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authorUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
commita334319f6530564d22e775935d9c91663623a1b4 (patch)
treeb5877475619e4c938e98757d518bb1e9cbead751 /nptl/sysdeps/unix/sysv/linux/smp.h
parent0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff)
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(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/smp.h')
-rw-r--r--nptl/sysdeps/unix/sysv/linux/smp.h30
1 files changed, 27 insertions, 3 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/smp.h b/nptl/sysdeps/unix/sysv/linux/smp.h
index fcc34f7681..4f4d358d32 100644
--- a/nptl/sysdeps/unix/sysv/linux/smp.h
+++ b/nptl/sysdeps/unix/sysv/linux/smp.h
@@ -1,5 +1,5 @@
 /* Determine whether the host has multiple processors.  Linux version.
-   Copyright (C) 1996, 2002, 2004, 2006 Free Software Foundation, Inc.
+   Copyright (C) 1996, 2002, 2004 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
@@ -17,12 +17,36 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/sysctl.h>
+#include <not-cancel.h>
+
 /* Test whether the machine has more than one processor.  This is not the
    best test but good enough.  More complicated tests would require `malloc'
    which is not available at that time.  */
 static inline int
 is_smp_system (void)
 {
-  /* Assume all machines are SMP and/or CMT and/or SMT.  */
-  return 1;
+  static const int sysctl_args[] = { CTL_KERN, KERN_VERSION };
+  char buf[512];
+  size_t reslen = sizeof (buf);
+
+  /* Try reading the number using `sysctl' first.  */
+  if (__sysctl ((int *) sysctl_args,
+		sizeof (sysctl_args) / sizeof (sysctl_args[0]),
+		buf, &reslen, NULL, 0) < 0)
+    {
+      /* This was not successful.  Now try reading the /proc filesystem.  */
+      int fd = open_not_cancel_2 ("/proc/sys/kernel/version", O_RDONLY);
+      if (__builtin_expect (fd, 0) == -1
+	  || (reslen = read_not_cancel (fd, buf, sizeof (buf))) <= 0)
+	/* This also didn't work.  We give up and say it's a UP machine.  */
+	buf[0] = '\0';
+
+      close_not_cancel_no_status (fd);
+    }
+
+  return strstr (buf, "SMP") != NULL;
 }