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- pages that points to page directory values of all processes,

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shared with the kernel, mapped into kernel address space; 
   kernel is notified of its location. kernel segment size is
   increased to make it fit.
 - map in kernel and other processes that don't have their
   own page table using single 4MB (global) mapping.
 - new sanity check facility: objects that are allocated with
   the slab allocator are, when running with sanity checking on,
   marked readonly until they are explicitly unlocked using the USE()
   macro.
 - another sanity check facility: collect all uses of memory and
   see if they don't overlap with (a) eachother and (b) free memory
 - own munmap() and munmap_text() functions.
 - exec() recovers from out-of-memory conditions properly now; this
   solves some weird exec() behaviour
 - chew off memory from the same side of the chunk as where we
   start scanning, solving some memory fragmentation issues
 - use avl trees for freelist and phys_ranges in regions
 - implement most useful part of munmap()
 - remap() stuff is GQ's for shared memory
This commit is contained in:
Ben Gras
2009-09-21 14:49:49 +00:00
parent f5459e38db
commit 32fbbd370c
36 changed files with 3607 additions and 997 deletions
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230
servers/vm/slaballoc.c
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@@ -13,6 +13,8 @@
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/bitmap.h>
#include <minix/debug.h>
#include <errno.h>
#include <string.h>
@@ -27,7 +29,7 @@
#define SLABSIZES 60
#define ITEMSPERPAGE(s, bytes) (DATABYTES / (bytes))
#define ITEMSPERPAGE(bytes) (DATABYTES / (bytes))
#define ELBITS (sizeof(element_t)*8)
#define BITPAT(b) (1UL << ((b) % ELBITS))
@@ -37,9 +39,37 @@
#define OFF(f, b) vm_assert(!GETBIT(f, b))
#define ON(f, b) vm_assert(GETBIT(f, b))
#if SANITYCHECKS
#define SLABDATAWRITABLE(data, wr) do { \
vm_assert(data->sdh.writable == WRITABLE_NONE); \
vm_assert(wr != WRITABLE_NONE); \
vm_pagelock(data, 0); \
data->sdh.writable = wr; \
} while(0)
#define SLABDATAUNWRITABLE(data) do { \
vm_assert(data->sdh.writable != WRITABLE_NONE); \
data->sdh.writable = WRITABLE_NONE; \
vm_pagelock(data, 1); \
} while(0)
#define SLABDATAUSE(data, code) do { \
SLABDATAWRITABLE(data, WRITABLE_HEADER); \
code \
SLABDATAUNWRITABLE(data); \
} while(0)
#else
#define SLABDATAWRITABLE(data, wr)
#define SLABDATAUNWRITABLE(data)
#define SLABDATAUSE(data, code) do { code } while(0)
#endif
#define GETBIT(f, b) (BITEL(f,b) & BITPAT(b))
#define SETBIT(f, b) {OFF(f,b); (BITEL(f,b)|= BITPAT(b)); (f)->sdh.nused++; }
#define CLEARBIT(f, b) {ON(f, b); (BITEL(f,b)&=~BITPAT(b)); (f)->sdh.nused--; (f)->sdh.freeguess = (b); }
#define SETBIT(f, b) {OFF(f,b); SLABDATAUSE(f, BITEL(f,b)|= BITPAT(b); (f)->sdh.nused++;); }
#define CLEARBIT(f, b) {ON(f, b); SLABDATAUSE(f, BITEL(f,b)&=~BITPAT(b); (f)->sdh.nused--; (f)->sdh.freeguess = (b);); }
#define MINSIZE 8
#define MAXSIZE (SLABSIZES-1+MINSIZE)
@@ -56,28 +86,32 @@ typedef element_t elements_t[USEELEMENTS];
* inconsistent state during a slaballoc() / slabfree(). So only do
* our own sanity checks here, with SLABSANITYCHECK.
