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 "busybox.h"
  32
  33 typedef int (*cmp_t)(procps_status_t *P, procps_status_t *Q);
  34
  35 static procps_status_t *top;   /* Hehe */
  36 static int ntop;
  37 static unsigned option_mask;
  38 #define OPT_BATCH_MODE (option_mask & 0x4)
  39
  40 #ifdef CONFIG_FEATURE_USE_TERMIOS
  41 static int pid_sort(procps_status_t *P, procps_status_t *Q)
  42 {
  43         return (Q->pid - P->pid);
  44 }
  45 #endif
  46
  47 static int mem_sort(procps_status_t *P, procps_status_t *Q)
  48 {
  49         return (int)(Q->rss - P->rss);
  50 }
  51
  52 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  53
  54 #define sort_depth 3
  55 static cmp_t sort_function[sort_depth];
  56
  57 static int pcpu_sort(procps_status_t *P, procps_status_t *Q)
  58 {
  59         return (Q->pcpu - P->pcpu);
  60 }
  61
  62 static int time_sort(procps_status_t *P, procps_status_t *Q)
  63 {
  64         return (int)((Q->stime + Q->utime) - (P->stime + P->utime));
  65 }
  66
  67 static int mult_lvl_cmp(void* a, void* b) {
  68         int i, cmp_val;
  69
  70         for (i = 0; i < sort_depth; i++) {
  71                 cmp_val = (*sort_function[i])(a, b);
  72                 if (cmp_val != 0)
  73                         return cmp_val;
  74         }
  75         return 0;
  76 }
  77
  78 /* This structure stores some critical information from one frame to
  79    the next. Mostly used for sorting. */
  80 struct save_hist {
  81         int ticks;
  82         int pid;
  83 };
  84
  85 /*
  86  * Calculates percent cpu usage for each task.
  87  */
  88
  89 static struct save_hist *prev_hist;
  90 static int prev_hist_count;
  91 /* static int hist_iterations; */
  92
  93
  94 static unsigned total_pcpu;
  95 /* static unsigned long total_rss; */
  96
  97 struct jiffy_counts {
  98         unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
  99         unsigned long long total;
 100         unsigned long long busy;
 101 };
 102 static struct jiffy_counts jif, prev_jif;
 103
 104 static void get_jiffy_counts(void)
 105 {
 106         FILE* fp = xfopen("stat", "r");
 107         prev_jif = jif;
 108         if (fscanf(fp, "cpu  %lld %lld %lld %lld %lld %lld %lld %lld",
 109                         &jif.usr,&jif.nic,&jif.sys,&jif.idle,
 110                         &jif.iowait,&jif.irq,&jif.softirq,&jif.steal) < 4) {
 111                 bb_error_msg_and_die("failed to read /proc/stat");
 112         }
 113         fclose(fp);
 114         jif.total = jif.usr + jif.nic + jif.sys + jif.idle
 115                         + jif.iowait + jif.irq + jif.softirq + jif.steal;
 116         /* procps 2.x does not count iowait as busy time */
 117         jif.busy = jif.total - jif.idle - jif.iowait;
 118 }
 119
 120 static void do_stats(void)
 121 {
 122         procps_status_t *cur;
 123         int pid, total_time, i, last_i, n;
 124         struct save_hist *new_hist;
 125
 126         get_jiffy_counts();
 127         total_pcpu = 0;
 128         /* total_rss = 0; */
 129         new_hist = xmalloc(sizeof(struct save_hist)*ntop);
 130         /*
 131          * Make a pass through the data to get stats.
 132          */
 133         /* hist_iterations = 0; */
 134         i = 0;
 135         for (n = 0; n < ntop; n++) {
 136                 cur = top + n;
 137
 138                 /*
 139                  * Calculate time in cur process.  Time is sum of user time
 140                  * and system time
 141                  */
 142                 pid = cur->pid;
 143                 total_time = cur->stime + cur->utime;
 144                 new_hist[n].ticks = total_time;
 145                 new_hist[n].pid = pid;
 146
 147                 /* find matching entry from previous pass */
 148                 cur->pcpu = 0;
 149                 /* do not start at index 0, continue at last used one
 150                  * (brought hist_iterations from ~14000 down to 172) */
 151                 last_i = i;
 152                 if (prev_hist_count) do {
 153                         if (prev_hist[i].pid == pid) {
 154                                 cur->pcpu = total_time - prev_hist[i].ticks;
 155                                 break;
 156                         }
 157                         i = (i+1) % prev_hist_count;
 158                         /* hist_iterations++; */
 159                 } while (i != last_i);
 160                 total_pcpu += cur->pcpu;
 161                 /* total_rss += cur->rss; */
 162         }
 163
 164         /*
 165          * Save cur frame's information.
