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-rw-r--r--linuxthreads/ChangeLog6
-rw-r--r--sysdeps/posix/clock_getres.c43
-rw-r--r--sysdeps/unix/clock_gettime.c21
-rw-r--r--sysdeps/unix/clock_nanosleep.c32
-rw-r--r--sysdeps/unix/clock_settime.c19
-rw-r--r--sysdeps/unix/sysv/linux/clock_getres.c76
-rw-r--r--sysdeps/unix/sysv/linux/clock_gettime.c76
-rw-r--r--sysdeps/unix/sysv/linux/clock_nanosleep.c65
-rw-r--r--sysdeps/unix/sysv/linux/clock_settime.c73
-rw-r--r--sysdeps/unix/sysv/linux/kernel-features.h8
-rw-r--r--sysdeps/unix/sysv/linux/sysconf.c51
11 files changed, 433 insertions, 37 deletions
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog
index c9d18a9632..76589b97e5 100644
--- a/linuxthreads/ChangeLog
+++ b/linuxthreads/ChangeLog
@@ -1,3 +1,9 @@
+2003-03-02  Ulrich Drepper  <drepper@redhat.com>
+
+	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
+	_POSIX_MONOTONIC_CLOCK.
+	* linuxthreads/sysdeps/unix/sysv/linux/i386/bits/posix_opt.h: Likewise.
+
 2003-03-01  Roland McGrath  <roland@redhat.com>
 
 	* sysdeps/powerpc/powerpc64/pt-machine.h
diff --git a/sysdeps/posix/clock_getres.c b/sysdeps/posix/clock_getres.c
index 8bf648f51f..91c57629ca 100644
--- a/sysdeps/posix/clock_getres.c
+++ b/sysdeps/posix/clock_getres.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2001, 2003 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
@@ -24,7 +24,7 @@
 #include <libc-internal.h>
 
 
-#if HP_TIMING_AVAIL
+#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
 /* Clock frequency of the processor.  */
 static long int nsec;
 #endif
@@ -38,24 +38,33 @@ clock_getres (clockid_t clock_id, struct timespec *res)
 
   switch (clock_id)
     {
-    case CLOCK_REALTIME:
-      {
-	long int clk_tck = sysconf (_SC_CLK_TCK);
-
-	if (__builtin_expect (clk_tck != -1, 1))
-	  {
-	    /* This implementation assumes that the realtime clock has a
-	       resolution higher than 1 second.  This is the case for any
-	       reasonable implementation.  */
-	    res->tv_sec = 0;
-	    res->tv_nsec = 1000000000 / clk_tck;
+#define HANDLE_REALTIME \
+      do {								      \
+	long int clk_tck = sysconf (_SC_CLK_TCK);			      \
+									      \
+	if (__builtin_expect (clk_tck != -1, 1))			      \
+	  {								      \
+	    /* This implementation assumes that the realtime clock has a      \
+	       resolution higher than 1 second.  This is the case for any     \
+	       reasonable implementation.  */				      \
+	    res->tv_sec = 0;						      \
+	    res->tv_nsec = 1000000000 / clk_tck;			      \
+									      \
+	    retval = 0;							      \
+	  }								      \
+      } while (0)
+
+#ifdef SYSDEP_GETRES
+      SYSDEP_GETRES;
+#endif
 
-	    retval = 0;
-	  }
-      }
+#ifndef HANDLED_REALTIME
+    case CLOCK_REALTIME:
+      HANDLE_REALTIME;
       break;
+#endif	/* handled REALTIME */
 
-#if HP_TIMING_AVAIL
+#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
     case CLOCK_PROCESS_CPUTIME_ID:
     case CLOCK_THREAD_CPUTIME_ID:
       {
diff --git a/sysdeps/unix/clock_gettime.c b/sysdeps/unix/clock_gettime.c
index 5dc329e1c0..4c26a370e6 100644
--- a/sysdeps/unix/clock_gettime.c
+++ b/sysdeps/unix/clock_gettime.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2001, 2002, 2003 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
@@ -46,12 +46,23 @@ clock_gettime (clockid_t clock_id, struct timespec *tp)
 
   switch (clock_id)
     {
+#define HANDLE_REALTIME \
+      do {								      \
+	retval = gettimeofday (&tv, NULL);				      \
+	if (retval == 0)						      \
+	  /* Convert into `timespec'.  */				      \
+	  TIMEVAL_TO_TIMESPEC (&tv, tp);				      \
+      } while (0)
+
+#ifdef SYSDEP_GETTIME
+      SYSDEP_GETTIME;
+#endif
+
+#ifndef HANDLED_REALTIME
     case CLOCK_REALTIME:
-      retval = gettimeofday (&tv, NULL);
-      if (retval == 0)
-	/* Convert into `timespec'.  */
-	TIMEVAL_TO_TIMESPEC (&tv, tp);
+      HANDLE_REALTIME;
       break;
+#endif
 
