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  * Sept 2008: Vineet Gupta <vineet.gupta@arc.com>
  21  * Added Support for reporting SMP Information
  22  * - CPU where process was last seen running
  23  *   (to see effect of sched_setaffinity() etc)
  24  * - CPU time split (idle/IO/wait etc) per CPU
  25  *
  26  * Copyright (c) 1992 Branko Lankester
  27  * Copyright (c) 1992 Roger Binns
  28  * Copyright (C) 1994-1996 Charles L. Blake.
  29  * Copyright (C) 1992-1998 Michael K. Johnson
  30  *
  31  * Licensed under GPLv2, see file LICENSE in this source tree.
  32  */
  33 /* How to snapshot /proc for debugging top problems:
  34  * for f in /proc/[0-9]*""/stat; do
  35  *         n=${f#/proc/}
  36  *         n=${n%/stat}_stat
  37  *         cp $f $n
  38  * done
  39  * cp /proc/stat /proc/meminfo /proc/loadavg .
  40  * top -bn1 >top.out
  41  *
  42  * ...and how to run top on it on another machine:
  43  * rm -rf proc; mkdir proc
  44  * for f in [0-9]*_stat; do
  45  *         p=${f%_stat}
  46  *         mkdir -p proc/$p
  47  *         cp $f proc/$p/stat
  48  * done
  49  * cp stat meminfo loadavg proc
  50  * chroot . ./top -bn1 >top1.out
  51  */
  52
  53 //config:config TOP
  54 //config:       bool "top"
  55 //config:       default y
  56 //config:       help
  57 //config:         The top program provides a dynamic real-time view of a running
  58 //config:         system.
  59 //config:
  60 //config:config FEATURE_TOP_CPU_USAGE_PERCENTAGE
  61 //config:       bool "Show CPU per-process usage percentage"
  62 //config:       default y
  63 //config:       depends on TOP
  64 //config:       help
  65 //config:         Make top display CPU usage for each process.
  66 //config:         This adds about 2k.
  67 //config:
  68 //config:config FEATURE_TOP_CPU_GLOBAL_PERCENTS
  69 //config:       bool "Show CPU global usage percentage"
  70 //config:       default y
  71 //config:       depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
  72 //config:       help
  73 //config:         Makes top display "CPU: NN% usr NN% sys..." line.
  74 //config:         This adds about 0.5k.
  75 //config:
  76 //config:config FEATURE_TOP_SMP_CPU
  77 //config:       bool "SMP CPU usage display ('c' key)"
  78 //config:       default y
  79 //config:       depends on FEATURE_TOP_CPU_GLOBAL_PERCENTS
  80 //config:       help
  81 //config:         Allow 'c' key to switch between individual/cumulative CPU stats
  82 //config:         This adds about 0.5k.
  83 //config:
  84 //config:config FEATURE_TOP_DECIMALS
  85 //config:       bool "Show 1/10th of a percent in CPU/mem statistics"
  86 //config:       default y
  87 //config:       depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
  88 //config:       help
  89 //config:         Show 1/10th of a percent in CPU/mem statistics.
  90 //config:         This adds about 0.3k.
  91 //config:
  92 //config:config FEATURE_TOP_SMP_PROCESS
  93 //config:       bool "Show CPU process runs on ('j' field)"
  94 //config:       default y
  95 //config:       depends on TOP
  96 //config:       help
  97 //config:         Show CPU where process was last found running on.
  98 //config:         This is the 'j' field.
  99 //config:
 100 //config:config FEATURE_TOPMEM
 101 //config:       bool "Topmem command ('s' key)"
 102 //config:       default y
 103 //config:       depends on TOP
 104 //config:       help
 105 //config:         Enable 's' in top (gives lots of memory info).
 106
 107 #include "libbb.h"
 108 #include "common_bufsiz.h"
 109
 110
 111 typedef struct top_status_t {
 112         unsigned long vsz;
 113 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 114         unsigned long ticks;
 115         unsigned pcpu; /* delta of ticks */
 116 #endif
 117         unsigned pid, ppid;
 118         unsigned uid;
 119         char state[4];
 120         char comm[COMM_LEN];
 121 #if ENABLE_FEATURE_TOP_SMP_PROCESS
 122         int last_seen_on_cpu;
 123 #endif
 124 } top_status_t;
 125
 126 typedef struct jiffy_counts_t {
 127         /* Linux 2.4.x has only first four */
 128         unsigned long long usr, nic, sys, idle;
 129         unsigned long long iowait, irq, softirq, steal;
 130         unsigned long long total;
 131         unsigned long long busy;
 132 } jiffy_counts_t;
 133
 134 /* This structure stores some critical information from one frame to
 135    the next. Used for finding deltas. */
 136 typedef struct save_hist {
 137         unsigned long ticks;
 138         pid_t pid;
 139 } save_hist;
 140
 141 typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
 142
 143
 144 enum { SORT_DEPTH = 3 };
 145
 146
 147 struct globals {
 148         top_status_t *top;
 149         int ntop;
 150         smallint inverted;
 151 #if ENABLE_FEATURE_TOPMEM
 152         smallint sort_field;
 153 #endif
 154 #if ENABLE_FEATURE_TOP_SMP_CPU
 155         smallint smp_cpu_info; /* one/many cpu info lines? */
 156 #endif
 157         unsigned lines;  /* screen height */
 158 #if ENABLE_FEATURE_USE_TERMIOS
 159         struct termios initial_settings;
 160         int scroll_ofs;
 161 #define G_scroll_ofs G.scroll_ofs
 162 #else
 163 #define G_scroll_ofs 0
 164 #endif
 165 #if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 166         cmp_funcp sort_function[1];
 167 #else
