waiter, current,
detect_deadlock);
/*
* If we got woken up by the owner then start loop
* all over without going into schedule to try
* to get the lock now:
*/
if (unlikely(!waiter->task)) {
/*
* Reset the return value. We might
* have returned with -EDEADLK and the
* owner released the lock while we
* were walking the pi chain.
*/
ret = 0;
continue;
}
if (unlikely(ret))
break;
}
raw_spin_unlock(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
if (waiter->task)
schedule_rt_mutex(lock);
schedule_rt_mutex(lock);
raw_spin_lock(&lock->wait_lock);
set_current_state(state);
@ -698,12 +624,11 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
int ret = 0;
debug_rt_mutex_init_waiter(&waiter);
waiter.task = NULL;
raw_spin_lock(&lock->wait_lock);
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock)) {
if (try_to_take_rt_mutex(lock, current, NULL)) {
raw_spin_unlock(&lock->wait_lock);
return 0;
}
@ -717,12 +642,14 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
timeout->task = NULL;
}
ret = __rt_mutex_slowlock(lock, state, timeout, &waiter,
detect_deadlock);
ret = task_blocks_on_rt_mutex(lock, &waiter, current, detect_deadlock);
if (likely(!ret))
ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
set_current_state(TASK_RUNNING);
if (unlikely(waiter.task))
if (unlikely(ret))
remove_waiter(lock, &waiter);
/*
@ -737,14 +664,6 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
if (unlikely(timeout))
hrtimer_cancel(&timeout->timer);
/*
* Readjust priority, when we did not get the lock. We might
* have been the pending owner and boosted. Since we did not
* take the lock, the PI boost has to go.
*/
if (unlikely(ret))
rt_mutex_adjust_prio(current);
debug_rt_mutex_free_waiter(&waiter);
return ret;
@ -762,7 +681,7 @@ rt_mutex_slowtrylock(struct rt_mutex *lock)
if (likely(rt_mutex_owner(lock) != current)) {
ret = try_to_take_rt_mutex(lock);
ret = try_to_take_rt_mutex(lock, current, NULL);
/*
* try_to_take_rt_mutex() sets the lock waiters
* bit unconditionally. Clean this up.
@ -992,7 +911,7 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
{
__rt_mutex_init(lock, NULL);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner, 0);
rt_mutex_set_owner(lock, proxy_owner);
rt_mutex_deadlock_account_lock(lock, proxy_owner);
}
@ -1008,7 +927,7 @@ void rt_mutex_proxy_unlock(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
debug_rt_mutex_proxy_unlock(lock);
rt_mutex_set_owner(lock, NULL, 0);
rt_mutex_set_owner(lock, NULL);
rt_mutex_deadlock_account_unlock(proxy_owner);
}
@ -1034,20 +953,14 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
raw_spin_lock(&lock->wait_lock);
mark_rt_mutex_waiters(lock);
if (!rt_mutex_owner(lock) || try_to_steal_lock(lock, task)) {
/* We got the lock for task. */
debug_rt_mutex_lock(lock);
rt_mutex_set_owner(lock, task, 0);
if (try_to_take_rt_mutex(lock, task, NULL)) {
raw_spin_unlock(&lock->wait_lock);
rt_mutex_deadlock_account_lock(lock, task);
return 1;
}
ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
if (ret && !waiter->task) {
if (ret && !rt_mutex_owner(lock)) {
/*
* Reset the return value. We might have
* returned with -EDEADLK and the owner
@ -1056,6 +969,10 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
*/
ret = 0;
}
if (unlikely(ret))
remove_waiter(lock, waiter);
raw_spin_unlock(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
@ -1110,12 +1027,11 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
set_current_state(TASK_INTERRUPTIBLE);
ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter,
detect_deadlock);
ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
set_current_state(TASK_RUNNING);
if (unlikely(waiter->task))
if (unlikely(ret))
remove_waiter(lock, waiter);
/*
@ -1126,13 +1042,5 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
raw_spin_unlock(&lock->wait_lock);
/*
* Readjust priority, when we did not get the lock. We might have been
* the pending owner and boosted. Since we did not take the lock, the
* PI boost has to go.
*/
if (unlikely(ret))
rt_mutex_adjust_prio(current);
return ret;
}

16
kernel/rtmutex_common.h
View file

@ -91,9 +91,8 @@ task_top_pi_waiter(struct task_struct *p)
/*
* lock->owner state tracking:
*/
#define RT_MUTEX_OWNER_PENDING 1UL
#define RT_MUTEX_HAS_WAITERS 2UL
#define RT_MUTEX_OWNER_MASKALL 3UL
#define RT_MUTEX_HAS_WAITERS 1UL
#define RT_MUTEX_OWNER_MASKALL 1UL
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
{
@ -101,17 +100,6 @@ static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL);
}
static inline struct task_struct *rt_mutex_real_owner(struct rt_mutex *lock)
{
return (struct task_struct *)
((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS);
}
static inline unsigned long rt_mutex_owner_pending(struct rt_mutex *lock)
{
return (unsigned long)lock->owner & RT_MUTEX_OWNER_PENDING;
}
/*
* PI-futex support (proxy locking functions, etc.):
*/

