New pthread rwlock that is more scalable.

This replaces the pthread rwlock with a new implementation that uses a
more scalable algorithm (primarily through not using a critical section
anymore to make state changes).  The fast path for rdlock acquisition and
release is now basically a single atomic read-modify write or CAS and a few
branches.  See nptl/pthread_rwlock_common.c for details.

	* nptl/DESIGN-rwlock.txt: Remove.
	* nptl/lowlevelrwlock.sym: Remove.
	* nptl/Makefile: Add new tests.
	* nptl/pthread_rwlock_common.c: New file.  Contains the new rwlock.
	* nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove.
	(PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED,
	PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT,
	PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER,
	PTHREAD_RWLOCK_FUTEX_USED): New.
	* nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new
	implementation.
	* nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove.
	(__pthread_rwlock_rdlock): Adapt.
	* nptl/pthread_rwlock_timedrdlock.c
	(pthread_rwlock_timedrdlock): Adapt.
	* nptl/pthread_rwlock_timedwrlock.c
	(pthread_rwlock_timedwrlock): Adapt.
	* nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt.
	* nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt.
	* nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt.
	* nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove.
	(__pthread_rwlock_wrlock): Adapt.
	* nptl/tst-rwlock10.c: Adapt.
	* nptl/tst-rwlock11.c: Adapt.
	* nptl/tst-rwlock17.c: New file.
	* nptl/tst-rwlock18.c: New file.
	* nptl/tst-rwlock19.c: New file.
	* nptl/tst-rwlock2b.c: New file.
	* nptl/tst-rwlock8.c: Adapt.
	* nptl/tst-rwlock9.c: Adapt.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* nptl/nptl-printers.py (): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-rwlock-printers.py: Adapt.
	* nptl/test-rwlockattr-printers.c: Adapt.
	* nptl/test-rwlockattr-printers.py: Adapt.

15 files changed, 147 insertions, 147 deletions

diff --git a/sysdeps/aarch64/nptl/bits/pthreadtypes.h b/sysdeps/aarch64/nptl/bits/pthreadtypes.h
index 76001d81c4..97d9407d00 100644
--- a/sysdeps/aarch64/nptl/bits/pthreadtypes.h
+++ b/sysdeps/aarch64/nptl/bits/pthreadtypes.h
@@ -154,13 +154,13 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
diff --git a/sysdeps/arm/nptl/bits/pthreadtypes.h b/sysdeps/arm/nptl/bits/pthreadtypes.h
index 4bb08aaa35..dae7bc4f06 100644
--- a/sysdeps/arm/nptl/bits/pthreadtypes.h
+++ b/sysdeps/arm/nptl/bits/pthreadtypes.h
@@ -141,12 +141,12 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
 #if __BYTE_ORDER == __BIG_ENDIAN
     unsigned char __pad1;
     unsigned char __pad2;
@@ -162,7 +162,7 @@ typedef union
     unsigned char __pad1;
     unsigned char __pad2;
 #endif
-    int __writer;
+    int __cur_writer;
   } __data;
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
   long int __align;
diff --git a/sysdeps/hppa/nptl/bits/pthreadtypes.h b/sysdeps/hppa/nptl/bits/pthreadtypes.h
index dd1f6e76db..e37111a2f3 100644
--- a/sysdeps/hppa/nptl/bits/pthreadtypes.h
+++ b/sysdeps/hppa/nptl/bits/pthreadtypes.h
@@ -168,13 +168,13 @@ typedef union
        next four words are all set to 1 by the Linuxthreads
        PTHREAD_RWLOCK_INITIALIZER. We ignore them in NPTL.  */
     int __compat_padding[4] __attribute__ ((__aligned__(16)));
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     /* An unused word, reserved for future use. It was added
        to maintain the location of the flags from the Linuxthreads
        layout of this structure.  */
diff --git a/sysdeps/ia64/nptl/bits/pthreadtypes.h b/sysdeps/ia64/nptl/bits/pthreadtypes.h
index 287de1ede7..c67ee862e2 100644
--- a/sysdeps/ia64/nptl/bits/pthreadtypes.h
+++ b/sysdeps/ia64/nptl/bits/pthreadtypes.h