 168         cmp_funcp sort_function[SORT_DEPTH];
 169         struct save_hist *prev_hist;
 170         int prev_hist_count;
 171         jiffy_counts_t cur_jif, prev_jif;
 172         /* int hist_iterations; */
 173         unsigned total_pcpu;
 174         /* unsigned long total_vsz; */
 175 #endif
 176 #if ENABLE_FEATURE_TOP_SMP_CPU
 177         /* Per CPU samples: current and last */
 178         jiffy_counts_t *cpu_jif, *cpu_prev_jif;
 179         int num_cpus;
 180 #endif
 181 #if ENABLE_FEATURE_USE_TERMIOS
 182         char kbd_input[KEYCODE_BUFFER_SIZE];
 183 #endif
 184         char line_buf[80];
 185 }; //FIX_ALIASING; - large code growth
 186 enum { LINE_BUF_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line_buf) };
 187 #define G (*(struct globals*)bb_common_bufsiz1)
 188 #define top              (G.top               )
 189 #define ntop             (G.ntop              )
 190 #define sort_field       (G.sort_field        )
 191 #define inverted         (G.inverted          )
 192 #define smp_cpu_info     (G.smp_cpu_info      )
 193 #define initial_settings (G.initial_settings  )
 194 #define sort_function    (G.sort_function     )
 195 #define prev_hist        (G.prev_hist         )
 196 #define prev_hist_count  (G.prev_hist_count   )
 197 #define cur_jif          (G.cur_jif           )
 198 #define prev_jif         (G.prev_jif          )
 199 #define cpu_jif          (G.cpu_jif           )
 200 #define cpu_prev_jif     (G.cpu_prev_jif      )
 201 #define num_cpus         (G.num_cpus          )
 202 #define total_pcpu       (G.total_pcpu        )
 203 #define line_buf         (G.line_buf          )
 204 #define INIT_G() do { \
 205         setup_common_bufsiz(); \
 206         BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 207         BUILD_BUG_ON(LINE_BUF_SIZE <= 80); \
 208 } while (0)
 209
 210 enum {
 211         OPT_d = (1 << 0),
 212         OPT_n = (1 << 1),
 213         OPT_b = (1 << 2),
 214         OPT_m = (1 << 3),
 215         OPT_EOF = (1 << 4), /* pseudo: "we saw EOF in stdin" */
 216 };
 217 #define OPT_BATCH_MODE (option_mask32 & OPT_b)
 218
 219
 220 #if ENABLE_FEATURE_USE_TERMIOS
 221 static int pid_sort(top_status_t *P, top_status_t *Q)
 222 {
 223         /* Buggy wrt pids with high bit set */
 224         /* (linux pids are in [1..2^15-1]) */
 225         return (Q->pid - P->pid);
 226 }
 227 #endif
 228
 229 static int mem_sort(top_status_t *P, top_status_t *Q)
 230 {
 231         /* We want to avoid unsigned->signed and truncation errors */
 232         if (Q->vsz < P->vsz) return -1;
 233         return Q->vsz != P->vsz; /* 0 if ==, 1 if > */
 234 }
 235
 236
 237 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 238
 239 static int pcpu_sort(top_status_t *P, top_status_t *Q)
 240 {
 241         /* Buggy wrt ticks with high bit set */
 242         /* Affects only processes for which ticks overflow */
 243         return (int)Q->pcpu - (int)P->pcpu;
 244 }
 245
 246 static int time_sort(top_status_t *P, top_status_t *Q)
 247 {
 248         /* We want to avoid unsigned->signed and truncation errors */
 249         if (Q->ticks < P->ticks) return -1;
 250         return Q->ticks != P->ticks; /* 0 if ==, 1 if > */
 251 }
 252
 253 static int mult_lvl_cmp(void* a, void* b)
 254 {
 255         int i, cmp_val;
 256
 257         for (i = 0; i < SORT_DEPTH; i++) {
 258                 cmp_val = (*sort_function[i])(a, b);
 259                 if (cmp_val != 0)
 260                         break;
 261         }
 262         return inverted ? -cmp_val : cmp_val;
 263 }
 264
 265 static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
 266 {
 267 #if !ENABLE_FEATURE_TOP_SMP_CPU
 268         static const char fmt[] ALIGN1 = "cpu %llu %llu %llu %llu %llu %llu %llu %llu";
 269 #else
 270         static const char fmt[] ALIGN1 = "cp%*s %llu %llu %llu %llu %llu %llu %llu %llu";
 271 #endif
 272         int ret;
 273
 274         if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
 275                 return 0;
 276         ret = sscanf(line_buf, fmt,
 277                         &p_jif->usr, &p_jif->nic, &p_jif->sys, &p_jif->idle,
 278                         &p_jif->iowait, &p_jif->irq, &p_jif->softirq,
 279                         &p_jif->steal);
 280         if (ret >= 4) {
 281                 p_jif->total = p_jif->usr + p_jif->nic + p_jif->sys + p_jif->idle
 282                         + p_jif->iowait + p_jif->irq + p_jif->softirq + p_jif->steal;
 283                 /* procps 2.x does not count iowait as busy time */
 284                 p_jif->busy = p_jif->total - p_jif->idle - p_jif->iowait;
 285         }
 286
 287         return ret;
 288 }
 289
 290 static void get_jiffy_counts(void)
 291 {
 292         FILE* fp = xfopen_for_read("stat");
 293
 294         /* We need to parse cumulative counts even if SMP CPU display is on,
 295          * they are used to calculate per process CPU% */
 296         prev_jif = cur_jif;
 297         if (read_cpu_jiffy(fp, &cur_jif) < 4)
 298                 bb_error_msg_and_die("can't read '%s'", "/proc/stat");
 299
 300 #if !ENABLE_FEATURE_TOP_SMP_CPU
 301         fclose(fp);
 302         return;
 303 #else
 304         if (!smp_cpu_info) {
 305                 fclose(fp);
 306                 return;
 307         }
 308
 309         if (!num_cpus) {
 310                 /* First time here. How many CPUs?
