15 files changed, 551 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/Makefile b/sysdeps/unix/sysv/linux/x86/Makefile
index 6412a9ef36..012125f30c 100644
--- a/sysdeps/unix/sysv/linux/x86/Makefile
+++ b/sysdeps/unix/sysv/linux/x86/Makefile
@@ -16,3 +16,9 @@ abi-x32-ld-soname := ld-linux-x32.so.2
 ifeq ($(subdir),misc)
 sysdep_headers += sys/elf.h sys/perm.h sys/reg.h sys/vm86.h sys/debugreg.h sys/io.h
 endif
+
+ifeq ($(subdir),nptl)
+libpthread-sysdep_routines += init-arch
+libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
+			      elision-trylock
+endif
diff --git a/sysdeps/unix/sysv/linux/x86/elision-conf.c b/sysdeps/unix/sysv/linux/x86/elision-conf.c
new file mode 100644
index 0000000000..e6f5d6d1ab
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-conf.c
@@ -0,0 +1,81 @@
+/* elision-conf.c: Lock elision tunable parameters.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include <pthreadP.h>
+#include <init-arch.h>
+#include <elision-conf.h>
+#include <unistd.h>
+
+/* Reasonable initial tuning values, may be revised in the future.
+   This is a conservative initial value.  */
+
+struct elision_config __elision_aconf =
+  {
+    /* How often to not attempt to use elision if a transaction aborted
+       because the lock is already acquired.  Expressed in number of lock
+       acquisition attempts.  */
+    .skip_lock_busy = 3,
+    /* How often to not attempt to use elision if a transaction aborted due
+       to reasons other than other threads' memory accesses.  Expressed in
+       number of lock acquisition attempts.  */
+    .skip_lock_internal_abort = 3,
+    /* How often we retry using elision if there is chance for the transaction
+       to finish execution (e.g., it wasn't aborted due to the lock being
+       already acquired.  */
+    .retry_try_xbegin = 3,
+    /* Same as SKIP_LOCK_INTERNAL_ABORT but for trylock.  */
+    .skip_trylock_internal_abort = 3,
+  };
+
+/* Set when the CPU supports elision.  When false elision is never attempted.
+ */
+
+int __elision_available attribute_hidden;
+
+/* Force elision for all new locks.  This is used to decide whether existing
+   DEFAULT locks should be automatically upgraded to elision in
+   pthread_mutex_lock().  Disabled for suid programs.  Only used when elision
+   is available.  */
+
+int __pthread_force_elision attribute_hidden;
+
+/* Initialize elison.  */
+
+static void
+elision_init (int argc __attribute__ ((unused)),
+	      char **argv  __attribute__ ((unused)),
+	      char **environ)
+{
+  __elision_available = HAS_RTM;
+#ifdef ENABLE_LOCK_ELISION
+  __pthread_force_elision = __libc_enable_secure ? 0 : __elision_available;
+#endif
+}
+
+#ifdef SHARED
+# define INIT_SECTION ".init_array"
+#else
+# define INIT_SECTION ".preinit_array"
+#endif
+
+void (*const __pthread_init_array []) (int, char **, char **)
+  __attribute__ ((section (INIT_SECTION), aligned (sizeof (void *)))) =
+{
+  &elision_init
+};
diff --git a/sysdeps/unix/sysv/linux/x86/elision-conf.h b/sysdeps/unix/sysv/linux/x86/elision-conf.h
new file mode 100644
index 0000000000..6790b5aa13
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-conf.h
@@ -0,0 +1,43 @@
+/* elision-conf.h: Lock elision tunable parameters.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+#ifndef _ELISION_CONF_H
+#define _ELISION_CONF_H 1
+
+#include <pthread.h>
+#include <cpuid.h>
+#include <time.h>
+
+/* Should make sure there is no false sharing on this.  */
+
+struct elision_config
+{
+  int skip_lock_busy;
+  int skip_lock_internal_abort;
+  int retry_try_xbegin;
+  int skip_trylock_internal_abort;
+};
+
+extern struct elision_config __elision_aconf attribute_hidden;
+
+extern int __elision_available attribute_hidden;
+extern int __pthread_force_elision attribute_hidden;
+
+/* Tell the test suite to test elision for this architecture.  */
+#define HAVE_ELISION 1
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/x86/elision-lock.c b/sysdeps/unix/sysv/linux/x86/elision-lock.c
new file mode 100644
index 0000000000..385ac31a52
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-lock.c
@@ -0,0 +1,95 @@
+/* elision-lock.c: Elided pthread mutex lock.
