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 #define OPT_BATCH_MODE (option_mask32 & 0x4)
  38
  39 #ifdef CONFIG_FEATURE_USE_TERMIOS
  40 static int pid_sort(procps_status_t *P, procps_status_t *Q)
  41 {
  42         return (Q->pid - P->pid);
  43 }
  44 #endif
  45
  46 static int mem_sort(procps_status_t *P, procps_status_t *Q)
  47 {
  48         return (int)(Q->rss - P->rss);
  49 }
  50
  51 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
  52
  53 #define sort_depth 3
  54 static cmp_t sort_function[sort_depth];
  55
  56 static int pcpu_sort(procps_status_t *P, procps_status_t *Q)
  57 {
  58         return (Q->pcpu - P->pcpu);
  59 }
  60
  61 static int time_sort(procps_status_t *P, procps_status_t *Q)
  62 {
  63         return (int)((Q->stime + Q->utime) - (P->stime + P->utime));
  64 }
  65
  66 static int mult_lvl_cmp(void* a, void* b) {
  67         int i, cmp_val;
  68
  69         for (i = 0; i < sort_depth; i++) {
  70                 cmp_val = (*sort_function[i])(a, b);
  71                 if (cmp_val != 0)
  72                         return cmp_val;
  73         }
  74         return 0;
  75 }
  76
  77 /* This structure stores some critical information from one frame to
  78    the next. Mostly used for sorting. */
  79 struct save_hist {
  80         int ticks;
  81         int pid;
  82 };
  83
  84 /*
  85  * Calculates percent cpu usage for each task.
  86  */
  87
  88 static struct save_hist *prev_hist;
  89 static int prev_hist_count;
  90 /* static int hist_iterations; */
  91
  92
  93 static unsigned total_pcpu;
  94 /* static unsigned long total_rss; */
  95
  96 struct jiffy_counts {
  97         unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
  98         unsigned long long total;
  99         unsigned long long busy;
 100 };
 101 static struct jiffy_counts jif, prev_jif;
 102
 103 static void get_jiffy_counts(void)
 104 {
 105         FILE* fp = xfopen("stat", "r");
 106         prev_jif = jif;
 107         if (fscanf(fp, "cpu  %lld %lld %lld %lld %lld %lld %lld %lld",
 108                         &jif.usr,&jif.nic,&jif.sys,&jif.idle,
 109                         &jif.iowait,&jif.irq,&jif.softirq,&jif.steal) < 4) {
 110                 bb_error_msg_and_die("failed to read /proc/stat");
 111         }
 112         fclose(fp);
 113         jif.total = jif.usr + jif.nic + jif.sys + jif.idle
 114                         + jif.iowait + jif.irq + jif.softirq + jif.steal;
 115         /* procps 2.x does not count iowait as busy time */
 116         jif.busy = jif.total - jif.idle - jif.iowait;
 117 }
 118
 119 static void do_stats(void)
 120 {
 121         procps_status_t *cur;
 122         int pid, total_time, i, last_i, n;
 123         struct save_hist *new_hist;
 124
 125         get_jiffy_counts();
 126         total_pcpu = 0;
 127         /* total_rss = 0; */
 128         new_hist = xmalloc(sizeof(struct save_hist)*ntop);
 129         /*
 130          * Make a pass through the data to get stats.
 131          */
 132         /* hist_iterations = 0; */
 133         i = 0;
 134         for (n = 0; n < ntop; n++) {
 135                 cur = top + n;
 136
 137                 /*
 138                  * Calculate time in cur process.  Time is sum of user time
 139                  * and system time
 140                  */
 141                 pid = cur->pid;
 142                 total_time = cur->stime + cur->utime;
 143                 new_hist[n].ticks = total_time;
 144                 new_hist[n].pid = pid;
 145
 146                 /* find matching entry from previous pass */
 147                 cur->pcpu = 0;
 148                 /* do not start at index 0, continue at last used one
 149                  * (brought hist_iterations from ~14000 down to 172) */
 150                 last_i = i;
 151                 if (prev_hist_count) do {
 152                         if (prev_hist[i].pid == pid) {
 153                                 cur->pcpu = total_time - prev_hist[i].ticks;
 154                                 break;
 155                         }
 156                         i = (i+1) % prev_hist_count;
 157                         /* hist_iterations++; */
 158                 } while (i != last_i);
 159                 total_pcpu += cur->pcpu;
 160                 /* total_rss += cur->rss; */
 161         }
 162
 163         /*
 164          * Save cur frame's information.
