aboutsummaryrefslogtreecommitdiff
path: root/procps/top.c
blob: 1eb33dc5d3d3d39a1224ce2472f23d5993c2906a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
/* vi: set sw=4 ts=4: */
/*
 * A tiny 'top' utility.
 *
 * This is written specifically for the linux /proc/<PID>/stat(m)
 * files format.
 *
 * This reads the PIDs of all processes and their status and shows
 * the status of processes (first ones that fit to screen) at given
 * intervals.
 *
 * NOTES:
 * - At startup this changes to /proc, all the reads are then
 *   relative to that.
 *
 * (C) Eero Tamminen <oak at welho dot com>
 *
 * Rewritten by Vladimir Oleynik (C) 2002 <dzo@simtreas.ru>
 *
 * Sept 2008: Vineet Gupta <vineet.gupta@arc.com>
 * Added Support for reporting SMP Information
 * - CPU where Process was last seen running
 *   (to see effect of sched_setaffinity() etc)
 * - CPU Time Split (idle/IO/wait etc) PER CPU
 *
 * Copyright (c) 1992 Branko Lankester
 * Copyright (c) 1992 Roger Binns
 * Copyright (C) 1994-1996 Charles L. Blake.
 * Copyright (C) 1992-1998 Michael K. Johnson
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

#include "libbb.h"


typedef struct top_status_t {
	unsigned long vsz;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
	unsigned long ticks;
	unsigned pcpu; /* delta of ticks */
#endif
	unsigned pid, ppid;
	unsigned uid;
	char state[4];
	char comm[COMM_LEN];
#if ENABLE_FEATURE_TOP_SMP_PROCESS
	int last_seen_on_cpu;
#endif
} top_status_t;

typedef struct jiffy_counts_t {
	/* Linux 2.4.x has only first four */
	unsigned long long usr, nic, sys, idle;
	unsigned long long iowait, irq, softirq, steal;
	unsigned long long total;
	unsigned long long busy;
} jiffy_counts_t;

/* This structure stores some critical information from one frame to
   the next. Used for finding deltas. */
typedef struct save_hist {
	unsigned long ticks;
	pid_t pid;
} save_hist;

typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);


enum { SORT_DEPTH = 3 };


struct globals {
	top_status_t *top;
	int ntop;
#if ENABLE_FEATURE_TOPMEM
	smallint sort_field;
	smallint inverted;
#endif
#if ENABLE_FEATURE_TOP_SMP_CPU
	smallint smp_cpu_info; /* one/many cpu info lines? */
#endif
#if ENABLE_FEATURE_USE_TERMIOS
	struct termios initial_settings;
#endif
#if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
	cmp_funcp sort_function[1];
#else
	cmp_funcp sort_function[SORT_DEPTH];
	struct save_hist *prev_hist;
	int prev_hist_count;
	jiffy_counts_t cur_jif, prev_jif;
	/* int hist_iterations; */
	unsigned total_pcpu;
	/* unsigned long total_vsz; */
#endif
#if ENABLE_FEATURE_TOP_SMP_CPU
	/* Per CPU samples: current and last */
	jiffy_counts_t *cpu_jif, *cpu_prev_jif;
	int num_cpus;
#endif
	char line_buf[80];
}; //FIX_ALIASING; - large code growth
enum { LINE_BUF_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line_buf) };
#define G (*(struct globals*)&bb_common_bufsiz1)
struct BUG_bad_size {
	char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
	char BUG_line_buf_too_small[LINE_BUF_SIZE > 80 ? 1 : -1];
};
#define INIT_G() do { } while (0)
#define top              (G.top               )
#define ntop             (G.ntop              )
#define sort_field       (G.sort_field        )
#define inverted         (G.inverted          )
#define smp_cpu_info     (G.smp_cpu_info      )
#define initial_settings (G.initial_settings  )
#define sort_function    (G.sort_function     )
#define prev_hist        (G.prev_hist         )
#define prev_hist_count  (G.prev_hist_count   )
#define cur_jif          (G.cur_jif           )
#define prev_jif         (G.prev_jif          )
#define cpu_jif          (G.cpu_jif           )
#define cpu_prev_jif     (G.cpu_prev_jif      )
#define num_cpus         (G.num_cpus          )
#define total_pcpu       (G.total_pcpu        )
#define line_buf         (G.line_buf          )

enum {
	OPT_d = (1 << 0),
	OPT_n = (1 << 1),
	OPT_b = (1 << 2),
	OPT_m = (1 << 3),
	OPT_EOF = (1 << 4), /* pseudo: "we saw EOF in stdin" */
};
#define OPT_BATCH_MODE (option_mask32 & OPT_b)


