machine.c revision 1.4 
1/*	$OpenBSD: machine.c,v 1.4 1997/08/22 07:39:27 downsj Exp $	*/
2
3/*
4 * top - a top users display for Unix
5 *
6 * SYNOPSIS:  For an OpenBSD system
7 *
8 * DESCRIPTION:
9 * This is the machine-dependent module for OpenBSD
10 * Tested on:
11 *	i386
12 *
13 * LIBS: -lkvm
14 *
15 * TERMCAP: -ltermlib
16 *
17 * CFLAGS: -DHAVE_GETOPT
18 *
19 * AUTHOR:  Thorsten Lockert <tholo@sigmasoft.com>
20 *          Adapted from BSD4.4 by Christos Zoulas <christos@ee.cornell.edu>
21 *          Patch for process wait display by Jarl F. Greipsland <jarle@idt.unit.no>
22 */
23
24#include <sys/types.h>
25#include <sys/signal.h>
26#include <sys/param.h>
27
28#define LASTPID
29#define DOSWAP
30
31#include <stdio.h>
32#include <stdlib.h>
33#include <string.h>
34#include <nlist.h>
35#include <math.h>
36#include <kvm.h>
37#include <unistd.h>
38#include <sys/errno.h>
39#include <sys/sysctl.h>
40#include <sys/dir.h>
41#include <sys/dkstat.h>
42#include <sys/file.h>
43#include <sys/time.h>
44#include <sys/resource.h>
45
46#ifdef DOSWAP
47#include <err.h>
48#include <sys/map.h>
49#include <sys/conf.h>
50#endif
51
52static int check_nlist __P((struct nlist *));
53static int getkval __P((unsigned long, int *, int, char *));
54static int swapmode __P((int *, int *));
55
56#include "top.h"
57#include "display.h"
58#include "machine.h"
59#include "utils.h"
60
61/* get_process_info passes back a handle.  This is what it looks like: */
62
63struct handle
64{
65    struct kinfo_proc **next_proc;	/* points to next valid proc pointer */
66    int remaining;		/* number of pointers remaining */
67};
68
69/* declarations for load_avg */
70#include "loadavg.h"
71
72#define PP(pp, field) ((pp)->kp_proc . field)
73#define EP(pp, field) ((pp)->kp_eproc . field)
74#define VP(pp, field) ((pp)->kp_eproc.e_vm . field)
75
76/* what we consider to be process size: */
77#define PROCSIZE(pp) (VP((pp), vm_tsize) + VP((pp), vm_dsize) + VP((pp), vm_ssize))
78
79/* definitions for indices in the nlist array */
80#define X_CP_TIME	0
81#define X_HZ		1
82
83#ifdef DOSWAP
84#define	VM_SWAPMAP	2
85#define	VM_NSWAPMAP	3
86#define	VM_SWDEVT	4
87#define	VM_NSWAP	5
88#define	VM_NSWDEV	6
89#define	VM_DMMAX	7
90#define	VM_NISWAP	8
91#define	VM_NISWDEV	9
92
93#define	X_LASTPID	10
94#elif defined(LASTPID)
95#define	X_LASTPID	2
96#endif
97
98static struct nlist nlst[] = {
99    { "_cp_time" },		/* 0 */
100    { "_hz" },			/* 1 */
101#ifdef DOSWAP
102    { "_swapmap" },		/* 2 */
103    { "_nswapmap" },		/* 3 */
104    { "_swdevt" },		/* 4 */
105    { "_nswap" },		/* 5 */
106    { "_nswdev" },		/* 6 */
107    { "_dmmax" },		/* 7 */
108    { "_niswap" },		/* 8 */
109    { "_niswdev" },		/* 9 */
110#endif
111#ifdef LASTPID
112    { "_lastpid" },		/* 2 / 10 */
113#endif
114    { 0 }
115};
116
117/*
118 *  These definitions control the format of the per-process area
119 */
120
121static char header[] =
122  "  PID X        PRI NICE  SIZE   RES STATE WAIT     TIME    CPU COMMAND";
123/* 0123456   -- field to fill in starts at header+6 */
124#define UNAME_START 6
125
126#define Proc_format \
127	"%5d %-8.8s %3d %4d %5s %5s %-5s %-6.6s %6s %5.2f%% %.14s"
128
129
130/* process state names for the "STATE" column of the display */
131/* the extra nulls in the string "run" are for adding a slash and
132   the processor number when needed */
133
134char *state_abbrev[] =
135{
136    "", "start", "run\0\0\0", "sleep", "stop", "zomb",
137};
138
139
140static kvm_t *kd;
141
142/* these are retrieved from the kernel in _init */
