procps/top.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * A tiny 'top' utility.
   4  *
   5  * This is written specifically for the linux /proc/<PID>/stat(m)
   6  * files format.
   7
   8  * This reads the PIDs of all processes and their status and shows
   9  * the status of processes (first ones that fit to screen) at given
  10  * intervals.
  11  *
  12  * NOTES:
  13  * - At startup this changes to /proc, all the reads are then
  14  *   relative to that.
  15  *
  16  * (C) Eero Tamminen <oak at welho dot com>
  17  *
  18  * Rewritten by Vladimir Oleynik (C) 2002 <dzo@simtreas.ru>
  19  */
  20
  21 /* Original code Copyrights */
  22 /*
  23  * Copyright (c) 1992 Branko Lankester
  24  * Copyright (c) 1992 Roger Binns
  25  * Copyright (C) 1994-1996 Charles L. Blake.
  26  * Copyright (C) 1992-1998 Michael K. Johnson
  27  * May be distributed under the conditions of the
  28  * GNU Library General Public License
  29  */
  30
  31 #include <sys/types.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <unistd.h>
  35 #include <string.h>
  36 #include <sys/ioctl.h>
  37 #include "busybox.h"
  38
  39 //#define CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE  /* + 2k */
  40
  41 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  42 #include <time.h>
  43 #include <sys/time.h>
  44 #include <fcntl.h>
  45 #include <netinet/in.h>  /* htons */
  46 #endif
  47
  48
  49 typedef int (*cmp_t)(procps_status_t *P, procps_status_t *Q);
  50
  51 static procps_status_t *top;   /* Hehe */
  52 static int ntop;
  53
  54 #ifdef CONFIG_FEATURE_USE_TERMIOS
  55 static int pid_sort(procps_status_t *P, procps_status_t *Q)
  56 {
  57         return (Q->pid - P->pid);
  58 }
  59 #endif
  60
  61 static int mem_sort(procps_status_t *P, procps_status_t *Q)
  62 {
  63         return (int)(Q->rss - P->rss);
  64 }
  65
  66 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  67
  68 #define sort_depth 3
  69 static cmp_t sort_function[sort_depth];
  70
  71 static int pcpu_sort(procps_status_t *P, procps_status_t *Q)
  72 {
  73         return (Q->pcpu - P->pcpu);
  74 }
  75
  76 static int time_sort(procps_status_t *P, procps_status_t *Q)
  77 {
  78         return (int)((Q->stime + Q->utime) - (P->stime + P->utime));
  79 }
  80
  81 static int mult_lvl_cmp(void* a, void* b) {
  82         int i, cmp_val;
  83
  84         for (i = 0; i < sort_depth; i++) {
  85                 cmp_val = (*sort_function[i])(a, b);
  86                 if (cmp_val != 0)
  87                         return cmp_val;
  88         }
  89         return 0;
  90 }
  91
  92 /* This structure stores some critical information from one frame to
  93    the next. mostly used for sorting. Added cumulative and resident fields. */
  94 struct save_hist {
  95         int ticks;
  96         int pid;
  97 };
  98
  99 /*
 100  * Calculates percent cpu usage for each task.
 101  */
 102
 103 static struct save_hist *prev_hist;
 104 static int prev_hist_count;
 105 /* static int hist_iterations; */
 106
 107
 108 static unsigned total_pcpu;
 109 /* static unsigned long total_rss; */
 110
 111 struct jiffy_counts {
 112         unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
 113         unsigned long long total;
 114         unsigned long long busy;
 115 };
 116 static struct jiffy_counts jif, prev_jif;
 117
 118 static void get_jiffy_counts(void)
 119 {
 120         FILE* fp = bb_xfopen("stat", "r");
 121         prev_jif = jif;
 122         if (fscanf(fp, "cpu  %lld %lld %lld %lld %lld %lld %lld %lld",
 123                         &jif.usr,&jif.nic,&jif.sys,&jif.idle,
 124                         &jif.iowait,&jif.irq,&jif.softirq,&jif.steal) < 4) {
 125                 bb_error_msg_and_die("failed to read 'stat'");
 126         }
 127         fclose(fp);
 128         jif.total = jif.usr + jif.nic + jif.sys + jif.idle
 129                         + jif.iowait + jif.irq + jif.softirq + jif.steal;
 130         /* procps 2.x does not count iowait as busy time */
 131         jif.busy = jif.total - jif.idle - jif.iowait;
 132 }
 133
 134 static void do_stats(void)
 135 {
 136         procps_status_t *cur;
 137         int pid, total_time, i, last_i, n;
 138         struct save_hist *new_hist;
 139
 140         get_jiffy_counts();
 141         total_pcpu = 0;
 142         /* total_rss = 0; */
 143         new_hist = xmalloc(sizeof(struct save_hist)*ntop);
 144         /*
 145          * Make a pass through the data to get stats.