#if ENABLE_FEATURE_USE_TERMIOS
static int pid_sort(top_status_t *P, top_status_t *Q)
{
	/* Buggy wrt pids with high bit set */
	/* (linux pids are in [1..2^15-1]) */
	return (Q->pid - P->pid);
}
#endif

static int mem_sort(top_status_t *P, top_status_t *Q)
{
	/* We want to avoid unsigned->signed and truncation errors */
	if (Q->vsz < P->vsz) return -1;
	return Q->vsz != P->vsz; /* 0 if ==, 1 if > */
}


#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE

static int pcpu_sort(top_status_t *P, top_status_t *Q)
{
	/* Buggy wrt ticks with high bit set */
	/* Affects only processes for which ticks overflow */
	return (int)Q->pcpu - (int)P->pcpu;
}

static int time_sort(top_status_t *P, top_status_t *Q)
{
	/* We want to avoid unsigned->signed and truncation errors */
	if (Q->ticks < P->ticks) return -1;
	return Q->ticks != P->ticks; /* 0 if ==, 1 if > */
}

static int mult_lvl_cmp(void* a, void* b)
{
	int i, cmp_val;

	for (i = 0; i < SORT_DEPTH; i++) {
		cmp_val = (*sort_function[i])(a, b);
		if (cmp_val != 0)
			return cmp_val;
	}
	return 0;
}

static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
{
#if !ENABLE_FEATURE_TOP_SMP_CPU
	static const char fmt[] = "cpu %llu %llu %llu %llu %llu %llu %llu %llu";
#else
	static const char fmt[] = "cp%*s %llu %llu %llu %llu %llu %llu %llu %llu";
#endif
	int ret;

	if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
		return 0;
	ret = sscanf(line_buf, fmt,
			&p_jif->usr, &p_jif->nic, &p_jif->sys, &p_jif->idle,
			&p_jif->iowait, &p_jif->irq, &p_jif->softirq,
			&p_jif->steal);
	if (ret >= 4) {
		p_jif->total = p_jif->usr + p_jif->nic + p_jif->sys + p_jif->idle
			+ p_jif->iowait + p_jif->irq + p_jif->softirq + p_jif->steal;
		/* procps 2.x does not count iowait as busy time */
		p_jif->busy = p_jif->total - p_jif->idle - p_jif->iowait;
	}

	return ret;
}

static void get_jiffy_counts(void)
{
	FILE* fp = xfopen_for_read("stat");

	/* We need to parse cumulative counts even if SMP CPU display is on,
	 * they are used to calculate per process CPU% */
	prev_jif = cur_jif;
	if (read_cpu_jiffy(fp, &cur_jif) < 4)
		bb_error_msg_and_die("can't read /proc/stat");

#if !ENABLE_FEATURE_TOP_SMP_CPU
	fclose(fp);
	return;
#else
	if (!smp_cpu_info) {
		fclose(fp);
		return;
	}

	if (!num_cpus) {
		/* First time here. How many CPUs?
		 * There will be at least 1 /proc/stat line with cpu%d
		 */
		while (1) {
			cpu_jif = xrealloc_vector(cpu_jif, 1, num_cpus);
			if (read_cpu_jiffy(fp, &cpu_jif[num_cpus]) <= 4)
				break;
			num_cpus++;
		}
		if (num_cpus == 0) /* /proc/stat with only "cpu ..." line?! */
			smp_cpu_info = 0;

		cpu_prev_jif = xzalloc(sizeof(cpu_prev_jif[0]) * num_cpus);

		/* Otherwise the first per cpu display shows all 100% idles */
		usleep(50000);
	} else { /* Non first time invocation */
		jiffy_counts_t *tmp;
		int i;

		/* First switch the sample pointers: no need to copy */
		tmp = cpu_prev_jif;
		cpu_prev_jif = cpu_jif;
		cpu_jif = tmp;

		/* Get the new samples */
		for (i = 0; i < num_cpus; i++)
			read_cpu_jiffy(fp, &cpu_jif[i]);
	}
#endif
	fclose(fp);
}

static void do_stats(void)
{
	top_status_t *cur;
	pid_t pid;
	int i, last_i, n;
	struct save_hist *new_hist;

	get_jiffy_counts();
	total_pcpu = 0;
	/* total_vsz = 0; */
	new_hist = xmalloc(sizeof(new_hist[0]) * ntop);
	/*
	 * Make a pass through the data to get stats.
	 */
	/* hist_iterations = 0; */
	i = 0;
	for (n = 0; n < ntop; n++) {
		cur = top + n;

		/*
		 * Calculate time in cur process.  Time is sum of user time
		 * and system time
		 */
		pid = cur->pid;
		new_hist[n].ticks = cur->ticks;
		new_hist[n].pid = pid;