 #if HP_TIMING_AVAIL
     case CLOCK_PROCESS_CPUTIME_ID:
diff --git a/sysdeps/unix/clock_nanosleep.c b/sysdeps/unix/clock_nanosleep.c
index 4f32b3685c..358269852a 100644
--- a/sysdeps/unix/clock_nanosleep.c
+++ b/sysdeps/unix/clock_nanosleep.c
@@ -1,5 +1,5 @@
 /* High-resolution sleep with the specified clock.
-   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 2000, 2001, 2003 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
@@ -24,11 +24,16 @@
 
 
 #if HP_TIMING_AVAIL
-# define CLOCK_P(clock) \
-  (clock) != CLOCK_PROCESS_CPUTIME_ID					      \
-  && (clock) != CLOCK_THREAD_CPUTIME_ID
+# define CPUCLOCK_P(clock) \
+  ((clock) != CLOCK_PROCESS_CPUTIME_ID					      \
+   && (clock) != CLOCK_THREAD_CPUTIME_ID)
 #else
-# define CLOCK_P(clock) 0
+# define CPUCLOCK_P(clock) 0
+#endif
+
+#ifndef INVALID_CLOCK_P
+# define INVALID_CLOCK_P(cl) \
+  ((cl) < CLOCK_REALTIME || (cl) > CLOCK_THREAD_CPUTIME_ID || CPUCLOCK_P (cl))
 #endif
 
 
@@ -44,6 +49,16 @@ clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
       || __builtin_expect (req->tv_nsec, 0) >= 1000000000)
     return EINVAL;
 
+  if (CPUCLOCK_P (clock_id))
+    return ENOTSUP;
+
+  if (INVALID_CLOCK_P (clock_id))
+    return EINVAL;
+
+#ifdef SYSDEP_NANOSLEEP
+  SYSDEP_NANOSLEEP;
+#endif
+
   /* If we got an absolute time, remap it.  */
   if (flags == TIMER_ABSTIME)
     {
@@ -76,11 +91,8 @@ clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
   else if (__builtin_expect (flags, 0) != 0)
     return EINVAL;
   else if (clock_id != CLOCK_REALTIME)
-    {
-      /* Make sure the clock ID is correct.  */
-      if (__builtin_expect (! CLOCK_P (clock_id), 0))
-	return EINVAL;
-    }
+    /* Not supported.  */
+    return ENOTSUP;
 
   return __builtin_expect (nanosleep (req, rem), 0) ? errno : 0;
 }
diff --git a/sysdeps/unix/clock_settime.c b/sysdeps/unix/clock_settime.c
index 407e759137..a6c7af19ec 100644
--- a/sysdeps/unix/clock_settime.c
+++ b/sysdeps/unix/clock_settime.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2001, 2002, 2003 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
@@ -52,11 +52,22 @@ clock_settime (clockid_t clock_id, const struct timespec *tp)
 
   switch (clock_id)
     {
-    case CLOCK_REALTIME:
-      TIMESPEC_TO_TIMEVAL (&tv, tp);
+#define HANDLE_REALTIME \
+      do {								      \
+	TIMESPEC_TO_TIMEVAL (&tv, tp);					      \
+									      \
+	retval = settimeofday (&tv, NULL);				      \
+	while (0)
+
+#ifdef SYSDEP_GETTIME
+      SYSDEP_GETTIME;
+#endif
 
-      retval = settimeofday (&tv, NULL);
+#ifndef HANDLED_REALTIME
+    case CLOCK_REALTIME:
+      HANDLE_REALTIME;
       break;
+#endif
 