*/
#if SANITYCHECKS
#define SLABSANITYCHECK(l) if((l) <= vm_sanitychecklevel) { \
slab_sanitycheck(__FILE__, __LINE__); }
#else
#define SLABSANITYCHECK(l)
#endif
/* Special writable values. */
#define WRITABLE_NONE -2
#define WRITABLE_HEADER -1
struct sdh {
#if SANITYCHECKS
u32_t magic1;
#endif
u8_t list;
u16_t nused; /* Number of data items used in this slab. */
#if SANITYCHECKS
u32_t magic;
#endif
int freeguess;
struct slabdata *next, *prev;
elements_t usebits;
phys_bytes phys;
#if SANITYCHECKS
int writable; /* data item number or WRITABLE_* */
u32_t magic2;
#endif
};
#define DATABYTES (VM_PAGE_SIZE-sizeof(struct sdh))
#define MAGIC 0x1f5b842f
#define MAGIC1 0x1f5b842f
#define MAGIC2 0x8bb5a420
#define JUNK 0xdeadbeef
#define NOJUNK 0xc0ffee
@@ -107,6 +141,7 @@ FORWARD _PROTOTYPE( int objstats, (void *, int, struct slabheader **, struct sla
#define LH(sl, l) (sl)->list_head[l]
/* move head of list l1 to list of l2 in slabheader sl. */
#define MOVEHEAD(sl, l1, l2) { \
struct slabdata *t; \
vm_assert(LH(sl,l1)); \
@@ -114,28 +149,35 @@ FORWARD _PROTOTYPE( int objstats, (void *, int, struct slabheader **, struct sla
ADDHEAD(t, sl, l2); \
}
/* remove head of list 'list' in sl, assign it unlinked to 'to'. */
#define REMOVEHEAD(sl, list, to) { \
(to) = LH(sl, list); \
vm_assert(to); \
LH(sl, list) = (to)->sdh.next; \
if(LH(sl, list)) LH(sl, list) = NULL; \
vm_assert((to)->sdh.magic == MAGIC);\
vm_assert(!(to)->sdh.prev); \
struct slabdata *dat; \
dat = (to) = LH(sl, list); \
vm_assert(dat); \
LH(sl, list) = dat->sdh.next; \
UNLINKNODE(dat); \
}
/* move slabdata nw to slabheader sl under list number l. */
#define ADDHEAD(nw, sl, l) { \
vm_assert((nw)->sdh.magic == MAGIC); \
(nw)->sdh.next = LH(sl, l); \
(nw)->sdh.prev = NULL; \
(nw)->sdh.list = l; \
SLABDATAUSE(nw, \
(nw)->sdh.next = LH(sl, l); \
(nw)->sdh.prev = NULL; \
(nw)->sdh.list = l;); \
LH(sl, l) = (nw); \
if((nw)->sdh.next) (nw)->sdh.next->sdh.prev = (nw); \
if((nw)->sdh.next) { \
SLABDATAUSE((nw)->sdh.next, \
(nw)->sdh.next->sdh.prev = (nw);); \
} \
}
#define UNLINKNODE(n) { \
if((f)->sdh.prev) (f)->sdh.prev->sdh.next = (f)->sdh.next; \
if((f)->sdh.next) (f)->sdh.next->sdh.prev = (f)->sdh.prev; \
}
#define UNLINKNODE(node) { \
struct slabdata *next, *prev; \
prev = (node)->sdh.prev; \
next = (node)->sdh.next; \
if(prev) { SLABDATAUSE(prev, prev->sdh.next = next;); } \
if(next) { SLABDATAUSE(next, next->sdh.prev = prev;); } \
}
struct slabdata *newslabdata(int list)
{
@@ -151,12 +193,18 @@ struct slabdata *newslabdata(int list)
n->sdh.phys = p;
#if SANITYCHECKS
n->sdh.magic = MAGIC;
n->sdh.magic1 = MAGIC1;
n->sdh.magic2 = MAGIC2;
#endif
n->sdh.nused = 0;
n->sdh.freeguess = 0;
n->sdh.list = list;
#if SANITYCHECKS
n->sdh.writable = WRITABLE_HEADER;
SLABDATAUNWRITABLE(n);
#endif
return n;
}
@@ -173,15 +221,17 @@ PRIVATE int checklist(char *file, int line,
while(n) {
int count = 0, i;
MYASSERT(n->sdh.magic1 == MAGIC1);
MYASSERT(n->sdh.magic2 == MAGIC2);
MYASSERT(n->sdh.list == l);
MYASSERT(n->sdh.magic == MAGIC);
MYASSERT(usedpages_add(n->sdh.phys, VM_PAGE_SIZE) == OK);
if(n->sdh.prev)
MYASSERT(n->sdh.prev->sdh.next == n);
else
MYASSERT(s->list_head[l] == n);