		/* find matching entry from previous pass */
		cur->pcpu = 0;
		/* do not start at index 0, continue at last used one
		 * (brought hist_iterations from ~14000 down to 172) */
		last_i = i;
		if (prev_hist_count) do {
			if (prev_hist[i].pid == pid) {
				cur->pcpu = cur->ticks - prev_hist[i].ticks;
				total_pcpu += cur->pcpu;
				break;
			}
			i = (i+1) % prev_hist_count;
			/* hist_iterations++; */
		} while (i != last_i);
		/* total_vsz += cur->vsz; */
	}

	/*
	 * Save cur frame's information.
	 */
	free(prev_hist);
	prev_hist = new_hist;
	prev_hist_count = ntop;
}

#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */

#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
/* formats 7 char string (8 with terminating NUL) */
static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
{
	unsigned t;
	if (value >= total) { /* 100% ? */
		strcpy(pbuf, "  100% ");
		return pbuf;
	}
	/* else generate " [N/space]N.N% " string */
	value = 1000 * value / total;
	t = value / 100;
	value = value % 100;
	pbuf[0] = ' ';
	pbuf[1] = t ? t + '0' : ' ';
	pbuf[2] = '0' + (value / 10);
	pbuf[3] = '.';
	pbuf[4] = '0' + (value % 10);
	pbuf[5] = '%';
	pbuf[6] = ' ';
	pbuf[7] = '\0';
	return pbuf;
}
#endif

#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
{
	/*
	 * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
	 */
	unsigned total_diff;
	jiffy_counts_t *p_jif, *p_prev_jif;
	int i;
# if ENABLE_FEATURE_TOP_SMP_CPU
	int n_cpu_lines;
# endif

	/* using (unsigned) casts to make operations cheaper */
# define  CALC_TOTAL_DIFF do { \
	total_diff = (unsigned)(p_jif->total - p_prev_jif->total); \
	if (total_diff == 0) total_diff = 1; \
} while (0)

# if ENABLE_FEATURE_TOP_DECIMALS
#  define CALC_STAT(xxx) char xxx[8]
#  define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
#  define FMT "%s"
# else
#  define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
#  define SHOW_STAT(xxx) xxx
#  define FMT "%4u%% "
# endif

# if !ENABLE_FEATURE_TOP_SMP_CPU
	{
		i = 1;
		p_jif = &cur_jif;
		p_prev_jif = &prev_jif;
# else
	/* Loop thru CPU(s) */
	n_cpu_lines = smp_cpu_info ? num_cpus : 1;
	if (n_cpu_lines > *lines_rem_p)
		n_cpu_lines = *lines_rem_p;

	for (i = 0; i < n_cpu_lines; i++) {
		p_jif = &cpu_jif[i];
		p_prev_jif = &cpu_prev_jif[i];
# endif
		CALC_TOTAL_DIFF;

		{ /* Need a block: CALC_STAT are declarations */
			CALC_STAT(usr);
			CALC_STAT(sys);
			CALC_STAT(nic);
			CALC_STAT(idle);
			CALC_STAT(iowait);
			CALC_STAT(irq);
			CALC_STAT(softirq);
			/*CALC_STAT(steal);*/

			snprintf(scrbuf, scr_width,
				/* Barely fits in 79 chars when in "decimals" mode. */
# if ENABLE_FEATURE_TOP_SMP_CPU
				"CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
				(smp_cpu_info ? utoa(i) : ""),
# else
				"CPU:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
# endif
				SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
				SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
				/*, SHOW_STAT(steal) - what is this 'steal' thing? */
				/* I doubt anyone wants to know it */
			);
			puts(scrbuf);
		}
	}
# undef SHOW_STAT
# undef CALC_STAT
# undef FMT
	*lines_rem_p -= i;
}
#else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
# define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
#endif

static unsigned long display_header(int scr_width, int *lines_rem_p)
{
	FILE *fp;
	char buf[80];
	char scrbuf[80];
	unsigned long total, used, mfree, shared, buffers, cached;

	/* read memory info */
	fp = xfopen_for_read("meminfo");

	/*
	 * Old kernels (such as 2.4.x) had a nice summary of memory info that
	 * we could parse, however this is gone entirely in 2.6. Try parsing
	 * the old way first, and if that fails, parse each field manually.
	 *
	 * First, we read in the first line. Old kernels will have bogus
	 * strings we don't care about, whereas new kernels will start right
	 * out with MemTotal:
	 *                              -- PFM.
	 */
	if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
		fgets(buf, sizeof(buf), fp);    /* skip first line */

		fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
			&total, &used, &mfree, &shared, &buffers, &cached);
		/* convert to kilobytes */
		used /= 1024;
		mfree /= 1024;
		shared /= 1024;
		buffers /= 1024;
		cached /= 1024;
		total /= 1024;
	} else {
		/*
		 * Revert to manual parsing, which incidentally already has the
		 * sizes in kilobytes. This should be safe for both 2.4 and
		 * 2.6.
		 */
		fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);

