ref: 88ccea37f65b87312292b2b1a107c39927c6a2c3
dir: /sys/src/cmd/cwfs/malloc.c/
#include "all.h" #include "io.h" #include <pool.h> static uvlong memsize(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. */ 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%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; } void iobufunmap(Iobuf *p) { p->iobuf = (char*)-1; }