 146          */
 147         /* hist_iterations = 0; */
 148         i = 0;
 149         for (n = 0; n < ntop; n++) {
 150                 cur = top + n;
 151
 152                 /*
 153                  * Calculate time in cur process.  Time is sum of user time
 154                  * and system time
 155                  */
 156                 pid = cur->pid;
 157                 total_time = cur->stime + cur->utime;
 158                 new_hist[n].ticks = total_time;
 159                 new_hist[n].pid = pid;
 160
 161                 /* find matching entry from previous pass */
 162                 cur->pcpu = 0;
 163                 /* do not start at index 0, continue at last used one
 164                  * (brought hist_iterations from ~14000 down to 172) */
 165                 last_i = i;
 166                 if (prev_hist_count) do {
 167                         if (prev_hist[i].pid == pid) {
 168                                 cur->pcpu = total_time - prev_hist[i].ticks;
 169                                 break;
 170                         }
 171                         i = (i+1) % prev_hist_count;
 172                         /* hist_iterations++; */
 173                 } while (i != last_i);
 174                 total_pcpu += cur->pcpu;
 175                 /* total_rss += cur->rss; */
 176         }
 177
 178         /*
 179          * Save cur frame's information.
 180          */
 181         free(prev_hist);
 182         prev_hist = new_hist;
 183         prev_hist_count = ntop;
 184 }
 185 #else
 186 static cmp_t sort_function;
 187 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 188
 189 /* display generic info (meminfo / loadavg) */
 190 static unsigned long display_generic(int scr_width)
 191 {
 192         FILE *fp;
 193         char buf[80];
 194         char scrbuf[80];
 195         char *end;
 196         unsigned long total, used, mfree, shared, buffers, cached;
 197         unsigned int needs_conversion = 1;
 198
 199         /* read memory info */
 200         fp = bb_xfopen("meminfo", "r");
 201
 202         /*
 203          * Old kernels (such as 2.4.x) had a nice summary of memory info that
 204          * we could parse, however this is gone entirely in 2.6. Try parsing
 205          * the old way first, and if that fails, parse each field manually.
 206          *
 207          * First, we read in the first line. Old kernels will have bogus
 208          * strings we don't care about, whereas new kernels will start right
 209          * out with MemTotal:
 210          *                              -- PFM.
 211          */
 212         if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
 213                 fgets(buf, sizeof(buf), fp);    /* skip first line */
 214
 215                 fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
 216                    &total, &used, &mfree, &shared, &buffers, &cached);
 217         } else {
 218                 /*
 219                  * Revert to manual parsing, which incidentally already has the
 220                  * sizes in kilobytes. This should be safe for both 2.4 and
 221                  * 2.6.
 222                  */
 223                 needs_conversion = 0;
 224
 225                 fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
 226
 227                 /*
 228                  * MemShared: is no longer present in 2.6. Report this as 0,
 229                  * to maintain consistent behavior with normal procps.
 230                  */
 231                 if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
 232                         shared = 0;
 233
 234                 fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
 235                 fscanf(fp, "Cached: %lu %s\n", &cached, buf);
 236
 237                 used = total - mfree;
 238         }
 239         fclose(fp);
 240
 241         /* read load average as a string */
 242         fp = bb_xfopen("loadavg", "r");
 243         buf[0] = '\0';
 244         fgets(buf, sizeof(buf), fp);
 245         end = strchr(buf, ' ');
 246         if (end) end = strchr(end+1, ' ');
 247         if (end) end = strchr(end+1, ' ');
 248         if (end) *end = '\0';
 249         fclose(fp);
 250
 251         if (needs_conversion) {
 252                 /* convert to kilobytes */
 253                 used /= 1024;
 254                 mfree /= 1024;
 255                 shared /= 1024;
 256                 buffers /= 1024;
 257                 cached /= 1024;
 258                 total /= 1024;
 259         }
 260
 261         /* output memory info and load average */
 262         /* clear screen & go to top */
 263         if (scr_width > sizeof(scrbuf))
 264                 scr_width = sizeof(scrbuf);
 265         snprintf(scrbuf, scr_width,
 266                 "Mem: %ldK used, %ldK free, %ldK shrd, %ldK buff, %ldK cached",
 267                 used, mfree, shared, buffers, cached);
 268         printf("\e[H\e[J%s\n", scrbuf);
 269         snprintf(scrbuf, scr_width,
 270                 "Load average: %s  (Status: S=sleeping R=running, W=waiting)", buf);
 271         printf("%s\n", scrbuf);
 272
 273         return total;
 274 }
 275
 276
 277 /* display process statuses */