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include "pthreadP.h"
+#include "lowlevellock.h"
+#include "hle.h"
+#include <elision-conf.h>
+
+#if !defined(LLL_LOCK) && !defined(EXTRAARG)
+/* Make sure the configuration code is always linked in for static
+   libraries.  */
+#include "elision-conf.c"
+#endif
+
+#ifndef EXTRAARG
+#define EXTRAARG
+#endif
+#ifndef LLL_LOCK
+#define LLL_LOCK(a,b) lll_lock(a,b), 0
+#endif
+
+#define aconf __elision_aconf
+
+/* Adaptive lock using transactions.
+   By default the lock region is run as a transaction, and when it
+   aborts or the lock is busy the lock adapts itself.  */
+
+int
+__lll_lock_elision (int *futex, short *adapt_count, EXTRAARG int private)
+{
+  if (*adapt_count <= 0)
+    {
+      unsigned status;
+      int try_xbegin;
+
+      for (try_xbegin = aconf.retry_try_xbegin;
+	   try_xbegin > 0;
+	   try_xbegin--)
+	{
+	  if ((status = _xbegin()) == _XBEGIN_STARTED)
+	    {
+	      if (*futex == 0)
+		return 0;
+
+	      /* Lock was busy.  Fall back to normal locking.
+		 Could also _xend here but xabort with 0xff code
+		 is more visible in the profiler.  */
+	      _xabort (_ABORT_LOCK_BUSY);
+	    }
+
+	  if (!(status & _XABORT_RETRY))
+	    {
+	      if ((status & _XABORT_EXPLICIT)
+			&& _XABORT_CODE (status) == _ABORT_LOCK_BUSY)
+	        {
+		  /* Right now we skip here.  Better would be to wait a bit
+		     and retry.  This likely needs some spinning.  */
+		  if (*adapt_count != aconf.skip_lock_busy)
+		    *adapt_count = aconf.skip_lock_busy;
+		}
+	      /* Internal abort.  There is no chance for retry.
+		 Use the normal locking and next time use lock.
+		 Be careful to avoid writing to the lock.  */
+	      else if (*adapt_count != aconf.skip_lock_internal_abort)
+		*adapt_count = aconf.skip_lock_internal_abort;
+	      break;
+	    }
+	}
+    }
+  else
+    {
+      /* Use a normal lock until the threshold counter runs out.
+	 Lost updates possible.  */
+      (*adapt_count)--;
+    }
+
+  /* Use a normal lock here.  */
+  return LLL_LOCK ((*futex), private);
+}
diff --git a/sysdeps/unix/sysv/linux/x86/elision-timed.c b/sysdeps/unix/sysv/linux/x86/elision-timed.c
new file mode 100644
index 0000000000..4fdaa0f9e9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-timed.c
@@ -0,0 +1,26 @@
+/* elision-timed.c: Lock elision timed lock.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <elision-conf.h>
+#include "lowlevellock.h"
+#define __lll_lock_elision __lll_timedlock_elision
+#define EXTRAARG const struct timespec *t,
+#undef LLL_LOCK
+#define LLL_LOCK(a, b) lll_timedlock(a, t, b)
+#include "elision-lock.c"
diff --git a/sysdeps/unix/sysv/linux/x86/elision-trylock.c b/sysdeps/unix/sysv/linux/x86/elision-trylock.c
new file mode 100644
index 0000000000..a478ac18e3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-trylock.c
@@ -0,0 +1,71 @@
+/* elision-trylock.c: Lock eliding trylock for pthreads.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <pthreadP.h>
+#include <lowlevellock.h>
+#include "hle.h"
+#include <elision-conf.h>
+
+#define aconf __elision_aconf
+
+/* Try to elide a futex trylock.  FUTEX is the futex variable.  ADAPT_COUNT is
+   the adaptation counter in the mutex.  */
+
+int
+__lll_trylock_elision (int *futex, short *adapt_count)
+{
+  /* Implement POSIX semantics by forbiding nesting
+     trylock.  Sorry.  After the abort the code is re-executed
+     non transactional and if the lock was already locked
+     return an error.  */
+  _xabort (_ABORT_NESTED_TRYLOCK);
+
+  /* Only try a transaction if it's worth it.  */
+  if (*adapt_count <= 0)
+    {
+      unsigned status;
+
+      if ((status = _xbegin()) == _XBEGIN_STARTED)
+	{
+	  if (*futex == 0)
+	    return 0;
+
+	  /* Lock was busy.  Fall back to normal locking.