		/*
		 * MemShared: is no longer present in 2.6. Report this as 0,
		 * to maintain consistent behavior with normal procps.
		 */
		if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
			shared = 0;

		fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
		fscanf(fp, "Cached: %lu %s\n", &cached, buf);

		used = total - mfree;
	}
	fclose(fp);

	/* output memory info */
	if (scr_width > (int)sizeof(scrbuf))
		scr_width = sizeof(scrbuf);
	snprintf(scrbuf, scr_width,
		"Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
		used, mfree, shared, buffers, cached);
	/* go to top & clear to the end of screen */
	printf(OPT_BATCH_MODE ? "%s\n" : "\033[H\033[J%s\n", scrbuf);
	(*lines_rem_p)--;

	/* Display CPU time split as percentage of total time
	 * This displays either a cumulative line or one line per CPU
	 */
	display_cpus(scr_width, scrbuf, lines_rem_p);

	/* read load average as a string */
	buf[0] = '\0';
	open_read_close("loadavg", buf, sizeof(buf) - 1);
	buf[sizeof(buf) - 1] = '\n';
	*strchr(buf, '\n') = '\0';
	snprintf(scrbuf, scr_width, "Load average: %s", buf);
	puts(scrbuf);
	(*lines_rem_p)--;

	return total;
}

static NOINLINE void display_process_list(int lines_rem, int scr_width)
{
	enum {
		BITS_PER_INT = sizeof(int) * 8
	};

	top_status_t *s;
	char vsz_str_buf[8];
	unsigned long total_memory = display_header(scr_width, &lines_rem); /* or use total_vsz? */
	/* xxx_shift and xxx_scale variables allow us to replace
	 * expensive divides with multiply and shift */
	unsigned pmem_shift, pmem_scale, pmem_half;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
	unsigned tmp_unsigned;
	unsigned pcpu_shift, pcpu_scale, pcpu_half;
	unsigned busy_jifs;
#endif

	/* what info of the processes is shown */
	printf(OPT_BATCH_MODE ? "%.*s" : "\033[7m%.*s\033[0m", scr_width,
		"  PID  PPID USER     STAT   VSZ %MEM"
		IF_FEATURE_TOP_SMP_PROCESS(" CPU")
		IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
		" COMMAND");
	lines_rem--;

#if ENABLE_FEATURE_TOP_DECIMALS
# define UPSCALE 1000
# define CALC_STAT(name, val) div_t name = div((val), 10)
# define SHOW_STAT(name) name.quot, '0'+name.rem
# define FMT "%3u.%c"
#else
# define UPSCALE 100
# define CALC_STAT(name, val) unsigned name = (val)
# define SHOW_STAT(name) name
# define FMT "%4u%%"
#endif
	/*
	 * MEM% = s->vsz/MemTotal
	 */
	pmem_shift = BITS_PER_INT-11;
	pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
	/* s->vsz is in kb. we want (s->vsz * pmem_scale) to never overflow */
	while (pmem_scale >= 512) {
		pmem_scale /= 4;
		pmem_shift -= 2;
	}
	pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
	busy_jifs = cur_jif.busy - prev_jif.busy;
	/* This happens if there were lots of short-lived processes
	 * between two top updates (e.g. compilation) */
	if (total_pcpu < busy_jifs) total_pcpu = busy_jifs;

	/*
	 * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
	 * (pcpu is delta of sys+user time between samples)
	 */
	/* (cur_jif.xxx - prev_jif.xxx) and s->pcpu are
	 * in 0..~64000 range (HZ*update_interval).
	 * we assume that unsigned is at least 32-bit.
	 */
	pcpu_shift = 6;
	pcpu_scale = UPSCALE*64 * (uint16_t)busy_jifs;
	if (pcpu_scale == 0)
		pcpu_scale = 1;
	while (pcpu_scale < (1U << (BITS_PER_INT-2))) {
		pcpu_scale *= 4;
		pcpu_shift += 2;
	}
	tmp_unsigned = (uint16_t)(cur_jif.total - prev_jif.total) * total_pcpu;
	if (tmp_unsigned != 0)
		pcpu_scale /= tmp_unsigned;
	/* we want (s->pcpu * pcpu_scale) to never overflow */
	while (pcpu_scale >= 1024) {
		pcpu_scale /= 4;
		pcpu_shift -= 2;
	}
	pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
	/* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
#endif

