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;
+}