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#include "all.h"
#include "io.h"
static ulong
memsize(void)
{
ulong pgsize, pgmax, userpgs, userused;
char *s, *f[2];
int n, mpcnt;
Biobuf *bp;
mpcnt = 25;
pgsize = userpgs = userused = 0;
if(bp = Bopen("#c/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;
pgmax = (1024*1024*1024)/pgsize; /* 1GB max */
if(userpgs > pgmax)
userpgs = pgmax;
return userpgs*pgsize;
}
return 16*MB;
}
long niob;
long 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(ulong n, int align)
{
void *p = mallocalign(n, align, 0, 0);
if (p == nil)
panic("ialloc: out of memory");
setmalloctag(p, getcallerpc(&n));
memset(p, 0, n);
return p;
}
enum { HWIDTH = 8 }; /* buffers per hash */
/*
* allocate rest of mem
* for io buffers.
*/
void
iobufinit(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%ld buffers; %ld hashes\n", niob, nhiob);
hiob = ialloc(nhiob * sizeof(Hiob), 0);
hp = hiob;
for(i=0; i<nhiob; i++) {
lock(hp);
unlock(hp);
hp++;
}
p = ialloc(niob * sizeof(Iobuf), 0);
xiop = ialloc(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;
}
void
iobufunmap(Iobuf *p)
{
p->iobuf = (char*)-1;
}
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