1 #include <stdio.h> 2 #include <unistd.h> 3 #include <stdlib.h> 4 #include <signal.h> 5 #include <linux/bpf.h> 6 #include <string.h> 7 #include "libbpf.h" 8 #include "bpf_load.h" 9 10 #define MAX_INDEX 64 11 #define MAX_STARS 38 12 13 static void stars(char *str, long val, long max, int width) 14 { 15 int i; 16 17 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) 18 str[i] = '*'; 19 if (val > max) 20 str[i - 1] = '+'; 21 str[i] = '\0'; 22 } 23 24 struct task { 25 char comm[16]; 26 __u64 pid_tgid; 27 __u64 uid_gid; 28 }; 29 30 struct hist_key { 31 struct task t; 32 __u32 index; 33 }; 34 35 #define SIZE sizeof(struct task) 36 37 static void print_hist_for_pid(int fd, void *task) 38 { 39 struct hist_key key = {}, next_key; 40 char starstr[MAX_STARS]; 41 long value; 42 long data[MAX_INDEX] = {}; 43 int max_ind = -1; 44 long max_value = 0; 45 int i, ind; 46 47 while (bpf_get_next_key(fd, &key, &next_key) == 0) { 48 if (memcmp(&next_key, task, SIZE)) { 49 key = next_key; 50 continue; 51 } 52 bpf_lookup_elem(fd, &next_key, &value); 53 ind = next_key.index; 54 data[ind] = value; 55 if (value && ind > max_ind) 56 max_ind = ind; 57 if (value > max_value) 58 max_value = value; 59 key = next_key; 60 } 61 62 printf(" syscall write() stats\n"); 63 printf(" byte_size : count distribution\n"); 64 for (i = 1; i <= max_ind + 1; i++) { 65 stars(starstr, data[i - 1], max_value, MAX_STARS); 66 printf("%8ld -> %-8ld : %-8ld |%-*s|\n", 67 (1l << i) >> 1, (1l << i) - 1, data[i - 1], 68 MAX_STARS, starstr); 69 } 70 } 71 72 static void print_hist(int fd) 73 { 74 struct hist_key key = {}, next_key; 75 static struct task tasks[1024]; 76 int task_cnt = 0; 77 int i; 78 79 while (bpf_get_next_key(fd, &key, &next_key) == 0) { 80 int found = 0; 81 82 for (i = 0; i < task_cnt; i++) 83 if (memcmp(&tasks[i], &next_key, SIZE) == 0) 84 found = 1; 85 if (!found) 86 memcpy(&tasks[task_cnt++], &next_key, SIZE); 87 key = next_key; 88 } 89 90 for (i = 0; i < task_cnt; i++) { 91 printf("\npid %d cmd %s uid %d\n", 92 (__u32) tasks[i].pid_tgid, 93 tasks[i].comm, 94 (__u32) tasks[i].uid_gid); 95 print_hist_for_pid(fd, &tasks[i]); 96 } 97 98 } 99 100 static void int_exit(int sig) 101 { 102 print_hist(map_fd[1]); 103 exit(0); 104 } 105 106 int main(int ac, char **argv) 107 { 108 char filename[256]; 109 long key, next_key, value; 110 FILE *f; 111 int i; 112 113 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 114 115 signal(SIGINT, int_exit); 116 117 /* start 'ping' in the background to have some kfree_skb events */ 118 f = popen("ping -c5 localhost", "r"); 119 (void) f; 120 121 /* start 'dd' in the background to have plenty of 'write' syscalls */ 122 f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r"); 123 (void) f; 124 125 if (load_bpf_file(filename)) { 126 printf("%s", bpf_log_buf); 127 return 1; 128 } 129 130 for (i = 0; i < 5; i++) { 131 key = 0; 132 while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) { 133 bpf_lookup_elem(map_fd[0], &next_key, &value); 134 printf("location 0x%lx count %ld\n", next_key, value); 135 key = next_key; 136 } 137 if (key) 138 printf("\n"); 139 sleep(1); 140 } 141 print_hist(map_fd[1]); 142 143 return 0; 144 } 145