 166          */
 167         free(prev_hist);
 168         prev_hist = new_hist;
 169         prev_hist_count = ntop;
 170 }
 171 #else
 172 static cmp_t sort_function;
 173 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 174
 175 /* display generic info (meminfo / loadavg) */
 176 static unsigned long display_generic(int scr_width)
 177 {
 178         FILE *fp;
 179         char buf[80];
 180         char scrbuf[80];
 181         char *end;
 182         unsigned long total, used, mfree, shared, buffers, cached;
 183         unsigned int needs_conversion = 1;
 184
 185         /* read memory info */
 186         fp = xfopen("meminfo", "r");
 187
 188         /*
 189          * Old kernels (such as 2.4.x) had a nice summary of memory info that
 190          * we could parse, however this is gone entirely in 2.6. Try parsing
 191          * the old way first, and if that fails, parse each field manually.
 192          *
 193          * First, we read in the first line. Old kernels will have bogus
 194          * strings we don't care about, whereas new kernels will start right
 195          * out with MemTotal:
 196          *                              -- PFM.
 197          */
 198         if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
 199                 fgets(buf, sizeof(buf), fp);    /* skip first line */
 200
 201                 fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
 202                    &total, &used, &mfree, &shared, &buffers, &cached);
 203         } else {
 204                 /*
 205                  * Revert to manual parsing, which incidentally already has the
 206                  * sizes in kilobytes. This should be safe for both 2.4 and
 207                  * 2.6.
 208                  */
 209                 needs_conversion = 0;
 210
 211                 fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
 212
 213                 /*
 214                  * MemShared: is no longer present in 2.6. Report this as 0,
 215                  * to maintain consistent behavior with normal procps.
 216                  */
 217                 if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
 218                         shared = 0;
 219
 220                 fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
 221                 fscanf(fp, "Cached: %lu %s\n", &cached, buf);
 222
 223                 used = total - mfree;
 224         }
 225         fclose(fp);
 226
 227         /* read load average as a string */
 228         fp = xfopen("loadavg", "r");
 229         buf[0] = '\0';
 230         fgets(buf, sizeof(buf), fp);
 231         end = strchr(buf, ' ');
 232         if (end) end = strchr(end+1, ' ');
 233         if (end) end = strchr(end+1, ' ');
 234         if (end) *end = '\0';
 235         fclose(fp);
 236
 237         if (needs_conversion) {
 238                 /* convert to kilobytes */
 239                 used /= 1024;
 240                 mfree /= 1024;
 241                 shared /= 1024;
 242                 buffers /= 1024;
 243                 cached /= 1024;
 244                 total /= 1024;
 245         }
 246
 247         /* output memory info and load average */
 248         /* clear screen & go to top */
 249         if (scr_width > sizeof(scrbuf))
 250                 scr_width = sizeof(scrbuf);
 251         snprintf(scrbuf, scr_width,
 252                 "Mem: %ldK used, %ldK free, %ldK shrd, %ldK buff, %ldK cached",
 253                 used, mfree, shared, buffers, cached);
 254
 255         printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
 256
 257         snprintf(scrbuf, scr_width,
 258                 "Load average: %s", buf);
 259         printf("%s\n", scrbuf);
 260
 261         return total;
 262 }
 263
 264
 265 /* display process statuses */
 266 static void display_status(int count, int scr_width)
 267 {
 268         enum {
 269                 bits_per_int = sizeof(int)*8
 270         };
 271
 272         procps_status_t *s = top;
 273         char rss_str_buf[8];
 274         unsigned long total_memory = display_generic(scr_width); /* or use total_rss? */
 275         unsigned pmem_shift, pmem_scale;
 276
 277 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 278         unsigned pcpu_shift, pcpu_scale;
 279
 280         /* what info of the processes is shown */
 281         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 282                 "  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND");
 283 #define MIN_WIDTH \
 284         sizeof( "  PID USER     STATUS   RSS  PPID %CPU %MEM C")
 285 #else
 286         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 287                 "  PID USER     STATUS   RSS  PPID %MEM COMMAND");
 288 #define MIN_WIDTH \
 289         sizeof( "  PID USER     STATUS   RSS  PPID %MEM C")
 290 #endif
 291
 292         /*
 293          * MEM% = s->rss/MemTotal
 294          */
 295         pmem_shift = bits_per_int-11;
 296         pmem_scale = 1000*(1U<<(bits_per_int-11)) / total_memory;
 297         /* s->rss is in kb. we want (s->rss * pmem_scale) to never overflow */
 298         while (pmem_scale >= 512) {
 299                 pmem_scale /= 4;
 300                 pmem_shift -= 2;
 301         }
 302 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 303         /*
 304          * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
 305          * (pcpu is delta of sys+user time between samples)
 306          */
 307         /* (jif.xxx - prev_jif.xxx) and s->pcpu are
 308          * in 0..~64000 range (HZ*update_interval).
