1 files changed, 53 insertions, 0 deletions
diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
index 1fbd7c947abc..19be2aaf4dc0 100644
--- a/tools/perf/bench/numa.c
+++ b/tools/perf/bench/numa.c
@@ -27,6 +27,7 @@
 #include <sys/resource.h>
 #include <sys/wait.h>
 #include <sys/prctl.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <linux/kernel.h>
 #include <linux/time64.h>
@@ -35,6 +36,7 @@
 
 #include "../util/header.h"
 #include "../util/mutex.h"
+#include <api/fs/fs.h>
 #include <numa.h>
 #include <numaif.h>
 
@@ -533,6 +535,57 @@ static int parse_cpu_list(const char *arg)
 	return 0;
 }
 
+/*
+ * Check whether a CPU is online
+ *
+ * Returns:
+ *     1 -> if CPU is online
+ *     0 -> if CPU is offline
+ *    -1 -> error case
+ */
+static int is_cpu_online(unsigned int cpu)
+{
+	char *str;
+	size_t strlen;
+	char buf[256];
+	int status = -1;
+	struct stat statbuf;
+
+	snprintf(buf, sizeof(buf),
+		"/sys/devices/system/cpu/cpu%d", cpu);
+	if (stat(buf, &statbuf) != 0)
+		return 0;
+
+	/*
+	 * Check if /sys/devices/system/cpu/cpux/online file
+	 * exists. Some cases cpu0 won't have online file since
+	 * it is not expected to be turned off generally.
+	 * In kernels without CONFIG_HOTPLUG_CPU, this
+	 * file won't exist
+	 */
+	snprintf(buf, sizeof(buf),
+		"/sys/devices/system/cpu/cpu%d/online", cpu);
+	if (stat(buf, &statbuf) != 0)
+		return 1;
+
+	/*
+	 * Read online file using sysfs__read_str.
+	 * If read or open fails, return -1.
+	 * If read succeeds, return value from file
+	 * which gets stored in "str"
+	 */
+	snprintf(buf, sizeof(buf),
+		"devices/system/cpu/cpu%d/online", cpu);
+
+	if (sysfs__read_str(buf, &str, &strlen) < 0)
+		return status;
+
+	status = atoi(str);
+
+	free(str);
+	return status;
+}
+
 static int parse_setup_cpu_list(void)
 {
 	struct thread_data *td;