1 files changed, 95 insertions, 0 deletions
diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c
new file mode 100644
index 000000000000..91b8d0896fbb
--- /dev/null
+++ b/samples/bpf/tracex2_user.c
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/bpf.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+
+#define MAX_INDEX	64
+#define MAX_STARS	38
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+static void print_hist(int fd)
+{
+	int key;
+	long value;
+	long data[MAX_INDEX] = {};
+	char starstr[MAX_STARS];
+	int i;
+	int max_ind = -1;
+	long max_value = 0;
+
+	for (key = 0; key < MAX_INDEX; key++) {
+		bpf_lookup_elem(fd, &key, &value);
+		data[key] = value;
+		if (value && key > max_ind)
+			max_ind = key;
+		if (value > max_value)
+			max_value = value;
+	}
+
+	printf("           syscall write() stats\n");
+	printf("     byte_size       : count     distribution\n");
+	for (i = 1; i <= max_ind + 1; i++) {
+		stars(starstr, data[i - 1], max_value, MAX_STARS);
+		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
+		       MAX_STARS, starstr);
+	}
+}
+static void int_exit(int sig)
+{
+	print_hist(map_fd[1]);
+	exit(0);
+}
+
+int main(int ac, char **argv)
+{
+	char filename[256];
+	long key, next_key, value;
+	FILE *f;
+	int i;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	signal(SIGINT, int_exit);
+
+	/* start 'ping' in the background to have some kfree_skb events */
+	f = popen("ping -c5 localhost", "r");
+	(void) f;
+
+	/* start 'dd' in the background to have plenty of 'write' syscalls */
+	f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r");
+	(void) f;
+
+	if (load_bpf_file(filename)) {
+		printf("%s", bpf_log_buf);
+		return 1;
+	}
+
+	for (i = 0; i < 5; i++) {
+		key = 0;
+		while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
+			bpf_lookup_elem(map_fd[0], &next_key, &value);
+			printf("location 0x%lx count %ld\n", next_key, value);
+			key = next_key;
+		}
+		if (key)
+			printf("\n");
+		sleep(1);
+	}
+	print_hist(map_fd[1]);
+
+	return 0;
+}