 309          * we assume that unsigned is at least 32-bit.
 310          */
 311         pcpu_shift = 6;
 312         pcpu_scale = (1000*64*(uint16_t)(jif.busy-prev_jif.busy) ? : 1);
 313         while (pcpu_scale < (1U<<(bits_per_int-2))) {
 314                 pcpu_scale *= 4;
 315                 pcpu_shift += 2;
 316         }
 317         pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
 318         /* we want (s->pcpu * pcpu_scale) to never overflow */
 319         while (pcpu_scale >= 1024) {
 320                 pcpu_scale /= 4;
 321                 pcpu_shift -= 2;
 322         }
 323         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 324 #endif
 325         if (OPT_BATCH_MODE) count--;
 326         while (count-- > 0) {
 327                 div_t pmem = div((s->rss*pmem_scale) >> pmem_shift, 10);
 328                 int col = scr_width+1;
 329                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(div_t pcpu;)
 330
 331                 if (s->rss >= 100*1024)
 332                         sprintf(rss_str_buf, "%6ldM", s->rss/1024);
 333                 else
 334                         sprintf(rss_str_buf, "%7ld", s->rss);
 335                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10);)
 336                 col -= printf("\n%5d %-8s %s  %s%6d%3u.%c" \
 337                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c") " ",
 338                                 s->pid, s->user, s->state, rss_str_buf, s->ppid,
 339                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu.quot, '0'+pcpu.rem,)
 340                                 pmem.quot, '0'+pmem.rem);
 341                 if (col>0)
 342                         printf("%.*s", col, s->short_cmd);
 343                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
 344                         jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
 345                 s++;
 346         }
 347         /* printf(" %d", hist_iterations); */
 348         putchar(OPT_BATCH_MODE ? '\n' : '\r');
 349         fflush(stdout);
 350 }
 351
 352 static void clearmems(void)
 353 {
 354         free(top);
 355         top = 0;
 356         ntop = 0;
 357 }
 358
 359 #ifdef CONFIG_FEATURE_USE_TERMIOS
 360 #include <termios.h>
 361 #include <signal.h>
 362
 363
 364 static struct termios initial_settings;
 365
 366 static void reset_term(void)
 367 {
 368         tcsetattr(0, TCSANOW, (void *) &initial_settings);
 369 #ifdef CONFIG_FEATURE_CLEAN_UP
 370         clearmems();
 371 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 372         free(prev_hist);
 373 #endif
 374 #endif /* CONFIG_FEATURE_CLEAN_UP */
 375 }
 376
 377 static void sig_catcher(int sig ATTRIBUTE_UNUSED)
 378 {
 379         reset_term();
 380         exit(1);
 381 }
 382 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 383
 384
 385 int top_main(int argc, char **argv)
 386 {
 387         int count, lines, col;
 388         int interval = 5; /* default update rate is 5 seconds */
 389         int iterations = -1; /* 2^32 iterations by default :) */
 390         char *sinterval, *siterations;
 391 #ifdef CONFIG_FEATURE_USE_TERMIOS
 392         struct termios new_settings;
 393         struct timeval tv;
 394         fd_set readfds;
 395         unsigned char c;
 396 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 397
 398         /* do normal option parsing */
 399         interval = 5;
 400         bb_opt_complementally = "-";
 401         option_mask = bb_getopt_ulflags(argc, argv, "d:n:b",
 402                 &sinterval, &siterations);
 403         if (option_mask & 0x1) interval = atoi(sinterval); // -d
 404         if (option_mask & 0x2) iterations = atoi(siterations); // -n
 405         //if (option_mask & 0x4) // -b
 406
 407         /* change to /proc */
 408         xchdir("/proc");
 409 #ifdef CONFIG_FEATURE_USE_TERMIOS
 410         tcgetattr(0, (void *) &initial_settings);
 411         memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 412         /* unbuffered input, turn off echo */
 413         new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
 414
 415         signal(SIGTERM, sig_catcher);
 416         signal(SIGINT, sig_catcher);
 417         tcsetattr(0, TCSANOW, (void *) &new_settings);
 418         atexit(reset_term);
 419 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 420
 421 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 422         sort_function[0] = pcpu_sort;
