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 <sys/wait.h>
  25 #include <signal.h>
  26
  27 #include <linux/genetlink.h>
  28 #include <linux/taskstats.h>
  29 #include <linux/cgroupstats.h>
  30
  31 /*
  32  * Generic macros for dealing with netlink sockets. Might be duplicated
  33  * elsewhere. It is recommended that commercial grade applications use
  34  * libnl or libnetlink and use the interfaces provided by the library
  35  */
  36 #define GENLMSG_DATA(glh)       ((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
  37 #define GENLMSG_PAYLOAD(glh)    (NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)
  38 #define NLA_DATA(na)            ((void *)((char*)(na) + NLA_HDRLEN))
  39 #define NLA_PAYLOAD(len)        (len - NLA_HDRLEN)
  40
  41 #define err(code, fmt, arg...)                  \
  42         do {                                    \
  43                 fprintf(stderr, fmt, ##arg);    \
  44                 exit(code);                     \
  45         } while (0)
  46
  47 int done;
  48 int rcvbufsz;
  49 char name[100];
  50 int dbg;
  51 int print_delays;
  52 int print_io_accounting;
  53 int print_task_context_switch_counts;
  54
  55 #define PRINTF(fmt, arg...) {                   \
  56             if (dbg) {                          \
  57                 printf(fmt, ##arg);             \
  58             }                                   \
  59         }
  60
  61 /* Maximum size of response requested or message sent */
  62 #define MAX_MSG_SIZE    1024
  63 /* Maximum number of cpus expected to be specified in a cpumask */
  64 #define MAX_CPUS        32
  65
  66 struct msgtemplate {
  67         struct nlmsghdr n;
  68         struct genlmsghdr g;
  69         char buf[MAX_MSG_SIZE];
  70 };
  71
  72 char cpumask[100+6*MAX_CPUS];
  73
  74 static void usage(void)
  75 {
  76         fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
  77                         "[-m cpumask] [-t tgid] [-p pid]\n");
  78         fprintf(stderr, "  -d: print delayacct stats\n");
  79         fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
  80         fprintf(stderr, "  -l: listen forever\n");
  81         fprintf(stderr, "  -v: debug on\n");
  82         fprintf(stderr, "  -C: container path\n");
  83 }
  84
  85 /*
  86  * Create a raw netlink socket and bind
  87  */
  88 static int create_nl_socket(int protocol)
  89 {
  90         int fd;
  91         struct sockaddr_nl local;
  92
  93         fd = socket(AF_NETLINK, SOCK_RAW, protocol);
  94         if (fd < 0)
  95                 return -1;
  96
  97         if (rcvbufsz)
  98                 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
  99                                 &rcvbufsz, sizeof(rcvbufsz)) < 0) {
 100                         fprintf(stderr, "Unable to set socket rcv buf size to %d\n",
 101                                 rcvbufsz);
 102                         goto error;
 103                 }
 104
 105         memset(&local, 0, sizeof(local));
 106         local.nl_family = AF_NETLINK;
 107
 108         if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
 109                 goto error;
 110
 111         return fd;
 112 error:
 113         close(fd);
 114         return -1;
 115 }
 116
 117
 118 static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
 119              __u8 genl_cmd, __u16 nla_type,
 120              void *nla_data, int nla_len)
 121 {
 122         struct nlattr *na;
 123         struct sockaddr_nl nladdr;
 124         int r, buflen;
 125         char *buf;
 126
 127         struct msgtemplate msg;
 128
 129         msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
 130         msg.n.nlmsg_type = nlmsg_type;
 131         msg.n.nlmsg_flags = NLM_F_REQUEST;
 132         msg.n.nlmsg_seq = 0;
 133         msg.n.nlmsg_pid = nlmsg_pid;
 134         msg.g.cmd = genl_cmd;
 135         msg.g.version = 0x1;
 136         na = (struct nlattr *) GENLMSG_DATA(&msg);
 137         na->nla_type = nla_type;
 138         na->nla_len = nla_len + 1 + NLA_HDRLEN;
 139         memcpy(NLA_DATA(na), nla_data, nla_len);
 140         msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
 141
 142         buf = (char *) &msg;
 143         buflen = msg.n.nlmsg_len ;
 144         memset(&nladdr, 0, sizeof(nladdr));
 145         nladdr.nl_family = AF_NETLINK;
 146         while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
 147                            sizeof(nladdr))) < buflen) {
 148                 if (r > 0) {
 149                         buf += r;
 150                         buflen -= r;
 151                 } else if (errno != EAGAIN)
 152                         return -1;
 153         }
 154         return 0;
 155 }
 156
 157
 158 /*
 159  * Probe the controller in genetlink to find the family id
 160  * for the TASKSTATS family
 161  */
 162 static int get_family_id(int sd)
 163 {
 164         struct {
 165                 struct nlmsghdr n;
 166                 struct genlmsghdr g;
 167                 char buf[256];
 168         } ans;
 169
 170         int id = 0, rc;
 171         struct nlattr *na;
 172         int rep_len;
 173
 174         strcpy(name, TASKSTATS_GENL_NAME);
 175         rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
 176                         CTRL_ATTR_FAMILY_NAME, (void *)name,
 177                         strlen(TASKSTATS_GENL_NAME)+1);
 178         if (rc < 0)
 179                 return 0;       /* sendto() failure? */
 180
 181         rep_len = recv(sd, &ans, sizeof(ans), 0);
 182         if (ans.n.nlmsg_type == NLMSG_ERROR ||
