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locking/mutex: Make mutex::wait_lock raw 

The wait_lock of mutex is really a low level lock. Convert it to a
raw_spinlock like the wait_lock of rtmutex.

[ mingo: backmerged the test_lockup.c build fix by bigeasy. ]

Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de
pull/78/merge
Thomas Gleixner 2021-08-15 23:28:36 +02:00 committed by Ingo Molnar
parent 4f1893ec8c
commit ebf4c55c1d
3 changed files with 14 additions and 14 deletions
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4
include/linux/mutex.h
View File

@ -50,7 +50,7 @@
*/ */
struct mutex { struct mutex {
atomic_long_t owner; atomic_long_t owner;
spinlock_t wait_lock; raw_spinlock_t wait_lock;
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
struct optimistic_spin_queue osq; /* Spinner MCS lock */ struct optimistic_spin_queue osq; /* Spinner MCS lock */
#endif #endif
@ -105,7 +105,7 @@ do { \
#define __MUTEX_INITIALIZER(lockname) \ #define __MUTEX_INITIALIZER(lockname) \
{ .owner = ATOMIC_LONG_INIT(0) \ { .owner = ATOMIC_LONG_INIT(0) \
, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ , .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
, .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
__DEBUG_MUTEX_INITIALIZER(lockname) \ __DEBUG_MUTEX_INITIALIZER(lockname) \
__DEP_MAP_MUTEX_INITIALIZER(lockname) } __DEP_MAP_MUTEX_INITIALIZER(lockname) }

22
kernel/locking/mutex.c
View File

@ -42,7 +42,7 @@ void
__mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
{ {
atomic_long_set(&lock->owner, 0); atomic_long_set(&lock->owner, 0);
spin_lock_init(&lock->wait_lock); raw_spin_lock_init(&lock->wait_lock);
INIT_LIST_HEAD(&lock->wait_list); INIT_LIST_HEAD(&lock->wait_list);
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
osq_lock_init(&lock->osq); osq_lock_init(&lock->osq);
@ -486,9 +486,9 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
* Uh oh, we raced in fastpath, check if any of the waiters need to * Uh oh, we raced in fastpath, check if any of the waiters need to
* die or wound us. * die or wound us.
*/ */
spin_lock(&lock->base.wait_lock); raw_spin_lock(&lock->base.wait_lock);
__ww_mutex_check_waiters(&lock->base, ctx); __ww_mutex_check_waiters(&lock->base, ctx);
spin_unlock(&lock->base.wait_lock); raw_spin_unlock(&lock->base.wait_lock);
} }
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
@ -966,7 +966,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
return 0; return 0;
} }
spin_lock(&lock->wait_lock); raw_spin_lock(&lock->wait_lock);
/* /*
* After waiting to acquire the wait_lock, try again. * After waiting to acquire the wait_lock, try again.
*/ */
@ -1032,7 +1032,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
goto err; goto err;
} }
spin_unlock(&lock->wait_lock); raw_spin_unlock(&lock->wait_lock);
schedule_preempt_disabled(); schedule_preempt_disabled();
first = __mutex_waiter_is_first(lock, &waiter); first = __mutex_waiter_is_first(lock, &waiter);
@ -1047,9 +1047,9 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
(first && mutex_optimistic_spin(lock, ww_ctx, &waiter))) (first && mutex_optimistic_spin(lock, ww_ctx, &waiter)))
break; break;
spin_lock(&lock->wait_lock); raw_spin_lock(&lock->wait_lock);
} }
spin_lock(&lock->wait_lock); raw_spin_lock(&lock->wait_lock);
acquired: acquired:
__set_current_state(TASK_RUNNING); __set_current_state(TASK_RUNNING);
@ -1074,7 +1074,7 @@ skip_wait:
if (ww_ctx) if (ww_ctx)
ww_mutex_lock_acquired(ww, ww_ctx); ww_mutex_lock_acquired(ww, ww_ctx);
spin_unlock(&lock->wait_lock); raw_spin_unlock(&lock->wait_lock);
preempt_enable(); preempt_enable();
return 0; return 0;
@ -1082,7 +1082,7 @@ err:
__set_current_state(TASK_RUNNING); __set_current_state(TASK_RUNNING);
__mutex_remove_waiter(lock, &waiter); __mutex_remove_waiter(lock, &waiter);
err_early_kill: err_early_kill:
spin_unlock(&lock->wait_lock); raw_spin_unlock(&lock->wait_lock);
debug_mutex_free_waiter(&waiter); debug_mutex_free_waiter(&waiter);
mutex_release(&lock->dep_map, ip); mutex_release(&lock->dep_map, ip);
preempt_enable(); preempt_enable();
@ -1243,7 +1243,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
} }
} }
spin_lock(&lock->wait_lock); raw_spin_lock(&lock->wait_lock);
debug_mutex_unlock(lock); debug_mutex_unlock(lock);
if (!list_empty(&lock->wait_list)) { if (!list_empty(&lock->wait_list)) {
/* get the first entry from the wait-list: */ /* get the first entry from the wait-list: */
@ -1260,7 +1260,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
if (owner & MUTEX_FLAG_HANDOFF) if (owner & MUTEX_FLAG_HANDOFF)
__mutex_handoff(lock, next); __mutex_handoff(lock, next);
spin_unlock(&lock->wait_lock); raw_spin_unlock(&lock->wait_lock);
wake_up_q(&wake_q); wake_up_q(&wake_q);
} }

2
lib/test_lockup.c
View File

@ -502,7 +502,7 @@ static int __init test_lockup_init(void)
offsetof(rwlock_t, magic), offsetof(rwlock_t, magic),
RWLOCK_MAGIC) || RWLOCK_MAGIC) ||
test_magic(lock_mutex_ptr, test_magic(lock_mutex_ptr,
offsetof(struct mutex, wait_lock.rlock.magic), offsetof(struct mutex, wait_lock.magic),
SPINLOCK_MAGIC) || SPINLOCK_MAGIC) ||
test_magic(lock_rwsem_ptr, test_magic(lock_rwsem_ptr,
offsetof(struct rw_semaphore, wait_lock.magic), offsetof(struct rw_semaphore, wait_lock.magic),