/*
 *  vmstat-- report system statistics
 *
 *  This version for use with the 2.9 BSD (Berkeley PDP11) system.
 */
#include <stdio.h>
#include <sys/param.h>
#include <sys/vm.h>
#include <a.out.h>
#include <sys/file.h>

#define	TIME	5		/* number of seconds for vmrate */
#define	MAXDISK	6		/* max disks that can be monitored */

struct nlist nl[] = {
#define	X_DKBUSY 0
	"_dk_busy",	0, 0,
#define	X_RATE 1
	"_rate",	0, 0,
#define X_TOTAL 2
	"_total",	0, 0,
#define X_SUM 3
	"_sum",		0, 0,
#define	X_BOOTIME 4
	"_bootime",	0, 0,
#define X_SYTIME 5
	"_sy_time",	0, 0,
#define	X_DKTIME 6
	"_dk_time",	0, 0,
#define	X_DKNUMB 7
	"_dk_numb",	0, 0,
#define	X_NDISK	 8
	"_ndisk",	0, 0,
	"\0\0\0\0\0\0\0\0", 0, 0
};

double	stat1();
struct
{
	int	busy;
	long	sy_time[8];
	long	dk_time[1<<MAXDISK];
	long	numb[MAXDISK];
} s, s1;
struct	vmrate rate;
struct	vmtotal	total;
struct	vmsum sum;
int	ndisk;

double	etime;
int 	mf;
int	showmem, showsum;

main(argc, argv)
char **argv;
{
	time_t now;
	int lines;
	extern char *ctime();
	register i,j;
	int iter;
	long nintv;
	time_t bootime;
	double f1, f2;
	long t;
	extern char _sobuf[];

	setbuf(stdout, _sobuf);
	if (nlist("/unix", nl) == -1 || (nl[0].n_type == 0)) {
		fprintf(stderr,"No /unix namelist\n");
		exit(1);
	}
	if (nl[X_SYTIME].n_type == 0) {
		fprintf(stderr,
			"sy_time not in /unix-- wrong version of vmstat\n");
		exit(1);
	}
	if (nl[X_RATE].n_type == 0) {
		fprintf(stderr,
			"Vmstat statistics not maintained in the system\n");
		exit(1);
	}
	mf = open("/dev/kmem", FATT_RDONLY);
	if(mf < 0) {
		perror("/dev/kmem");
		exit(1);
	}
	lseek(mf, (long)nl[X_BOOTIME].n_value, FSEEK_ABSOLUTE);
	read(mf, &bootime, sizeof bootime);
	time(&now);
	nintv = now - bootime;
	if (nintv <= 0 || nintv > 60L*60L*24L*365L*10L) {
		fprintf(stderr,
			"Time makes no sense... namelist must be wrong.\n");
		exit(1);
	}
	lseek(mf, (long)nl[X_NDISK].n_value, FSEEK_ABSOLUTE);
	read(mf, (char *)&ndisk, sizeof ndisk);
	if (ndisk <= 0 || ndisk > MAXDISK) {
	    fprintf(stderr, "Too many disks monitored (or system mismatch)\n");
	    exit(1);
	}
	iter = 0;
	argc--, argv++;
	while (argc>0 && argv[0][0]=='-') {
		char *cp = *argv++;
		argc--;
		while (*++cp) switch (*cp) {

		case 'z':
			close(mf);
			if (access("/dev/kmem", FACCESS_WRITE) != -1)	{
				if ((mf = open("/dev/kmem", FATT_RDWR)) < 0) {
					perror("/dev/kmem");
					exit(1);
				}
				lseek(mf, (long)nl[X_SUM].n_value, FSEEK_ABSOLUTE);
				write(mf, &sum, sizeof sum);
				exit(0);
			}
			else	{
				perror("/dev/kmem");
				exit(1);
				}
		
		case 's':
			dosum();
			showsum++;
/*			exit(0);*/
			break;

		case 'm':
			showmem++;
			break;

		default:
			fprintf(stderr,
			   "usage: vmstat [ -sm ] [ interval ] [ count]\n");
			exit(1);
		}
	}
	if(argc > 1)
		iter = atoi(argv[1]);
reprint:
	lines = 20;

	if (!showmem) 
		if (!showsum) {
			printf(
"  Procs   Virtual Real  Swap   Disk, tps         Faults/sec           Cpu, %%\n");
			printf(
"RQ DW SW   AVM TX  FRE  I  O  D0 D1 D2 D3  PD  IN  SY  TR   OV  CS  US NI SY ID\n");
		} else 
			exit(0);
	else	{
		printf(
"    ----- VIRTUAL -------   ------- REAL ---------  FREE\n");
		printf(
"    VM VMTXT   AVM AVMTXT    RM   RMT   ARM ARMTXT   MEM\n");  
	}