@@ -138,13 +138,13 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
diff --git a/sysdeps/m68k/nptl/bits/pthreadtypes.h b/sysdeps/m68k/nptl/bits/pthreadtypes.h
index bd89e20398..9a16bbfaf1 100644
--- a/sysdeps/m68k/nptl/bits/pthreadtypes.h
+++ b/sysdeps/m68k/nptl/bits/pthreadtypes.h
@@ -142,19 +142,19 @@ typedef union
 {
   struct
   {
-    int __lock __attribute__ ((__aligned__ (4)));
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers  __attribute__ ((__aligned__ (4)));
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     unsigned char __pad1;
     unsigned char __pad2;
     unsigned char __shared;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
-    int __writer;
+    int __cur_writer;
   } __data;
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
   long int __align;
diff --git a/sysdeps/microblaze/nptl/bits/pthreadtypes.h b/sysdeps/microblaze/nptl/bits/pthreadtypes.h
index 7535ce865e..7c5db6b5c7 100644
--- a/sysdeps/microblaze/nptl/bits/pthreadtypes.h
+++ b/sysdeps/microblaze/nptl/bits/pthreadtypes.h
@@ -136,12 +136,12 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
 #  if __BYTE_ORDER == __BIG_ENDIAN
     unsigned char __pad1;
     unsigned char __pad2;
@@ -157,7 +157,7 @@ typedef union
     unsigned char __pad1;
     unsigned char __pad2;
 #  endif
-    int __writer;
+    int __cur_writer;
   } __data;
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
   long int __align;
diff --git a/sysdeps/mips/nptl/bits/pthreadtypes.h b/sysdeps/mips/nptl/bits/pthreadtypes.h
index cca72abc29..b1ebf4ec95 100644
--- a/sysdeps/mips/nptl/bits/pthreadtypes.h
+++ b/sysdeps/mips/nptl/bits/pthreadtypes.h
@@ -171,13 +171,13 @@ typedef union
 # if _MIPS_SIM == _ABI64
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
@@ -188,12 +188,12 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
 #if __BYTE_ORDER == __BIG_ENDIAN
     unsigned char __pad1;
     unsigned char __pad2;
@@ -209,7 +209,7 @@ typedef union
     unsigned char __pad1;
     unsigned char __pad2;
 #endif
-    int __writer;
+    int __cur_writer;
   } __data;
 # endif
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
diff --git a/sysdeps/nios2/nptl/bits/pthreadtypes.h b/sysdeps/nios2/nptl/bits/pthreadtypes.h
index 795d26c226..8247013b9e 100644
--- a/sysdeps/nios2/nptl/bits/pthreadtypes.h
+++ b/sysdeps/nios2/nptl/bits/pthreadtypes.h
@@ -141,12 +141,12 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
 #if __BYTE_ORDER == __BIG_ENDIAN
     unsigned char __pad1;
     unsigned char __pad2;
@@ -162,7 +162,7 @@ typedef union
     unsigned char __pad1;
     unsigned char __pad2;
 #endif
-    int __writer;
+    int __cur_writer;
   } __data;
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
   long int __align;
diff --git a/sysdeps/s390/nptl/bits/pthreadtypes.h b/sysdeps/s390/nptl/bits/pthreadtypes.h
index ad0a6d8010..48ffdb447b 100644
--- a/sysdeps/s390/nptl/bits/pthreadtypes.h
+++ b/sysdeps/s390/nptl/bits/pthreadtypes.h
@@ -191,13 +191,13 @@ typedef union
 # if __WORDSIZE == 64
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
@@ -208,19 +208,19 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     unsigned char __pad1;
     unsigned char __pad2;
     unsigned char __shared;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
-    int __writer;
+    int __cur_writer;
   } __data;
 # endif
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
diff --git a/sysdeps/sh/nptl/bits/pthreadtypes.h b/sysdeps/sh/nptl/bits/pthreadtypes.h
index d2e6d832bb..eec58118bd 100644
--- a/sysdeps/sh/nptl/bits/pthreadtypes.h
+++ b/sysdeps/sh/nptl/bits/pthreadtypes.h
@@ -141,12 +141,12 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
 #if __BYTE_ORDER == __BIG_ENDIAN
     unsigned char __pad1;
     unsigned char __pad2;
@@ -162,7 +162,7 @@ typedef union
