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         pid_t 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         pid_t pid;
 123         int 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         buf[0] = '\0';
 229         open_read_close("loadavg", buf, sizeof(buf));
 230         end = strchr(buf, ' ');
 231         if (end) end = strchr(end+1, ' ');
 232         if (end) end = strchr(end+1, ' ');
 233         if (end) *end = '\0';
 234
 235         if (needs_conversion) {
 236                 /* convert to kilobytes */
 237                 used /= 1024;
 238                 mfree /= 1024;
 239                 shared /= 1024;
 240                 buffers /= 1024;
 241                 cached /= 1024;
 242                 total /= 1024;
 243         }
 244
 245         /* output memory info and load average */
 246         /* clear screen & go to top */
 247         if (scr_width > sizeof(scrbuf))
 248                 scr_width = sizeof(scrbuf);
 249         snprintf(scrbuf, scr_width,
 250                 "Mem: %ldK used, %ldK free, %ldK shrd, %ldK buff, %ldK cached",
 251                 used, mfree, shared, buffers, cached);
 252
 253         printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
 254
 255         snprintf(scrbuf, scr_width, "Load average: %s", buf);
 256         printf("%s\n", scrbuf);
 257
 258         return total;
 259 }
 260
 261
 262 /* display process statuses */
 263 static void display_status(int count, int scr_width)
 264 {
 265         enum {
 266                 bits_per_int = sizeof(int)*8
 267         };
 268
 269         procps_status_t *s = top;
 270         char rss_str_buf[8];
 271         unsigned long total_memory = display_generic(scr_width); /* or use total_rss? */
 272         unsigned pmem_shift, pmem_scale;
 273
 274 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 275         unsigned pcpu_shift, pcpu_scale;
 276
 277         /* what info of the processes is shown */
 278         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 279                 "  PID USER     STATUS   RSS  PPID %CPU %MEM COMMAND");
 280 #define MIN_WIDTH \
 281         sizeof( "  PID USER     STATUS   RSS  PPID %CPU %MEM C")
 282 #else
 283         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
 284                 "  PID USER     STATUS   RSS  PPID %MEM COMMAND");
 285 #define MIN_WIDTH \
 286         sizeof( "  PID USER     STATUS   RSS  PPID %MEM C")
 287 #endif
 288
 289         /*
 290          * MEM% = s->rss/MemTotal
 291          */
 292         pmem_shift = bits_per_int-11;
 293         pmem_scale = 1000*(1U<<(bits_per_int-11)) / total_memory;
 294         /* s->rss is in kb. we want (s->rss * pmem_scale) to never overflow */
 295         while (pmem_scale >= 512) {
 296                 pmem_scale /= 4;
 297                 pmem_shift -= 2;
 298         }
 299 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 300         /*
 301          * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
 302          * (pcpu is delta of sys+user time between samples)
 303          */
 304         /* (jif.xxx - prev_jif.xxx) and s->pcpu are
 305          * in 0..~64000 range (HZ*update_interval).
 306          * we assume that unsigned is at least 32-bit.
 307          */
 308         pcpu_shift = 6;
 309         pcpu_scale = (1000*64*(uint16_t)(jif.busy-prev_jif.busy) ? : 1);
 310         while (pcpu_scale < (1U<<(bits_per_int-2))) {
 311                 pcpu_scale *= 4;
 312                 pcpu_shift += 2;
 313         }
 314         pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
 315         /* we want (s->pcpu * pcpu_scale) to never overflow */
 316         while (pcpu_scale >= 1024) {
 317                 pcpu_scale /= 4;
 318                 pcpu_shift -= 2;
 319         }
 320         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 321 #endif
 322         while (count-- > 0) {
 323                 div_t pmem = div((s->rss*pmem_scale) >> pmem_shift, 10);
 324                 int col = scr_width+1;
 325                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(div_t pcpu;)
 326
 327                 if (s->rss >= 100*1024)
 328                         sprintf(rss_str_buf, "%6ldM", s->rss/1024);
 329                 else
 330                         sprintf(rss_str_buf, "%7ld", s->rss);
 331                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10);)
 332                 col -= printf("\n%5u %-8s %s  %s%6u%3u.%c" \
 333                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c") " ",
 334                                 (unsigned)s->pid, s->user, s->state, rss_str_buf, (unsigned)s->ppid,
 335                                 USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu.quot, '0'+pcpu.rem,)
 336                                 pmem.quot, '0'+pmem.rem);
 337                 if (col > 0)
 338                         printf("%.*s", col, s->short_cmd);
 339                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
 340                         jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
 341                 s++;
 342         }
 343         /* printf(" %d", hist_iterations); */
 344         putchar(OPT_BATCH_MODE ? '\n' : '\r');
 345         fflush(stdout);
 346 }
 347
 348 static void clearmems(void)
 349 {
 350         free(top);
 351         top = 0;
 352         ntop = 0;
 353 }
 354
 355 #ifdef CONFIG_FEATURE_USE_TERMIOS
 356 #include <termios.h>
 357 #include <signal.h>
 358
 359
 360 static struct termios initial_settings;
 361
 362 static void reset_term(void)
 363 {
 364         tcsetattr(0, TCSANOW, (void *) &initial_settings);
 365 #ifdef CONFIG_FEATURE_CLEAN_UP
 366         clearmems();
 367 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 368         free(prev_hist);
 369 #endif
 370 #endif /* CONFIG_FEATURE_CLEAN_UP */
 371 }
 372
 373 static void sig_catcher(int sig ATTRIBUTE_UNUSED)
 374 {
 375         reset_term();
 376         exit(1);
 377 }
 378 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 379