 165          */
 166         free(prev_hist);
 167         prev_hist = new_hist;
 168         prev_hist_count = ntop;
 169 }
 170 #else
 171 static cmp_t sort_function;
 172 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 173
 174 /* display generic info (meminfo / loadavg) */
 175 static unsigned long display_generic(int scr_width)
 176 {
 177         FILE *fp;
 178         char buf[80];
 179         char scrbuf[80];
 180         char *end;
 181         unsigned long total, used, mfree, shared, buffers, cached;
 182         unsigned int needs_conversion = 1;
 183
 184         /* read memory info */
 185         fp = xfopen("meminfo", "r");
 186
 187         /*
 188          * Old kernels (such as 2.4.x) had a nice summary of memory info that
 189          * we could parse, however this is gone entirely in 2.6. Try parsing
 190          * the old way first, and if that fails, parse each field manually.
 191          *
 192          * First, we read in the first line. Old kernels will have bogus
 193          * strings we don't care about, whereas new kernels will start right
 194          * out with MemTotal:
 195          *                              -- PFM.
 196          */
 197         if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
 198                 fgets(buf, sizeof(buf), fp);    /* skip first line */
 199
 200                 fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
 201                    &total, &used, &mfree, &shared, &buffers, &cached);
 202         } else {
 203                 /*
 204                  * Revert to manual parsing, which incidentally already has the
 205                  * sizes in kilobytes. This should be safe for both 2.4 and
 206                  * 2.6.
 207                  */
 208                 needs_conversion = 0;
 209
 210                 fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
 211
 212                 /*
 213                  * MemShared: is no longer present in 2.6. Report this as 0,
 214                  * to maintain consistent behavior with normal procps.
 215                  */
 216                 if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
 217                         shared = 0;
 218
 219                 fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
 220                 fscanf(fp, "Cached: %lu %s\n", &cached, buf);
 221
 222                 used = total - mfree;
 223         }
 224         fclose(fp);
 225
 226         /* read load average as a string */
 227         fp = xfopen("loadavg", "r");
 228         buf[0] = '\0';
 229         fgets(buf, sizeof(buf), fp);
 230         end = strchr(buf, ' ');
 231         if (end) end = strchr(end+1, ' ');
 232         if (end) end = strchr(end+1, ' ');
 233         if (end) *end = '\0';
 234         fclose(fp);
 235
 236         if (needs_conversion) {
 237                 /* convert to kilobytes */
 238                 used /= 1024;
 239                 mfree /= 1024;
 240                 shared /= 1024;
 241                 buffers /= 1024;
 242                 cached /= 1024;
 243                 total /= 1024;
 244         }
 245
 246         /* output memory info and load average */
 247         /* clear screen & go to top */
 248         if (scr_width > sizeof(scrbuf))
 249                 scr_width = sizeof(scrbuf);
 250         snprintf(scrbuf, scr_width,
 251                 "Mem: %ldK used, %ldK free, %ldK shrd, %ldK buff, %ldK cached",
 252                 used, mfree, shared, buffers, cached);
 253
 254         printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
 255
 256         snprintf(scrbuf, scr_width,
 257                 "Load average: %s", buf);
 258         printf("%s\n", scrbuf);
 259
 260         return total;
 261 }
 262
 263
 264 /* display process statuses */
 265 static void display_status(int count, int scr_width)
 266 {
 267         enum {
 268                 bits_per_int = sizeof(int)*8
 269         };
 270
 271         procps_status_t *s = top;
 272         char rss_str_buf[8];
 273         unsigned long total_memory = display_generic(scr_width); /* or use total_rss? */
 274         unsigned pmem_shift, pmem_scale;
 275
 276 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 277         unsigned pcpu_shift, pcpu_scale;
 278
 279         /* what info of the processes is shown */
 280         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 281                 "  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND");
 282 #define MIN_WIDTH \
 283         sizeof( "  PID USER     STATUS   RSS  PPID %CPU %MEM C")
 284 #else
 285         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 286                 "  PID USER     STATUS   RSS  PPID %MEM COMMAND");
 287 #define MIN_WIDTH \
 288         sizeof( "  PID USER     STATUS   RSS  PPID %MEM C")
 289 #endif
 290
 291         /*
 292          * MEM% = s->rss/MemTotal
 293          */
 294         pmem_shift = bits_per_int-11;
 295         pmem_scale = 1000*(1U<<(bits_per_int-11)) / total_memory;
 296         /* s->rss is in kb. we want (s->rss * pmem_scale) to never overflow */
 297         while (pmem_scale >= 512) {
 298                 pmem_scale /= 4;
 299                 pmem_shift -= 2;
 300         }
 301 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 302         /*
 303          * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
 304          * (pcpu is delta of sys+user time between samples)
 305          */
 306         /* (jif.xxx - prev_jif.xxx) and s->pcpu are
 307          * in 0..~64000 range (HZ*update_interval).