     unsigned char __pad1;
     unsigned char __pad2;
 #endif
-    pthread_t __writer;
+    pthread_t __cur_writer;
   } __data;
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
   long int __align;
diff --git a/sysdeps/sparc/nptl/bits/pthreadtypes.h b/sysdeps/sparc/nptl/bits/pthreadtypes.h
index 5685d950e5..525988c742 100644
--- a/sysdeps/sparc/nptl/bits/pthreadtypes.h
+++ b/sysdeps/sparc/nptl/bits/pthreadtypes.h
@@ -171,13 +171,13 @@ typedef union
 # if __WORDSIZE == 64
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
@@ -188,19 +188,19 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     unsigned char __pad1;
     unsigned char __pad2;
     unsigned char __shared;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
-    int __writer;
+    int __cur_writer;
   } __data;
 # endif
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
diff --git a/sysdeps/tile/nptl/bits/pthreadtypes.h b/sysdeps/tile/nptl/bits/pthreadtypes.h
index bba4aec8a4..1632d82cf3 100644
--- a/sysdeps/tile/nptl/bits/pthreadtypes.h
+++ b/sysdeps/tile/nptl/bits/pthreadtypes.h
@@ -171,13 +171,13 @@ typedef union
 # if __WORDSIZE == 64
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
@@ -188,19 +188,19 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
     unsigned char __shared;
     unsigned char __pad1;
     unsigned char __pad2;
-    int __writer;
+    int __cur_writer;
   } __data;
 # endif
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];
diff --git a/sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h b/sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
index 8023bd012c..1beaf109a8 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
@@ -137,13 +137,13 @@ typedef union
 {
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned long int __pad1;
     unsigned long int __pad2;
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h b/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
index 251cec6de5..e5cda79ad2 100644
--- a/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
@@ -177,13 +177,13 @@ typedef union
 # if __WORDSIZE == 64
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     unsigned char __rwelision;
     unsigned char __pad1[7];
@@ -196,19 +196,19 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     unsigned char __rwelision;
     unsigned char __pad2;
     unsigned char __shared;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
-    int __writer;
+    int __cur_writer;
 #define __PTHREAD_RWLOCK_ELISION_EXTRA 0
   } __data;
 # endif
diff --git a/sysdeps/x86/bits/pthreadtypes.h b/sysdeps/x86/bits/pthreadtypes.h
index bc7f68bfdf..c3055cac7f 100644
--- a/sysdeps/x86/bits/pthreadtypes.h
+++ b/sysdeps/x86/bits/pthreadtypes.h
@@ -189,13 +189,13 @@ typedef union
 # ifdef __x86_64__
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
-    int __writer;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
+    int __cur_writer;
     int __shared;
     signed char __rwelision;
 #  ifdef  __ILP32__
@@ -214,12 +214,12 @@ typedef union
 # else
   struct
   {
-    int __lock;
-    unsigned int __nr_readers;
-    unsigned int __readers_wakeup;
-    unsigned int __writer_wakeup;
-    unsigned int __nr_readers_queued;
-    unsigned int __nr_writers_queued;
+    unsigned int __readers;
+    unsigned int __writers;
+    unsigned int __wrphase_futex;
+    unsigned int __writers_futex;
+    unsigned int __pad3;
+    unsigned int __pad4;
     /* FLAGS must stay at this position in the structure to maintain
        binary compatibility.  */
     unsigned char __flags;
@@ -227,7 +227,7 @@ typedef union
     signed char __rwelision;
 # define __PTHREAD_RWLOCK_ELISION_EXTRA 0
     unsigned char __pad2;
-    int __writer;
+    int __cur_writer;
   } __data;
 # endif
   char __size[__SIZEOF_PTHREAD_RWLOCK_T];