Documentation/accounting/getdelays.c

   1 /* getdelays.c
   2  *
   3  * Utility to get per-pid and per-tgid delay accounting statistics
   4  * Also illustrates usage of the taskstats interface
   5  *
   6  * Copyright (C) Shailabh Nagar, IBM Corp. 2005
   7  * Copyright (C) Balbir Singh, IBM Corp. 2006
   8  * Copyright (c) Jay Lan, SGI. 2006
   9  *
  10  * Compile with
  11  *      gcc -I/usr/src/linux/include getdelays.c -o getdelays
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <errno.h>
  17 #include <unistd.h>
  18 #include <poll.h>
  19 #include <string.h>
  20 #include <fcntl.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <sys/socket.h>
  24 #include <signal.h>
  25
  26 #include <linux/genetlink.h>
  27 #include <linux/taskstats.h>
  28
  29 /*
  30  * Generic macros for dealing with netlink sockets. Might be duplicated
  31  * elsewhere. It is recommended that commercial grade applications use
  32  * libnl or libnetlink and use the interfaces provided by the library
  33  */
  34 #define GENLMSG_DATA(glh)       ((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
  35 #define GENLMSG_PAYLOAD(glh)    (NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)
  36 #define NLA_DATA(na)            ((void *)((char*)(na) + NLA_HDRLEN))
  37 #define NLA_PAYLOAD(len)        (len - NLA_HDRLEN)
  38
  39 #define err(code, fmt, arg...)                  \
  40         do {                                    \
  41                 fprintf(stderr, fmt, ##arg);    \
  42                 exit(code);                     \
  43         } while (0)
  44
  45 int done;
  46 int rcvbufsz;
  47 char name[100];
  48 int dbg;
  49 int print_delays;
  50 int print_io_accounting;
  51 int print_task_context_switch_counts;
  52 __u64 stime, utime;
  53
  54 #define PRINTF(fmt, arg...) {                   \
  55             if (dbg) {                          \
  56                 printf(fmt, ##arg);             \
  57             }                                   \
  58         }
  59
  60 /* Maximum size of response requested or message sent */
  61 #define MAX_MSG_SIZE    1024
  62 /* Maximum number of cpus expected to be specified in a cpumask */
  63 #define MAX_CPUS        32
  64
  65 struct msgtemplate {
  66         struct nlmsghdr n;
  67         struct genlmsghdr g;
  68         char buf[MAX_MSG_SIZE];
  69 };
  70
  71 char cpumask[100+6*MAX_CPUS];
  72
  73 static void usage(void)
  74 {
  75         fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
  76                         "[-m cpumask] [-t tgid] [-p pid]\n");
  77         fprintf(stderr, "  -d: print delayacct stats\n");
  78         fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
  79         fprintf(stderr, "  -l: listen forever\n");
  80         fprintf(stderr, "  -v: debug on\n");
  81 }
  82
  83 /*
  84  * Create a raw netlink socket and bind
  85  */
  86 static int create_nl_socket(int protocol)
  87 {
  88         int fd;
  89         struct sockaddr_nl local;
  90
  91         fd = socket(AF_NETLINK, SOCK_RAW, protocol);
  92         if (fd < 0)
  93                 return -1;
  94
  95         if (rcvbufsz)
  96                 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
  97                                 &rcvbufsz, sizeof(rcvbufsz)) < 0) {
  98                         fprintf(stderr, "Unable to set socket rcv buf size "
  99                                         "to %d\n",
 100                                 rcvbufsz);
 101                         return -1;
 102                 }
 103
 104         memset(&local, 0, sizeof(local));
 105         local.nl_family = AF_NETLINK;
 106
 107         if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
 108                 goto error;
 109
 110         return fd;
 111 error:
 112         close(fd);
 113         return -1;
 114 }
 115
 116
 117 int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
 118              __u8 genl_cmd, __u16 nla_type,
 119              void *nla_data, int nla_len)
 120 {
 121         struct nlattr *na;
 122         struct sockaddr_nl nladdr;
 123         int r, buflen;
 124         char *buf;
 125
 126         struct msgtemplate msg;
 127
 128         msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
 129         msg.n.nlmsg_type = nlmsg_type;
 130         msg.n.nlmsg_flags = NLM_F_REQUEST;
 131         msg.n.nlmsg_seq = 0;
 132         msg.n.nlmsg_pid = nlmsg_pid;
 133         msg.g.cmd = genl_cmd;
 134         msg.g.version = 0x1;
 135         na = (struct nlattr *) GENLMSG_DATA(&msg);
 136         na->nla_type = nla_type;
 137         na->nla_len = nla_len + 1 + NLA_HDRLEN;
 138         memcpy(NLA_DATA(na), nla_data, nla_len);
 139         msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
 140
 141         buf = (char *) &msg;
 142         buflen = msg.n.nlmsg_len ;
 143         memset(&nladdr, 0, sizeof(nladdr));
 144         nladdr.nl_family = AF_NETLINK;
 145         while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
 146                            sizeof(nladdr))) < buflen) {
 147                 if (r > 0) {
 148                         buf += r;
 149                         buflen -= r;
 150                 } else if (errno != EAGAIN)
 151                         return -1;
 152         }
 153         return 0;
 154 }
 155
 156
 157 /*
 158  * Probe the controller in genetlink to find the family id
 159  * for the TASKSTATS family
 160  */
 161 int get_family_id(int sd)
 162 {
 163         struct {
 164                 struct nlmsghdr n;
 165                 struct genlmsghdr g;
 166                 char buf[256];
 167         } ans;
 168
 169         int id, rc;
 170         struct nlattr *na;
 171         int rep_len;
 172
 173         strcpy(name, TASKSTATS_GENL_NAME);
 174         rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
 175                         CTRL_ATTR_FAMILY_NAME, (void *)name,
 176                         strlen(TASKSTATS_GENL_NAME)+1);
 177
 178         rep_len = recv(sd, &ans, sizeof(ans), 0);
 179         if (ans.n.nlmsg_type == NLMSG_ERROR ||