if(n->sdh.next) MYASSERT(n->sdh.next->sdh.prev == n);
for(i = 0; i < USEELEMENTS*8; i++)
if(i >= ITEMSPERPAGE(s, bytes))
if(i >= ITEMSPERPAGE(bytes))
MYASSERT(!GETBIT(n, i));
else
if(GETBIT(n,i))
@@ -211,21 +261,25 @@ PUBLIC void slab_sanitycheck(char *file, int line)
/*===========================================================================*
* int slabsane *
*===========================================================================*/
PUBLIC int slabsane(void *mem, int bytes)
PUBLIC int slabsane_f(char *file, int line, void *mem, int bytes)
{
struct slabheader *s;
struct slabdata *f;
int i;
return (objstats(mem, bytes, &s, &f, &i) == OK);
}
#endif
static int nojunkwarning = 0;
/*===========================================================================*
* void *slaballoc *
*===========================================================================*/
PUBLIC void *slaballoc(int bytes)
{
int i, n = 0;
int i;
int count = 0;
struct slabheader *s;
struct slabdata *firstused;
@@ -242,10 +296,10 @@ PUBLIC void *slaballoc(int bytes)
/* Make sure there is something on the freelist. */
SLABSANITYCHECK(SCL_DETAIL);
if(!LH(s, LIST_FREE)) {
struct slabdata *n = newslabdata(LIST_FREE);
struct slabdata *nd = newslabdata(LIST_FREE);
SLABSANITYCHECK(SCL_DETAIL);
if(!n) return NULL;
ADDHEAD(n, s, LIST_FREE);
if(!nd) return NULL;
ADDHEAD(nd, s, LIST_FREE);
SLABSANITYCHECK(SCL_DETAIL);
}
@@ -260,18 +314,21 @@ PUBLIC void *slaballoc(int bytes)
vm_assert(s);
firstused = LH(s, LIST_USED);
vm_assert(firstused);
vm_assert(firstused->sdh.magic == MAGIC);
vm_assert(firstused->sdh.magic1 == MAGIC1);
vm_assert(firstused->sdh.magic2 == MAGIC2);
vm_assert(firstused->sdh.nused < ITEMSPERPAGE(bytes));
for(i = firstused->sdh.freeguess; n < ITEMSPERPAGE(s, bytes); n++, i++) {
for(i = firstused->sdh.freeguess;
count < ITEMSPERPAGE(bytes); count++, i++) {
SLABSANITYCHECK(SCL_DETAIL);
i = i % ITEMSPERPAGE(s, bytes);
i = i % ITEMSPERPAGE(bytes);
if(!GETBIT(firstused, i)) {
struct slabdata *f;
char *ret;
SETBIT(firstused, i);
SLABSANITYCHECK(SCL_DETAIL);
if(firstused->sdh.nused == ITEMSPERPAGE(s, bytes)) {
if(firstused->sdh.nused == ITEMSPERPAGE(bytes)) {
SLABSANITYCHECK(SCL_DETAIL);
MOVEHEAD(s, LIST_USED, LIST_FULL);
SLABSANITYCHECK(SCL_DETAIL);
@@ -280,20 +337,21 @@ PUBLIC void *slaballoc(int bytes)
ret = ((char *) firstused->data) + i*bytes;
#if SANITYCHECKS
f = (struct slabdata *) ((char *) ret - (vir_bytes) ret % VM_PAGE_SIZE);
if(f->sdh.magic != MAGIC) {
printf("slaballoc bogus pointer 0x%lx, "
"rounded 0x%lx, bad magic 0x%lx\n",
ret, f, f->sdh.magic);
vm_panic("slaballoc check failed", NO_NUM);
}
nojunkwarning++;
slabunlock(ret, bytes);
nojunkwarning--;
vm_assert(!nojunkwarning);
*(u32_t *) ret = NOJUNK;
slablock(ret, bytes);
#endif
SLABSANITYCHECK(SCL_FUNCTIONS);
firstused->sdh.freeguess = i+1;
SLABDATAUSE(firstused, firstused->sdh.freeguess = i+1;);
#if SANITYCHECKS
if(!slabsane(ret, bytes))
if(bytes >= SLABSIZES+MINSIZE) {
printf("slaballoc: odd, bytes %d?\n", bytes);
}
if(!slabsane_f(__FILE__, __LINE__, ret, bytes))
vm_panic("slaballoc: slabsane failed", NO_NUM);
#endif
@@ -317,12 +375,16 @@ PUBLIC void *slaballoc(int bytes)
PRIVATE int objstats(void *mem, int bytes,
