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__u64 stime, utime;
  55
  56#define PRINTF(fmt, arg...) {                   \
  57            if (dbg) {                          \
  58                printf(fmt, ##arg);             \
  59            }                                   \
  60        }
  61
  62/* Maximum size of response requested or message sent */
  63#define MAX_MSG_SIZE    1024
  64/* Maximum number of cpus expected to be specified in a cpumask */
  65#define MAX_CPUS        32
  66
  67struct msgtemplate {
  68        struct nlmsghdr n;
  69        struct genlmsghdr g;
  70        char buf[MAX_MSG_SIZE];
  71};
  72
  73char cpumask[100+6*MAX_CPUS];
  74
  75static void usage(void)
  76{
  77        fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
  78                        "[-m cpumask] [-t tgid] [-p pid]\n");
  79        fprintf(stderr, "  -d: print delayacct stats\n");
  80        fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
  81        fprintf(stderr, "  -l: listen forever\n");
  82        fprintf(stderr, "  -v: debug on\n");
  83        fprintf(stderr, "  -C: container path\n");
  84}
  85
  86/*
  87 * Create a raw netlink socket and bind
  88 */
  89static int create_nl_socket(int protocol)
  90{
  91        int fd;
  92        struct sockaddr_nl local;
  93
  94        fd = socket(AF_NETLINK, SOCK_RAW, protocol);
  95        if (fd < 0)
  96                return -1;
  97
  98        if (rcvbufsz)
  99                if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
 100                                &rcvbufsz, sizeof(rcvbufsz)) < 0) {
 101                        fprintf(stderr, "Unable to set socket rcv buf size "
 102                                        "to %d\n",
 103                                rcvbufsz);
 104                        return -1;
 105                }
 106
 107        memset(&local, 0, sizeof(local));
 108        local.nl_family = AF_NETLINK;
 109
 110        if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
 111                goto error;
 112
 113        return fd;
 114error:
 115        close(fd);
 116        return -1;
 117}
 118
 119
 120static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
 121             __u8 genl_cmd, __u16 nla_type,
 122             void *nla_data, int nla_len)
 123{
 124        struct nlattr *na;
 125        struct sockaddr_nl nladdr;
 126        int r, buflen;
 127        char *buf;
 128
 129        struct msgtemplate msg;
 130
 131        msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
 132        msg.n.nlmsg_type = nlmsg_type;
 133        msg.n.nlmsg_flags = NLM_F_REQUEST;
 134        msg.n.nlmsg_seq = 0;
 135        msg.n.nlmsg_pid = nlmsg_pid;
 136        msg.g.cmd = genl_cmd;
 137        msg.g.version = 0x1;
 138        na = (struct nlattr *) GENLMSG_DATA(&msg);
 139        na->nla_type = nla_type;
 140        na->nla_len = nla_len + 1 + NLA_HDRLEN;
 141        memcpy(NLA_DATA(na), nla_data, nla_len);
 142        msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
 143
 144        buf = (char *) &msg;
 145        buflen = msg.n.nlmsg_len ;
 146        memset(&nladdr, 0, sizeof(nladdr));
 147        nladdr.nl_family = AF_NETLINK;
 148        while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
 149                           sizeof(nladdr))) < buflen) {
 150                if (r > 0) {
 151                        buf += r;
 152                        buflen -= r;
 153                } else if (errno != EAGAIN)
 154                        return -1;
 155        }
 156        return 0;
 157}
 158
 159
 160/*
 161 * Probe the controller in genetlink to find the family id
 162 * for the TASKSTATS family
 163 */
 164static int get_family_id(int sd)
 165{
 166        struct {
 167                struct nlmsghdr n;
 168                struct genlmsghdr g;
 169                char buf[256];
 170        } ans;
 171
 172        int id = 0, rc;
 173        struct nlattr *na;
 174        int rep_len;
 175
 176        strcpy(name, TASKSTATS_GENL_NAME);
 177        rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
 178                        CTRL_ATTR_FAMILY_NAME, (void *)name,
 179                        strlen(TASKSTATS_GENL_NAME)+1);
 180        if (rc < 0)
 181                return 0;       /* sendto() failure? */
 182
 183        rep_len = recv(sd, &ans, sizeof(ans), 0);
 184        if (ans.n.nlmsg_type == NLMSG_ERROR ||
 185            (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
 186                return 0;
 187
 188        na = (struct nlattr *) GENLMSG_DATA(&ans);
 189        na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
 190        if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
 191                id = *(__u16 *) NLA_DATA(na);
 192        }
 193        return id;
 194}
 195
 196#define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
 197
 198static void print_delayacct(struct taskstats *t)
 199{
 200        printf("\n\nCPU   %15s%15s%15s%15s%15s\n"
 201               "      %15llu%15llu%15llu%15llu%15.3fms\n"
 202               "IO    %15s%15s%15s\n"
 203               "      %15llu%15llu%15llums\n"
 204               "SWAP  %15s%15s%15s\n"
 205               "      %15llu%15llu%15llums\n"
 206               "RECLAIM  %12s%15s%15s\n"
 207               "      %15llu%15llu%15llums\n",
 208               "count", "real total", "virtual total",
 209               "delay total", "delay average",
 210               (unsigned long long)t->cpu_count,
 211               (unsigned long long)t->cpu_run_real_total,
 212               (unsigned long long)t->cpu_run_virtual_total,
 213               (unsigned long long)t->cpu_delay_total,
 214               average_ms((double)t->cpu_delay_total, t->cpu_count),
 215               "count", "delay total", "delay average",
 216               (unsigned long long)t->blkio_count,
 217               (unsigned long long)t->blkio_delay_total,
 218               average_ms(t->blkio_delay_total, t->blkio_count),
 219               "count", "delay total", "delay average",
 220               (unsigned long long)t->swapin_count,
 221               (unsigned long long)t->swapin_delay_total,
 222               average_ms(t->swapin_delay_total, t->swapin_count),
 223               "count", "delay total", "delay average",
 224               (unsigned long long)t->freepages_count,
 225               (unsigned long long)t->freepages_delay_total,
 226               average_ms(t->freepages_delay_total, t->freepages_count));