 278 static void display_status(int count, int scr_width)
 279 {
 280         enum {
 281                 bits_per_int = sizeof(int)*8
 282         };
 283
 284         procps_status_t *s = top;
 285         char rss_str_buf[8];
 286         unsigned long total_memory = display_generic(scr_width); /* or use total_rss? */
 287         unsigned pmem_shift, pmem_scale;
 288
 289 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 290         unsigned pcpu_shift, pcpu_scale;
 291
 292         /* what info of the processes is shown */
 293         printf("\e[7m%.*s\e[0m", scr_width,
 294                 "  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND");
 295 #define MIN_WIDTH \
 296         sizeof( "  PID USER     STATUS   RSS  PPID %CPU %MEM C")
 297 #else
 298         printf("\e[7m%.*s\e[0m", scr_width,
 299                 "  PID USER     STATUS   RSS  PPID %MEM COMMAND");
 300 #define MIN_WIDTH \
 301         sizeof( "  PID USER     STATUS   RSS  PPID %MEM C")
 302 #endif
 303
 304         /*
 305          * MEM% = s->rss/MemTotal
 306          */
 307         pmem_shift = bits_per_int-11;
 308         pmem_scale = 1000*(1U<<(bits_per_int-11)) / total_memory;
 309         /* s->rss is in kb. we want (s->rss * pmem_scale) to never overflow */
 310         while (pmem_scale >= 512) {
 311                 pmem_scale /= 4;
 312                 pmem_shift -= 2;
 313         }
 314 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 315         /*
 316          * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
 317          * (pcpu is delta of sys+user time between samples)
 318          */
 319         /* (jif.xxx - prev_jif.xxx) and s->pcpu are
 320          * in 0..~64000 range (HZ*update_interval).
 321          * we assume that unsigned is at least 32-bit.
 322          */
 323         pcpu_shift = 6;
 324         pcpu_scale = (1000*64*(uint16_t)(jif.busy-prev_jif.busy) ? : 1);
 325         while (pcpu_scale < (1U<<(bits_per_int-2))) {
 326                 pcpu_scale *= 4;
 327                 pcpu_shift += 2;
 328         }
 329         pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
 330         /* we want (s->pcpu * pcpu_scale) to never overflow */
 331         while (pcpu_scale >= 1024) {
 332                 pcpu_scale /= 4;
 333                 pcpu_shift -= 2;
 334         }
 335         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 336 #endif
 337
 338         while (count--) {
 339                 div_t pmem = div( (s->rss*pmem_scale) >> pmem_shift, 10);
 340                 int col = scr_width+1;
 341
 342                 if (s->rss >= 100*1024)
 343                         sprintf(rss_str_buf, "%6ldM", s->rss/1024);
 344                 else
 345                         sprintf(rss_str_buf, "%7ld", s->rss);
 346                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(div_t pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10));
 347                 col -= printf("\n%5d %-8s %s  %s%6d%3u.%c" \
 348                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c") " ",
 349                                 s->pid, s->user, s->state, rss_str_buf, s->ppid,
 350                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu.quot, '0'+pcpu.rem,)
 351                                 pmem.quot, '0'+pmem.rem);
 352                 if (col>0)
 353                         printf("%.*s", col, s->short_cmd);
 354                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
 355                         jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
 356                 s++;
 357         }
 358         /* printf(" %d", hist_iterations); */
 359         putchar('\r');
 360         fflush(stdout);
 361 }
 362
 363 static void clearmems(void)
 364 {
 365         free(top);
 366         top = 0;
 367         ntop = 0;
 368 }
 369
 370 #ifdef CONFIG_FEATURE_USE_TERMIOS
 371 #include <termios.h>
 372 #include <sys/time.h>
 373 #include <signal.h>
 374
 375
 376 static struct termios initial_settings;
 377
 378 static void reset_term(void)
 379 {
 380         tcsetattr(0, TCSANOW, (void *) &initial_settings);
 381 #ifdef CONFIG_FEATURE_CLEAN_UP
 382         clearmems();
 383 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 384         free(prev_hist);
 385 #endif
 386 #endif /* CONFIG_FEATURE_CLEAN_UP */
 387 }
 388
 389 static void sig_catcher(int sig ATTRIBUTE_UNUSED)
 390 {
 391         reset_term();
 392 }
 393 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 394
 395
 396 int top_main(int argc, char **argv)
 397 {
 398         int opt, interval, lines, col;
 399         char *sinterval;
 400 #ifdef CONFIG_FEATURE_USE_TERMIOS
 401         struct termios new_settings;
 402         struct timeval tv;
 403         fd_set readfds;
 404         unsigned char c;
 405         struct sigaction sa;
 406 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 407
 408         /* do normal option parsing */
 409         opt = bb_getopt_ulflags(argc, argv, "d:", &sinterval);
 410         if ((opt & 1)) {
 411                 interval = atoi(sinterval);
 412         } else {
 413                 /* Default update rate is 5 seconds */
 414                 interval = 5;
 415         }
 416
 417         /* change to /proc */