 #if HP_TIMING_AVAIL
     case CLOCK_PROCESS_CPUTIME_ID:
diff --git a/sysdeps/unix/sysv/linux/clock_getres.c b/sysdeps/unix/sysv/linux/clock_getres.c
new file mode 100644
index 0000000000..442fbd5705
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/clock_getres.c
@@ -0,0 +1,76 @@
+/* Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+#include "kernel-features.h"
+
+
+#ifdef __ASSUME_POSIX_TIMERS
+/* This means the REALTIME and MONOTONIC clock are definitely
+   supported in the kernel.  */
+# define SYSDEP_GETRES \
+  case CLOCK_REALTIME:							      \
+  case CLOCK_MONOTONIC:							      \
+    retval = INLINE_SYSCALL (clock_getres, 2, clock_id, res);		      \
+    break
+#elif defined __NR_clock_getres
+/* Is the syscall known to exist?  */
+extern int __libc_missing_posix_timers attribute_hidden;
+
+/* The REALTIME and MONOTONIC clock might be available.  Try the
+   syscall first.  */
+# define SYSDEP_GETRES \
+  case CLOCK_REALTIME:							      \
+  case CLOCK_MONOTONIC:							      \
+    {									      \
+      int e = EINVAL;							      \
+									      \
+      if (!__libc_missing_posix_timers)					      \
+	{								      \
+	  INTERNAL_SYSCALL_DECL (err);					      \
+	  int r = INTERNAL_SYSCALL (clock_getres, err, 2, clock_id, res);     \
+	  if (!INTERNAL_SYSCALL_ERROR_P (r, err))			      \
+	    {								      \
+	      retval = 0;						      \
+	      break;							      \
+	    }								      \
+									      \
+	  e = INTERNAL_SYSCALL_ERRNO (r, err);				      \
+	  if (e == ENOSYS)						      \
+	    {								      \
+	      __libc_missing_posix_timers = 1;				      \
+	      e = EINVAL;						      \
+	    }								      \
+	}								      \
+									      \
+      /* Fallback code.  */						      \
+      if (e == EINVAL && clock_id == CLOCK_REALTIME)			      \
+	HANDLE_REALTIME;						      \
+      else								      \
+	__set_errno (e);						      \
+    }									      \
+    break
+#endif
+
+#ifdef __NR_clock_getres
+/* We handled the REALTIME clock here.  */
+# define HANDLED_REALTIME	1
+#endif
+
+#include <sysdeps/posix/clock_getres.c>
diff --git a/sysdeps/unix/sysv/linux/clock_gettime.c b/sysdeps/unix/sysv/linux/clock_gettime.c
new file mode 100644
index 0000000000..522fac32a7
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/clock_gettime.c
@@ -0,0 +1,76 @@
+/* Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+#include "kernel-features.h"
+
+
+#ifdef __ASSUME_POSIX_TIMERS
+/* This means the REALTIME and MONOTONIC clock are definitely
+   supported in the kernel.  */
+# define SYSDEP_GETTIME \
+  case CLOCK_REALTIME:							      \
+  case CLOCK_MONOTONIC:							      \
+    retval = INLINE_SYSCALL (clock_gettime, 2, clock_id, tp);		      \
+    break
+#elif defined __NR_clock_gettime
+/* Is the syscall known to exist?  */
+int __libc_missing_posix_timers attribute_hidden;
+
+/* The REALTIME and MONOTONIC clock might be available.  Try the
+   syscall first.  */
+# define SYSDEP_GETTIME \
+  case CLOCK_REALTIME:							      \
+  case CLOCK_MONOTONIC:							      \
+    {									      \
+      int e = EINVAL;							      \
+									      \
+      if (!__libc_missing_posix_timers)					      \
+	{								      \
+	  INTERNAL_SYSCALL_DECL (err);					      \
+	  int r = INTERNAL_SYSCALL (clock_gettime, err, 2, clock_id, tp);     \
+	  if (!INTERNAL_SYSCALL_ERROR_P (r, err))			      \
+	    {								      \
+	      retval = 0;						      \
+	      break;							      \
+	    }								      \
+									      \
+	  e = INTERNAL_SYSCALL_ERRNO (r, err);				      \
+	  if (e == ENOSYS)						      \
+	    {								      \
+	      __libc_missing_posix_timers = 1;				      \
+	      e = EINVAL;						      \
+	    }								      \
+	}								      \
+									      \
+      /* Fallback code.  */						      \
+      if (e == EINVAL && clock_id == CLOCK_REALTIME)			      \
+	HANDLE_REALTIME;						      \
+      else								      \
+	__set_errno (e);						      \
+    }									      \
+    break
+#endif
+
+#ifdef __NR_clock_gettime
+/* We handled the REALTIME clock here.  */
+# define HANDLED_REALTIME	1
+#endif
+
+#include <sysdeps/unix/clock_gettime.c>
diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
new file mode 100644
index 0000000000..ceb3801eb9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
@@ -0,0 +1,65 @@
+/* Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <time.h>
+
+#include <sysdep.h>
+#include "kernel-features.h"
+
+
+#ifdef __ASSUME_POSIX_TIMERS
+/* We can simply use the syscall.  The CPU clocks are not supported
+   with this function.  */
+int
+clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
+		 struct timespec *rem)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  int r;