 183             (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
 184                 return 0;
 185
 186         na = (struct nlattr *) GENLMSG_DATA(&ans);
 187         na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
 188         if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
 189                 id = *(__u16 *) NLA_DATA(na);
 190         }
 191         return id;
 192 }
 193
 194 #define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
 195
 196 static void print_delayacct(struct taskstats *t)
 197 {
 198         printf("\n\nCPU   %15s%15s%15s%15s%15s\n"
 199                "      %15llu%15llu%15llu%15llu%15.3fms\n"
 200                "IO    %15s%15s%15s\n"
 201                "      %15llu%15llu%15llums\n"
 202                "SWAP  %15s%15s%15s\n"
 203                "      %15llu%15llu%15llums\n"
 204                "RECLAIM  %12s%15s%15s\n"
 205                "      %15llu%15llu%15llums\n",
 206                "count", "real total", "virtual total",
 207                "delay total", "delay average",
 208                (unsigned long long)t->cpu_count,
 209                (unsigned long long)t->cpu_run_real_total,
 210                (unsigned long long)t->cpu_run_virtual_total,
 211                (unsigned long long)t->cpu_delay_total,
 212                average_ms((double)t->cpu_delay_total, t->cpu_count),
 213                "count", "delay total", "delay average",
 214                (unsigned long long)t->blkio_count,
 215                (unsigned long long)t->blkio_delay_total,
 216                average_ms(t->blkio_delay_total, t->blkio_count),
 217                "count", "delay total", "delay average",
 218                (unsigned long long)t->swapin_count,
 219                (unsigned long long)t->swapin_delay_total,
 220                average_ms(t->swapin_delay_total, t->swapin_count),
 221                "count", "delay total", "delay average",
 222                (unsigned long long)t->freepages_count,
 223                (unsigned long long)t->freepages_delay_total,
 224                average_ms(t->freepages_delay_total, t->freepages_count));
 225 }
 226
 227 static void task_context_switch_counts(struct taskstats *t)
 228 {
 229         printf("\n\nTask   %15s%15s\n"
 230                "       %15llu%15llu\n",
 231                "voluntary", "nonvoluntary",
 232                (unsigned long long)t->nvcsw, (unsigned long long)t->nivcsw);
 233 }
 234
 235 static void print_cgroupstats(struct cgroupstats *c)
 236 {
 237         printf("sleeping %llu, blocked %llu, running %llu, stopped %llu, "
 238                 "uninterruptible %llu\n", (unsigned long long)c->nr_sleeping,
 239                 (unsigned long long)c->nr_io_wait,
 240                 (unsigned long long)c->nr_running,
 241                 (unsigned long long)c->nr_stopped,
 242                 (unsigned long long)c->nr_uninterruptible);
 243 }
 244
 245
 246 static void print_ioacct(struct taskstats *t)
 247 {
 248         printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
 249                 t->ac_comm,
 250                 (unsigned long long)t->read_bytes,
 251                 (unsigned long long)t->write_bytes,
 252                 (unsigned long long)t->cancelled_write_bytes);
 253 }
 254
 255 int main(int argc, char *argv[])
 256 {
 257         int c, rc, rep_len, aggr_len, len2;
 258         int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
 259         __u16 id;
 260         __u32 mypid;
 261
 262         struct nlattr *na;
 263         int nl_sd = -1;
 264         int len = 0;
 265         pid_t tid = 0;
 266         pid_t rtid = 0;
 267
 268         int fd = 0;
 269         int count = 0;
 270         int write_file = 0;
 271         int maskset = 0;
 272         char *logfile = NULL;
 273         int loop = 0;
 274         int containerset = 0;
 275         char *containerpath = NULL;
 276         int cfd = 0;
 277         int forking = 0;
 278         sigset_t sigset;
 279
 280         struct msgtemplate msg;
 281
 282         while (!forking) {
 283                 c = getopt(argc, argv, "qdiw:r:m:t:p:vlC:c:");
 284                 if (c < 0)
 285                         break;
 286
 287                 switch (c) {
 288                 case 'd':
 289                         printf("print delayacct stats ON\n");
 290                         print_delays = 1;
 291                         break;
 292                 case 'i':
 293                         printf("printing IO accounting\n");
 294                         print_io_accounting = 1;
 295                         break;
 296                 case 'q':
 297                         printf("printing task/process context switch rates\n");
 298                         print_task_context_switch_counts = 1;
 299                         break;
 300                 case 'C':
 301                         containerset = 1;
 302                         containerpath = optarg;
 303                         break;
 304                 case 'w':
 305                         logfile = strdup(optarg);
 306                         printf("write to file %s\n", logfile);
 307                         write_file = 1;
 308                         break;
 309                 case 'r':
 310                         rcvbufsz = atoi(optarg);
 311                         printf("receive buf size %d\n", rcvbufsz);
 312                         if (rcvbufsz < 0)
 313                                 err(1, "Invalid rcv buf size\n");
 314                         break;
 315                 case 'm':
 316                         strncpy(cpumask, optarg, sizeof(cpumask));