 308          * we assume that unsigned is at least 32-bit.
 309          */
 310         pcpu_shift = 6;
 311         pcpu_scale = (1000*64*(uint16_t)(jif.busy-prev_jif.busy) ? : 1);
 312         while (pcpu_scale < (1U<<(bits_per_int-2))) {
 313                 pcpu_scale *= 4;
 314                 pcpu_shift += 2;
 315         }
 316         pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
 317         /* we want (s->pcpu * pcpu_scale) to never overflow */
 318         while (pcpu_scale >= 1024) {
 319                 pcpu_scale /= 4;
 320                 pcpu_shift -= 2;
 321         }
 322         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 323 #endif
 324         if (OPT_BATCH_MODE) count--;
 325         while (count-- > 0) {
 326                 div_t pmem = div((s->rss*pmem_scale) >> pmem_shift, 10);
 327                 int col = scr_width+1;
 328                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(div_t pcpu;)
 329
 330                 if (s->rss >= 100*1024)
 331                         sprintf(rss_str_buf, "%6ldM", s->rss/1024);
 332                 else
 333                         sprintf(rss_str_buf, "%7ld", s->rss);
 334                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10);)
 335                 col -= printf("\n%5d %-8s %s  %s%6d%3u.%c" \
 336                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c") " ",
 337                                 s->pid, s->user, s->state, rss_str_buf, s->ppid,
 338                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu.quot, '0'+pcpu.rem,)
 339                                 pmem.quot, '0'+pmem.rem);
 340                 if (col>0)
 341                         printf("%.*s", col, s->short_cmd);
 342                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
 343                         jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
 344                 s++;
 345         }
 346         /* printf(" %d", hist_iterations); */
 347         putchar(OPT_BATCH_MODE ? '\n' : '\r');
 348         fflush(stdout);
 349 }
 350
 351 static void clearmems(void)
 352 {
 353         free(top);
 354         top = 0;
 355         ntop = 0;
 356 }
 357
 358 #ifdef CONFIG_FEATURE_USE_TERMIOS
 359 #include <termios.h>
 360 #include <signal.h>
 361
 362
 363 static struct termios initial_settings;
 364
 365 static void reset_term(void)
 366 {
 367         tcsetattr(0, TCSANOW, (void *) &initial_settings);
 368 #ifdef CONFIG_FEATURE_CLEAN_UP
 369         clearmems();
 370 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 371         free(prev_hist);
 372 #endif
 373 #endif /* CONFIG_FEATURE_CLEAN_UP */
 374 }
 375
 376 static void sig_catcher(int sig ATTRIBUTE_UNUSED)
 377 {
 378         reset_term();
 379         exit(1);
 380 }
 381 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 382
 383
 384 int top_main(int argc, char **argv)
 385 {
 386         int count, lines, col;
 387         unsigned interval = 5; /* default update rate is 5 seconds */
 388         unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
 389         char *sinterval, *siterations;
 390 #ifdef CONFIG_FEATURE_USE_TERMIOS
 391         struct termios new_settings;
 392         struct timeval tv;
 393         fd_set readfds;
 394         unsigned char c;
 395 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 396
 397         /* do normal option parsing */
 398         interval = 5;
 399         opt_complementary = "-";
 400         getopt32(argc, argv, "d:n:b",
 401                 &sinterval, &siterations);
 402         if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
 403         if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
 404         //if (option_mask32 & 0x4) // -b
 405
 406         /* change to /proc */
 407         xchdir("/proc");
 408 #ifdef CONFIG_FEATURE_USE_TERMIOS
 409         tcgetattr(0, (void *) &initial_settings);
 410         memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 411         /* unbuffered input, turn off echo */
 412         new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
 413
 414         signal(SIGTERM, sig_catcher);
 415         signal(SIGINT, sig_catcher);
 416         tcsetattr(0, TCSANOW, (void *) &new_settings);
 417         atexit(reset_term);
 418 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 419
 420 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 421         sort_function[0] = pcpu_sort;