 311                  * There will be at least 1 /proc/stat line with cpu%d
 312                  */
 313                 while (1) {
 314                         cpu_jif = xrealloc_vector(cpu_jif, 1, num_cpus);
 315                         if (read_cpu_jiffy(fp, &cpu_jif[num_cpus]) <= 4)
 316                                 break;
 317                         num_cpus++;
 318                 }
 319                 if (num_cpus == 0) /* /proc/stat with only "cpu ..." line?! */
 320                         smp_cpu_info = 0;
 321
 322                 cpu_prev_jif = xzalloc(sizeof(cpu_prev_jif[0]) * num_cpus);
 323
 324                 /* Otherwise the first per cpu display shows all 100% idles */
 325                 usleep(50000);
 326         } else { /* Non first time invocation */
 327                 jiffy_counts_t *tmp;
 328                 int i;
 329
 330                 /* First switch the sample pointers: no need to copy */
 331                 tmp = cpu_prev_jif;
 332                 cpu_prev_jif = cpu_jif;
 333                 cpu_jif = tmp;
 334
 335                 /* Get the new samples */
 336                 for (i = 0; i < num_cpus; i++)
 337                         read_cpu_jiffy(fp, &cpu_jif[i]);
 338         }
 339 #endif
 340         fclose(fp);
 341 }
 342
 343 static void do_stats(void)
 344 {
 345         top_status_t *cur;
 346         pid_t pid;
 347         int i, last_i, n;
 348         struct save_hist *new_hist;
 349
 350         get_jiffy_counts();
 351         total_pcpu = 0;
 352         /* total_vsz = 0; */
 353         new_hist = xmalloc(sizeof(new_hist[0]) * ntop);
 354         /*
 355          * Make a pass through the data to get stats.
 356          */
 357         /* hist_iterations = 0; */
 358         i = 0;
 359         for (n = 0; n < ntop; n++) {
 360                 cur = top + n;
 361
 362                 /*
 363                  * Calculate time in cur process.  Time is sum of user time
 364                  * and system time
 365                  */
 366                 pid = cur->pid;
 367                 new_hist[n].ticks = cur->ticks;
 368                 new_hist[n].pid = pid;
 369
 370                 /* find matching entry from previous pass */
 371                 cur->pcpu = 0;
 372                 /* do not start at index 0, continue at last used one
 373                  * (brought hist_iterations from ~14000 down to 172) */
 374                 last_i = i;
 375                 if (prev_hist_count) do {
 376                         if (prev_hist[i].pid == pid) {
 377                                 cur->pcpu = cur->ticks - prev_hist[i].ticks;
 378                                 total_pcpu += cur->pcpu;
 379                                 break;
 380                         }
 381                         i = (i+1) % prev_hist_count;
 382                         /* hist_iterations++; */
 383                 } while (i != last_i);
 384                 /* total_vsz += cur->vsz; */
 385         }
 386
 387         /*
 388          * Save cur frame's information.
 389          */
 390         free(prev_hist);
 391         prev_hist = new_hist;
 392         prev_hist_count = ntop;
 393 }
 394
 395 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 396
 397 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
 398 /* formats 7 char string (8 with terminating NUL) */
 399 static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
 400 {
 401         unsigned t;
 402         if (value >= total) { /* 100% ? */
 403                 strcpy(pbuf, "  100% ");
 404                 return pbuf;
 405         }
 406         /* else generate " [N/space]N.N% " string */
 407         value = 1000 * value / total;
 408         t = value / 100;
 409         value = value % 100;
 410         pbuf[0] = ' ';
 411         pbuf[1] = t ? t + '0' : ' ';
 412         pbuf[2] = '0' + (value / 10);
 413         pbuf[3] = '.';
 414         pbuf[4] = '0' + (value % 10);
 415         pbuf[5] = '%';
 416         pbuf[6] = ' ';
 417         pbuf[7] = '\0';
 418         return pbuf;
 419 }
 420 #endif
 421
 422 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
 423 static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
 424 {
 425         /*
 426          * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
 427          */
 428         unsigned total_diff;
 429         jiffy_counts_t *p_jif, *p_prev_jif;
 430         int i;
 431 # if ENABLE_FEATURE_TOP_SMP_CPU
 432         int n_cpu_lines;
 433 # endif
 434
 435         /* using (unsigned) casts to make operations cheaper */
 436 # define  CALC_TOTAL_DIFF do { \
 437         total_diff = (unsigned)(p_jif->total - p_prev_jif->total); \
 438         if (total_diff == 0) total_diff = 1; \
 439 } while (0)
 440
 441 # if ENABLE_FEATURE_TOP_DECIMALS
 442 #  define CALC_STAT(xxx) char xxx[8]
 443 #  define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
 444 #  define FMT "%s"
 445 # else
 446 #  define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
 447 #  define SHOW_STAT(xxx) xxx
 448 #  define FMT "%4u%% "
 449 # endif
 450
 451 # if !ENABLE_FEATURE_TOP_SMP_CPU
 452         {
 453                 i = 1;
 454                 p_jif = &cur_jif;
 455                 p_prev_jif = &prev_jif;
 456 # else
 457         /* Loop thru CPU(s) */
 458         n_cpu_lines = smp_cpu_info ? num_cpus : 1;
 459         if (n_cpu_lines > *lines_rem_p)
 460                 n_cpu_lines = *lines_rem_p;
 461
 462         for (i = 0; i < n_cpu_lines; i++) {
 463                 p_jif = &cpu_jif[i];
 464                 p_prev_jif = &cpu_prev_jif[i];
 465 # endif
 466                 CALC_TOTAL_DIFF;
 467
 468                 { /* Need a block: CALC_STAT are declarations */
 469                         CALC_STAT(usr);
 470                         CALC_STAT(sys);
 471                         CALC_STAT(nic);
 472                         CALC_STAT(idle);
 473                         CALC_STAT(iowait);
 474                         CALC_STAT(irq);
 475                         CALC_STAT(softirq);
 476                         /*CALC_STAT(steal);*/
 477
 478                         snprintf(scrbuf, scr_width,
 479                                 /* Barely fits in 79 chars when in "decimals" mode. */
 480 # if ENABLE_FEATURE_TOP_SMP_CPU
 481                                 "CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
 482                                 (smp_cpu_info ? utoa(i) : ""),
 483 # else