+	     Could also _xend here but xabort with 0xff code
+	     is more visible in the profiler.  */
+	  _xabort (_ABORT_LOCK_BUSY);
+	}
+
+      if (!(status & _XABORT_RETRY))
+        {
+          /* Internal abort.  No chance for retry.  For future
+             locks don't try speculation for some time.  */
+          if (*adapt_count != aconf.skip_trylock_internal_abort)
+            *adapt_count = aconf.skip_trylock_internal_abort;
+        }
+      /* Could do some retries here.  */
+    }
+  else
+    {
+      /* Lost updates are possible, but harmless.  */
+      (*adapt_count)--;
+    }
+
+  return lll_trylock (*futex);
+}
diff --git a/sysdeps/unix/sysv/linux/x86/elision-unlock.c b/sysdeps/unix/sysv/linux/x86/elision-unlock.c
new file mode 100644
index 0000000000..b9be19ccc4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/elision-unlock.c
@@ -0,0 +1,33 @@
+/* elision-unlock.c: Commit an elided pthread lock.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "pthreadP.h"
+#include "lowlevellock.h"
+#include "hle.h"
+
+int
+__lll_unlock_elision(int *lock, int private)
+{
+  /* When the lock was free we're in a transaction.
+     When you crash here you unlocked a free lock.  */
+  if (*lock == 0)
+    _xend();
+  else
+    lll_unlock ((*lock), private);
+  return 0;
+}
diff --git a/sysdeps/unix/sysv/linux/x86/force-elision.h b/sysdeps/unix/sysv/linux/x86/force-elision.h
new file mode 100644
index 0000000000..945f8867fc
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/force-elision.h
@@ -0,0 +1,31 @@
+/* force-elision.h: Automatic enabling of elision for mutexes
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Check for elision on this lock without upgrading.  */
+#define DO_ELISION(m)							\
+  (__pthread_force_elision						\
+   && (m->__data.__kind & PTHREAD_MUTEX_NO_ELISION_NP) == 0)		\
+
+/* Automatically enable elision for existing user lock kinds.  */
+#define FORCE_ELISION(m, s)						\
+  if (__pthread_force_elision						\
+      && (m->__data.__kind & PTHREAD_MUTEX_ELISION_FLAGS_NP) == 0)	\
+    {									\
+      mutex->__data.__kind |= PTHREAD_MUTEX_ELISION_NP;			\
+      s;								\
+    }
diff --git a/sysdeps/unix/sysv/linux/x86/hle.h b/sysdeps/unix/sysv/linux/x86/hle.h
new file mode 100644
index 0000000000..4a7b9e3bf7
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/hle.h
@@ -0,0 +1,75 @@
+/* Shared RTM header.  Emulate TSX intrinsics for compilers and assemblers
+   that do not support the intrinsics and instructions yet.  */
+#ifndef _HLE_H
+#define _HLE_H 1
+
+#ifdef __ASSEMBLER__
+
+.macro XBEGIN target
+	.byte 0xc7,0xf8
+	.long \target-1f
+1:
+.endm
+
+.macro XEND
+	.byte 0x0f,0x01,0xd5
+.endm
+
+.macro XABORT code
+	.byte 0xc6,0xf8,\code
+.endm
+
+.macro XTEST
+	 .byte 0x0f,0x01,0xd6
+.endm
+
+#endif
+
+/* Official RTM intrinsics interface matching gcc/icc, but works
+   on older gcc compatible compilers and binutils.
