linux/Documentation/accounting/getdelays.c
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   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
  47int done;
  48int rcvbufsz;
  49char name[100];
  50int dbg;
  51int print_delays;
  52int print_io_accounting;
  53int 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
  66struct msgtemplate {
  67        struct nlmsghdr n;
  68        struct genlmsghdr g;
  69        char buf[MAX_MSG_SIZE];
  70};
  71
  72char cpumask[100+6*MAX_CPUS];
  73
  74static 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 */
  88static 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;
 112error:
 113        close(fd);
 114        return -1;
 115}
 116
 117
 118static 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 */
 162static 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
 196static 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
 227static 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
 235static 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
 246static 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
 255int 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                        maskset = 1;
 318                        printf("cpumask %s maskset %d\n", cpumask, maskset);
 319                        break;
 320                case 't':
 321                        tid = atoi(optarg);
 322                        if (!tid)
 323                                err(1, "Invalid tgid\n");
 324                        cmd_type = TASKSTATS_CMD_ATTR_TGID;
 325                        break;
 326                case 'p':
 327                        tid = atoi(optarg);
 328                        if (!tid)
 329                                err(1, "Invalid pid\n");
 330                        cmd_type = TASKSTATS_CMD_ATTR_PID;
 331                        break;
 332                case 'c':
 333
 334                        /* Block SIGCHLD for sigwait() later */
 335                        if (sigemptyset(&sigset) == -1)
 336                                err(1, "Failed to empty sigset");
 337                        if (sigaddset(&sigset, SIGCHLD))
 338                                err(1, "Failed to set sigchld in sigset");
 339                        sigprocmask(SIG_BLOCK, &sigset, NULL);
 340
 341                        /* fork/exec a child */
 342                        tid = fork();
 343                        if (tid < 0)
 344                                err(1, "Fork failed\n");
 345                        if (tid == 0)
 346                                if (execvp(argv[optind - 1],
 347                                    &argv[optind - 1]) < 0)
 348                                        exit(-1);
 349
 350                        /* Set the command type and avoid further processing */
 351                        cmd_type = TASKSTATS_CMD_ATTR_PID;
 352                        forking = 1;
 353                        break;
 354                case 'v':
 355                        printf("debug on\n");
 356                        dbg = 1;
 357                        break;
 358                case 'l':
 359                        printf("listen forever\n");
 360                        loop = 1;
 361                        break;
 362                default:
 363                        usage();
 364                        exit(-1);
 365                }
 366        }
 367
 368        if (write_file) {
 369                fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
 370                          S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 371                if (fd == -1) {
 372                        perror("Cannot open output file\n");
 373                        exit(1);
 374                }
 375        }
 376
 377        if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 0)
 378                err(1, "error creating Netlink socket\n");
 379
 380
 381        mypid = getpid();
 382        id = get_family_id(nl_sd);
 383        if (!id) {
 384                fprintf(stderr, "Error getting family id, errno %d\n", errno);
 385                goto err;
 386        }
 387        PRINTF("family id %d\n", id);
 388
 389        if (maskset) {
 390                rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 391                              TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
 392                              &cpumask, strlen(cpumask) + 1);
 393                PRINTF("Sent register cpumask, retval %d\n", rc);
 394                if (rc < 0) {
 395                        fprintf(stderr, "error sending register cpumask\n");
 396                        goto err;
 397                }
 398        }
 399
 400        if (tid && containerset) {
 401                fprintf(stderr, "Select either -t or -C, not both\n");
 402                goto err;
 403        }
 404
 405        /*
 406         * If we forked a child, wait for it to exit. Cannot use waitpid()
 407         * as all the delicious data would be reaped as part of the wait
 408         */
 409        if (tid && forking) {
 410                int sig_received;
 411                sigwait(&sigset, &sig_received);
 412        }
 413
 414        if (tid) {
 415                rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 416                              cmd_type, &tid, sizeof(__u32));
 417                PRINTF("Sent pid/tgid, retval %d\n", rc);
 418                if (rc < 0) {
 419                        fprintf(stderr, "error sending tid/tgid cmd\n");
 420                        goto done;
 421                }
 422        }
 423
 424        if (containerset) {
 425                cfd = open(containerpath, O_RDONLY);
 426                if (cfd < 0) {
 427                        perror("error opening container file");
 428                        goto err;
 429                }
 430                rc = send_cmd(nl_sd, id, mypid, CGROUPSTATS_CMD_GET,
 431                              CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32));
 432                if (rc < 0) {