 484                                 "CPU:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
 485 # endif
 486                                 SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
 487                                 SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
 488                                 /*, SHOW_STAT(steal) - what is this 'steal' thing? */
 489                                 /* I doubt anyone wants to know it */
 490                         );
 491                         puts(scrbuf);
 492                 }
 493         }
 494 # undef SHOW_STAT
 495 # undef CALC_STAT
 496 # undef FMT
 497         *lines_rem_p -= i;
 498 }
 499 #else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
 500 # define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
 501 #endif
 502
 503 enum {
 504         MI_MEMTOTAL,
 505         MI_MEMFREE,
 506         MI_MEMSHARED,
 507         MI_SHMEM,
 508         MI_BUFFERS,
 509         MI_CACHED,
 510         MI_SWAPTOTAL,
 511         MI_SWAPFREE,
 512         MI_DIRTY,
 513         MI_WRITEBACK,
 514         MI_ANONPAGES,
 515         MI_MAPPED,
 516         MI_SLAB,
 517         MI_MAX
 518 };
 519
 520 static void parse_meminfo(unsigned long meminfo[MI_MAX])
 521 {
 522         static const char fields[] ALIGN1 =
 523                 "MemTotal\0"
 524                 "MemFree\0"
 525                 "MemShared\0"
 526                 "Shmem\0"
 527                 "Buffers\0"
 528                 "Cached\0"
 529                 "SwapTotal\0"
 530                 "SwapFree\0"
 531                 "Dirty\0"
 532                 "Writeback\0"
 533                 "AnonPages\0"
 534                 "Mapped\0"
 535                 "Slab\0";
 536         char buf[60]; /* actual lines we expect are ~30 chars or less */
 537         FILE *f;
 538         int i;
 539
 540         memset(meminfo, 0, sizeof(meminfo[0]) * MI_MAX);
 541         f = xfopen_for_read("meminfo");
 542         while (fgets(buf, sizeof(buf), f) != NULL) {
 543                 char *c = strchr(buf, ':');
 544                 if (!c)
 545                         continue;
 546                 *c = '\0';
 547                 i = index_in_strings(fields, buf);
 548                 if (i >= 0)
 549                         meminfo[i] = strtoul(c+1, NULL, 10);
 550         }
 551         fclose(f);
 552 }
 553
 554 static unsigned long display_header(int scr_width, int *lines_rem_p)
 555 {
 556         char scrbuf[100]; /* [80] was a bit too low on 8Gb ram box */
 557         char *buf;
 558         unsigned long meminfo[MI_MAX];
 559
 560         parse_meminfo(meminfo);
 561
 562         /* Output memory info */
 563         if (scr_width > (int)sizeof(scrbuf))
 564                 scr_width = sizeof(scrbuf);
 565         snprintf(scrbuf, scr_width,
 566                 "Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
 567                 meminfo[MI_MEMTOTAL] - meminfo[MI_MEMFREE],
 568                 meminfo[MI_MEMFREE],
 569                 meminfo[MI_MEMSHARED] + meminfo[MI_SHMEM],
 570                 meminfo[MI_BUFFERS],
 571                 meminfo[MI_CACHED]);
 572         /* Go to top & clear to the end of screen */
 573         printf(OPT_BATCH_MODE ? "%s\n" : "\033[H\033[J%s\n", scrbuf);
 574         (*lines_rem_p)--;
 575
 576         /* Display CPU time split as percentage of total time.
 577          * This displays either a cumulative line or one line per CPU.
 578          */
 579         display_cpus(scr_width, scrbuf, lines_rem_p);
 580
 581         /* Read load average as a string */
 582         buf = stpcpy(scrbuf, "Load average: ");
 583         open_read_close("loadavg", buf, sizeof(scrbuf) - sizeof("Load average: "));
 584         scrbuf[scr_width - 1] = '\0';
 585         strchrnul(buf, '\n')[0] = '\0';
 586         puts(scrbuf);
 587         (*lines_rem_p)--;
 588
 589         return meminfo[MI_MEMTOTAL];
 590 }
 591
 592 static NOINLINE void display_process_list(int lines_rem, int scr_width)
 593 {
 594         enum {
 595                 BITS_PER_INT = sizeof(int) * 8
 596         };
 597
 598         top_status_t *s;
 599         char vsz_str_buf[8];
 600         unsigned long total_memory = display_header(scr_width, &lines_rem); /* or use total_vsz? */
 601         /* xxx_shift and xxx_scale variables allow us to replace
 602          * expensive divides with multiply and shift */
 603         unsigned pmem_shift, pmem_scale, pmem_half;
 604 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 605         unsigned tmp_unsigned;
 606         unsigned pcpu_shift, pcpu_scale, pcpu_half;
 607         unsigned busy_jifs;
 608 #endif
 609
 610         /* what info of the processes is shown */
 611         printf(OPT_BATCH_MODE ? "%.*s" : "\033[7m%.*s\033[0m", scr_width,
 612                 "  PID  PPID USER     STAT   VSZ %VSZ"
 613                 IF_FEATURE_TOP_SMP_PROCESS(" CPU")
 614                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
 615                 " COMMAND");
 616         lines_rem--;
 617
 618 #if ENABLE_FEATURE_TOP_DECIMALS
 619 # define UPSCALE 1000
 620 # define CALC_STAT(name, val) div_t name = div((val), 10)
 621 # define SHOW_STAT(name) name.quot, '0'+name.rem
 622 # define FMT "%3u.%c"
 623 #else
 624 # define UPSCALE 100
 625 # define CALC_STAT(name, val) unsigned name = (val)
 626 # define SHOW_STAT(name) name
 627 # define FMT "%4u%%"
 628 #endif
 629         /*
 630          * %VSZ = s->vsz/MemTotal
 631          */
 632         pmem_shift = BITS_PER_INT-11;
 633         pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
 634         /* s->vsz is in kb. we want (s->vsz * pmem_scale) to never overflow */
 635         while (pmem_scale >= 512) {
 636                 pmem_scale /= 4;
 637                 pmem_shift -= 2;
 638         }
 639         pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
 640 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 641         busy_jifs = cur_jif.busy - prev_jif.busy;
 642         /* This happens if there were lots of short-lived processes
 643          * between two top updates (e.g. compilation) */
 644         if (total_pcpu < busy_jifs) total_pcpu = busy_jifs;
 645
 646         /*
 647          * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
 648          * (pcpu is delta of sys+user time between samples)
 649          */
 650         /* (cur_jif.xxx - prev_jif.xxx) and s->pcpu are
 651          * in 0..~64000 range (HZ*update_interval).
