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