sys/src/cmd/cwfs/malloc.c

   1 #include "all.h"
   2 #include "io.h"
   3
   4 #include <pool.h>
   5
   6 static uvlong
   7 memsize(void)
   8 {
   9         ulong pgsize, userpgs, userused;
  10         char *s, *f[2];
  11         int n, mpcnt;
  12         Biobuf *bp;
  13
  14         mpcnt = 25;
  15         pgsize = userpgs = userused = 0;
  16         if(bp = Bopen("/dev/swap", OREAD)) {
  17                 while(s = Brdline(bp, '\n')) {
  18                         if((n = Blinelen(bp)) < 1)
  19                                 continue;
  20                         s[n-1] = '\0';
  21                         if(tokenize(s, f, nelem(f)) != 2)
  22                                 continue;
  23                         if(strcmp(f[1], "pagesize") == 0)
  24                                 pgsize = strtoul(f[0], 0, 0);
  25                         else if(strcmp(f[1], "user") == 0) {
  26                                 userused =  strtoul(f[0], &s, 0);
  27                                 if(*s == '/')
  28                                         userpgs = strtoul(s+1, 0, 0);
  29                         }
  30                 }
  31                 Bterm(bp);
  32         }
  33         if(pgsize && userused < userpgs){
  34                 userpgs -= userused;
  35                 if(s = getenv("fsmempercent")){
  36                         mpcnt = atoi(s);
  37                         free(s);
  38                 }
  39                 if(mpcnt < 1)
  40                         mpcnt = 1;
  41                 userpgs = (userpgs*mpcnt)/100;
  42                 return (uvlong)userpgs*pgsize;
  43         }
  44         return 16*MB;
  45 }
  46
  47 uint    niob;
  48 uint    nhiob;
  49 Hiob    *hiob;
  50
  51 /*
  52  * Called to allocate permanent data structures
  53  * Alignment is in number of bytes. It pertains both to the start and
  54  * end of the allocated memory.
  55  */
  56 void*
  57 ialloc(uintptr n, int align)
  58 {
  59         char *p;
  60         int m;
  61
  62         if(align <= 0)
  63                 align = sizeof(uintptr);
  64
  65         mainmem->lock(mainmem);
  66
  67         p = sbrk(0);
  68         if(m = n % align)
  69                 n += align - m;
  70         if(m = (uintptr)p % align)
  71                 p += align - m;
  72         if(brk(p+n) < 0)
  73                 panic("ialloc: out of memory");
  74
  75         mainmem->unlock(mainmem);
  76
  77         return p;
  78 }
  79
  80 enum { HWIDTH = 8 };            /* buffers per hash */
  81
  82 /*
  83  * allocate rest of mem
  84  * for io buffers.
  85  */
  86 void
  87 iobufinit(void)
  88 {
  89         int i;
  90         char *xiop;
  91         Iobuf *p, *q;
  92         Hiob *hp;
  93
  94         wlock(&mainlock);       /* init */
  95         wunlock(&mainlock);
  96
  97         niob = memsize() / (sizeof(Iobuf) + RBUFSIZE + sizeof(Hiob)/HWIDTH);
  98         nhiob = niob / HWIDTH;
  99         while(!prime(nhiob))
 100                 nhiob++;
 101         if(chatty)
 102                 print("\t%ud buffers; %ud hashes\n", niob, nhiob);
 103         hiob = ialloc((uintptr)nhiob * sizeof(Hiob), 0);
 104         hp = hiob;
 105         for(i=0; i<nhiob; i++) {
 106                 lock(hp);
 107                 unlock(hp);
 108                 hp++;
 109         }
 110         p = ialloc((uintptr)niob * sizeof(Iobuf), 0);
 111         xiop = ialloc((uintptr)niob * RBUFSIZE, 0);
 112         hp = hiob;
 113         for(i=0; i < niob; i++) {
 114                 qlock(p);
 115                 qunlock(p);
 116                 if(hp == hiob)
 117                         hp = hiob + nhiob;
 118                 hp--;
 119                 q = hp->link;
 120                 if(q) {
 121                         p->fore = q;
 122                         p->back = q->back;
 123                         q->back = p;
 124                         p->back->fore = p;
 125                 } else {
 126                         hp->link = p;
 127                         p->fore = p;
 128                         p->back = p;
 129                 }
 130                 p->dev = devnone;
 131                 p->addr = -1;
 132                 p->xiobuf = xiop;
 133                 p->iobuf = (char*)-1;
 134                 p++;
 135                 xiop += RBUFSIZE;
 136         }
 137 }
 138
 139 void*
 140 iobufmap(Iobuf *p)
 141 {
 142         return p->iobuf = p->xiobuf;
 143 }
 144
 145 void
 146 iobufunmap(Iobuf *p)
 147 {
 148         p->iobuf = (char*)-1;
 149 }