	/* Ok, all preliminary data is ready, go through the list */
	scr_width += 2; /* account for leading '\n' and trailing NUL */
	if (lines_rem > ntop)
		lines_rem = ntop;
	s = top;
	while (--lines_rem >= 0) {
		unsigned col;
		CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
		CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
#endif

		if (s->vsz >= 100000)
			sprintf(vsz_str_buf, "%6ldm", s->vsz/1024);
		else
			sprintf(vsz_str_buf, "%7ld", s->vsz);
		/* PID PPID USER STAT VSZ %MEM [%CPU] COMMAND */
		col = snprintf(line_buf, scr_width,
				"\n" "%5u%6u %-8.8s %s%s" FMT
				IF_FEATURE_TOP_SMP_PROCESS(" %3d")
				IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
				" ",
				s->pid, s->ppid, get_cached_username(s->uid),
				s->state, vsz_str_buf,
				SHOW_STAT(pmem)
				IF_FEATURE_TOP_SMP_PROCESS(, s->last_seen_on_cpu)
				IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
		);
		if ((int)(col + 1) < scr_width)
			read_cmdline(line_buf + col, scr_width - col, s->pid, s->comm);
		fputs(line_buf, stdout);
		/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
			cur_jif.busy - prev_jif.busy, cur_jif.total - prev_jif.total); */
		s++;
	}
	/* printf(" %d", hist_iterations); */
	bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
	fflush_all();
}
#undef UPSCALE
#undef SHOW_STAT
#undef CALC_STAT
#undef FMT

static void clearmems(void)
{
	clear_username_cache();
	free(top);
	top = NULL;
	ntop = 0;
}

#if ENABLE_FEATURE_USE_TERMIOS

static void reset_term(void)
{
	tcsetattr_stdin_TCSANOW(&initial_settings);
	if (ENABLE_FEATURE_CLEAN_UP) {
		clearmems();
# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
		free(prev_hist);
# endif
	}
}

static void sig_catcher(int sig UNUSED_PARAM)
{
	reset_term();
	_exit(EXIT_FAILURE);
}

#endif /* FEATURE_USE_TERMIOS */

/*
 * TOPMEM support
 */

typedef unsigned long mem_t;

typedef struct topmem_status_t {
	unsigned pid;
	char comm[COMM_LEN];
	/* vsz doesn't count /dev/xxx mappings except /dev/zero */
	mem_t vsz     ;
	mem_t vszrw   ;
	mem_t rss     ;
	mem_t rss_sh  ;
	mem_t dirty   ;
	mem_t dirty_sh;
	mem_t stack   ;
} topmem_status_t;

enum { NUM_SORT_FIELD = 7 };

#define topmem ((topmem_status_t*)top)

#if ENABLE_FEATURE_TOPMEM

static int topmem_sort(char *a, char *b)
{
	int n;
	mem_t l, r;

	n = offsetof(topmem_status_t, vsz) + (sort_field * sizeof(mem_t));
	l = *(mem_t*)(a + n);
	r = *(mem_t*)(b + n);
	if (l == r) {
		l = ((topmem_status_t*)a)->dirty;
		r = ((topmem_status_t*)b)->dirty;
	}
	/* We want to avoid unsigned->signed and truncation errors */
	/* l>r: -1, l=r: 0, l<r: 1 */
	n = (l > r) ? -1 : (l != r);
	return inverted ? -n : n;
}

/* display header info (meminfo / loadavg) */
static void display_topmem_header(int scr_width, int *lines_rem_p)
{
	enum {
		TOTAL = 0, MFREE, BUF, CACHE,
		SWAPTOTAL, SWAPFREE, DIRTY,
		MWRITE, ANON, MAP, SLAB,
		NUM_FIELDS
	};
	static const char match[NUM_FIELDS][12] = {
		"\x09" "MemTotal:",  // TOTAL
		"\x08" "MemFree:",   // MFREE
		"\x08" "Buffers:",   // BUF
		"\x07" "Cached:",    // CACHE
		"\x0a" "SwapTotal:", // SWAPTOTAL
		"\x09" "SwapFree:",  // SWAPFREE
		"\x06" "Dirty:",     // DIRTY
		"\x0a" "Writeback:", // MWRITE
		"\x0a" "AnonPages:", // ANON
		"\x07" "Mapped:",    // MAP
		"\x05" "Slab:",      // SLAB
	};
	char meminfo_buf[4 * 1024];
	const char *Z[NUM_FIELDS];
	unsigned i;
	int sz;

	for (i = 0; i < NUM_FIELDS; i++)
		Z[i] = "?";

