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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-08-15 23:28:22 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-08-17 17:41:24 +0200 |
| commit | 051790eecc03aff6978763791d38c1daea94c2f8 (patch) | |
| tree | 4448509f285c4fd2589dc9f5b5d9b160a191490f | |
| parent | e4e17af3b7f8841279b5a429de14907e26845c39 (diff) | |
| download | lwn-051790eecc03aff6978763791d38c1daea94c2f8.tar.gz lwn-051790eecc03aff6978763791d38c1daea94c2f8.zip | |
locking/spinlock: Provide RT specific spinlock_t
RT replaces spinlocks with a simple wrapper around an rtmutex, which turns
spinlocks on RT into 'sleeping' spinlocks. The actual implementation of the
spinlock API differs from a regular rtmutex, as it does neither handle
timeouts nor signals and it is state preserving across the lock operation.
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/20210815211303.654230709@linutronix.de
| -rw-r--r-- | include/linux/spinlock_types.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h index 42be1116e051..8a9aadbaf293 100644 --- a/include/linux/spinlock_types.h +++ b/include/linux/spinlock_types.h @@ -11,6 +11,9 @@ #include <linux/spinlock_types_raw.h> +#ifndef CONFIG_PREEMPT_RT + +/* Non PREEMPT_RT kernels map spinlock to raw_spinlock */ typedef struct spinlock { union { struct raw_spinlock rlock; @@ -39,6 +42,29 @@ typedef struct spinlock { #define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x) +#else /* !CONFIG_PREEMPT_RT */ + +/* PREEMPT_RT kernels map spinlock to rt_mutex */ +#include <linux/rtmutex.h> + +typedef struct spinlock { + struct rt_mutex_base lock; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} spinlock_t; + +#define __SPIN_LOCK_UNLOCKED(name) \ + { \ + .lock = __RT_MUTEX_BASE_INITIALIZER(name.lock), \ + SPIN_DEP_MAP_INIT(name) \ + } + +#define DEFINE_SPINLOCK(name) \ + spinlock_t name = __SPIN_LOCK_UNLOCKED(name) + +#endif /* CONFIG_PREEMPT_RT */ + #include <linux/rwlock_types.h> #endif /* __LINUX_SPINLOCK_TYPES_H */ |