 180             (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
 181                 return 0;
 182
 183         na = (struct nlattr *) GENLMSG_DATA(&ans);
 184         na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
 185         if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
 186                 id = *(__u16 *) NLA_DATA(na);
 187         }
 188         return id;
 189 }
 190
 191 void print_delayacct(struct taskstats *t)
 192 {
 193         printf("\n\nCPU   %15s%15s%15s%15s\n"
 194                "      %15llu%15llu%15llu%15llu\n"
 195                "IO    %15s%15s\n"
 196                "      %15llu%15llu\n"
 197                "MEM   %15s%15s\n"
 198                "      %15llu%15llu\n",
 199                "count", "real total", "virtual total", "delay total",
 200                t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
 201                t->cpu_delay_total,
 202                "count", "delay total",
 203                t->blkio_count, t->blkio_delay_total,
 204                "count", "delay total", t->swapin_count, t->swapin_delay_total);
 205 }
 206
 207 void task_context_switch_counts(struct taskstats *t)
 208 {
 209         printf("\n\nTask   %15s%15s\n"
 210                "       %15lu%15lu\n",
 211                "voluntary", "nonvoluntary",
 212                t->nvcsw, t->nivcsw);
 213 }
 214
 215 void print_ioacct(struct taskstats *t)
 216 {
 217         printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
 218                 t->ac_comm,
 219                 (unsigned long long)t->read_bytes,
 220                 (unsigned long long)t->write_bytes,
 221                 (unsigned long long)t->cancelled_write_bytes);
 222 }
 223
 224 int main(int argc, char *argv[])
 225 {
 226         int c, rc, rep_len, aggr_len, len2, cmd_type;
 227         __u16 id;
 228         __u32 mypid;
 229
 230         struct nlattr *na;
 231         int nl_sd = -1;
 232         int len = 0;
 233         pid_t tid = 0;
 234         pid_t rtid = 0;
 235
 236         int fd = 0;
 237         int count = 0;
 238         int write_file = 0;
 239         int maskset = 0;
 240         char *logfile = NULL;
 241         int loop = 0;
 242
 243         struct msgtemplate msg;
 244
 245         while (1) {
 246                 c = getopt(argc, argv, "qdiw:r:m:t:p:vl");
 247                 if (c < 0)
 248                         break;
 249
 250                 switch (c) {
 251                 case 'd':
 252                         printf("print delayacct stats ON\n");
 253                         print_delays = 1;
 254                         break;
 255                 case 'i':
 256                         printf("printing IO accounting\n");
 257                         print_io_accounting = 1;
 258                         break;
 259                 case 'q':
 260                         printf("printing task/process context switch rates\n");
 261                         print_task_context_switch_counts = 1;
 262                         break;
 263                 case 'w':
 264                         logfile = strdup(optarg);
 265                         printf("write to file %s\n", logfile);
 266                         write_file = 1;
 267                         break;
 268                 case 'r':
 269                         rcvbufsz = atoi(optarg);
 270                         printf("receive buf size %d\n", rcvbufsz);
 271                         if (rcvbufsz < 0)
 272                                 err(1, "Invalid rcv buf size\n");
 273                         break;
 274                 case 'm':
 275                         strncpy(cpumask, optarg, sizeof(cpumask));
 276                         maskset = 1;
 277                         printf("cpumask %s maskset %d\n", cpumask, maskset);
 278                         break;
 279                 case 't':
 280                         tid = atoi(optarg);
 281                         if (!tid)
 282                                 err(1, "Invalid tgid\n");
 283                         cmd_type = TASKSTATS_CMD_ATTR_TGID;
 284                         break;
 285                 case 'p':
 286                         tid = atoi(optarg);
 287                         if (!tid)
 288                                 err(1, "Invalid pid\n");
 289                         cmd_type = TASKSTATS_CMD_ATTR_PID;
 290                         break;
 291                 case 'v':
 292                         printf("debug on\n");
 293                         dbg = 1;
 294                         break;
 295                 case 'l':
 296                         printf("listen forever\n");
 297                         loop = 1;
 298                         break;
 299                 default:
 300                         usage();
 301                         exit(-1);
 302                 }
 303         }
 304
 305         if (write_file) {
 306                 fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
 307                           S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 308                 if (fd == -1) {
 309                         perror("Cannot open output file\n");
 310                         exit(1);
 311                 }
 312         }
 313
 314         if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 0)
 315                 err(1, "error creating Netlink socket\n");
 316
 317
 318         mypid = getpid();
 319         id = get_family_id(nl_sd);
 320         if (!id) {
 321                 fprintf(stderr, "Error getting family id, errno %d\n", errno);
 322                 goto err;
 323         }
 324         PRINTF("family id %d\n", id);
 325
 326         if (maskset) {
 327                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 328                               TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
 329                               &cpumask, strlen(cpumask) + 1);
 330                 PRINTF("Sent register cpumask, retval %d\n", rc);
 331                 if (rc < 0) {
 332                         fprintf(stderr, "error sending register cpumask\n");