143
144static          int hz;
145
146/* these are offsets obtained via nlist and used in the get_ functions */
147
148static unsigned long cp_time_offset;
149#ifdef LASTPID
150static unsigned long lastpid_offset;
151static pid_t lastpid;
152#endif
153
154/* these are for calculating cpu state percentages */
155static int cp_time[CPUSTATES];
156static int cp_old[CPUSTATES];
157static int cp_diff[CPUSTATES];
158
159/* these are for detailing the process states */
160
161int process_states[7];
162char *procstatenames[] = {
163    "", " starting, ", " running, ", " idle, ", " stopped, ", " zombie, ",
164    NULL
165};
166
167/* these are for detailing the cpu states */
168
169int cpu_states[CPUSTATES];
170char *cpustatenames[] = {
171    "user", "nice", "system", "interrupt", "idle", NULL
172};
173
174/* these are for detailing the memory statistics */
175
176int memory_stats[8];
177char *memorynames[] = {
178    "Real: ", "K/", "K act/tot  ", "Free: ", "K  ",
179#ifdef DOSWAP
180    "Swap: ", "K/", "K used/tot",
181#endif
182    NULL
183};
184
185/* these are for keeping track of the proc array */
186
187static int nproc;
188static int onproc = -1;
189static int pref_len;
190static struct kinfo_proc *pbase;
191static struct kinfo_proc **pref;
192
193/* these are for getting the memory statistics */
194
195static int pageshift;		/* log base 2 of the pagesize */
196
197/* define pagetok in terms of pageshift */
198
199#define pagetok(size) ((size) << pageshift)
200
201int
202machine_init(statics)
203
204struct statics *statics;
205
206{
207    register int i = 0;
208    register int pagesize;
209
210    if ((kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open")) == NULL)
211	return -1;
212
213
214    /* get the list of symbols we want to access in the kernel */
215    (void) kvm_nlist(kd, nlst);
216    if (nlst[0].n_type == 0)
217    {
218	fprintf(stderr, "top: nlist failed\n");
219	return(-1);
220    }
221
222    /* make sure they were all found */
223    if (i > 0 && check_nlist(nlst) > 0)
224    {
225	return(-1);
226    }
227
228    /* get the symbol values out of kmem */
229    (void) getkval(nlst[X_HZ].n_value,     (int *)(&hz),	sizeof(hz),
230	    nlst[X_HZ].n_name);
231
232    /* stash away certain offsets for later use */
233    cp_time_offset = nlst[X_CP_TIME].n_value;
234#ifdef LASTPID
235    lastpid_offset = nlst[X_LASTPID].n_value;
236#endif
237
238    pbase = NULL;
239    pref = NULL;
240    onproc = -1;
241    nproc = 0;
242
243    /* get the page size with "getpagesize" and calculate pageshift from it */
244    pagesize = getpagesize();
245    pageshift = 0;
246    while (pagesize > 1)
247    {
248	pageshift++;
249	pagesize >>= 1;
250    }
251
252    /* we only need the amount of log(2)1024 for our conversion */
253    pageshift -= LOG1024;
254
255    /* fill in the statics information */
256    statics->procstate_names = procstatenames;
257    statics->cpustate_names = cpustatenames;
258    statics->memory_names = memorynames;
259
260    /* all done! */
261    return(0);
262}
263
264char *format_header(uname_field)
265
266register char *uname_field;
267
268{
269    register char *ptr;
270
271    ptr = header + UNAME_START;
272    while (*uname_field != '\0')
273    {
274	*ptr++ = *uname_field++;
275    }
276
277    return(header);
278}
279
280void
281get_system_info(si)
282
283struct system_info *si;
284
285{
286    int total;
287
288    /* get the cp_time array */
289    (void) getkval(cp_time_offset, (int *)cp_time, sizeof(cp_time),
290		   "_cp_time");