 227}
 228
 229static void task_context_switch_counts(struct taskstats *t)
 230{
 231        printf("\n\nTask   %15s%15s\n"
 232               "       %15llu%15llu\n",
 233               "voluntary", "nonvoluntary",
 234               (unsigned long long)t->nvcsw, (unsigned long long)t->nivcsw);
 235}
 236
 237static void print_cgroupstats(struct cgroupstats *c)
 238{
 239        printf("sleeping %llu, blocked %llu, running %llu, stopped %llu, "
 240                "uninterruptible %llu\n", (unsigned long long)c->nr_sleeping,
 241                (unsigned long long)c->nr_io_wait,
 242                (unsigned long long)c->nr_running,
 243                (unsigned long long)c->nr_stopped,
 244                (unsigned long long)c->nr_uninterruptible);
 245}
 246
 247
 248static void print_ioacct(struct taskstats *t)
 249{
 250        printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
 251                t->ac_comm,
 252                (unsigned long long)t->read_bytes,
 253                (unsigned long long)t->write_bytes,
 254                (unsigned long long)t->cancelled_write_bytes);
 255}
 256
 257int main(int argc, char *argv[])
 258{
 259        int c, rc, rep_len, aggr_len, len2;
 260        int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
 261        __u16 id;
 262        __u32 mypid;
 263
 264        struct nlattr *na;
 265        int nl_sd = -1;
 266        int len = 0;
 267        pid_t tid = 0;
 268        pid_t rtid = 0;
 269
 270        int fd = 0;
 271        int count = 0;
 272        int write_file = 0;
 273        int maskset = 0;
 274        char *logfile = NULL;
 275        int loop = 0;
 276        int containerset = 0;
 277        char containerpath[1024];
 278        int cfd = 0;
 279        int forking = 0;
 280        sigset_t sigset;
 281
 282        struct msgtemplate msg;
 283
 284        while (!forking) {
 285                c = getopt(argc, argv, "qdiw:r:m:t:p:vlC:c:");
 286                if (c < 0)
 287                        break;
 288
 289                switch (c) {
 290                case 'd':
 291                        printf("print delayacct stats ON\n");
 292                        print_delays = 1;
 293                        break;
 294                case 'i':
 295                        printf("printing IO accounting\n");
 296                        print_io_accounting = 1;
 297                        break;
 298                case 'q':
 299                        printf("printing task/process context switch rates\n");
 300                        print_task_context_switch_counts = 1;
 301                        break;
 302                case 'C':
 303                        containerset = 1;
 304                        strncpy(containerpath, optarg, strlen(optarg) + 1);
 305                        break;
 306                case 'w':
 307                        logfile = strdup(optarg);
 308                        printf("write to file %s\n", logfile);
 309                        write_file = 1;
 310                        break;
 311                case 'r':
 312                        rcvbufsz = atoi(optarg);
 313                        printf("receive buf size %d\n", rcvbufsz);
 314                        if (rcvbufsz < 0)
 315                                err(1, "Invalid rcv buf size\n");
 316                        break;
 317                case 'm':
 318                        strncpy(cpumask, optarg, sizeof(cpumask));
 319                        maskset = 1;
 320                        printf("cpumask %s maskset %d\n", cpumask, maskset);
 321                        break;
 322                case 't':
 323                        tid = atoi(optarg);
 324                        if (!tid)
 325                                err(1, "Invalid tgid\n");
 326                        cmd_type = TASKSTATS_CMD_ATTR_TGID;
 327                        break;
 328                case 'p':
 329                        tid = atoi(optarg);
 330                        if (!tid)
 331                                err(1, "Invalid pid\n");
 332                        cmd_type = TASKSTATS_CMD_ATTR_PID;
 333                        break;
 334                case 'c':
 335
 336                        /* Block SIGCHLD for sigwait() later */
 337                        if (sigemptyset(&sigset) == -1)
 338                                err(1, "Failed to empty sigset");
 339                        if (sigaddset(&sigset, SIGCHLD))
 340                                err(1, "Failed to set sigchld in sigset");
 341                        sigprocmask(SIG_BLOCK, &sigset, NULL);
 342
 343                        /* fork/exec a child */
 344                        tid = fork();
 345                        if (tid < 0)
 346                                err(1, "Fork failed\n");
 347                        if (tid == 0)
 348                                if (execvp(argv[optind - 1],
 349                                    &argv[optind - 1]) < 0)
 350                                        exit(-1);
 351
 352                        /* Set the command type and avoid further processing */
 353                        cmd_type = TASKSTATS_CMD_ATTR_PID;
 354                        forking = 1;
 355                        break;
 356                case 'v':
 357                        printf("debug on\n");
 358                        dbg = 1;
 359                        break;
 360                case 'l':
 361                        printf("listen forever\n");
 362                        loop = 1;
 363                        break;
 364                default:
 365                        usage();
 366                        exit(-1);
 367                }
 368        }
 369
 370        if (write_file) {
 371                fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
 372                          S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 373                if (fd == -1) {
 374                        perror("Cannot open output file\n");
 375                        exit(1);
 376                }
 377        }
 378
 379        if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 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);
 531done:
 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        }
 540err:
 541        close(nl_sd);
 542        if (fd)
 543                close(fd);
 544        if (cfd)
 545                close(cfd);
 546        return 0;
 547}
 548
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