23
kernel/timer.c
View file

@ -970,6 +970,25 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
* add_timer_on(). Upon exit the timer is not queued and the handler is
* not running on any CPU.
*
* Note: You must not hold locks that are held in interrupt context
* while calling this function. Even if the lock has nothing to do
* with the timer in question. Here's why:
*
* CPU0 CPU1
* ---- ----
* <SOFTIRQ>
* call_timer_fn();
* base->running_timer = mytimer;
* spin_lock_irq(somelock);
* <IRQ>
* spin_lock(somelock);
* del_timer_sync(mytimer);
* while (base->running_timer == mytimer);
*
* Now del_timer_sync() will never return and never release somelock.
* The interrupt on the other CPU is waiting to grab somelock but
* it has interrupted the softirq that CPU0 is waiting to finish.
*
* The function returns whether it has deactivated a pending timer or not.
*/
int del_timer_sync(struct timer_list *timer)
@ -977,6 +996,10 @@ int del_timer_sync(struct timer_list *timer)
#ifdef CONFIG_LOCKDEP
unsigned long flags;
/*
* If lockdep gives a backtrace here, please reference
* the synchronization rules above.
*/
local_irq_save(flags);
lock_map_acquire(&timer->lockdep_map);
lock_map_release(&timer->lockdep_map);

10
lib/rwsem.c
View file

@ -222,8 +222,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
/*
* wait for the read lock to be granted
*/
asmregparm struct rw_semaphore __sched *
rwsem_down_read_failed(struct rw_semaphore *sem)
struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
{
return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_READ,
-RWSEM_ACTIVE_READ_BIAS);
@ -232,8 +231,7 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
/*
* wait for the write lock to be granted
*/
asmregparm struct rw_semaphore __sched *
rwsem_down_write_failed(struct rw_semaphore *sem)
struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
{
return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_WRITE,
-RWSEM_ACTIVE_WRITE_BIAS);
@ -243,7 +241,7 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
* handle waking up a waiter on the semaphore
* - up_read/up_write has decremented the active part of count if we come here
*/
asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
{
unsigned long flags;
@ -263,7 +261,7 @@ asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
* - caller incremented waiting part of count and discovered it still negative
* - just wake up any readers at the front of the queue
*/
asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
{
unsigned long flags;

5
scripts/checkpatch.pl
View file

@ -2654,11 +2654,6 @@ sub process {
WARN("Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt\n" . $herecurr);
}
# SPIN_LOCK_UNLOCKED & RW_LOCK_UNLOCKED are deprecated
if ($line =~ /\b(SPIN_LOCK_UNLOCKED|RW_LOCK_UNLOCKED)/) {
ERROR("Use of $1 is deprecated: see Documentation/spinlocks.txt\n" . $herecurr);
}
# warn about #if 0
if ($line =~ /^.\s*\#\s*if\s+0\b/) {
CHK("if this code is redundant consider removing it\n" .

2
scripts/rt-tester/rt-tester.py
View file

@ -33,8 +33,6 @@ cmd_opcodes = {
"lockintnowait" : "6",
"lockcont" : "7",
"unlock" : "8",
"lockbkl" : "9",
"unlockbkl" : "10",
"signal" : "11",
"resetevent" : "98",
"reset" : "99",

5
scripts/rt-tester/t2-l1-2rt-sameprio.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal 0
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t2-l1-pi.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal 0
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t2-l1-signal.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal 0
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t2-l2-2rt-deadlock.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal 0
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l1-pi-1rt.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l1-pi-2rt.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l1-pi-3rt.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l1-pi-signal.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l1-pi-steal.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t3-l2-pi.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t4-l2-pi-deboost.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t5-l4-pi-boost-deboost-setsched.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number

5
scripts/rt-tester/t5-l4-pi-boost-deboost.tst
View file

@ -19,8 +19,6 @@
# lockintnowait lock nr (0-7)
# lockcont lock nr (0-7)
# unlock lock nr (0-7)
# lockbkl lock nr (0-7)
# unlockbkl lock nr (0-7)
# signal thread to signal (0-7)
# reset 0
# resetevent 0
@ -39,9 +37,6 @@
# blocked lock nr (0-7)
# blockedwake lock nr (0-7)
# unlocked lock nr (0-7)
# lockedbkl dont care
# blockedbkl dont care
# unlockedbkl dont care
# opcodeeq command opcode or number
# opcodelt number
# opcodegt number