+
+  r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
+  return (INTERNAL_SYSCALL_ERROR_P (r, err)
+	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
+}
+
+#else
+# ifdef __NR_clock_nanosleep
+/* Is the syscall known to exist?  */
+extern int __libc_missing_posix_timers attribute_hidden;
+
+/* The REALTIME and MONOTONIC clock might be available.  Try the
+   syscall first.  */
+#  define SYSDEP_NANOSLEEP \
+  if (!__libc_missing_posix_timers)					      \
+    {									      \
+      INTERNAL_SYSCALL_DECL (err);					      \
+      int r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags,     \
+				req, rem);				      \
+									      \
+      if (!INTERNAL_SYSCALL_ERROR_P (r, err))				      \
+	return 0;							      \
+									      \
+      if (INTERNAL_SYSCALL_ERRNO (r, err) != ENOSYS)			      \
+	return INTERNAL_SYSCALL_ERRNO (r, err);				      \
+      									      \
+      __libc_missing_posix_timers = 1;					      \
+    }
+# endif
+
+# include <sysdeps/unix/clock_nanosleep.c>
+#endif
diff --git a/sysdeps/unix/sysv/linux/clock_settime.c b/sysdeps/unix/sysv/linux/clock_settime.c
new file mode 100644
index 0000000000..d57c70e5e1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/clock_settime.c
@@ -0,0 +1,73 @@
+/* Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+#include "kernel-features.h"
+
+
+#ifdef __ASSUME_POSIX_TIMERS
+/* This means the REALTIME clock is definitely supported in the
+   kernel.  */
+# define SYSDEP_SETTIME \
+  case CLOCK_REALTIME:							      \
+    retval = INLINE_SYSCALL (clock_settime, 2, clock_id, tp);		      \
+    break
+#elif defined __NR_clock_settime
+/* Is the syscall known to exist?  */
+extern int __libc_missing_posix_timers attribute_hidden;
+
+/* The REALTIME clock might be available.  Try the syscall first.  */
+# define SYSDEP_SETTIME \
+  case CLOCK_REALTIME:							      \
+    {									      \
+      int e = EINVAL;							      \
+									      \
+      if (!__libc_missing_posix_timers)					      \
+	{								      \
+	  INTERNAL_SYSCALL_DECL (err);					      \
+	  int r = INTERNAL_SYSCALL (clock_settime, err, 2, clock_id, tp);     \
+	  if (!INTERNAL_SYSCALL_ERROR_P (r, err))			      \
+	    {								      \
+	      retval = 0;						      \
+	      break;							      \
+	    }								      \
+									      \
+	  e = INTERNAL_SYSCALL_ERRNO (r, err);				      \
+	  if (e == ENOSYS)						      \
+	    {								      \
+	      __libc_missing_posix_timers = 1;				      \
+	      e = EINVAL;						      \
+	    }								      \
+	}								      \
+									      \
+      /* Fallback code.  */						      \
+      if (e == EINVAL && clock_id == CLOCK_REALTIME)			      \
+	HANDLE_REALTIME;						      \
+      else								      \
+	__set_errno (e);						      \
+    }									      \
+    break
+#endif
+
+#ifdef __NR_clock_settime
+/* We handled the REALTIME clock here.  */
+# define HANDLED_REALTIME	1
+#endif
+
+#include <sysdeps/unix/clock_settime.c>
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 239d6379b4..f9d1f09050 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -1,6 +1,6 @@
 /* Set flags signalling availability of kernel features based on given
    kernel version number.
-   Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2000, 2001, 2002, 2003 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
@@ -264,3 +264,9 @@
 # define __ASSUME_FCNTL64		1
 # define __ASSUME_VFORK_SYSCALL		1
 #endif
+
+/* Beginning with 2.5.63 support for realtime and monotonic clocks and
+   timers based on them is available.  */
+#if __LINUX_KERNEL_VERSION >= 132415
+# define __ASSUME_POSIX_TIMERS		1
+#endif
diff --git a/sysdeps/unix/sysv/linux/sysconf.c b/sysdeps/unix/sysv/linux/sysconf.c
new file mode 100644
index 0000000000..92b1e66782
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sysconf.c
@@ -0,0 +1,51 @@
+/* Get file-specific information about a file.  Linux version.
+   Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <time.h>
+#include <unistd.h>
+
+static long int posix_sysconf (int name);
+
+/* Define this first, so it can be inlined.  */
+#define __sysconf static posix_sysconf
+#include <sysdeps/posix/sysconf.c>
+
+
+/* Get the value of the system variable NAME.  */
+long int
+__sysconf (int name)
+{
+  switch (name)
+    {
+#ifdef __NR_clock_getres
+    case _SC_MONOTONIC_CLOCK:
+      /* Check using the clock_getres system call.  */
+      {
+	struct timespec ts;
+	INTERNAL_SYSCALL_DECL (err);
+	int r = INTERNAL_SYSCALL (clock_getres, err, 2, CLOCK_MONOTONIC, &ts);
+	return INTERNAL_SYSCALL_ERROR_P (r, err) ? 0 : 1;
+      }
+#endif
+
+    default:
+      return posix_sysconf (name);
+    }
+}