src/common/lib/libc/atomic/atomic_init_testset.c - diff

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Diff for /src/common/lib/libc/atomic/atomic_init_testset.c between version 1.13 and 1.14

-version 1.13, 2014/02/22 17:08:30
+version 1.14, 2014/02/24 17:18:27
 Line 53  __RCSID("$NetBSD$");
 Line 53  __RCSID("$NetBSD$");
 Line 53  __RCSID("$NetBSD$");
  #define I128    I16 I16 I16 I16 I16 I16 I16 I16
  static __cpu_simple_lock_t atomic_locks[128] = { I128 };
+ /*
+  * Pick a lock out of above array depending on the object address
+  * passed. Most variables used atomically will not be in the same
+  * cacheline - and if they are, using the same lock is fine.
+  */
+ #define HASH(PTR)       (((uintptr_t)(PTR) >> 3) & 127)
  #ifdef  __HAVE_ASM_ATOMIC_CAS_UP
  extern uint32_t _atomic_cas_up(volatile uint32_t *, uint32_t, uint32_t);
-Line 143  _atomic_cas_mp(volatile uint32_t *ptr, u
+Line 149  _atomic_cas_mp(volatile uint32_t *ptr, u
 Line 143  _atomic_cas_mp(volatile uint32_t *ptr, u
 Line 149  _atomic_cas_mp(volatile uint32_t *ptr, u
          __cpu_simple_lock_t *lock;
          uint32_t ret;
-         lock = &atomic_locks[((uintptr_t)ptr >> 3) & 127];
+         lock = &atomic_locks[HASH(ptr)];
+         __cpu_simple_lock(lock);
+         ret = *ptr;
+         if (__predict_true(ret == old)) {
+                 *ptr = new;
+         }
+         __cpu_simple_unlock(lock);
+         return ret;
+ }
+ static uint16_t
+ _atomic_cas_16_mp(volatile uint16_t *ptr, uint16_t old, uint16_t new)
+ {
+         __cpu_simple_lock_t *lock;
+         uint16_t ret;
+         lock = &atomic_locks[HASH(ptr)];
+         __cpu_simple_lock(lock);
+         ret = *ptr;
+         if (__predict_true(ret == old)) {
+                 *ptr = new;
+         }
+         __cpu_simple_unlock(lock);
+         return ret;
+ }
+ static uint8_t
+ _atomic_cas_8_mp(volatile uint8_t *ptr, uint8_t old, uint8_t new)
+ {
+         __cpu_simple_lock_t *lock;
+         uint8_t ret;
+         lock = &atomic_locks[HASH(ptr)];
          __cpu_simple_lock(lock);
          ret = *ptr;
          if (__predict_true(ret == old)) {
-Line 186  __libc_atomic_init(void)
+Line 226  __libc_atomic_init(void)
 Line 186  __libc_atomic_init(void)
 Line 226  __libc_atomic_init(void)
          size_t len;
          _atomic_cas_fn = _atomic_cas_mp;
+         _atomic_cas_16_fn = _atomic_cas_16_mp;
+         _atomic_cas_8_fn = _atomic_cas_8_mp;
          mib[0] = CTL_HW;
          mib[1] = HW_NCPU;

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