 418         bb_xchdir("/proc");
 419 #ifdef CONFIG_FEATURE_USE_TERMIOS
 420         tcgetattr(0, (void *) &initial_settings);
 421         memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 422         new_settings.c_lflag &= ~(ISIG | ICANON); /* unbuffered input */
 423         /* Turn off echoing */
 424         new_settings.c_lflag &= ~(ECHO | ECHONL);
 425
 426         signal(SIGTERM, sig_catcher);
 427         sigaction(SIGTERM, (struct sigaction *) 0, &sa);
 428         sa.sa_flags |= SA_RESTART;
 429         sa.sa_flags &= ~SA_INTERRUPT;
 430         sigaction(SIGTERM, &sa, (struct sigaction *) 0);
 431         sigaction(SIGINT, &sa, (struct sigaction *) 0);
 432         tcsetattr(0, TCSANOW, (void *) &new_settings);
 433         atexit(reset_term);
 434 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 435
 436 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 437         sort_function[0] = pcpu_sort;
 438         sort_function[1] = mem_sort;
 439         sort_function[2] = time_sort;
 440 #else
 441         sort_function = mem_sort;
 442 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 443
 444         while (1) {
 445                 procps_status_t *p;
 446
 447                 /* Default to 25 lines - 5 lines for status */
 448                 lines = 24 - 3;
 449                 col = 79;
 450 #ifdef CONFIG_FEATURE_USE_TERMIOS
 451                 get_terminal_width_height(0, &col, &lines);
 452                 if (lines < 5 || col < MIN_WIDTH) {
 453                         sleep(interval);
 454                         continue;
 455                 }
 456                 lines -= 3;
 457 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 458
 459                 /* read process IDs & status for all the processes */
 460                 while ((p = procps_scan(0)) != 0) {
 461                         int n = ntop;
 462
 463                         top = xrealloc(top, (++ntop)*sizeof(procps_status_t));
 464                         memcpy(top + n, p, sizeof(procps_status_t));
 465                 }
 466                 if (ntop == 0) {
 467                         bb_error_msg_and_die("Can't find process info in /proc");
 468                 }
 469 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 470                 if (!prev_hist_count) {
 471                         do_stats();
 472                         sleep(1);
 473                         clearmems();
 474                         continue;
 475                 }
 476                 do_stats();
 477                 qsort(top, ntop, sizeof(procps_status_t), (void*)mult_lvl_cmp);
 478 #else
 479                 qsort(top, ntop, sizeof(procps_status_t), (void*)sort_function);
 480 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 481                 opt = lines;
 482                 if (opt > ntop) {
 483                         opt = ntop;
 484                 }
 485                 /* show status for each of the processes */
 486                 display_status(opt, col);
 487 #ifdef CONFIG_FEATURE_USE_TERMIOS
 488                 tv.tv_sec = interval;
 489                 tv.tv_usec = 0;
 490                 FD_ZERO(&readfds);
 491                 FD_SET(0, &readfds);
 492                 select(1, &readfds, NULL, NULL, &tv);
 493                 if (FD_ISSET(0, &readfds)) {
 494                         if (read(0, &c, 1) <= 0) {   /* signal */
 495                                 return EXIT_FAILURE;
 496                         }
 497                         if (c == 'q' || c == initial_settings.c_cc[VINTR])
 498                                 break;
 499                         if (c == 'M') {
 500 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 501                                 sort_function[0] = mem_sort;
 502                                 sort_function[1] = pcpu_sort;
 503                                 sort_function[2] = time_sort;
 504 #else
 505                                 sort_function = mem_sort;
 506 #endif
 507                         }
 508 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 509                         if (c == 'P') {
 510                                 sort_function[0] = pcpu_sort;
 511                                 sort_function[1] = mem_sort;
 512                                 sort_function[2] = time_sort;
 513                         }
 514                         if (c == 'T') {
 515                                 sort_function[0] = time_sort;
 516                                 sort_function[1] = mem_sort;
 517                                 sort_function[2] = pcpu_sort;
 518                         }
 519 #endif
 520                         if (c == 'N') {
 521 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 522                                 sort_function[0] = pid_sort;
 523 #else
 524                                 sort_function = pid_sort;
 525 #endif
 526                         }
 527                 }
 528 #else
 529                 sleep(interval);
 530 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 531                 clearmems();
 532         }
 533         if (ENABLE_FEATURE_CLEAN_UP)
 534                 clearmems();
 535         putchar('\n');
 536         return EXIT_SUCCESS;
 537 }