loop:
	if (showmem) {
		domem();
		goto contin;
	}
	lseek(mf, (long)nl[X_DKBUSY].n_value, FSEEK_ABSOLUTE);
	read(mf, (char *)&(s.busy), sizeof (s.busy));
	lseek(mf, (long)nl[X_SYTIME].n_value, FSEEK_ABSOLUTE);
	read(mf, (char *)&(s.sy_time), sizeof (s.sy_time));
	lseek(mf, (long)nl[X_DKTIME].n_value, FSEEK_ABSOLUTE);
	read(mf, (char *)&(s.dk_time), (1 << ndisk) * sizeof (s.dk_time[0]));
	lseek(mf, (long)nl[X_DKNUMB].n_value, FSEEK_ABSOLUTE);
	read(mf, (char *)&(s.numb), ndisk * sizeof (s.numb[0]));
	etime = 0;
	for(i=0; i < 8; i++) {
		t = s.sy_time[i];
		s.sy_time[i] -= s1.sy_time[i];
		s1.sy_time[i] = t;
		etime += s.sy_time[i];
	}
	if(etime == 0.)
		etime = 1.;
	for(i=0; i < (1 << ndisk); i++) {
		t = s.dk_time[i];
		s.dk_time[i] -= s1.dk_time[i];
		s1.dk_time[i] = t;
	}
	for(i=0; i < ndisk; i++) {
		t = s.numb[i];
		s.numb[i] -= s1.numb[i];
		s1.numb[i] = t;
	}
	if (nintv != 1) {
		lseek(mf, (long)nl[X_SUM].n_value, FSEEK_ABSOLUTE);
		read(mf, &sum, sizeof sum);
		rate.v_swpin = sum.vs_swpin/(nintv/5);
		rate.v_swpout = sum.vs_swpout/(nintv/5);
		rate.v_intr = sum.vs_intr/nintv;
		rate.v_pdma = sum.vs_pdma/nintv;
		rate.v_trap = sum.vs_trap/nintv;
		rate.v_syscall = sum.vs_syscall/nintv;
		rate.v_ovly = sum.vs_ovly/nintv;
		rate.v_swtch = sum.vs_swtch/nintv;
	} else {
		lseek(mf, (long)nl[X_RATE].n_value, FSEEK_ABSOLUTE);
		read(mf, &rate, sizeof rate);
	}
	lseek(mf, (long)nl[X_TOTAL].n_value, FSEEK_ABSOLUTE);
	read(mf, &total, sizeof total);

	/* Procs RQ DW SW */
	printf("%2d%3d%3d", total.t_rq, total.t_dw,
	    total.t_sw);

	/* Memory AVM TX FRE */
	printf("%6ld%3d%5d", total.t_avm/16,
	    pct(total.t_avmtxt, total.t_avm), total.t_free);

	/* Swap I O */
	printf("%3d%3d", rate.v_swpin, rate.v_swpout);

	/* Disk D0 D1 D2 D3 */
	etime /= 60.;
	printf(" ");
	/* formatted for D0-D3 only; could change header above */
	for(i=0; i<4; i++)
		stats(i);

	/* Faults PD IN SY TR OV */
	printf("%4d%4d%4d%4d %4d",
		rate.v_pdma/TIME,
		(rate.v_intr-rate.v_trap)/TIME,
		rate.v_syscall/TIME,
		rate.v_trap/TIME,
		rate.v_ovly/TIME);

	/* context switches CS */
	printf("%4d ", rate.v_swtch/TIME);

	/* Cpu  US NI SY ID */
	for(i=0; i < 8; i += 2)
		printf("%3.0f", stat1(i));
	printf("\n");
contin:
	fflush(stdout);
	nintv = 1;
	--iter;
	if(iter)
	if(argc > 0) {
		sleep(atoi(argv[0]));
		if (--lines <= 0)
			goto reprint;
		goto loop;
	}
}

dosum()
{

	lseek(mf, (long)nl[X_SUM].n_value, FSEEK_ABSOLUTE);
	read(mf, &sum, sizeof sum);
	printf("%9ld swap ins\n", sum.vs_swpin);
	printf("%9ld swap outs\n", sum.vs_swpout);
	printf("%9ld pages swapped in\n", sum.vs_pswpin / CLSIZE);
	printf("%9ld pages swapped out\n", sum.vs_pswpout / CLSIZE);
	printf("%9ld cpu context switches\n", sum.vs_swtch);
	printf("%9ld device interrupts\n", sum.vs_intr);
	printf("%9ld pseudo-DMA interrupts\n", sum.vs_pdma);
	printf("%9ld traps\n", sum.vs_trap);
	printf("%9ld system calls\n", sum.vs_syscall);
	printf("%9ld overlay traps\n", sum.vs_ovly);
}

domem() {
	lseek(mf, (long)nl[X_TOTAL].n_value, FSEEK_ABSOLUTE);
	read(mf, &total, sizeof total);

	printf("%6ld%6ld%6ld%6ld ",
		total.t_vm/16, total.t_vmtxt/16,
		total.t_avm/16, total.t_avmtxt/16);
	printf("%6d%6d%6d%6d ",
		total.t_rm/16, total.t_rmtxt/16,
		total.t_arm/16, total.t_armtxt/16); 
	printf("%6d\n",total.t_free);
}

stats(dn)
{

	if (dn >= ndisk) {
		printf("  0");
		return;
	}
	printf("%3.0f", s.numb[dn]/etime);
}

double
stat1(row)
{
	double f;

	f = s.sy_time[row] + s.sy_time[row+1];
	return(f*100./(etime*60.));
}

pct(top, bot)
long top, bot;
{
	int ret;

	if (bot == 0)
		return (0);
	ret = (top * 100) / bot;
	return ret;
}