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 <sys/resource.h> 8 9 #include "libbpf.h" 10 #include "bpf_load.h" 11 #include "bpf_util.h" 12 13 #define MAX_INDEX 64 14 #define MAX_STARS 38 15 16 static void stars(char *str, long val, long max, int width) 17 { 18 int i; 19 20 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) 21 str[i] = '*'; 22 if (val > max) 23 str[i - 1] = '+'; 24 str[i] = '\0'; 25 } 26 27 struct task { 28 char comm[16]; 29 __u64 pid_tgid; 30 __u64 uid_gid; 31 }; 32 33 struct hist_key { 34 struct task t; 35 __u32 index; 36 }; 37 38 #define SIZE sizeof(struct task) 39 40 static void print_hist_for_pid(int fd, void *task) 41 { 42 unsigned int nr_cpus = bpf_num_possible_cpus(); 43 struct hist_key key = {}, next_key; 44 long values[nr_cpus]; 45 char starstr[MAX_STARS]; 46 long value; 47 long data[MAX_INDEX] = {}; 48 int max_ind = -1; 49 long max_value = 0; 50 int i, ind; 51 52 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { 53 if (memcmp(&next_key, task, SIZE)) { 54 key = next_key; 55 continue; 56 } 57 bpf_map_lookup_elem(fd, &next_key, values); 58 value = 0; 59 for (i = 0; i < nr_cpus; i++) 60 value += values[i]; 61 ind = next_key.index; 62 data[ind] = value; 63 if (value && ind > max_ind) 64 max_ind = ind; 65 if (value > max_value) 66 max_value = value; 67 key = next_key; 68 } 69 70 printf(" syscall write() stats\n"); 71 printf(" byte_size : count distribution\n"); 72 for (i = 1; i <= max_ind + 1; i++) { 73 stars(starstr, data[i - 1], max_value, MAX_STARS); 74 printf("%8ld -> %-8ld : %-8ld |%-*s|\n", 75 (1l << i) >> 1, (1l << i) - 1, data[i - 1], 76 MAX_STARS, starstr); 77 } 78 } 79 80 static void print_hist(int fd) 81 { 82 struct hist_key key = {}, next_key; 83 static struct task tasks[1024]; 84 int task_cnt = 0; 85 int i; 86 87 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { 88 int found = 0; 89 90 for (i = 0; i < task_cnt; i++) 91 if (memcmp(&tasks[i], &next_key, SIZE) == 0) 92 found = 1; 93 if (!found) 94 memcpy(&tasks[task_cnt++], &next_key, SIZE); 95 key = next_key; 96 } 97 98 for (i = 0; i < task_cnt; i++) { 99 printf("\npid %d cmd %s uid %d\n", 100 (__u32) tasks[i].pid_tgid, 101 tasks[i].comm, 102 (__u32) tasks[i].uid_gid); 103 print_hist_for_pid(fd, &tasks[i]); 104 } 105 106 } 107 108 static void int_exit(int sig) 109 { 110 print_hist(map_fd[1]); 111 exit(0); 112 } 113 114 int main(int ac, char **argv) 115 { 116 struct rlimit r = {1024*1024, RLIM_INFINITY}; 117 char filename[256]; 118 long key, next_key, value; 119 FILE *f; 120 int i; 121 122 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 123 124 if (setrlimit(RLIMIT_MEMLOCK, &r)) { 125 perror("setrlimit(RLIMIT_MEMLOCK)"); 126 return 1; 127 } 128 129 signal(SIGINT, int_exit); 130 signal(SIGTERM, int_exit); 131 132 /* start 'ping' in the background to have some kfree_skb events */ 133 f = popen("ping -c5 localhost", "r"); 134 (void) f; 135 136 /* start 'dd' in the background to have plenty of 'write' syscalls */ 137 f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r"); 138 (void) f; 139 140 if (load_bpf_file(filename)) { 141 printf("%s", bpf_log_buf); 142 return 1; 143 } 144 145 for (i = 0; i < 5; i++) { 146 key = 0; 147 while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) { 148 bpf_map_lookup_elem(map_fd[0], &next_key, &value); 149 printf("location 0x%lx count %ld\n", next_key, value); 150 key = next_key; 151 } 152 if (key) 153 printf("\n"); 154 sleep(1); 155 } 156 print_hist(map_fd[1]); 157 158 return 0; 159 } 160