 652          * we assume that unsigned is at least 32-bit.
 653          */
 654         pcpu_shift = 6;
 655         pcpu_scale = UPSCALE*64 * (uint16_t)busy_jifs;
 656         if (pcpu_scale == 0)
 657                 pcpu_scale = 1;
 658         while (pcpu_scale < (1U << (BITS_PER_INT-2))) {
 659                 pcpu_scale *= 4;
 660                 pcpu_shift += 2;
 661         }
 662         tmp_unsigned = (uint16_t)(cur_jif.total - prev_jif.total) * total_pcpu;
 663         if (tmp_unsigned != 0)
 664                 pcpu_scale /= tmp_unsigned;
 665         /* we want (s->pcpu * pcpu_scale) to never overflow */
 666         while (pcpu_scale >= 1024) {
 667                 pcpu_scale /= 4;
 668                 pcpu_shift -= 2;
 669         }
 670         pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
 671         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 672 #endif
 673
 674         /* Ok, all preliminary data is ready, go through the list */
 675         scr_width += 2; /* account for leading '\n' and trailing NUL */
 676         if (lines_rem > ntop - G_scroll_ofs)
 677                 lines_rem = ntop - G_scroll_ofs;
 678         s = top + G_scroll_ofs;
 679         while (--lines_rem >= 0) {
 680                 unsigned col;
 681                 CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
 682 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 683                 CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
 684 #endif
 685
 686                 if (s->vsz >= 100000)
 687                         sprintf(vsz_str_buf, "%6ldm", s->vsz/1024);
 688                 else
 689                         sprintf(vsz_str_buf, "%7lu", s->vsz);
 690                 /* PID PPID USER STAT VSZ %VSZ [%CPU] COMMAND */
 691                 col = snprintf(line_buf, scr_width,
 692                                 "\n" "%5u%6u %-8.8s %s%s" FMT
 693                                 IF_FEATURE_TOP_SMP_PROCESS(" %3d")
 694                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
 695                                 " ",
 696                                 s->pid, s->ppid, get_cached_username(s->uid),
 697                                 s->state, vsz_str_buf,
 698                                 SHOW_STAT(pmem)
 699                                 IF_FEATURE_TOP_SMP_PROCESS(, s->last_seen_on_cpu)
 700                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
 701                 );
 702                 if ((int)(col + 1) < scr_width)
 703                         read_cmdline(line_buf + col, scr_width - col, s->pid, s->comm);
 704                 fputs(line_buf, stdout);
 705                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
 706                         cur_jif.busy - prev_jif.busy, cur_jif.total - prev_jif.total); */
 707                 s++;
 708         }
 709         /* printf(" %d", hist_iterations); */
 710         bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
 711         fflush_all();
 712 }
 713 #undef UPSCALE
 714 #undef SHOW_STAT
 715 #undef CALC_STAT
 716 #undef FMT
 717
 718 static void clearmems(void)
 719 {
 720         clear_username_cache();
 721         free(top);
 722         top = NULL;
 723 }
 724
 725 #if ENABLE_FEATURE_USE_TERMIOS
 726
 727 static void reset_term(void)
 728 {
 729         if (!OPT_BATCH_MODE)
 730                 tcsetattr_stdin_TCSANOW(&initial_settings);
 731 }
 732
 733 static void sig_catcher(int sig)
 734 {
 735         reset_term();
 736         kill_myself_with_sig(sig);
 737 }
 738
 739 #endif /* FEATURE_USE_TERMIOS */
 740
 741 /*
 742  * TOPMEM support
 743  */
 744
 745 typedef unsigned long mem_t;
 746
 747 typedef struct topmem_status_t {
 748         unsigned pid;
 749         char comm[COMM_LEN];
 750         /* vsz doesn't count /dev/xxx mappings except /dev/zero */
 751         mem_t vsz     ;
 752         mem_t vszrw   ;
 753         mem_t rss     ;
 754         mem_t rss_sh  ;
 755         mem_t dirty   ;
 756         mem_t dirty_sh;
 757         mem_t stack   ;
 758 } topmem_status_t;
 759
 760 enum { NUM_SORT_FIELD = 7 };
 761
 762 #define topmem ((topmem_status_t*)top)
 763
 764 #if ENABLE_FEATURE_TOPMEM
 765
 766 static int topmem_sort(char *a, char *b)
 767 {
 768         int n;
 769         mem_t l, r;
 770
 771         n = offsetof(topmem_status_t, vsz) + (sort_field * sizeof(mem_t));
 772         l = *(mem_t*)(a + n);
 773         r = *(mem_t*)(b + n);
 774         if (l == r) {
 775                 l = ((topmem_status_t*)a)->dirty;
 776                 r = ((topmem_status_t*)b)->dirty;
 777         }
 778         /* We want to avoid unsigned->signed and truncation errors */
 779         /* l>r: -1, l=r: 0, l<r: 1 */
 780         n = (l > r) ? -1 : (l != r);
 781         return inverted ? -n : n;
 782 }
 783
 784 /* display header info (meminfo / loadavg) */
 785 static void display_topmem_header(int scr_width, int *lines_rem_p)
 786 {
 787         unsigned long meminfo[MI_MAX];
 788
 789         parse_meminfo(meminfo);
 790
 791         snprintf(line_buf, LINE_BUF_SIZE,
 792                 "Mem total:%lu anon:%lu map:%lu free:%lu",
 793                 meminfo[MI_MEMTOTAL],
 794                 meminfo[MI_ANONPAGES],
 795                 meminfo[MI_MAPPED],
 796                 meminfo[MI_MEMFREE]);
 797         printf(OPT_BATCH_MODE ? "%.*s\n" : "\033[H\033[J%.*s\n", scr_width, line_buf);
 798
 799         snprintf(line_buf, LINE_BUF_SIZE,
 800                 " slab:%lu buf:%lu cache:%lu dirty:%lu write:%lu",
 801                 meminfo[MI_SLAB],
 802                 meminfo[MI_BUFFERS],
 803                 meminfo[MI_CACHED],
 804                 meminfo[MI_DIRTY],
 805                 meminfo[MI_WRITEBACK]);
 806         printf("%.*s\n", scr_width, line_buf);
 807
 808         snprintf(line_buf, LINE_BUF_SIZE,
 809                 "Swap total:%lu free:%lu", // TODO: % used?
