#include "all.h"#include "io.h" #include <pool.h> static uvlongmemsize(void){	ulong pgsize, userpgs, userused;	char *s, *f[2];	int n, mpcnt;	Biobuf *bp; 	mpcnt = 25;	pgsize = userpgs = userused = 0;	if(bp = Bopen("/dev/swap", OREAD)) {		while(s = Brdline(bp, '\n')) {			if((n = Blinelen(bp)) < 1)				continue;			s[n-1] = '\0';			if(tokenize(s, f, nelem(f)) != 2)				continue;			if(strcmp(f[1], "pagesize") == 0)				pgsize = strtoul(f[0], 0, 0);			else if(strcmp(f[1], "user") == 0) {				userused =  strtoul(f[0], &s, 0);				if(*s == '/')					userpgs = strtoul(s+1, 0, 0);			}		}		Bterm(bp);	}	if(pgsize && userused < userpgs){		userpgs -= userused;		if(s = getenv("fsmempercent")){			mpcnt = atoi(s);			free(s);		}		if(mpcnt < 1)			mpcnt = 1;		userpgs = (userpgs*mpcnt)/100;		return (uvlong)userpgs*pgsize;	}	return 16*MB;} uint	niob;uint	nhiob;Hiob	*hiob; /* * Called to allocate permanent data structures * Alignment is in number of bytes. It pertains both to the start and * end of the allocated memory. */void*ialloc(uintptr n, int align){	char *p;	int m; 	if(align <= 0)		align = sizeof(uintptr); 	mainmem->lock(mainmem); 	p = sbrk(0);	if(m = n % align)		n += align - m;	if(m = (uintptr)p % align)		p += align - m;	if(brk(p+n) < 0)		panic("ialloc: out of memory"); 	mainmem->unlock(mainmem); 	return p;} enum { HWIDTH = 8 };		/* buffers per hash */ /* * allocate rest of mem * for io buffers. */voidiobufinit(void){	int i;	char *xiop;	Iobuf *p, *q;	Hiob *hp; 	wlock(&mainlock);	/* init */	wunlock(&mainlock); 	niob = memsize() / (sizeof(Iobuf) + RBUFSIZE + sizeof(Hiob)/HWIDTH);	nhiob = niob / HWIDTH;	while(!prime(nhiob))		nhiob++;	if(chatty)		print("\t%ud buffers; %ud hashes\n", niob, nhiob);	hiob = ialloc((uintptr)nhiob * sizeof(Hiob), 0);	hp = hiob;	for(i=0; i<nhiob; i++) {		lock(hp);		unlock(hp);		hp++;	}	p = ialloc((uintptr)niob * sizeof(Iobuf), 0);	xiop = ialloc((uintptr)niob * RBUFSIZE, 0);	hp = hiob;	for(i=0; i < niob; i++) {		qlock(p);		qunlock(p);		if(hp == hiob)			hp = hiob + nhiob;		hp--;		q = hp->link;		if(q) {			p->fore = q;			p->back = q->back;			q->back = p;			p->back->fore = p;		} else {			hp->link = p;			p->fore = p;			p->back = p;		}		p->dev = devnone;		p->addr = -1;		p->xiobuf = xiop;		p->iobuf = (char*)-1;		p++;		xiop += RBUFSIZE;	}} void*iobufmap(Iobuf *p){	return p->iobuf = p->xiobuf;} voidiobufunmap(Iobuf *p){	p->iobuf = (char*)-1;}