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Commit 830e6acc authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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locking/rtmutex: Split out the inner parts of 'struct rtmutex' 

RT builds substitutions for rwsem, mutex, spinlock and rwlock around
rtmutexes. Split the inner working out so each lock substitution can use
them with the appropriate lockdep annotations. This avoids having an extra
unused lockdep map in the wrapped rtmutex.

No functional change.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.784739994@linutronix.de
parent 531ae4b0
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Inline Side-by-side
Showing with 97 additions and 79 deletions
include/linux/rtmutex.h
View file @ 830e6acc
......@@ -19,6 +19,21 @@
extern int max_lock_depth; /* for sysctl */
struct rt_mutex_base {
raw_spinlock_t wait_lock;
struct rb_root_cached waiters;
struct task_struct *owner;
};
#define __RT_MUTEX_BASE_INITIALIZER(rtbasename) \
{ \
.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock), \
.waiters = RB_ROOT_CACHED, \
.owner = NULL \
}
extern void rt_mutex_base_init(struct rt_mutex_base *rtb);
/**
* The rt_mutex structure
*
......@@ -28,9 +43,7 @@ extern int max_lock_depth; /* for sysctl */
* @owner: the mutex owner
*/
struct rt_mutex {
raw_spinlock_t wait_lock;
struct rb_root_cached waiters;
struct task_struct *owner;
struct rt_mutex_base rtmutex;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
......@@ -63,9 +76,7 @@ do { \
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ \
.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock), \
.waiters = RB_ROOT_CACHED, \
.owner = NULL, \
.rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex), \
__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
}
......
kernel/futex.c
View file @ 830e6acc
......@@ -179,7 +179,7 @@ struct futex_pi_state {
/*
* The PI object:
*/
struct rt_mutex pi_mutex;
struct rt_mutex_base pi_mutex;
struct task_struct *owner;
refcount_t refcount;
......@@ -3254,7 +3254,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
ret = ret < 0 ? ret : 0;
}
} else {
struct rt_mutex *pi_mutex;
struct rt_mutex_base *pi_mutex;
/*
* We have been woken up by futex_unlock_pi(), a timeout, or a
......
kernel/locking/rtmutex.c
View file @ 830e6acc
This diff is collapsed.
kernel/locking/rtmutex_api.c
View file @ 830e6acc
......@@ -26,12 +26,18 @@ static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock,
might_sleep();
mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
ret = __rt_mutex_lock(lock, state);
ret = __rt_mutex_lock(&lock->rtmutex, state);
if (ret)
mutex_release(&lock->dep_map, _RET_IP_);
return ret;
}
void rt_mutex_base_init(struct rt_mutex_base *rtb)
{
__rt_mutex_base_init(rtb);
}
EXPORT_SYMBOL(rt_mutex_base_init);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
/**
* rt_mutex_lock_nested - lock a rt_mutex
......@@ -93,7 +99,7 @@ int __sched rt_mutex_trylock(struct rt_mutex *lock)
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
return 0;
ret = __rt_mutex_trylock(lock);
ret = __rt_mutex_trylock(&lock->rtmutex);
if (ret)
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
......@@ -109,19 +115,19 @@ EXPORT_SYMBOL_GPL(rt_mutex_trylock);
void __sched rt_mutex_unlock(struct rt_mutex *lock)
{
mutex_release(&lock->dep_map, _RET_IP_);
__rt_mutex_unlock(lock);
__rt_mutex_unlock(&lock->rtmutex);
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
/*
* Futex variants, must not use fastpath.
*/
int __sched rt_mutex_futex_trylock(struct rt_mutex *lock)
int __sched rt_mutex_futex_trylock(struct rt_mutex_base *lock)
{
return rt_mutex_slowtrylock(lock);
}
int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
int __sched __rt_mutex_futex_trylock(struct rt_mutex_base *lock)
{
return __rt_mutex_slowtrylock(lock);
}
......@@ -133,7 +139,7 @@ int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
* @lock: The rt_mutex to be unlocked
* @wake_q: The wake queue head from which to get the next lock waiter
*/
bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
struct wake_q_head *wake_q)
{
lockdep_assert_held(&lock->wait_lock);
......@@ -156,7 +162,7 @@ bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
return true; /* call postunlock() */
}
void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
void __sched rt_mutex_futex_unlock(struct rt_mutex_base *lock)
{
DEFINE_WAKE_Q(wake_q);
unsigned long flags;
......@@ -182,12 +188,11 @@ void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
* Initializing of a locked rt_mutex is not allowed
*/
void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name,
struct lock_class_key *key)
struct lock_class_key *key)
{
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
__rt_mutex_base_init(&lock->rtmutex);
lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
__rt_mutex_basic_init(lock);
}
EXPORT_SYMBOL_GPL(__rt_mutex_init);
......@@ -205,10 +210,10 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init);
* possible at this point because the pi_state which contains the rtmutex
* is not yet visible to other tasks.
*/
void __sched rt_mutex_init_proxy_locked(struct rt_mutex *lock,
void __sched rt_mutex_init_proxy_locked(struct rt_mutex_base *lock,
struct task_struct *proxy_owner)
{
__rt_mutex_basic_init(lock);
__rt_mutex_base_init(lock);
rt_mutex_set_owner(lock, proxy_owner);
}
......@@ -224,7 +229,7 @@ void __sched rt_mutex_init_proxy_locked(struct rt_mutex *lock,
* possible because it belongs to the pi_state which is about to be freed
* and it is not longer visible to other tasks.
