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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;
}