 380
 381 int top_main(int argc, char **argv)
 382 {
 383         int count, lines, col;
 384         unsigned interval = 5; /* default update rate is 5 seconds */
 385         unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
 386         char *sinterval, *siterations;
 387 #ifdef CONFIG_FEATURE_USE_TERMIOS
 388         struct termios new_settings;
 389         struct timeval tv;
 390         fd_set readfds;
 391         unsigned char c;
 392 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 393
 394         /* do normal option parsing */
 395         interval = 5;
 396         opt_complementary = "-";
 397         getopt32(argc, argv, "d:n:b",
 398                 &sinterval, &siterations);
 399         if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
 400         if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
 401         //if (option_mask32 & 0x4) // -b
 402
 403         /* change to /proc */
 404         xchdir("/proc");
 405 #ifdef CONFIG_FEATURE_USE_TERMIOS
 406         tcgetattr(0, (void *) &initial_settings);
 407         memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 408         /* unbuffered input, turn off echo */
 409         new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
 410
 411         signal(SIGTERM, sig_catcher);
 412         signal(SIGINT, sig_catcher);
 413         tcsetattr(0, TCSANOW, (void *) &new_settings);
 414         atexit(reset_term);
 415 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 416
 417 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 418         sort_function[0] = pcpu_sort;
 419         sort_function[1] = mem_sort;
 420         sort_function[2] = time_sort;
 421 #else
 422         sort_function = mem_sort;
 423 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 424
 425         while (1) {
 426                 procps_status_t *p;
 427
 428                 /* Default to 25 lines - 5 lines for status */
 429                 lines = 24 - 3;
 430                 col = 79;
 431 #ifdef CONFIG_FEATURE_USE_TERMIOS
 432                 get_terminal_width_height(0, &col, &lines);
 433                 if (lines < 5 || col < MIN_WIDTH) {
 434                         sleep(interval);
 435                         continue;
 436                 }
 437                 lines -= 3;
 438 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 439
 440                 /* read process IDs & status for all the processes */
 441                 while ((p = procps_scan(0)) != 0) {
 442                         int n = ntop;
 443
 444                         top = xrealloc(top, (++ntop)*sizeof(procps_status_t));
 445                         memcpy(top + n, p, sizeof(procps_status_t));
 446                 }
 447                 if (ntop == 0) {
 448                         bb_error_msg_and_die("can't find process info in /proc");
 449                 }
 450 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 451                 if (!prev_hist_count) {
 452                         do_stats();
 453                         sleep(1);
 454                         clearmems();
 455                         continue;
 456                 }
 457                 do_stats();
 458                 qsort(top, ntop, sizeof(procps_status_t), (void*)mult_lvl_cmp);
 459 #else
 460                 qsort(top, ntop, sizeof(procps_status_t), (void*)sort_function);
 461 #endif /* CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 462                 count = lines;
 463                 if (OPT_BATCH_MODE || count > ntop) {
 464                         count = ntop;
 465                 }
 466                 /* show status for each of the processes */
 467                 display_status(count, col);
 468 #ifdef CONFIG_FEATURE_USE_TERMIOS
 469                 tv.tv_sec = interval;
 470                 tv.tv_usec = 0;
 471                 FD_ZERO(&readfds);
 472                 FD_SET(0, &readfds);
 473                 select(1, &readfds, NULL, NULL, &tv);
 474                 if (FD_ISSET(0, &readfds)) {
 475                         if (read(0, &c, 1) <= 0) {   /* signal */
 476                                 return EXIT_FAILURE;
 477                         }
 478                         if (c == 'q' || c == initial_settings.c_cc[VINTR])
 479                                 break;
 480                         if (c == 'M') {
 481 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 482                                 sort_function[0] = mem_sort;
 483                                 sort_function[1] = pcpu_sort;
 484                                 sort_function[2] = time_sort;
 485 #else
 486                                 sort_function = mem_sort;
 487 #endif
 488                         }
 489 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 490                         if (c == 'P') {
 491                                 sort_function[0] = pcpu_sort;
 492                                 sort_function[1] = mem_sort;
 493                                 sort_function[2] = time_sort;
 494                         }
 495                         if (c == 'T') {
 496                                 sort_function[0] = time_sort;
 497                                 sort_function[1] = mem_sort;
 498                                 sort_function[2] = pcpu_sort;
 499                         }
 500 #endif
 501                         if (c == 'N') {
 502 #ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 503                                 sort_function[0] = pid_sort;
 504 #else
 505                                 sort_function = pid_sort;
 506 #endif
 507                         }
 508                 }
 509                 if (!--iterations)
 510                         break;
 511 #else
 512                 sleep(interval);
 513 #endif /* CONFIG_FEATURE_USE_TERMIOS */
 514                 clearmems();
 515         }
 516         if (ENABLE_FEATURE_CLEAN_UP)
 517                 clearmems();
 518         putchar('\n');
 519         return EXIT_SUCCESS;
 520 }