291#ifdef LASTPID
292    (void) getkval(lastpid_offset, (int *)&lastpid, sizeof(lastpid),
293		   "!");
294#endif
295
296    /* convert load averages to doubles */
297    {
298	register int i;
299	register double *infoloadp;
300	struct loadavg sysload;
301	size_t size = sizeof(sysload);
302	static int mib[] = { CTL_VM, VM_LOADAVG };
303
304	if (sysctl(mib, 2, &sysload, &size, NULL, 0) < 0) {
305	    (void) fprintf(stderr, "top: sysctl failed: %s\n", strerror(errno));
306	    bzero(&total, sizeof(total));
307	}
308
309	infoloadp = si->load_avg;
310	for (i = 0; i < 3; i++)
311	    *infoloadp++ = ((double) sysload.ldavg[i]) / sysload.fscale;
312    }
313
314    /* convert cp_time counts to percentages */
315    total = percentages(CPUSTATES, cpu_states, cp_time, cp_old, cp_diff);
316
317    /* sum memory statistics */
318    {
319	struct vmtotal total;
320	size_t size = sizeof(total);
321	static int mib[] = { CTL_VM, VM_METER };
322
323	/* get total -- systemwide main memory usage structure */
324	if (sysctl(mib, 2, &total, &size, NULL, 0) < 0) {
325	    (void) fprintf(stderr, "top: sysctl failed: %s\n", strerror(errno));
326	    bzero(&total, sizeof(total));
327	}
328	/* convert memory stats to Kbytes */
329	memory_stats[0] = -1;
330	memory_stats[1] = pagetok(total.t_arm);
331	memory_stats[2] = pagetok(total.t_rm);
332	memory_stats[3] = -1;
333	memory_stats[4] = pagetok(total.t_free);
334	memory_stats[5] = -1;
335#ifdef DOSWAP
336	if (!swapmode(&memory_stats[6], &memory_stats[7])) {
337	    memory_stats[6] = 0;
338	    memory_stats[7] = 0;
339	}
340#endif
341    }
342
343    /* set arrays and strings */
344    si->cpustates = cpu_states;
345    si->memory = memory_stats;
346#ifdef LASTPID
347    if (lastpid > 0)
348	si->last_pid = lastpid;
349    else
350#endif
351	si->last_pid = -1;
352}
353
354static struct handle handle;
355
356caddr_t get_process_info(si, sel, compare)
357
358struct system_info *si;
359struct process_select *sel;
360int (*compare) __P((const void *, const void *));
361
362{
363    register int i;
364    register int total_procs;
365    register int active_procs;
366    register struct kinfo_proc **prefp;
367    register struct kinfo_proc *pp;
368
369    /* these are copied out of sel for speed */
370    int show_idle;
371    int show_system;
372    int show_uid;
373    int show_command;
374
375
376    pbase = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nproc);
377    if (nproc > onproc)
378	pref = (struct kinfo_proc **) realloc(pref, sizeof(struct kinfo_proc *)
379		* (onproc = nproc));
380    if (pref == NULL || pbase == NULL) {
381	(void) fprintf(stderr, "top: Out of memory.\n");
382	quit(23);
383    }
384    /* get a pointer to the states summary array */
385    si->procstates = process_states;
386
387    /* set up flags which define what we are going to select */
388    show_idle = sel->idle;
389    show_system = sel->system;
390    show_uid = sel->uid != -1;
391    show_command = sel->command != NULL;
392
393    /* count up process states and get pointers to interesting procs */
394    total_procs = 0;
395    active_procs = 0;
396    memset((char *)process_states, 0, sizeof(process_states));
397    prefp = pref;
398    for (pp = pbase, i = 0; i < nproc; pp++, i++)
399    {
400	/*
401	 *  Place pointers to each valid proc structure in pref[].
402	 *  Process slots that are actually in use have a non-zero
403	 *  status field.  Processes with SSYS set are system
404	 *  processes---these get ignored unless show_sysprocs is set.