 317                         cpumask[sizeof(cpumask) - 1] = '\0';
 318                         maskset = 1;
 319                         printf("cpumask %s maskset %d\n", cpumask, maskset);
 320                         break;
 321                 case 't':
 322                         tid = atoi(optarg);
 323                         if (!tid)
 324                                 err(1, "Invalid tgid\n");
 325                         cmd_type = TASKSTATS_CMD_ATTR_TGID;
 326                         break;
 327                 case 'p':
 328                         tid = atoi(optarg);
 329                         if (!tid)
 330                                 err(1, "Invalid pid\n");
 331                         cmd_type = TASKSTATS_CMD_ATTR_PID;
 332                         break;
 333                 case 'c':
 334
 335                         /* Block SIGCHLD for sigwait() later */
 336                         if (sigemptyset(&sigset) == -1)
 337                                 err(1, "Failed to empty sigset");
 338                         if (sigaddset(&sigset, SIGCHLD))
 339                                 err(1, "Failed to set sigchld in sigset");
 340                         sigprocmask(SIG_BLOCK, &sigset, NULL);
 341
 342                         /* fork/exec a child */
 343                         tid = fork();
 344                         if (tid < 0)
 345                                 err(1, "Fork failed\n");
 346                         if (tid == 0)
 347                                 if (execvp(argv[optind - 1],
 348                                     &argv[optind - 1]) < 0)
 349                                         exit(-1);
 350
 351                         /* Set the command type and avoid further processing */
 352                         cmd_type = TASKSTATS_CMD_ATTR_PID;
 353                         forking = 1;
 354                         break;
 355                 case 'v':
 356                         printf("debug on\n");
 357                         dbg = 1;
 358                         break;
 359                 case 'l':
 360                         printf("listen forever\n");
 361                         loop = 1;
 362                         break;
 363                 default:
 364                         usage();
 365                         exit(-1);
 366                 }
 367         }
 368
 369         if (write_file) {
 370                 fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
 371                           S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 372                 if (fd == -1) {
 373                         perror("Cannot open output file\n");
 374                         exit(1);
 375                 }
 376         }
 377
 378         nl_sd = create_nl_socket(NETLINK_GENERIC);
 379         if (nl_sd < 0)
 380                 err(1, "error creating Netlink socket\n");
 381
 382
 383         mypid = getpid();
 384         id = get_family_id(nl_sd);
 385         if (!id) {
 386                 fprintf(stderr, "Error getting family id, errno %d\n", errno);
 387                 goto err;
 388         }
 389         PRINTF("family id %d\n", id);
 390
 391         if (maskset) {
 392                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 393                               TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
 394                               &cpumask, strlen(cpumask) + 1);
 395                 PRINTF("Sent register cpumask, retval %d\n", rc);
 396                 if (rc < 0) {
 397                         fprintf(stderr, "error sending register cpumask\n");
 398                         goto err;
 399                 }
 400         }
 401
 402         if (tid && containerset) {
 403                 fprintf(stderr, "Select either -t or -C, not both\n");
 404                 goto err;
 405         }
 406
 407         /*
 408          * If we forked a child, wait for it to exit. Cannot use waitpid()
 409          * as all the delicious data would be reaped as part of the wait
 410          */
 411         if (tid && forking) {
 412                 int sig_received;
 413                 sigwait(&sigset, &sig_received);
 414         }
 415
 416         if (tid) {
 417                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 418                               cmd_type, &tid, sizeof(__u32));
 419                 PRINTF("Sent pid/tgid, retval %d\n", rc);
 420                 if (rc < 0) {
 421                         fprintf(stderr, "error sending tid/tgid cmd\n");
 422                         goto done;
 423                 }
 424         }
 425
 426         if (containerset) {
 427                 cfd = open(containerpath, O_RDONLY);
 428                 if (cfd < 0) {
 429                         perror("error opening container file");
 430                         goto err;
 431                 }
 432                 rc = send_cmd(nl_sd, id, mypid, CGROUPSTATS_CMD_GET,
 433                               CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32));
 434                 if (rc < 0) {
 435                         perror("error sending cgroupstats command");
 436                         goto err;
 437                 }
 438         }
 439         if (!maskset && !tid && !containerset) {
 440                 usage();
 441                 goto err;
 442         }
 443
 444         do {
 445                 rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
 446                 PRINTF("received %d bytes\n", rep_len);
 447
 448                 if (rep_len < 0) {
