commit b023e4ca99f5e81f90d87d23cd267ef2abd2388c
Author: Andi Kleen <ak@linux.intel.com>
Date:   Sat Dec 22 00:58:34 2012 -0800

    Add new internal mutex type flags for elision.
    
    Add Enable/disable flags used internally
    
    Extend the mutex initializers to have the fields needed for
    elision. The layout stays the same, and this is not visible
    to programs.
    
    These changes are not exposed outside pthread
Index: glibc-2.17-c758a686/nptl/pthreadP.h
===================================================================
--- glibc-2.17-c758a686.orig/nptl/pthreadP.h
+++ glibc-2.17-c758a686/nptl/pthreadP.h
@@ -61,6 +61,10 @@
 enum
 {
   PTHREAD_MUTEX_KIND_MASK_NP = 3,
+
+  PTHREAD_MUTEX_ELISION_NP    = 256,
+  PTHREAD_MUTEX_NO_ELISION_NP = 512,
+
   PTHREAD_MUTEX_ROBUST_NORMAL_NP = 16,
   PTHREAD_MUTEX_ROBUST_RECURSIVE_NP
   = PTHREAD_MUTEX_ROBUST_NORMAL_NP | PTHREAD_MUTEX_RECURSIVE_NP,
@@ -93,12 +97,21 @@ enum
   PTHREAD_MUTEX_PP_ERRORCHECK_NP
   = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ERRORCHECK_NP,
   PTHREAD_MUTEX_PP_ADAPTIVE_NP
-  = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ADAPTIVE_NP
+  = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ADAPTIVE_NP,
+  PTHREAD_MUTEX_ELISION_FLAGS_NP
+  = PTHREAD_MUTEX_ELISION_NP | PTHREAD_MUTEX_NO_ELISION_NP,
+
+  PTHREAD_MUTEX_TIMED_ELISION_NP =
+	  PTHREAD_MUTEX_TIMED_NP | PTHREAD_MUTEX_ELISION_NP,
+  PTHREAD_MUTEX_TIMED_NO_ELISION_NP =
+	  PTHREAD_MUTEX_TIMED_NP | PTHREAD_MUTEX_NO_ELISION_NP,
 };
 #define PTHREAD_MUTEX_PSHARED_BIT 128
 
 #define PTHREAD_MUTEX_TYPE(m) \
   ((m)->__data.__kind & 127)
+#define PTHREAD_MUTEX_TYPE_ELISION(m) \
+  ((m)->__data.__kind & (127|PTHREAD_MUTEX_ELISION_FLAGS_NP))
 
 #if LLL_PRIVATE == 0 && LLL_SHARED == 128
 # define PTHREAD_MUTEX_PSHARED(m) \
Index: glibc-2.17-c758a686/nptl/sysdeps/pthread/pthread.h
===================================================================
--- glibc-2.17-c758a686.orig/nptl/sysdeps/pthread/pthread.h
+++ glibc-2.17-c758a686/nptl/sysdeps/pthread/pthread.h
@@ -83,27 +83,39 @@ enum
 
 
 /* Mutex initializers.  */
+#if __PTHREAD_MUTEX_HAVE_ELISION == 1 /* 64bit layout.  */
+#define __PTHREAD_SPINS 0, 0
+#elif __PTHREAD_MUTEX_HAVE_ELISION == 2 /* 32bit layout.  */
+#define __PTHREAD_SPINS { 0, 0 }
+#else
+#define __PTHREAD_SPINS 0
+#endif
+
 #ifdef __PTHREAD_MUTEX_HAVE_PREV
 # define PTHREAD_MUTEX_INITIALIZER \
-  { { 0, 0, 0, 0, 0, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, 0, __PTHREAD_SPINS, { 0, 0 } } }
 # ifdef __USE_GNU
 #  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
 #  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, __PTHREAD_SPINS, { 0, 0 } } }
 #  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
+#  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
+
 # endif
 #else
 # define PTHREAD_MUTEX_INITIALIZER \
-  { { 0, 0, 0, 0, 0, { 0 } } }
+  { { 0, 0, 0, 0, 0, { __PTHREAD_SPINS } } }
 # ifdef __USE_GNU
 #  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { __PTHREAD_SPINS } } }
 #  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { __PTHREAD_SPINS } } }
 #  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { __PTHREAD_SPINS } } }
+
 # endif
 #endif