Clean up BUSY_WAIT_NOP and atomic_delay.

This patch combines BUSY_WAIT_NOP and atomic_delay into a new
atomic_spin_nop function and adjusts all clients.  The new function is
put into atomic.h because what is best done in a spin loop is
architecture-specific, and atomics must be used for spinning.  The
function name is meant to tell users that this has no effect on
synchronization semantics but is a performance aid for spinning.

1 files changed, 2 insertions, 4 deletions

diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index 96075129b8..9a3b46624d 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -23,6 +23,7 @@
 #include <sys/param.h>
 #include <not-cancel.h>
 #include "pthreadP.h"
+#include <atomic.h>
 #include <lowlevellock.h>
 #include <stap-probe.h>
 
@@ -135,10 +136,7 @@ __pthread_mutex_lock (mutex)
 		  LLL_MUTEX_LOCK (mutex);
 		  break;
 		}
-
-#ifdef BUSY_WAIT_NOP
-	      BUSY_WAIT_NOP;
-#endif
+	      atomic_spin_nop ();
 	    }
 	  while (LLL_MUTEX_TRYLOCK (mutex) != 0);