405	 */
406	if (PP(pp, p_stat) != 0 &&
407	    (show_system || ((PP(pp, p_flag) & P_SYSTEM) == 0)))
408	{
409	    total_procs++;
410	    process_states[(unsigned char) PP(pp, p_stat)]++;
411	    if ((PP(pp, p_stat) != SZOMB) &&
412		(show_idle || (PP(pp, p_pctcpu) != 0) ||
413		 (PP(pp, p_stat) == SRUN)) &&
414		(!show_uid || EP(pp, e_pcred.p_ruid) == (uid_t)sel->uid))
415	    {
416		*prefp++ = pp;
417		active_procs++;
418	    }
419	}
420    }
421
422    /* if requested, sort the "interesting" processes */
423    if (compare != NULL)
424    {
425	qsort((char *)pref, active_procs, sizeof(struct kinfo_proc *), compare);
426    }
427
428    /* remember active and total counts */
429    si->p_total = total_procs;
430    si->p_active = pref_len = active_procs;
431
432    /* pass back a handle */
433    handle.next_proc = pref;
434    handle.remaining = active_procs;
435    return((caddr_t)&handle);
436}
437
438char fmt[MAX_COLS];		/* static area where result is built */
439
440char *format_next_process(handle, get_userid)
441
442caddr_t handle;
443char *(*get_userid)();
444
445{
446    register struct kinfo_proc *pp;
447    register int cputime;
448    register double pct;
449    struct handle *hp;
450    char waddr[sizeof(void *) * 2 + 3];	/* Hexify void pointer */
451    char *p_wait;
452
453    /* find and remember the next proc structure */
454    hp = (struct handle *)handle;
455    pp = *(hp->next_proc++);
456    hp->remaining--;
457
458
459    /* get the process's user struct and set cputime */
460    if ((PP(pp, p_flag) & P_INMEM) == 0) {
461	/*
462	 * Print swapped processes as <pname>
463	 */
464	char *comm = PP(pp, p_comm);
465#define COMSIZ sizeof(PP(pp, p_comm))
466	char buf[COMSIZ];
467	(void) strncpy(buf, comm, COMSIZ);
468	comm[0] = '<';
469	(void) strncpy(&comm[1], buf, COMSIZ - 2);
470	comm[COMSIZ - 2] = '\0';
471	(void) strncat(comm, ">", COMSIZ - 1);
472	comm[COMSIZ - 1] = '\0';
473    }
474
475    cputime = (PP(pp, p_uticks) + PP(pp, p_sticks) + PP(pp, p_iticks)) / hz;
476
477    /* calculate the base for cpu percentages */
478    pct = pctdouble(PP(pp, p_pctcpu));
479
480    if (PP(pp, p_wchan))
481        if (PP(pp, p_wmesg))
482	    p_wait = EP(pp, e_wmesg);
483	else {
484	    snprintf(waddr, sizeof(waddr), "%lx",
485		(unsigned int)(PP(pp, p_wchan)) & ~KERNBASE);
486	    p_wait = waddr;
487        }
488    else
489	p_wait = "-";
490
491    /* format this entry */
492    snprintf(fmt, MAX_COLS,
493	    Proc_format,
494	    PP(pp, p_pid),
495	    (*get_userid)(EP(pp, e_pcred.p_ruid)),
496	    PP(pp, p_priority) - PZERO,
497	    PP(pp, p_nice) - NZERO,
498	    format_k(pagetok(PROCSIZE(pp))),
499	    format_k(pagetok(VP(pp, vm_rssize))),
500	    (PP(pp, p_stat) == SSLEEP && PP(pp, p_slptime) > MAXSLP)
501	     ? "idle" : state_abbrev[(unsigned char) PP(pp, p_stat)],
502	    p_wait,
503	    format_time(cputime),
504	    100.0 * pct,
505	    printable(PP(pp, p_comm)));
506
507    /* return the result */
508    return(fmt);
509}
510
511
512/*
513 * check_nlist(nlst) - checks the nlist to see if any symbols were not
514 *		found.  For every symbol that was not found, a one-line
515 *		message is printed to stderr.  The routine returns the
516 *		number of symbols NOT found.
517 */
518
519static int check_nlist(nlst)
520
521register struct nlist *nlst;
522
523{
524    register int i;
525
526    /* check to see if we got ALL the symbols we requested */
527    /* this will write one line to stderr for every symbol not found */
528
529    i = 0;
530    while (nlst->n_name != NULL)
531    {
532	if (nlst->n_type == 0)
533	{
534	    /* this one wasn't found */
535	    (void) fprintf(stderr, "kernel: no symbol named `%s'\n",
536			   nlst->n_name);
537	    i = 1;
538	}
539	nlst++;
540    }
541
542    return(i);
543}
544
545
546/*
547 *  getkval(offset, ptr, size, refstr) - get a value out of the kernel.
548 *	"offset" is the byte offset into the kernel for the desired value,
549 *  	"ptr" points to a buffer into which the value is retrieved,
550 *  	"size" is the size of the buffer (and the object to retrieve),
551 *  	"refstr" is a reference string used when printing error meessages,
552 *	    if "refstr" starts with a '!', then a failure on read will not
553 *  	    be fatal (this may seem like a silly way to do things, but I
554 *  	    really didn't want the overhead of another argument).
555 *
556 */
557
558static int getkval(offset, ptr, size, refstr)
559
560unsigned long offset;
561int *ptr;
562int size;
563char *refstr;
564
565{
566    if (kvm_read(kd, offset, (char *) ptr, size) != size)
567    {
568	if (*refstr == '!')