 449                         fprintf(stderr, "nonfatal reply error: errno %d\n",
 450                                 errno);
 451                         continue;
 452                 }
 453                 if (msg.n.nlmsg_type == NLMSG_ERROR ||
 454                     !NLMSG_OK((&msg.n), rep_len)) {
 455                         struct nlmsgerr *err = NLMSG_DATA(&msg);
 456                         fprintf(stderr, "fatal reply error,  errno %d\n",
 457                                 err->error);
 458                         goto done;
 459                 }
 460
 461                 PRINTF("nlmsghdr size=%zu, nlmsg_len=%d, rep_len=%d\n",
 462                        sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
 463
 464
 465                 rep_len = GENLMSG_PAYLOAD(&msg.n);
 466
 467                 na = (struct nlattr *) GENLMSG_DATA(&msg);
 468                 len = 0;
 469                 while (len < rep_len) {
 470                         len += NLA_ALIGN(na->nla_len);
 471                         switch (na->nla_type) {
 472                         case TASKSTATS_TYPE_AGGR_TGID:
 473                                 /* Fall through */
 474                         case TASKSTATS_TYPE_AGGR_PID:
 475                                 aggr_len = NLA_PAYLOAD(na->nla_len);
 476                                 len2 = 0;
 477                                 /* For nested attributes, na follows */
 478                                 na = (struct nlattr *) NLA_DATA(na);
 479                                 done = 0;
 480                                 while (len2 < aggr_len) {
 481                                         switch (na->nla_type) {
 482                                         case TASKSTATS_TYPE_PID:
 483                                                 rtid = *(int *) NLA_DATA(na);
 484                                                 if (print_delays)
 485                                                         printf("PID\t%d\n", rtid);
 486                                                 break;
 487                                         case TASKSTATS_TYPE_TGID:
 488                                                 rtid = *(int *) NLA_DATA(na);
 489                                                 if (print_delays)
 490                                                         printf("TGID\t%d\n", rtid);
 491                                                 break;
 492                                         case TASKSTATS_TYPE_STATS:
 493                                                 count++;
 494                                                 if (print_delays)
 495                                                         print_delayacct((struct taskstats *) NLA_DATA(na));
 496                                                 if (print_io_accounting)
 497                                                         print_ioacct((struct taskstats *) NLA_DATA(na));
 498                                                 if (print_task_context_switch_counts)
 499                                                         task_context_switch_counts((struct taskstats *) NLA_DATA(na));
 500                                                 if (fd) {
 501                                                         if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
 502                                                                 err(1,"write error\n");
 503                                                         }
 504                                                 }
 505                                                 if (!loop)
 506                                                         goto done;
 507                                                 break;
 508                                         default:
 509                                                 fprintf(stderr, "Unknown nested"
 510                                                         " nla_type %d\n",
 511                                                         na->nla_type);
 512                                                 break;
 513                                         }
 514                                         len2 += NLA_ALIGN(na->nla_len);
 515                                         na = (struct nlattr *) ((char *) na + len2);
 516                                 }
 517                                 break;
 518
 519                         case CGROUPSTATS_TYPE_CGROUP_STATS:
 520                                 print_cgroupstats(NLA_DATA(na));
 521                                 break;
 522                         default:
 523                                 fprintf(stderr, "Unknown nla_type %d\n",
 524                                         na->nla_type);
 525                         case TASKSTATS_TYPE_NULL:
 526                                 break;
 527                         }
 528                         na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
 529                 }
 530         } while (loop);
 531 done:
 532         if (maskset) {
 533                 rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 534                               TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
 535                               &cpumask, strlen(cpumask) + 1);
 536                 printf("Sent deregister mask, retval %d\n", rc);
 537                 if (rc < 0)
 538                         err(rc, "error sending deregister cpumask\n");
 539         }
 540 err:
 541         close(nl_sd);
 542         if (fd)
 543                 close(fd);
 544         if (cfd)
 545                 close(cfd);
 546         return 0;
 547 }