	/* read memory info */
	sz = open_read_close("meminfo", meminfo_buf, sizeof(meminfo_buf) - 1);
	if (sz >= 0) {
		char *p = meminfo_buf;
		meminfo_buf[sz] = '\0';
		/* Note that fields always appear in the match[] order */
		for (i = 0; i < NUM_FIELDS; i++) {
			char *found = strstr(p, match[i] + 1);
			if (found) {
				/* Cut "NNNN" out of "    NNNN kb" */
				char *s = skip_whitespace(found + match[i][0]);
				p = skip_non_whitespace(s);
				*p++ = '\0';
				Z[i] = s;
			}
		}
	}

	snprintf(line_buf, LINE_BUF_SIZE,
		"Mem total:%s anon:%s map:%s free:%s",
		Z[TOTAL], Z[ANON], Z[MAP], Z[MFREE]);
	printf(OPT_BATCH_MODE ? "%.*s\n" : "\033[H\033[J%.*s\n", scr_width, line_buf);

	snprintf(line_buf, LINE_BUF_SIZE,
		" slab:%s buf:%s cache:%s dirty:%s write:%s",
		Z[SLAB], Z[BUF], Z[CACHE], Z[DIRTY], Z[MWRITE]);
	printf("%.*s\n", scr_width, line_buf);

	snprintf(line_buf, LINE_BUF_SIZE,
		"Swap total:%s free:%s", // TODO: % used?
		Z[SWAPTOTAL], Z[SWAPFREE]);
	printf("%.*s\n", scr_width, line_buf);

	(*lines_rem_p) -= 3;
}

static void ulltoa6_and_space(unsigned long long ul, char buf[6])
{
	/* see http://en.wikipedia.org/wiki/Tera */
	smart_ulltoa5(ul, buf, " mgtpezy");
	buf[5] = ' ';
}

static NOINLINE void display_topmem_process_list(int lines_rem, int scr_width)
{
#define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
#define MIN_WIDTH sizeof(HDR_STR)
	const topmem_status_t *s = topmem;

	display_topmem_header(scr_width, &lines_rem);
	strcpy(line_buf, HDR_STR " COMMAND");
	line_buf[5 + sort_field * 6] = '*';
	printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width, line_buf);
	lines_rem--;

	if (lines_rem > ntop)
		lines_rem = ntop;
	while (--lines_rem >= 0) {
		/* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
		ulltoa6_and_space(s->pid     , &line_buf[0*6]);
		ulltoa6_and_space(s->vsz     , &line_buf[1*6]);
		ulltoa6_and_space(s->vszrw   , &line_buf[2*6]);
		ulltoa6_and_space(s->rss     , &line_buf[3*6]);
		ulltoa6_and_space(s->rss_sh  , &line_buf[4*6]);
		ulltoa6_and_space(s->dirty   , &line_buf[5*6]);
		ulltoa6_and_space(s->dirty_sh, &line_buf[6*6]);
		ulltoa6_and_space(s->stack   , &line_buf[7*6]);
		line_buf[8*6] = '\0';
		if (scr_width > (int)MIN_WIDTH) {
			read_cmdline(&line_buf[8*6], scr_width - MIN_WIDTH, s->pid, s->comm);
		}
		printf("\n""%.*s", scr_width, line_buf);
		s++;
	}
	bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
	fflush_all();
#undef HDR_STR
#undef MIN_WIDTH
}

#else
void display_topmem_process_list(int lines_rem, int scr_width);
int topmem_sort(char *a, char *b);
#endif /* TOPMEM */

/*
 * end TOPMEM support
 */

enum {
	TOP_MASK = 0
		| PSSCAN_PID
		| PSSCAN_PPID
		| PSSCAN_VSZ
		| PSSCAN_STIME
		| PSSCAN_UTIME
		| PSSCAN_STATE
		| PSSCAN_COMM
		| PSSCAN_CPU
		| PSSCAN_UIDGID,
	TOPMEM_MASK = 0
		| PSSCAN_PID
		| PSSCAN_SMAPS
		| PSSCAN_COMM,
};