569	{
570	    return(0);
571	}
572	else
573	{
574	    fprintf(stderr, "top: kvm_read for %s: %s\n",
575		refstr, strerror(errno));
576	    quit(23);
577	}
578    }
579    return(1);
580}
581
582/* comparison routine for qsort */
583
584/*
585 *  proc_compare - comparison function for "qsort"
586 *	Compares the resource consumption of two processes using five
587 *  	distinct keys.  The keys (in descending order of importance) are:
588 *  	percent cpu, cpu ticks, state, resident set size, total virtual
589 *  	memory usage.  The process states are ordered as follows (from least
590 *  	to most important):  zombie, sleep, stop, start, run.  The array
591 *  	declaration below maps a process state index into a number that
592 *  	reflects this ordering.
593 */
594
595static unsigned char sorted_state[] =
596{
597    0,	/* not used		*/
598    4,	/* start		*/
599    5,	/* run			*/
600    2,	/* sleep		*/
601    3,	/* stop			*/
602    1	/* zombie		*/
603};
604
605int
606proc_compare(v1, v2)
607
608const void *v1, *v2;
609
610{
611    register struct proc **pp1 = (struct proc **)v1;
612    register struct proc **pp2 = (struct proc **)v2;
613    register struct kinfo_proc *p1;
614    register struct kinfo_proc *p2;
615    register int result;
616    register pctcpu lresult;
617
618    /* remove one level of indirection */
619    p1 = *(struct kinfo_proc **) pp1;
620    p2 = *(struct kinfo_proc **) pp2;
621
622    /* compare percent cpu (pctcpu) */
623    if ((lresult = PP(p2, p_pctcpu) - PP(p1, p_pctcpu)) == 0)
624    {
625	/* use cpticks to break the tie */
626	if ((result = PP(p2, p_cpticks) - PP(p1, p_cpticks)) == 0)
627	{
628	    /* use process state to break the tie */
629	    if ((result = sorted_state[(unsigned char) PP(p2, p_stat)] -
630			  sorted_state[(unsigned char) PP(p1, p_stat)])  == 0)
631	    {
632		/* use priority to break the tie */
633		if ((result = PP(p2, p_priority) - PP(p1, p_priority)) == 0)
634		{
635		    /* use resident set size (rssize) to break the tie */
636		    if ((result = VP(p2, vm_rssize) - VP(p1, vm_rssize)) == 0)
637		    {
638			/* use total memory to break the tie */
639			result = PROCSIZE(p2) - PROCSIZE(p1);
640		    }
641		}
642	    }
643	}
644    }
645    else
646    {
647	result = lresult < 0 ? -1 : 1;
648    }
649
650    return(result);
651}
652
653
654/*
655 * proc_owner(pid) - returns the uid that owns process "pid", or -1 if
656 *		the process does not exist.
657 *		It is EXTREMLY IMPORTANT that this function work correctly.
658 *		If top runs setuid root (as in SVR4), then this function
659 *		is the only thing that stands in the way of a serious
660 *		security problem.  It validates requests for the "kill"
661 *		and "renice" commands.
662 */
663
664int proc_owner(pid)
665
666pid_t pid;
667
668{
669    register int cnt;
670    register struct kinfo_proc **prefp;
671    register struct kinfo_proc *pp;
672
673    prefp = pref;
674    cnt = pref_len;
675    while (--cnt >= 0)
676    {
677	pp = *prefp++;
678	if (PP(pp, p_pid) == pid)
679	{
680	    return((int)EP(pp, e_pcred.p_ruid));
681	}
682    }
683    return(-1);
684}
685
686#ifdef DOSWAP
687/*
688 * swapmode is based on a program called swapinfo written
689 * by Kevin Lahey <kml@rokkaku.atl.ga.us>.