 433                        perror("error sending cgroupstats command");
 434                        goto err;
 435                }
 436        }
 437        if (!maskset && !tid && !containerset) {
 438                usage();
 439                goto err;
 440        }
 441
 442        do {
 443                rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
 444                PRINTF("received %d bytes\n", rep_len);
 445
 446                if (rep_len < 0) {
 447                        fprintf(stderr, "nonfatal reply error: errno %d\n",
 448                                errno);
 449                        continue;
 450                }
 451                if (msg.n.nlmsg_type == NLMSG_ERROR ||
 452                    !NLMSG_OK((&msg.n), rep_len)) {
 453                        struct nlmsgerr *err = NLMSG_DATA(&msg);
 454                        fprintf(stderr, "fatal reply error,  errno %d\n",
 455                                err->error);
 456                        goto done;
 457                }
 458
 459                PRINTF("nlmsghdr size=%zu, nlmsg_len=%d, rep_len=%d\n",
 460                       sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
 461
 462
 463                rep_len = GENLMSG_PAYLOAD(&msg.n);
 464
 465                na = (struct nlattr *) GENLMSG_DATA(&msg);
 466                len = 0;
 467                while (len < rep_len) {
 468                        len += NLA_ALIGN(na->nla_len);
 469                        switch (na->nla_type) {
 470                        case TASKSTATS_TYPE_AGGR_TGID:
 471                                /* Fall through */
 472                        case TASKSTATS_TYPE_AGGR_PID:
 473                                aggr_len = NLA_PAYLOAD(na->nla_len);
 474                                len2 = 0;
 475                                /* For nested attributes, na follows */
 476                                na = (struct nlattr *) NLA_DATA(na);
 477                                done = 0;
 478                                while (len2 < aggr_len) {
 479                                        switch (na->nla_type) {
 480                                        case TASKSTATS_TYPE_PID:
 481                                                rtid = *(int *) NLA_DATA(na);
 482                                                if (print_delays)
 483                                                        printf("PID\t%d\n", rtid);
 484                                                break;
 485                                        case TASKSTATS_TYPE_TGID:
 486                                                rtid = *(int *) NLA_DATA(na);
 487                                                if (print_delays)
 488                                                        printf("TGID\t%d\n", rtid);
 489                                                break;
 490                                        case TASKSTATS_TYPE_STATS:
 491                                                count++;
 492                                                if (print_delays)
 493                                                        print_delayacct((struct taskstats *) NLA_DATA(na));
 494                                                if (print_io_accounting)
 495                                                        print_ioacct((struct taskstats *) NLA_DATA(na));
 496                                                if (print_task_context_switch_counts)
 497                                                        task_context_switch_counts((struct taskstats *) NLA_DATA(na));
 498                                                if (fd) {
 499                                                        if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
 500                                                                err(1,"write error\n");
 501                                                        }
 502                                                }
 503                                                if (!loop)
 504                                                        goto done;
 505                                                break;
 506                                        default:
 507                                                fprintf(stderr, "Unknown nested"
 508                                                        " nla_type %d\n",
 509                                                        na->nla_type);
 510                                                break;
 511                                        }
 512                                        len2 += NLA_ALIGN(na->nla_len);
 513                                        na = (struct nlattr *) ((char *) na + len2);
 514                                }
 515                                break;
 516
 517                        case CGROUPSTATS_TYPE_CGROUP_STATS:
 518                                print_cgroupstats(NLA_DATA(na));
 519                                break;
 520                        default:
 521                                fprintf(stderr, "Unknown nla_type %d\n",
 522                                        na->nla_type);
 523                        case TASKSTATS_TYPE_NULL:
 524                                break;
 525                        }
 526                        na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
 527                }
 528        } while (loop);
 529done:
 530        if (maskset) {
 531                rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
 532                              TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
 533                              &cpumask, strlen(cpumask) + 1);
 534                printf("Sent deregister mask, retval %d\n", rc);
 535                if (rc < 0)
 536                        err(rc, "error sending deregister cpumask\n");
 537        }
 538err:
 539        close(nl_sd);
 540        if (fd)
 541                close(fd);
 542        if (cfd)
 543                close(cfd);
 544        return 0;
 545}
 546
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