//usage:#if ENABLE_FEATURE_SHOW_THREADS || ENABLE_FEATURE_TOP_SMP_CPU
//usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...) __VA_ARGS__
//usage:#else
//usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...)
//usage:#endif
//usage:#define top_trivial_usage
//usage:       "[-b] [-nCOUNT] [-dSECONDS]" IF_FEATURE_TOPMEM(" [-m]")
//usage:#define top_full_usage "\n\n"
//usage:       "Provide a view of process activity in real time."
//usage:   "\n""Read the status of all processes from /proc each SECONDS"
//usage:   "\n""and display a screenful of them."
//usage:   "\n""Keys:"
//usage:   "\n""	N/M"
//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/P")
//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/T")
//usage:           ": " IF_FEATURE_TOPMEM("show CPU usage, ") "sort by pid/mem"
//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/cpu")
//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/time")
//usage:	IF_FEATURE_TOPMEM(
//usage:   "\n""	S: show memory, R: reverse memory sort"
//usage:	)
//usage:	IF_SHOW_THREADS_OR_TOP_SMP(
//usage:   "\n""	"
//usage:                IF_FEATURE_SHOW_THREADS("H: toggle threads")
//usage:                IF_FEATURE_SHOW_THREADS(IF_FEATURE_TOP_SMP_CPU(", "))
//usage:                IF_FEATURE_TOP_SMP_CPU("1: toggle SMP")
//usage:	)
//usage:   "\n""	Q,^C: exit"

int top_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int top_main(int argc UNUSED_PARAM, char **argv)
{
	int iterations;
	unsigned lines, col;
	int lines_rem;
	unsigned interval;
	char *str_interval, *str_iterations;
	unsigned scan_mask = TOP_MASK;
#if ENABLE_FEATURE_USE_TERMIOS
	struct termios new_settings;
	struct pollfd pfd[1];
	unsigned char c;

	pfd[0].fd = 0;
	pfd[0].events = POLLIN;
#endif

	INIT_G();

	interval = 5; /* default update interval is 5 seconds */
	iterations = 0; /* infinite */
#if ENABLE_FEATURE_TOP_SMP_CPU
	/*num_cpus = 0;*/
	/*smp_cpu_info = 0;*/  /* to start with show aggregate */
	cpu_jif = &cur_jif;
	cpu_prev_jif = &prev_jif;
#endif

	/* all args are options; -n NUM */
	opt_complementary = "-"; /* options can be specified w/o dash */
	col = getopt32(argv, "d:n:b"IF_FEATURE_TOPMEM("m"), &str_interval, &str_iterations);
#if ENABLE_FEATURE_TOPMEM
	if (col & OPT_m) /* -m (busybox specific) */
		scan_mask = TOPMEM_MASK;
#endif
	if (col & OPT_d) {
		/* work around for "-d 1" -> "-d -1" done by getopt32
		 * (opt_complementary == "-" does this) */
		if (str_interval[0] == '-')
			str_interval++;
		/* Need to limit it to not overflow poll timeout */
		interval = xatou16(str_interval);
	}
	if (col & OPT_n) {
		if (str_iterations[0] == '-')
			str_iterations++;
		iterations = xatou(str_iterations);
	}

	/* change to /proc */
	xchdir("/proc");
#if ENABLE_FEATURE_USE_TERMIOS
	tcgetattr(0, (void *) &initial_settings);
	memcpy(&new_settings, &initial_settings, sizeof(new_settings));
	/* unbuffered input, turn off echo */
	new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);

	bb_signals(BB_FATAL_SIGS, sig_catcher);
	tcsetattr_stdin_TCSANOW(&new_settings);
#endif

#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
	sort_function[0] = pcpu_sort;
	sort_function[1] = mem_sort;
	sort_function[2] = time_sort;
#else
	sort_function[0] = mem_sort;
#endif

	while (1) {
		procps_status_t *p = NULL;

		lines = 24; /* default */
		col = 79;
#if ENABLE_FEATURE_USE_TERMIOS
		/* We output to stdout, we need size of stdout (not stdin)! */
		get_terminal_width_height(STDOUT_FILENO, &col, &lines);
		if (lines < 5 || col < 10) {
			sleep(interval);
			continue;
		}
#endif
		if (col > LINE_BUF_SIZE-2) /* +2 bytes for '\n', NUL, */
			col = LINE_BUF_SIZE-2;