+   We should somehow detect if the compiler supports it, because
+   it may be able to generate slightly better code.  */
+
+#define _XBEGIN_STARTED		(~0u)
+#define _XABORT_EXPLICIT	(1 << 0)
+#define _XABORT_RETRY		(1 << 1)
+#define _XABORT_CONFLICT	(1 << 2)
+#define _XABORT_CAPACITY	(1 << 3)
+#define _XABORT_DEBUG		(1 << 4)
+#define _XABORT_NESTED		(1 << 5)
+#define _XABORT_CODE(x)		(((x) >> 24) & 0xff)
+
+#define _ABORT_LOCK_BUSY 	0xff
+#define _ABORT_LOCK_IS_LOCKED	0xfe
+#define _ABORT_NESTED_TRYLOCK	0xfd
+
+#ifndef __ASSEMBLER__
+
+#define __force_inline __attribute__((__always_inline__)) inline
+
+static __force_inline int _xbegin(void)
+{
+  int ret = _XBEGIN_STARTED;
+  asm volatile (".byte 0xc7,0xf8 ; .long 0" : "+a" (ret) :: "memory");
+  return ret;
+}
+
+static __force_inline void _xend(void)
+{
+  asm volatile (".byte 0x0f,0x01,0xd5" ::: "memory");
+}
+
+static __force_inline void _xabort(const unsigned int status)
+{
+  asm volatile (".byte 0xc6,0xf8,%P0" :: "i" (status) : "memory");
+}
+
+static __force_inline int _xtest(void)
+{
+  unsigned char out;
+  asm volatile (".byte 0x0f,0x01,0xd6 ; setnz %0" : "=r" (out) :: "memory");
+  return out;
+}
+
+#endif
+#endif
diff --git a/sysdeps/unix/sysv/linux/x86/init-arch.c b/sysdeps/unix/sysv/linux/x86/init-arch.c
new file mode 100644
index 0000000000..00a94d83dc
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/init-arch.c
@@ -0,0 +1 @@
+#include <sysdeps/x86_64/multiarch/init-arch.c>
diff --git a/sysdeps/unix/sysv/linux/x86/init-arch.h b/sysdeps/unix/sysv/linux/x86/init-arch.h
new file mode 100644
index 0000000000..cd2d0befee
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/init-arch.h
@@ -0,0 +1 @@
+#include <sysdeps/x86_64/multiarch/init-arch.h>
diff --git a/sysdeps/unix/sysv/linux/x86/pthread_mutex_cond_lock.c b/sysdeps/unix/sysv/linux/x86/pthread_mutex_cond_lock.c
new file mode 100644
index 0000000000..34c705235a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthread_mutex_cond_lock.c
@@ -0,0 +1,22 @@
+/* Copyright (C) 2013-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* The cond lock is not actually elided yet, but we still need to handle
+   already elided locks.  */
+#include <elision-conf.h>
+
+#include "sysdeps/unix/sysv/linux/pthread_mutex_cond_lock.c"
diff --git a/sysdeps/unix/sysv/linux/x86/pthread_mutex_lock.c b/sysdeps/unix/sysv/linux/x86/pthread_mutex_lock.c
new file mode 100644
index 0000000000..b8a33c1869
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthread_mutex_lock.c
@@ -0,0 +1,22 @@
+/* Elided version of pthread_mutex_lock.
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <elision-conf.h>
+#include "force-elision.h"
+
+#include "nptl/pthread_mutex_lock.c"
diff --git a/sysdeps/unix/sysv/linux/x86/pthread_mutex_timedlock.c b/sysdeps/unix/sysv/linux/x86/pthread_mutex_timedlock.c
new file mode 100644
index 0000000000..d33dd2a112
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthread_mutex_timedlock.c
@@ -0,0 +1,22 @@
+/* Elided version of pthread_mutex_timedlock.
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <elision-conf.h>
+#include "force-elision.h"
+
+#include "nptl/pthread_mutex_timedlock.c"
diff --git a/sysdeps/unix/sysv/linux/x86/pthread_mutex_trylock.c b/sysdeps/unix/sysv/linux/x86/pthread_mutex_trylock.c
new file mode 100644
index 0000000000..6534e9693b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/pthread_mutex_trylock.c
@@ -0,0 +1,22 @@
+/* Elided version of pthread_mutex_trylock.
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <elision-conf.h>
+#include "force-elision.h"
+
+#include "nptl/pthread_mutex_trylock.c"