* init.c (__pthread_initialize_minimal_internal): Check for

	FUTEX_CLOCK_REALTIME flag.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S (__lll_timedlock_wait):
	Use FUTEX_WAIT_BITSET|FUTEX_CLOCK_READTIME instead of computing
	relative timeout.

3 files changed, 88 insertions, 2 deletions

diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 70fc0b1e1e..ae652ff738 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,5 +1,11 @@
 2009-01-02  Ulrich Drepper  <drepper@redhat.com>
 
+	* init.c (__pthread_initialize_minimal_internal): Check for
+	FUTEX_CLOCK_REALTIME flag.
+	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S (__lll_timedlock_wait):
+	Use FUTEX_WAIT_BITSET|FUTEX_CLOCK_READTIME instead of computing
+	relative timeout.
+
 	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Define
 	FUTEX_CLOCK_REALTIME and FUTEX_BITSET_MATCH_ANY.
 	* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise.
diff --git a/nptl/init.c b/nptl/init.c
index d445de0795..af5bb24b59 100644
--- a/nptl/init.c
+++ b/nptl/init.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002,2003,2004,2005,2006,2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2007, 2008, 2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -18,6 +18,7 @@
    02111-1307 USA.  */
 
 #include <assert.h>
+#include <errno.h>
 #include <limits.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -49,6 +50,15 @@ int __set_robust_list_avail;
 # define set_robust_list_not_avail() do { } while (0)
 #endif
 
+#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
+/* Nonzero if we do not have FUTEX_CLOCK_REALTIME.  */
+int __have_futex_clock_realtime;
+# define __set_futex_clock_realtime() \
+  __have_futex_clock_realtime = 1
+#else
+#define __set_futex_clock_realtime() do { } while (0)
+#endif
+
 /* Version of the library, used in libthread_db to detect mismatches.  */
 static const char nptl_version[] __attribute_used__ = VERSION;
 
@@ -292,6 +302,20 @@ __pthread_initialize_minimal_internal (void)
   }
 #endif
 
+#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
+  {
+    int word = 0;
+    word = INTERNAL_SYSCALL (futex, err, 6, &word,
+			     FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
+			     | FUTEX_PRIVATE_FLAG, 1, NULL, 0,
+			     FUTEX_BITSET_MATCH_ANY);
+    if (!INTERNAL_SYSCALL_ERROR_P (word, err)
+	|| (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS
+	    && INTERNAL_SYSCALL_ERRNO (word, err) != EINVAL))
+      __set_futex_clock_realtime ();
+  }
+#endif
+
   /* Set initial thread's stack block from 0 up to __libc_stack_end.
      It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
      purposes this is good enough.  */
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
index 4505e2cec6..72c3858238 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002-2006, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2006, 2007, 2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -31,6 +31,8 @@
 	movl	$(FUTEX_WAKE | FUTEX_PRIVATE_FLAG), reg
 # define LOAD_FUTEX_WAIT(reg) \
 	xorl	$(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg
+# define LOAD_FUTEX_WAIT_ABS(reg) \
+	xorl	$(FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME), reg
 # define LOAD_FUTEX_WAKE(reg) \
 	xorl	$(FUTEX_WAKE | FUTEX_PRIVATE_FLAG), reg
 #else
@@ -55,6 +57,10 @@
 	andl	%fs:PRIVATE_FUTEX, reg ; \
 	orl	$FUTEX_WAIT, reg
 # endif
+# define LOAD_FUTEX_WAIT_ABS(reg) \
+	xorl	$FUTEX_PRIVATE_FLAG, reg ; \
+	andl	%fs:PRIVATE_FUTEX, reg ; \
+	orl	$FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME, reg
 # define LOAD_FUTEX_WAKE(reg) \
 	xorl	$FUTEX_PRIVATE_FLAG, reg ; \
 	andl	%fs:PRIVATE_FUTEX, reg ; \
@@ -143,12 +149,61 @@ __lll_lock_wait:
 	cfi_endproc
 	.size	__lll_lock_wait,.-__lll_lock_wait
 
+	/*      %rdi: futex
+		%rsi: flags
+		%rdx: timeout
+		%eax: futex value
+	*/
 	.globl	__lll_timedlock_wait
 	.type	__lll_timedlock_wait,@function
 	.hidden	__lll_timedlock_wait
 	.align	16
 __lll_timedlock_wait:
 	cfi_startproc
+# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
+#  ifdef PIC
+	cmpl	$0, __have_futex_clock_realtime(%rip)
+#  else
+	cmpl	$0, __have_futex_clock_realtime
+#  endif
+	je	.Lreltmo
+# endif
+
+	pushq	%r9
+	cfi_adjust_cfa_offset(9)
+	cfi_offset(%r9, -16)
+	movq	%rdx, %r10
+	movl	$0xffffffff, %r9d
+	LOAD_FUTEX_WAIT_ABS (%esi)
+
+	movl	$2, %edx
+	cmpl	%edx, %eax
+	jne	2f
+
+1:	movl	$SYS_futex, %eax
+	movl	$2, %edx
+	syscall
+
+2:	xchgl	%edx, (%rdi)	/* NB:   lock is implied */
+
+	testl	%edx, %edx
+	jz	3f
+
+	cmpl	$-ETIMEDOUT, %eax
+	je	4f
+	cmpl	$-EINVAL, %eax
+	jne	1b
+4:	movl	%eax, %edx
+	negl	%edx
+
+3:	movl	%edx, %eax
+	popq	%r9
+	cfi_adjust_cfa_offset(-8)
+	cfi_restore(%r9)
+	retq
+
+# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
+.Lreltmo:
 	/* Check for a valid timeout value.  */
 	cmpq	$1000000000, 8(%rdx)
 	jae	3f
@@ -253,6 +308,7 @@ __lll_timedlock_wait:
 
 3:	movl	$EINVAL, %eax
 	retq
+# endif
 	cfi_endproc
 	.size	__lll_timedlock_wait,.-__lll_timedlock_wait
 #endif