		/* read process IDs & status for all the processes */
		while ((p = procps_scan(p, scan_mask)) != NULL) {
			int n;
#if ENABLE_FEATURE_TOPMEM
			if (scan_mask != TOPMEM_MASK)
#endif
			{
				n = ntop;
				top = xrealloc_vector(top, 6, ntop++);
				top[n].pid = p->pid;
				top[n].ppid = p->ppid;
				top[n].vsz = p->vsz;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
				top[n].ticks = p->stime + p->utime;
#endif
				top[n].uid = p->uid;
				strcpy(top[n].state, p->state);
				strcpy(top[n].comm, p->comm);
#if ENABLE_FEATURE_TOP_SMP_PROCESS
				top[n].last_seen_on_cpu = p->last_seen_on_cpu;
#endif
			}
#if ENABLE_FEATURE_TOPMEM
			else { /* TOPMEM */
				if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
					continue; /* kernel threads are ignored */
				n = ntop;
				/* No bug here - top and topmem are the same */
				top = xrealloc_vector(topmem, 6, ntop++);
				strcpy(topmem[n].comm, p->comm);
				topmem[n].pid      = p->pid;
				topmem[n].vsz      = p->smaps.mapped_rw + p->smaps.mapped_ro;
				topmem[n].vszrw    = p->smaps.mapped_rw;
				topmem[n].rss_sh   = p->smaps.shared_clean + p->smaps.shared_dirty;
				topmem[n].rss      = p->smaps.private_clean + p->smaps.private_dirty + topmem[n].rss_sh;
				topmem[n].dirty    = p->smaps.private_dirty + p->smaps.shared_dirty;
				topmem[n].dirty_sh = p->smaps.shared_dirty;
				topmem[n].stack    = p->smaps.stack;
			}
#endif
		} /* end of "while we read /proc" */
		if (ntop == 0) {
			bb_error_msg("no process info in /proc");
			break;
		}

		if (scan_mask != TOPMEM_MASK) {
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
			if (!prev_hist_count) {
				do_stats();
				usleep(100000);
				clearmems();
				continue;
			}
			do_stats();
			/* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
			qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
#else
			qsort(top, ntop, sizeof(top_status_t), (void*)(sort_function[0]));
#endif
		}
#if ENABLE_FEATURE_TOPMEM
		else { /* TOPMEM */
			qsort(topmem, ntop, sizeof(topmem_status_t), (void*)topmem_sort);
		}
#endif
		lines_rem = lines;
		if (OPT_BATCH_MODE) {
			lines_rem = INT_MAX;
		}
		if (scan_mask != TOPMEM_MASK)
			display_process_list(lines_rem, col);
#if ENABLE_FEATURE_TOPMEM
		else
			display_topmem_process_list(lines_rem, col);
#endif
		clearmems();
		if (iterations >= 0 && !--iterations)
			break;
#if !ENABLE_FEATURE_USE_TERMIOS
		sleep(interval);
#else
		if (option_mask32 & (OPT_b|OPT_EOF))
			 /* batch mode, or EOF on stdin ("top </dev/null") */
			sleep(interval);
		else if (safe_poll(pfd, 1, interval * 1000) > 0) {
			if (safe_read(STDIN_FILENO, &c, 1) != 1) { /* error/EOF? */
				option_mask32 |= OPT_EOF;
				continue;
			}
			if (c == initial_settings.c_cc[VINTR])
				break;
			c |= 0x20; /* lowercase */
			if (c == 'q')
				break;
			if (c == 'n') {
				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
				sort_function[0] = pid_sort;
			}
			if (c == 'm') {
				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
				sort_function[0] = mem_sort;
# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
				sort_function[1] = pcpu_sort;
				sort_function[2] = time_sort;
# endif
			}
# if ENABLE_FEATURE_SHOW_THREADS
			if (c == 'h'
			 IF_FEATURE_TOPMEM(&& scan_mask != TOPMEM_MASK)
			) {
				scan_mask ^= PSSCAN_TASKS;
			}
# endif
# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
			if (c == 'p') {
				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
				sort_function[0] = pcpu_sort;
				sort_function[1] = mem_sort;
				sort_function[2] = time_sort;
			}
			if (c == 't') {
				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
				sort_function[0] = time_sort;
				sort_function[1] = mem_sort;
				sort_function[2] = pcpu_sort;
			}
#  if ENABLE_FEATURE_TOPMEM
			if (c == 's') {
				scan_mask = TOPMEM_MASK;
				free(prev_hist);
				prev_hist = NULL;
				prev_hist_count = 0;
				sort_field = (sort_field + 1) % NUM_SORT_FIELD;
			}
			if (c == 'r')
				inverted ^= 1;
#  endif
#  if ENABLE_FEATURE_TOP_SMP_CPU
			/* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
			if (c == 'c' || c == '1') {
				/* User wants to toggle per cpu <> aggregate */
				if (smp_cpu_info) {
					free(cpu_prev_jif);
					free(cpu_jif);
					cpu_jif = &cur_jif;
					cpu_prev_jif = &prev_jif;
				} else {
					/* Prepare for xrealloc() */
					cpu_jif = cpu_prev_jif = NULL;
				}
				num_cpus = 0;
				smp_cpu_info = !smp_cpu_info;
				get_jiffy_counts();
			}
#  endif
# endif
		}
#endif /* FEATURE_USE_TERMIOS */
	} /* end of "while (1)" */

	bb_putchar('\n');
#if ENABLE_FEATURE_USE_TERMIOS
	reset_term();
#endif
	return EXIT_SUCCESS;
}