 810                 meminfo[MI_SWAPTOTAL],
 811                 meminfo[MI_SWAPFREE]);
 812         printf("%.*s\n", scr_width, line_buf);
 813
 814         (*lines_rem_p) -= 3;
 815 }
 816
 817 static void ulltoa6_and_space(unsigned long long ul, char buf[6])
 818 {
 819         /* see http://en.wikipedia.org/wiki/Tera */
 820         smart_ulltoa5(ul, buf, " mgtpezy")[0] = ' ';
 821 }
 822
 823 static NOINLINE void display_topmem_process_list(int lines_rem, int scr_width)
 824 {
 825 #define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
 826 #define MIN_WIDTH sizeof(HDR_STR)
 827         const topmem_status_t *s = topmem + G_scroll_ofs;
 828         char *cp, ch;
 829
 830         display_topmem_header(scr_width, &lines_rem);
 831
 832         strcpy(line_buf, HDR_STR " COMMAND");
 833         /* Mark the ^FIELD^ we sort by */
 834         cp = &line_buf[5 + sort_field * 6];
 835         ch = "^_"[inverted];
 836         cp[6] = ch;
 837         do *cp++ = ch; while (*cp == ' ');
 838
 839         printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width, line_buf);
 840         lines_rem--;
 841
 842         if (lines_rem > ntop - G_scroll_ofs)
 843                 lines_rem = ntop - G_scroll_ofs;
 844         while (--lines_rem >= 0) {
 845                 /* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
 846                 ulltoa6_and_space(s->pid     , &line_buf[0*6]);
 847                 ulltoa6_and_space(s->vsz     , &line_buf[1*6]);
 848                 ulltoa6_and_space(s->vszrw   , &line_buf[2*6]);
 849                 ulltoa6_and_space(s->rss     , &line_buf[3*6]);
 850                 ulltoa6_and_space(s->rss_sh  , &line_buf[4*6]);
 851                 ulltoa6_and_space(s->dirty   , &line_buf[5*6]);
 852                 ulltoa6_and_space(s->dirty_sh, &line_buf[6*6]);
 853                 ulltoa6_and_space(s->stack   , &line_buf[7*6]);
 854                 line_buf[8*6] = '\0';
 855                 if (scr_width > (int)MIN_WIDTH) {
 856                         read_cmdline(&line_buf[8*6], scr_width - MIN_WIDTH, s->pid, s->comm);
 857                 }
 858                 printf("\n""%.*s", scr_width, line_buf);
 859                 s++;
 860         }
 861         bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
 862         fflush_all();
 863 #undef HDR_STR
 864 #undef MIN_WIDTH
 865 }
 866
 867 #else
 868 void display_topmem_process_list(int lines_rem, int scr_width);
 869 int topmem_sort(char *a, char *b);
 870 #endif /* TOPMEM */
 871
 872 /*
 873  * end TOPMEM support
 874  */
 875
 876 enum {
 877         TOP_MASK = 0
 878                 | PSSCAN_PID
 879                 | PSSCAN_PPID
 880                 | PSSCAN_VSZ
 881                 | PSSCAN_STIME
 882                 | PSSCAN_UTIME
 883                 | PSSCAN_STATE
 884                 | PSSCAN_COMM
 885                 | PSSCAN_CPU
 886                 | PSSCAN_UIDGID,
 887         TOPMEM_MASK = 0
 888                 | PSSCAN_PID
 889                 | PSSCAN_SMAPS
 890                 | PSSCAN_COMM,
 891         EXIT_MASK = (unsigned)-1,
 892 };
 893
 894 #if ENABLE_FEATURE_USE_TERMIOS
 895 static unsigned handle_input(unsigned scan_mask, unsigned interval)
 896 {
 897         if (option_mask32 & OPT_EOF) {
 898                 /* EOF on stdin ("top </dev/null") */
 899                 sleep(interval);
 900                 return scan_mask;
 901         }
 902
 903         while (1) {
 904                 int32_t c;
 905
 906                 c = read_key(STDIN_FILENO, G.kbd_input, interval * 1000);
 907                 if (c == -1 && errno != EAGAIN) {
 908                         /* error/EOF */
 909                         option_mask32 |= OPT_EOF;
 910                         break;
 911                 }
 912                 interval = 0;
 913
 914                 if (c == initial_settings.c_cc[VINTR])
 915                         return EXIT_MASK;
 916                 if (c == initial_settings.c_cc[VEOF])
 917                         return EXIT_MASK;
 918
 919                 if (c == KEYCODE_UP) {
 920                         G_scroll_ofs--;
 921                         goto normalize_ofs;
 922                 }
 923                 if (c == KEYCODE_DOWN) {
 924                         G_scroll_ofs++;
 925                         goto normalize_ofs;
 926                 }
 927                 if (c == KEYCODE_HOME) {
 928                         G_scroll_ofs = 0;
 929                         break;
 930                 }
 931                 if (c == KEYCODE_END) {
 932                         G_scroll_ofs = ntop - G.lines / 2;
 933                         goto normalize_ofs;
 934                 }
 935                 if (c == KEYCODE_PAGEUP) {
 936                         G_scroll_ofs -= G.lines / 2;
 937                         goto normalize_ofs;
 938                 }
 939                 if (c == KEYCODE_PAGEDOWN) {
 940                         G_scroll_ofs += G.lines / 2;
 941  normalize_ofs:
 942                         if (G_scroll_ofs >= ntop)
 943                                 G_scroll_ofs = ntop - 1;
 944                         if (G_scroll_ofs < 0)
 945                                 G_scroll_ofs = 0;
 946                         break;
 947                 }
 948
 949                 c |= 0x20; /* lowercase */
 950                 if (c == 'q')
 951                         return EXIT_MASK;
 952
 953                 if (c == 'n') {
 954                         IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 955                         sort_function[0] = pid_sort;