*/
void __sched rt_mutex_proxy_unlock(struct rt_mutex *lock)
void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock)
{
debug_rt_mutex_proxy_unlock(lock);
rt_mutex_set_owner(lock, NULL);
......@@ -249,7 +254,7 @@ void __sched rt_mutex_proxy_unlock(struct rt_mutex *lock)
*
* Special API call for PI-futex support.
*/
int __sched __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
{
......@@ -296,7 +301,7 @@ int __sched __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
*
* Special API call for PI-futex support.
*/
int __sched rt_mutex_start_proxy_lock(struct rt_mutex *lock,
int __sched rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task)
{
......@@ -328,7 +333,7 @@ int __sched rt_mutex_start_proxy_lock(struct rt_mutex *lock,
*
* Special API call for PI-futex support
*/
int __sched rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
int __sched rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock,
struct hrtimer_sleeper *to,
struct rt_mutex_waiter *waiter)
{
......@@ -368,7 +373,7 @@ int __sched rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
*
* Special API call for PI-futex support
*/
bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter)
{
bool cleanup = false;
......@@ -413,7 +418,7 @@ bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
void __sched rt_mutex_adjust_pi(struct task_struct *task)
{
struct rt_mutex_waiter *waiter;
struct rt_mutex *next_lock;
struct rt_mutex_base *next_lock;
unsigned long flags;
raw_spin_lock_irqsave(&task->pi_lock, flags);
......
kernel/locking/rtmutex_common.h
View file @ 830e6acc
......@@ -32,7 +32,7 @@ struct rt_mutex_waiter {
struct rb_node tree_entry;
struct rb_node pi_tree_entry;
struct task_struct *task;
struct rt_mutex *lock;
struct rt_mutex_base *lock;
int prio;
u64 deadline;
};
......@@ -40,26 +40,26 @@ struct rt_mutex_waiter {
/*
* PI-futex support (proxy locking functions, etc.):
*/
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
extern void rt_mutex_init_proxy_locked(struct rt_mutex_base *lock,
struct task_struct *proxy_owner);
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock);
extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
extern void rt_mutex_proxy_unlock(struct rt_mutex_base *lock);
extern int __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task);
extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
extern int rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task);
extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock,
extern int rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock,
struct hrtimer_sleeper *to,
struct rt_mutex_waiter *waiter);
extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock,
extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock,
struct rt_mutex_waiter *waiter);
extern int rt_mutex_futex_trylock(struct rt_mutex *l);
extern int __rt_mutex_futex_trylock(struct rt_mutex *l);
extern int rt_mutex_futex_trylock(struct rt_mutex_base *l);
extern int __rt_mutex_futex_trylock(struct rt_mutex_base *l);
extern void rt_mutex_futex_unlock(struct rt_mutex *lock);
extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
extern void rt_mutex_futex_unlock(struct rt_mutex_base *lock);
extern bool __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
struct wake_q_head *wake_q);
extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
......@@ -69,12 +69,12 @@ extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
* unconditionally.
*/
#ifdef CONFIG_RT_MUTEXES
static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
static inline int rt_mutex_has_waiters(struct rt_mutex_base *lock)
{
return !RB_EMPTY_ROOT(&lock->waiters.rb_root);
}
static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex *lock)
static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex_base *lock)
{
struct rb_node *leftmost = rb_first_cached(&lock->waiters);
struct rt_mutex_waiter *w = NULL;
......@@ -99,7 +99,7 @@ static inline struct rt_mutex_waiter *task_top_pi_waiter(struct task_struct *p)
#define RT_MUTEX_HAS_WAITERS 1UL
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
{
unsigned long owner = (unsigned long) READ_ONCE(lock->owner);
......@@ -121,21 +121,21 @@ enum rtmutex_chainwalk {
RT_MUTEX_FULL_CHAINWALK,
};
static inline void __rt_mutex_basic_init(struct rt_mutex *lock)
static inline void __rt_mutex_base_init(struct rt_mutex_base *lock)
{
lock->owner = NULL;
raw_spin_lock_init(&lock->wait_lock);
lock->waiters = RB_ROOT_CACHED;
lock->owner = NULL;
}
/* Debug functions */
static inline void debug_rt_mutex_unlock(struct rt_mutex *lock)
static inline void debug_rt_mutex_unlock(struct rt_mutex_base *lock)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
}
static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex_base *lock)
{
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES))
DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
......@@ -163,7 +163,7 @@ static inline void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
#else /* CONFIG_RT_MUTEXES */
/* Used in rcu/tree_plugin.h */
static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
{
return NULL;
}
......
kernel/rcu/tree_plugin.h
View file @ 830e6acc
......@@ -559,7 +559,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
WRITE_ONCE(rnp->exp_tasks, np);
if (IS_ENABLED(CONFIG_RCU_BOOST)) {
/* Snapshot ->boost_mtx ownership w/rnp->lock held. */
drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t;
drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t;
if (&t->rcu_node_entry == rnp->boost_tasks)
WRITE_ONCE(rnp->boost_tasks, np);
}
......@@ -586,7 +586,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
/* Unboost if we were boosted. */
if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
rt_mutex_futex_unlock(&rnp->boost_mtx);
rt_mutex_futex_unlock(&rnp->boost_mtx.rtmutex);
/*
* If this was the last task on the expedited lists,
......@@ -1083,7 +1083,7 @@ static int rcu_boost(struct rcu_node *rnp)
* section.
*/
t = container_of(tb, struct task_struct, rcu_node_entry);
rt_mutex_init_proxy_locked(&rnp->boost_mtx, t);
rt_mutex_init_proxy_locked(&rnp->boost_mtx.rtmutex, t);
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/* Lock only for side effect: boosts task t's priority. */
rt_mutex_lock(&rnp->boost_mtx);
......
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