From 8282947f67345246b4a6344dbceb07484d3d4dad Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 15 Aug 2021 23:28:28 +0200 Subject: locking/rwlock: Provide RT variant Similar to rw_semaphores, on RT the rwlock substitution is not writer fair, because it's not feasible to have a writer inherit its priority to multiple readers. Readers blocked on a writer follow the normal rules of priority inheritance. Like RT spinlocks, RT rwlocks are state preserving across the slow lock operations (contended case). Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210815211303.882793524@linutronix.de --- kernel/locking/spinlock_debug.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/locking/spinlock_debug.c') diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index b9d93087ee66..14235671a1a7 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, EXPORT_SYMBOL(__raw_spin_lock_init); +#ifndef CONFIG_PREEMPT_RT void __rwlock_init(rwlock_t *lock, const char *name, struct lock_class_key *key) { @@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name, } EXPORT_SYMBOL(__rwlock_init); +#endif static void spin_dump(raw_spinlock_t *lock, const char *msg) { @@ -139,6 +141,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock) arch_spin_unlock(&lock->raw_lock); } +#ifndef CONFIG_PREEMPT_RT static void rwlock_bug(rwlock_t *lock, const char *msg) { if (!debug_locks_off()) @@ -228,3 +231,5 @@ void do_raw_write_unlock(rwlock_t *lock) debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock); } + +#endif /* !CONFIG_PREEMPT_RT */ -- cgit v1.2.3