 956                         continue;
 957                 }
 958                 if (c == 'm') {
 959                         IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 960                         sort_function[0] = mem_sort;
 961 # if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 962                         sort_function[1] = pcpu_sort;
 963                         sort_function[2] = time_sort;
 964 # endif
 965                         continue;
 966                 }
 967 # if ENABLE_FEATURE_SHOW_THREADS
 968                 if (c == 'h'
 969                 IF_FEATURE_TOPMEM(&& scan_mask != TOPMEM_MASK)
 970                 ) {
 971                         scan_mask ^= PSSCAN_TASKS;
 972                         continue;
 973                 }
 974 # endif
 975 # if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 976                 if (c == 'p') {
 977                         IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 978                         sort_function[0] = pcpu_sort;
 979                         sort_function[1] = mem_sort;
 980                         sort_function[2] = time_sort;
 981                         continue;
 982                 }
 983                 if (c == 't') {
 984                         IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 985                         sort_function[0] = time_sort;
 986                         sort_function[1] = mem_sort;
 987                         sort_function[2] = pcpu_sort;
 988                         continue;
 989                 }
 990 #  if ENABLE_FEATURE_TOPMEM
 991                 if (c == 's') {
 992                         scan_mask = TOPMEM_MASK;
 993                         free(prev_hist);
 994                         prev_hist = NULL;
 995                         prev_hist_count = 0;
 996                         sort_field = (sort_field + 1) % NUM_SORT_FIELD;
 997                         continue;
 998                 }
 999 #  endif
1000                 if (c == 'r') {
1001                         inverted ^= 1;
1002                         continue;
1003                 }
1004 #  if ENABLE_FEATURE_TOP_SMP_CPU
1005                 /* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
1006                 if (c == 'c' || c == '1') {
1007                         /* User wants to toggle per cpu <> aggregate */
1008                         if (smp_cpu_info) {
1009                                 free(cpu_prev_jif);
1010                                 free(cpu_jif);
1011                                 cpu_jif = &cur_jif;
1012                                 cpu_prev_jif = &prev_jif;
1013                         } else {
1014                                 /* Prepare for xrealloc() */
1015                                 cpu_jif = cpu_prev_jif = NULL;
1016                         }
1017                         num_cpus = 0;
1018                         smp_cpu_info = !smp_cpu_info;
1019                         get_jiffy_counts();
1020                         continue;
1021                 }
1022 #  endif
1023 # endif
1024                 break; /* unknown key -> force refresh */
1025         }
1026
1027         return scan_mask;
1028 }
1029 #endif
1030
1031 //usage:#if ENABLE_FEATURE_SHOW_THREADS || ENABLE_FEATURE_TOP_SMP_CPU
1032 //usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...) __VA_ARGS__
1033 //usage:#else
1034 //usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...)
1035 //usage:#endif
1036 //usage:#define top_trivial_usage
1037 //usage:       "[-b] [-nCOUNT] [-dSECONDS]" IF_FEATURE_TOPMEM(" [-m]")
1038 //usage:#define top_full_usage "\n\n"
1039 //usage:       "Provide a view of process activity in real time."
1040 //usage:   "\n""Read the status of all processes from /proc each SECONDS"
1041 //usage:   "\n""and display a screenful of them."
1042 //usage:   "\n""Keys:"
1043 //usage:   "\n""        N/M"
1044 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/P")
1045 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/T")
1046 //usage:           ": " IF_FEATURE_TOPMEM("show CPU usage, ") "sort by pid/mem"
1047 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/cpu")
1048 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/time")
1049 //usage:        IF_FEATURE_TOPMEM(
1050 //usage:   "\n""        S: show memory"
1051 //usage:        )
1052 //usage:   "\n""        R: reverse sort"
1053 //usage:        IF_SHOW_THREADS_OR_TOP_SMP(
1054 //usage:   "\n""        "
1055 //usage:                IF_FEATURE_SHOW_THREADS("H: toggle threads")
1056 //usage:                IF_FEATURE_SHOW_THREADS(IF_FEATURE_TOP_SMP_CPU(", "))
1057 //usage:                IF_FEATURE_TOP_SMP_CPU("1: toggle SMP")
1058 //usage:        )
1059 //usage:   "\n""        Q,^C: exit"
1060 //usage:   "\n"
1061 //usage:   "\n""Options:"
1062 //usage:   "\n""        -b      Batch mode"
1063 //usage:   "\n""        -n N    Exit after N iterations"
1064 //usage:   "\n""        -d N    Delay between updates"
1065 //usage:        IF_FEATURE_TOPMEM(
1066 //usage:   "\n""        -m      Same as 's' key"
1067 //usage:        )
1068
1069 /* Interactive testing:
1070  * echo sss | ./busybox top
1071  * - shows memory screen
1072  * echo sss | ./busybox top -bn1 >mem
1073  * - saves memory screen - the *whole* list, not first NROWS processes!
1074  * echo .m.s.s.s.s.s.s.q | ./busybox top -b >z
1075  * - saves several different screens, and exits
1076  *
1077  * TODO: -i STRING param as a better alternative?