690 */
691
692#define	SVAR(var) __STRING(var)	/* to force expansion */
693#define	KGET(idx, var)							\
694	KGET1(idx, &var, sizeof(var), SVAR(var))
695#define	KGET1(idx, p, s, msg)						\
696	KGET2(nlst[idx].n_value, p, s, msg)
697#define	KGET2(addr, p, s, msg)						\
698	if (kvm_read(kd, (u_long)(addr), p, s) != s)			\
699		warnx("cannot read %s: %s", msg, kvm_geterr(kd))
700
701static int
702swapmode(used, total)
703int *used;
704int *total;
705{
706	int nswap, nswdev, dmmax, nswapmap, niswap, niswdev;
707	int s, e, i, l, nfree;
708	struct swdevt *sw;
709	long *perdev;
710	struct map *swapmap, *kswapmap;
711	struct mapent *mp, *freemp;
712
713	KGET(VM_NSWAP, nswap);
714	KGET(VM_NSWDEV, nswdev);
715	KGET(VM_DMMAX, dmmax);
716	KGET(VM_NSWAPMAP, nswapmap);
717	KGET(VM_SWAPMAP, kswapmap);	/* kernel `swapmap' is a pointer */
718	if ((sw = malloc(nswdev * sizeof(*sw))) == NULL ||
719	    (perdev = malloc(nswdev * sizeof(*perdev))) == NULL ||
720	    (freemp = mp = malloc(nswapmap * sizeof(*mp))) == NULL)
721		err(1, "malloc");
722	KGET1(VM_SWDEVT, sw, nswdev * sizeof(*sw), "swdevt");
723	KGET2((long)kswapmap, mp, nswapmap * sizeof(*mp), "swapmap");
724
725	/* Supports sequential swap */
726	if (nlst[VM_NISWAP].n_value != 0) {
727		KGET(VM_NISWAP, niswap);
728		KGET(VM_NISWDEV, niswdev);
729	} else {
730		niswap = nswap;
731		niswdev = nswdev;
732	}
733
734	/* First entry in map is `struct map'; rest are mapent's. */
735	swapmap = (struct map *)mp;
736	if (nswapmap != swapmap->m_limit - (struct mapent *)kswapmap)
737		errx(1, "panic: nswapmap goof");
738
739	/* Count up swap space. */
740	nfree = 0;
741	memset(perdev, 0, nswdev * sizeof(*perdev));
742	for (mp++; mp->m_addr != 0; mp++) {
743		s = mp->m_addr;			/* start of swap region */
744		e = mp->m_addr + mp->m_size;	/* end of region */
745		nfree += mp->m_size;
746
747		/*
748		 * Swap space is split up among the configured disks.
749		 *
750		 * For interleaved swap devices, the first dmmax blocks
751		 * of swap space some from the first disk, the next dmmax
752		 * blocks from the next, and so on up to niswap blocks.
753		 *
754		 * Sequential swap devices follow the interleaved devices
755		 * (i.e. blocks starting at niswap) in the order in which
756		 * they appear in the swdev table.  The size of each device
757		 * will be a multiple of dmmax.
758		 *
759		 * The list of free space joins adjacent free blocks,
760		 * ignoring device boundries.  If we want to keep track
761		 * of this information per device, we'll just have to
762		 * extract it ourselves.  We know that dmmax-sized chunks
763		 * cannot span device boundaries (interleaved or sequential)
764		 * so we loop over such chunks assigning them to devices.
765		 */
766		i = -1;
767		while (s < e) {		/* XXX this is inefficient */
768			int bound = roundup(s+1, dmmax);
769
770			if (bound > e)
771				bound = e;
772			if (bound <= niswap) {
773				/* Interleaved swap chunk. */
774				if (i == -1)
775					i = (s / dmmax) % niswdev;
776				perdev[i] += bound - s;
777				if (++i >= niswdev)
778					i = 0;
779			} else {
780				/* Sequential swap chunk. */
781				if (i < niswdev) {
782					i = niswdev;
783					l = niswap + sw[i].sw_nblks;
784				}
785				while (s >= l) {
786					/* XXX don't die on bogus blocks */
787					if (i == nswdev-1)
788						break;
789					l += sw[++i].sw_nblks;
790				}
791				perdev[i] += bound - s;
792			}
793			s = bound;
794		}
795	}
796
797	*total = 0;
798	for (i = 0; i < nswdev; i++) {
799		int xsize, xfree;
800
801		xsize = sw[i].sw_nblks;
802		xfree = perdev[i];
803		*total += xsize;
804	}
805
806	/*
807	 * If only one partition has been set up via swapon(8), we don't
808	 * need to bother with totals.
809	 */
810#if DEV_BSHIFT < 10
811	*used = (*total - nfree) >> (10 - DEV_BSHIFT);
812	*total >>= 10 - DEV_BSHIFT;
813#elif DEV_BSHIFT > 10
814	*used = (*total - nfree) >> (DEV_BSHIFT - 10);
815	*total >>= DEV_BSHIFT - 10;
816#endif
817	free (sw); free (freemp); free (perdev);
818	return 1;
819}
820#endif
821