1 files changed, 73 insertions, 0 deletions
diff --git a/src/kernel/tests/lib/tst_cpu.c b/src/kernel/tests/lib/tst_cpu.c
new file mode 100644
index 0000000..033155e
--- /dev/null
+++ b/src/kernel/tests/lib/tst_cpu.c
@@ -0,0 +1,73 @@
+/*
+ *   Copyright (c) 2012 Fujitsu Ltd.
+ *   Author: Wanlong Gao <gaowanlong@cn.fujitsu.com>
+ *
+ *   This program is free software;  you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program 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 General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include "test.h"
+#include "safe_macros.h"
+
+long tst_ncpus(void)
+{
+	long ncpus = -1;
+#ifdef _SC_NPROCESSORS_ONLN
+	ncpus = SAFE_SYSCONF(NULL, _SC_NPROCESSORS_ONLN);
+#else
+	tst_brkm(TBROK, NULL, "could not determine number of CPUs online");
+#endif
+	return ncpus;
+}
+
+long tst_ncpus_conf(void)
+{
+	long ncpus_conf = -1;
+#ifdef _SC_NPROCESSORS_CONF
+	ncpus_conf = SAFE_SYSCONF(NULL, _SC_NPROCESSORS_CONF);
+#else
+	tst_brkm(TBROK, NULL, "could not determine number of CPUs configured");
+#endif
+	return ncpus_conf;
+}
+
+#define KERNEL_MAX "/sys/devices/system/cpu/kernel_max"
+
+long tst_ncpus_max(void)
+{
+	long ncpus_max = -1;
+	struct stat buf;
+
+	/* sched_getaffinity() and sched_setaffinity() cares about number of
+	 * possible CPUs the OS or hardware can support, which can be larger
+	 * than what sysconf(_SC_NPROCESSORS_CONF) currently provides
+	 * (by enumarating /sys/devices/system/cpu/cpu* entries).
+	 *
+	 *  Use /sys/devices/system/cpu/kernel_max, if available. This
+	 *  represents NR_CPUS-1, a compile time option which specifies
+	 *  "maximum number of CPUs which this kernel will support".
+	 *  This should provide cpu mask size large enough for any purposes. */
+	if (stat(KERNEL_MAX, &buf) == 0) {
+		SAFE_FILE_SCANF(NULL, KERNEL_MAX, "%ld", &ncpus_max);
+		/* this is maximum CPU index allowed by the kernel
+		 * configuration, so # of cpus allowed by config is +1 */
+		ncpus_max++;
+	} else {
+		/* fall back to _SC_NPROCESSORS_CONF */
+		ncpus_max = tst_ncpus_conf();
+	}
+	return ncpus_max;
+}