diff --git a/src/include/storage/s_lock.h b/src/include/storage/s_lock.h index 8a5a905e38..af1145d98f 100644 --- a/src/include/storage/s_lock.h +++ b/src/include/storage/s_lock.h @@ -337,6 +337,23 @@ tas(volatile slock_t *lock) #define S_UNLOCK(lock) __sync_lock_release(lock) +/* + * Using an ISB instruction to delay in spinlock loops appears beneficial on + * high-core-count ARM64 processors. It seems mostly a wash for smaller gear, + * and ISB doesn't exist at all on pre-v7 ARM chips. + */ +#if defined(__aarch64__) || defined(__aarch64) + +#define SPIN_DELAY() spin_delay() + +static __inline__ void +spin_delay(void) +{ + __asm__ __volatile__( + " isb; \n"); +} + +#endif /* __aarch64__ || __aarch64 */ #endif /* HAVE_GCC__SYNC_INT32_TAS */ #endif /* __arm__ || __arm || __aarch64__ || __aarch64 */