struct slabheader **sp, struct slabdata **fp, int *ip)
{
#if SANITYCHECKS
#define OBJSTATSCHECK(cond) \
if(!(cond)) { \
printf("VM:objstats: %s failed for ptr 0x%p, %d bytes\n", \
printf("VM: objstats: %s failed for ptr 0x%p, %d bytes\n", \
#cond, mem, bytes); \
return EINVAL; \
}
#else
#define OBJSTATSCHECK(cond)
#endif
struct slabheader *s;
struct slabdata *f;
@@ -331,21 +393,19 @@ PRIVATE int objstats(void *mem, int bytes,
OBJSTATSCHECK((char *) mem >= (char *) VM_PAGE_SIZE);
#if SANITYCHECKS
if(*(u32_t *) mem == JUNK) {
if(*(u32_t *) mem == JUNK && !nojunkwarning) {
util_stacktrace();
printf("VM: WARNING: JUNK seen in slab object\n");
}
#endif
/* Retrieve entry in slabs[]. */
GETSLAB(bytes, s);
/* Round address down to VM_PAGE_SIZE boundary to get header. */
f = (struct slabdata *) ((char *) mem - (vir_bytes) mem % VM_PAGE_SIZE);
#if SANITYCHECKS
OBJSTATSCHECK(f->sdh.magic == MAGIC);
#endif
OBJSTATSCHECK(f->sdh.magic1 == MAGIC1);
OBJSTATSCHECK(f->sdh.magic2 == MAGIC2);
OBJSTATSCHECK(f->sdh.list == LIST_USED || f->sdh.list == LIST_FULL);
/* Make sure it's in range. */
@@ -379,22 +439,26 @@ PUBLIC void slabfree(void *mem, int bytes)
SLABSANITYCHECK(SCL_FUNCTIONS);
#if SANITYCHECKS
if(*(u32_t *) mem == JUNK) {
printf("VM: WARNING: likely double free, JUNK seen\n");
}
#endif
if(objstats(mem, bytes, &s, &f, &i) != OK) {
vm_panic("slabfree objstats failed", NO_NUM);
}
#if SANITYCHECKS
if(*(u32_t *) mem == JUNK) {
printf("VM: WARNING: likely double free, JUNK seen\n");
}
slabunlock(mem, bytes);
*(u32_t *) mem = JUNK;
nojunkwarning++;
slablock(mem, bytes);
nojunkwarning--;
vm_assert(!nojunkwarning);
#endif
/* Free this data. */
CLEARBIT(f, i);
#if SANITYCHECKS
*(u32_t *) mem = JUNK;
#endif
/* Check if this slab changes lists. */
if(f->sdh.nused == 0) {
/* Now become FREE; must've been USED */
@@ -404,7 +468,7 @@ PUBLIC void slabfree(void *mem, int bytes)
LH(s, LIST_USED) = f->sdh.next;
ADDHEAD(f, s, LIST_FREE);
SLABSANITYCHECK(SCL_DETAIL);
} else if(f->sdh.nused == ITEMSPERPAGE(s, bytes)-1) {
} else if(f->sdh.nused == ITEMSPERPAGE(bytes)-1) {
/* Now become USED; must've been FULL */
vm_assert(f->sdh.list == LIST_FULL);
UNLINKNODE(f);
@@ -422,6 +486,42 @@ PUBLIC void slabfree(void *mem, int bytes)
return;
}
/*===========================================================================*
* void *slablock *
*===========================================================================*/
PUBLIC void slablock(void *mem, int bytes)
{
int i;
struct slabheader *s;
struct slabdata *f;
if(objstats(mem, bytes, &s, &f, &i) != OK)
vm_panic("slablock objstats failed", NO_NUM);
SLABDATAUNWRITABLE(f);
FIXME("verify new contents");
return;
}
/*===========================================================================*
* void *slabunlock *
*===========================================================================*/
PUBLIC void slabunlock(void *mem, int bytes)
{
int i;
struct slabheader *s;
struct slabdata *f;
if(objstats(mem, bytes, &s, &f, &i) != OK)
vm_panic("slablock objstats failed", NO_NUM);
SLABDATAWRITABLE(f, i);
return;
}
#if SANITYCHECKS
/*===========================================================================*
* void slabstats *