diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-08-15 23:28:28 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-08-17 17:50:51 +0200 |
| commit | 8282947f67345246b4a6344dbceb07484d3d4dad (patch) | |
| tree | aeb316bc3ec77d94c819bb6bea21e45c7296fcd9 /kernel/locking/spinlock.c | |
| parent | 0f383b6dc96e976dfbf2721b0bf10bd96103b341 (diff) | |
| download | linux-8282947f67345246b4a6344dbceb07484d3d4dad.tar.bz2 | |
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 <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/20210815211303.882793524@linutronix.de
Diffstat (limited to 'kernel/locking/spinlock.c')
| -rw-r--r-- | kernel/locking/spinlock.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index c8d7ad9fb9b2..c5830cfa379a 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \ * __[spin|read|write]_lock_bh() */ BUILD_LOCK_OPS(spin, raw_spinlock); + +#ifndef CONFIG_PREEMPT_RT BUILD_LOCK_OPS(read, rwlock); BUILD_LOCK_OPS(write, rwlock); +#endif #endif @@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock) EXPORT_SYMBOL(_raw_spin_unlock_bh); #endif +#ifndef CONFIG_PREEMPT_RT + #ifndef CONFIG_INLINE_READ_TRYLOCK int __lockfunc _raw_read_trylock(rwlock_t *lock) { @@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock) EXPORT_SYMBOL(_raw_write_unlock_bh); #endif +#endif /* !CONFIG_PREEMPT_RT */ + #ifdef CONFIG_DEBUG_LOCK_ALLOC void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass) |