 422         sort_function[1] = mem_sort;
 423         sort_function[2] = time_sort;
 424 #else
 425         sort_function = mem_sort;
 426 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 427
 428         while (1) {
 429                 procps_status_t *p;
 430
 431                 /* Default to 25 lines - 5 lines for status */
 432                 lines = 24 - 3;
 433                 col = 79;
 434 #ifdef CONFIG_FEATURE_USE_TERMIOS
 435                 get_terminal_width_height(0, &col, &lines);
 436                 if (lines < 5 || col < MIN_WIDTH) {
 437                         sleep(interval);
 438                         continue;
 439                 }
 440                 lines -= 3;
 441 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 442
 443                 /* read process IDs & status for all the processes */
 444                 while ((p = procps_scan(0)) != 0) {
 445                         int n = ntop;
 446
 447                         top = xrealloc(top, (++ntop)*sizeof(procps_status_t));
 448                         memcpy(top + n, p, sizeof(procps_status_t));
 449                 }
 450                 if (ntop == 0) {
 451                         bb_error_msg_and_die("can't find process info in /proc");
 452                 }
 453 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 454                 if (!prev_hist_count) {
 455                         do_stats();
 456                         sleep(1);
 457                         clearmems();
 458                         continue;
 459                 }
 460                 do_stats();
 461                 qsort(top, ntop, sizeof(procps_status_t), (void*)mult_lvl_cmp);
 462 #else
 463                 qsort(top, ntop, sizeof(procps_status_t), (void*)sort_function);
 464 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 465                 count = lines;
 466                 if (count > ntop) {
 467                         count = ntop;
 468                 }
 469                 /* show status for each of the processes */
 470                 display_status(count, col);
 471 #ifdef CONFIG_FEATURE_USE_TERMIOS
 472                 tv.tv_sec = interval;
 473                 tv.tv_usec = 0;
 474                 FD_ZERO(&readfds);
 475                 FD_SET(0, &readfds);
 476                 select(1, &readfds, NULL, NULL, &tv);
 477                 if (FD_ISSET(0, &readfds)) {
 478                         if (read(0, &c, 1) <= 0) {   /* signal */
 479                                 return EXIT_FAILURE;
 480                         }
 481                         if (c == 'q' || c == initial_settings.c_cc[VINTR])
 482                                 break;
 483                         if (c == 'M') {
 484 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 485                                 sort_function[0] = mem_sort;
 486                                 sort_function[1] = pcpu_sort;
 487                                 sort_function[2] = time_sort;
 488 #else
 489                                 sort_function = mem_sort;
 490 #endif
 491                         }
 492 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 493                         if (c == 'P') {
 494                                 sort_function[0] = pcpu_sort;
 495                                 sort_function[1] = mem_sort;
 496                                 sort_function[2] = time_sort;
 497                         }
 498                         if (c == 'T') {
 499                                 sort_function[0] = time_sort;
 500                                 sort_function[1] = mem_sort;
 501                                 sort_function[2] = pcpu_sort;
 502                         }
 503 #endif
 504                         if (c == 'N') {
 505 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 506                                 sort_function[0] = pid_sort;
 507 #else
 508                                 sort_function = pid_sort;
 509 #endif
 510                         }
 511                 }
 512                 if (!--iterations)
 513                         break;
 514 #else
 515                 sleep(interval);
 516 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 517                 clearmems();
 518         }
 519         if (ENABLE_FEATURE_CLEAN_UP)
 520                 clearmems();
 521         putchar('\n');
 522         return EXIT_SUCCESS;
 523 }