1078  */
1079
1080 int top_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1081 int top_main(int argc UNUSED_PARAM, char **argv)
1082 {
1083         int iterations;
1084         unsigned col;
1085         unsigned interval;
1086         char *str_interval, *str_iterations;
1087         unsigned scan_mask = TOP_MASK;
1088 #if ENABLE_FEATURE_USE_TERMIOS
1089         struct termios new_settings;
1090 #endif
1091
1092         INIT_G();
1093
1094         interval = 5; /* default update interval is 5 seconds */
1095         iterations = 0; /* infinite */
1096 #if ENABLE_FEATURE_TOP_SMP_CPU
1097         /*num_cpus = 0;*/
1098         /*smp_cpu_info = 0;*/  /* to start with show aggregate */
1099         cpu_jif = &cur_jif;
1100         cpu_prev_jif = &prev_jif;
1101 #endif
1102
1103         /* all args are options; -n NUM */
1104         opt_complementary = "-"; /* options can be specified w/o dash */
1105         col = getopt32(argv, "d:n:b"IF_FEATURE_TOPMEM("m"), &str_interval, &str_iterations);
1106 #if ENABLE_FEATURE_TOPMEM
1107         if (col & OPT_m) /* -m (busybox specific) */
1108                 scan_mask = TOPMEM_MASK;
1109 #endif
1110         if (col & OPT_d) {
1111                 /* work around for "-d 1" -> "-d -1" done by getopt32
1112                  * (opt_complementary == "-" does this) */
1113                 if (str_interval[0] == '-')
1114                         str_interval++;
1115                 /* Need to limit it to not overflow poll timeout */
1116                 interval = xatou16(str_interval);
1117         }
1118         if (col & OPT_n) {
1119                 if (str_iterations[0] == '-')
1120                         str_iterations++;
1121                 iterations = xatou(str_iterations);
1122         }
1123
1124         /* change to /proc */
1125         xchdir("/proc");
1126
1127 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1128         sort_function[0] = pcpu_sort;
1129         sort_function[1] = mem_sort;
1130         sort_function[2] = time_sort;
1131 #else
1132         sort_function[0] = mem_sort;
1133 #endif
1134
1135         if (OPT_BATCH_MODE) {
1136                 option_mask32 |= OPT_EOF;
1137         }
1138 #if ENABLE_FEATURE_USE_TERMIOS
1139         else {
1140                 tcgetattr(0, (void *) &initial_settings);
1141                 memcpy(&new_settings, &initial_settings, sizeof(new_settings));
1142                 /* unbuffered input, turn off echo */
1143                 new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
1144                 tcsetattr_stdin_TCSANOW(&new_settings);
1145         }
1146
1147         bb_signals(BB_FATAL_SIGS, sig_catcher);
1148
1149         /* Eat initial input, if any */
1150         scan_mask = handle_input(scan_mask, 0);
1151 #endif
1152
1153         while (scan_mask != EXIT_MASK) {
1154                 procps_status_t *p = NULL;
1155
1156                 if (OPT_BATCH_MODE) {
1157                         G.lines = INT_MAX;
1158                         col = LINE_BUF_SIZE - 2; /* +2 bytes for '\n', NUL */
1159                 } else {
1160                         G.lines = 24; /* default */
1161                         col = 79;
1162 #if ENABLE_FEATURE_USE_TERMIOS
1163                         /* We output to stdout, we need size of stdout (not stdin)! */
1164                         get_terminal_width_height(STDOUT_FILENO, &col, &G.lines);
1165                         if (G.lines < 5 || col < 10) {
1166                                 sleep(interval);
1167                                 continue;
1168                         }
1169 #endif
1170                         if (col > LINE_BUF_SIZE - 2)
1171                                 col = LINE_BUF_SIZE - 2;
1172                 }
1173
1174                 /* read process IDs & status for all the processes */
1175                 ntop = 0;
1176                 while ((p = procps_scan(p, scan_mask)) != NULL) {
1177                         int n;
1178
1179                         IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
1180                                 n = ntop;
1181                                 top = xrealloc_vector(top, 6, ntop++);
1182                                 top[n].pid = p->pid;
1183                                 top[n].ppid = p->ppid;
1184                                 top[n].vsz = p->vsz;
1185 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1186                                 top[n].ticks = p->stime + p->utime;
1187 #endif
1188                                 top[n].uid = p->uid;
1189                                 strcpy(top[n].state, p->state);
1190                                 strcpy(top[n].comm, p->comm);
1191 #if ENABLE_FEATURE_TOP_SMP_PROCESS
1192                                 top[n].last_seen_on_cpu = p->last_seen_on_cpu;
1193 #endif
1194                         }
1195 #if ENABLE_FEATURE_TOPMEM
1196                         else { /* TOPMEM */
1197                                 if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
1198                                         continue; /* kernel threads are ignored */
1199                                 n = ntop;
1200                                 /* No bug here - top and topmem are the same */
1201                                 top = xrealloc_vector(topmem, 6, ntop++);
1202                                 strcpy(topmem[n].comm, p->comm);
1203                                 topmem[n].pid      = p->pid;
1204                                 topmem[n].vsz      = p->smaps.mapped_rw + p->smaps.mapped_ro;
1205                                 topmem[n].vszrw    = p->smaps.mapped_rw;
1206                                 topmem[n].rss_sh   = p->smaps.shared_clean + p->smaps.shared_dirty;
1207                                 topmem[n].rss      = p->smaps.private_clean + p->smaps.private_dirty + topmem[n].rss_sh;
1208                                 topmem[n].dirty    = p->smaps.private_dirty + p->smaps.shared_dirty;
1209                                 topmem[n].dirty_sh = p->smaps.shared_dirty;
1210                                 topmem[n].stack    = p->smaps.stack;
1211                         }
1212 #endif
1213                 } /* end of "while we read /proc" */
1214                 if (ntop == 0) {
1215                         bb_error_msg("no process info in /proc");
1216                         break;
1217                 }
1218
1219                 IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
1220 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1221                         if (!prev_hist_count) {
1222                                 do_stats();
1223                                 usleep(100000);
1224                                 clearmems();
1225                                 continue;
1226                         }
1227                         do_stats();
1228                         /* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
1229                         qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
1230 #else
1231                         qsort(top, ntop, sizeof(top_status_t), (void*)(sort_function[0]));
1232 #endif
1233                         display_process_list(G.lines, col);
1234                 }
1235 #if ENABLE_FEATURE_TOPMEM
1236                 else { /* TOPMEM */
1237                         qsort(topmem, ntop, sizeof(topmem_status_t), (void*)topmem_sort);
1238                         display_topmem_process_list(G.lines, col);
1239                 }
1240 #endif
1241                 clearmems();
1242                 if (iterations >= 0 && !--iterations)
1243                         break;
1244 #if !ENABLE_FEATURE_USE_TERMIOS
1245                 sleep(interval);
1246 #else
1247                 scan_mask = handle_input(scan_mask, interval);
1248 #endif
1249         } /* end of "while (not Q)" */
1250
1251         bb_putchar('\n');
1252 #if ENABLE_FEATURE_USE_TERMIOS
1253         reset_term();
1254 #endif
1255         if (ENABLE_FEATURE_CLEAN_UP) {
1256                 clearmems();
1257 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1258                 free(prev_hist);
1259 #endif
1260         }
1261         return EXIT_SUCCESS;
1262 }