 333                         goto err;
 334                 }
 335         }
 336
 337         if (tid) {
 338                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 339                               cmd_type, &tid, sizeof(__u32));
 340                 PRINTF("Sent pid/tgid, retval %d\n", rc);
 341                 if (rc < 0) {
 342                         fprintf(stderr, "error sending tid/tgid cmd\n");
 343                         goto done;
 344                 }
 345         }
 346
 347         do {
 348                 int i;
 349
 350                 rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
 351                 PRINTF("received %d bytes\n", rep_len);
 352
 353                 if (rep_len < 0) {
 354                         fprintf(stderr, "nonfatal reply error: errno %d\n",
 355                                 errno);
 356                         continue;
 357                 }
 358                 if (msg.n.nlmsg_type == NLMSG_ERROR ||
 359                     !NLMSG_OK((&msg.n), rep_len)) {
 360                         struct nlmsgerr *err = NLMSG_DATA(&msg);
 361                         fprintf(stderr, "fatal reply error,  errno %d\n",
 362                                 err->error);
 363                         goto done;
 364                 }
 365
 366                 PRINTF("nlmsghdr size=%d, nlmsg_len=%d, rep_len=%d\n",
 367                        sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
 368
 369
 370                 rep_len = GENLMSG_PAYLOAD(&msg.n);
 371
 372                 na = (struct nlattr *) GENLMSG_DATA(&msg);
 373                 len = 0;
 374                 i = 0;
 375                 while (len < rep_len) {
 376                         len += NLA_ALIGN(na->nla_len);
 377                         switch (na->nla_type) {
 378                         case TASKSTATS_TYPE_AGGR_TGID:
 379                                 /* Fall through */
 380                         case TASKSTATS_TYPE_AGGR_PID:
 381                                 aggr_len = NLA_PAYLOAD(na->nla_len);
 382                                 len2 = 0;
 383                                 /* For nested attributes, na follows */
 384                                 na = (struct nlattr *) NLA_DATA(na);
 385                                 done = 0;
 386                                 while (len2 < aggr_len) {
 387                                         switch (na->nla_type) {
 388                                         case TASKSTATS_TYPE_PID:
 389                                                 rtid = *(int *) NLA_DATA(na);
 390                                                 if (print_delays)
 391                                                         printf("PID\t%d\n", rtid);
 392                                                 break;
 393                                         case TASKSTATS_TYPE_TGID:
 394                                                 rtid = *(int *) NLA_DATA(na);
 395                                                 if (print_delays)
 396                                                         printf("TGID\t%d\n", rtid);
 397                                                 break;
 398                                         case TASKSTATS_TYPE_STATS:
 399                                                 count++;
 400                                                 if (print_delays)
 401                                                         print_delayacct((struct taskstats *) NLA_DATA(na));
 402                                                 if (print_io_accounting)
 403                                                         print_ioacct((struct taskstats *) NLA_DATA(na));
 404                                                 if (print_task_context_switch_counts)
 405                                                         task_context_switch_counts((struct taskstats *) NLA_DATA(na));
 406                                                 if (fd) {
 407                                                         if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
 408                                                                 err(1,"write error\n");
 409                                                         }
 410                                                 }
 411                                                 if (!loop)
 412                                                         goto done;
 413                                                 break;
 414                                         default:
 415                                                 fprintf(stderr, "Unknown nested"
 416                                                         " nla_type %d\n",
 417                                                         na->nla_type);
 418                                                 break;
 419                                         }
 420                                         len2 += NLA_ALIGN(na->nla_len);
 421                                         na = (struct nlattr *) ((char *) na + len2);
 422                                 }
 423                                 break;
 424
 425                         default:
 426                                 fprintf(stderr, "Unknown nla_type %d\n",
 427                                         na->nla_type);
 428                                 break;
 429                         }
 430                         na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
 431                 }
 432         } while (loop);
 433 done:
 434         if (maskset) {
 435                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 436                               TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
 437                               &cpumask, strlen(cpumask) + 1);
 438                 printf("Sent deregister mask, retval %d\n", rc);
 439                 if (rc < 0)
 440                         err(rc, "error sending deregister cpumask\n");
 441         }
 442 err:
 443         close(nl_sd);
 444         if (fd)
 445                 close(fd);
 446         return 0;
 447 }