 423         sort_function[1] = mem_sort;
 424         sort_function[2] = time_sort;
 425 #else
 426         sort_function = mem_sort;
 427 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 428
 429         while (1) {
 430                 procps_status_t *p;
 431
 432                 /* Default to 25 lines - 5 lines for status */
 433                 lines = 24 - 3;
 434                 col = 79;
 435 #ifdef CONFIG_FEATURE_USE_TERMIOS
 436                 get_terminal_width_height(0, &col, &lines);
 437                 if (lines < 5 || col < MIN_WIDTH) {
 438                         sleep(interval);
 439                         continue;
 440                 }
 441                 lines -= 3;
 442 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 443
 444                 /* read process IDs & status for all the processes */
 445                 while ((p = procps_scan(0)) != 0) {
 446                         int n = ntop;
 447
 448                         top = xrealloc(top, (++ntop)*sizeof(procps_status_t));
 449                         memcpy(top + n, p, sizeof(procps_status_t));
 450                 }
 451                 if (ntop == 0) {
 452                         bb_error_msg_and_die("Can't find process info in /proc");
 453                 }
 454 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 455                 if (!prev_hist_count) {
 456                         do_stats();
 457                         sleep(1);
 458                         clearmems();
 459                         continue;
 460                 }
 461                 do_stats();
 462                 qsort(top, ntop, sizeof(procps_status_t), (void*)mult_lvl_cmp);
 463 #else
 464                 qsort(top, ntop, sizeof(procps_status_t), (void*)sort_function);
 465 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 466                 count = lines;
 467                 if (count > ntop) {
 468                         count = ntop;
 469                 }
 470                 /* show status for each of the processes */
 471                 display_status(count, col);
 472 #ifdef CONFIG_FEATURE_USE_TERMIOS
 473                 tv.tv_sec = interval;
 474                 tv.tv_usec = 0;
 475                 FD_ZERO(&readfds);
 476                 FD_SET(0, &readfds);
 477                 select(1, &readfds, NULL, NULL, &tv);
 478                 if (FD_ISSET(0, &readfds)) {
 479                         if (read(0, &c, 1) <= 0) {   /* signal */
 480                                 return EXIT_FAILURE;
 481                         }
 482                         if (c == 'q' || c == initial_settings.c_cc[VINTR])
 483                                 break;
 484                         if (c == 'M') {
 485 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 486                                 sort_function[0] = mem_sort;
 487                                 sort_function[1] = pcpu_sort;
 488                                 sort_function[2] = time_sort;
 489 #else
 490                                 sort_function = mem_sort;
 491 #endif
 492                         }
 493 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 494                         if (c == 'P') {
 495                                 sort_function[0] = pcpu_sort;
 496                                 sort_function[1] = mem_sort;
 497                                 sort_function[2] = time_sort;
 498                         }
 499                         if (c == 'T') {
 500                                 sort_function[0] = time_sort;
 501                                 sort_function[1] = mem_sort;
 502                                 sort_function[2] = pcpu_sort;
 503                         }
 504 #endif
 505                         if (c == 'N') {
 506 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 507                                 sort_function[0] = pid_sort;
 508 #else
 509                                 sort_function = pid_sort;
 510 #endif
 511                         }
 512                 }
 513                 if (!--iterations)
 514                         break;
 515 #else
 516                 sleep(interval);
 517 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 518                 clearmems();
 519         }
 520         if (ENABLE_FEATURE_CLEAN_UP)
 521                 clearmems();
 522         putchar('\n');
 523         return EXIT_SUCCESS;
 524 }