1 files changed, 5 insertions, 10 deletions
diff --git a/includes/rts/SpinLock.h b/includes/rts/SpinLock.h
index 0ac51455dd..c1fe6c866c 100644
--- a/includes/rts/SpinLock.h
+++ b/includes/rts/SpinLock.h
@@ -39,19 +39,14 @@ typedef struct SpinLock_
 #define IF_PROF_SPIN(x)
 #endif
 
+void acquire_spin_lock_slow_path(SpinLock * p);
+
 // acquire spin lock
 INLINE_HEADER void ACQUIRE_SPIN_LOCK(SpinLock * p)
 {
-    do {
-        for (uint32_t i = 0; i < SPIN_COUNT; i++) {
-            StgWord32 r = cas((StgVolatilePtr)&(p->lock), 1, 0);
-            if (r != 0) return;
-            IF_PROF_SPIN(__atomic_fetch_add(&p->spin, 1, __ATOMIC_RELAXED));
-            busy_wait_nop();
-        }
-        IF_PROF_SPIN(__atomic_fetch_add(&p->yield, 1, __ATOMIC_RELAXED));
-        yieldThread();
-    } while (1);
+    StgWord32 r = cas((StgVolatilePtr)&(p->lock), 1, 0);
+    if (RTS_UNLIKELY(r == 0))
+        acquire_spin_lock_slow_path(p);
 }
 
 // release spin lock