diff options
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 11 | ||||
| -rw-r--r-- | kernel/locking/rwsem.c | 30 |
2 files changed, 26 insertions, 15 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 81e87280513e..64a13eb56078 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5238,9 +5238,10 @@ __lock_set_class(struct lockdep_map *lock, const char *name, return 0; } - lockdep_init_map_waits(lock, name, key, 0, - lock->wait_type_inner, - lock->wait_type_outer); + lockdep_init_map_type(lock, name, key, 0, + lock->wait_type_inner, + lock->wait_type_outer, + lock->lock_type); class = register_lock_class(lock, subclass, 0); hlock->class_idx = class - lock_classes; @@ -5432,7 +5433,7 @@ static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock) * be guessable and still allows some pin nesting in * our u32 pin_count. */ - cookie.val = 1 + (prandom_u32() >> 16); + cookie.val = 1 + (sched_clock() & 0xffff); hlock->pin_count += cookie.val; return cookie; } @@ -6570,7 +6571,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) /* * If a CPU is in the RCU-free window in idle (ie: in the section - * between rcu_idle_enter() and rcu_idle_exit(), then RCU + * between ct_idle_enter() and ct_idle_exit(), then RCU * considers that CPU to be in an "extended quiescent state", * which means that RCU will be completely ignoring that CPU. * Therefore, rcu_read_lock() and friends have absolutely no diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 9d1db4a54d34..65f0262f635e 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -335,8 +335,6 @@ struct rwsem_waiter { struct task_struct *task; enum rwsem_waiter_type type; unsigned long timeout; - - /* Writer only, not initialized in reader */ bool handoff_set; }; #define rwsem_first_waiter(sem) \ @@ -459,10 +457,12 @@ static void rwsem_mark_wake(struct rw_semaphore *sem, * to give up the lock), request a HANDOFF to * force the issue. */ - if (!(oldcount & RWSEM_FLAG_HANDOFF) && - time_after(jiffies, waiter->timeout)) { - adjustment -= RWSEM_FLAG_HANDOFF; - lockevent_inc(rwsem_rlock_handoff); + if (time_after(jiffies, waiter->timeout)) { + if (!(oldcount & RWSEM_FLAG_HANDOFF)) { + adjustment -= RWSEM_FLAG_HANDOFF; + lockevent_inc(rwsem_rlock_handoff); + } + waiter->handoff_set = true; } atomic_long_add(-adjustment, &sem->count); @@ -599,7 +599,7 @@ rwsem_del_wake_waiter(struct rw_semaphore *sem, struct rwsem_waiter *waiter, static inline bool rwsem_try_write_lock(struct rw_semaphore *sem, struct rwsem_waiter *waiter) { - bool first = rwsem_first_waiter(sem) == waiter; + struct rwsem_waiter *first = rwsem_first_waiter(sem); long count, new; lockdep_assert_held(&sem->wait_lock); @@ -609,11 +609,20 @@ static inline bool rwsem_try_write_lock(struct rw_semaphore *sem, bool has_handoff = !!(count & RWSEM_FLAG_HANDOFF); if (has_handoff) { - if (!first) + /* + * Honor handoff bit and yield only when the first + * waiter is the one that set it. Otherwisee, we + * still try to acquire the rwsem. + */ + if (first->handoff_set && (waiter != first)) return false; - /* First waiter inherits a previously set handoff bit */ - waiter->handoff_set = true; + /* + * First waiter can inherit a previously set handoff + * bit and spin on rwsem if lock acquisition fails. + */ + if (waiter == first) + waiter->handoff_set = true; } new = count; @@ -1027,6 +1036,7 @@ queue: waiter.task = current; waiter.type = RWSEM_WAITING_FOR_READ; waiter.timeout = jiffies + RWSEM_WAIT_TIMEOUT; + waiter.handoff_set = false; raw_spin_lock_irq(&sem->wait_lock); if (list_empty(&sem->wait_list)) { |