*/
struct metaheader
{
- /* Length (after this header). (FIXME: implied by page bits!). */
- unsigned long metalen;
/* Next meta header, or 0 */
unsigned long next;
/* Bits start here. */
BUILD_ASSERT(FREE == 0);
memset(pool, 0, len);
- /* Set up metalen */
- mh->metalen = len - pool_offset(pool, mh + 1);
-
/* Mark the pagestate and metadata page(s) allocated. */
set_page_state(pool, 0, TAKEN_START);
for (i = 1; i < div_up(len, getpagesize()); i++)
return page*getpagesize() + (i-1)*BITMAP_GRANULARITY;
}
-static uint8_t *alloc_metaspace(struct metaheader *mh, unsigned long bytes,
+/* We look at the page states to figure out where the allocation for this
+ * metadata ends. */
+static unsigned long get_metalen(void *pool, unsigned long poolsize,
+ struct metaheader *mh)
+{
+ unsigned long i, first, pages = poolsize / getpagesize();
+
+ first = pool_offset(pool, mh + 1)/getpagesize();
+
+ for (i = first + 1; i < pages && get_page_state(pool,i) == TAKEN; i++);
+
+ return i * getpagesize() - pool_offset(pool, mh + 1);
+}
+
+static uint8_t *alloc_metaspace(void *pool, unsigned long poolsize,
+ struct metaheader *mh, unsigned long bytes,
enum sub_metadata_type type)
{
uint8_t *meta = (uint8_t *)(mh + 1);
- unsigned long free = 0, len;
- unsigned long i;
+ unsigned long free = 0, len, i, metalen;
+
+ metalen = get_metalen(pool, poolsize, mh);
/* TAKEN tags end a subpage alloc. */
- for (i = 0; i < mh->metalen * CHAR_BIT / BITS_PER_PAGE; i += len) {
+ for (i = 0; i < metalen * CHAR_BIT / BITS_PER_PAGE; i += len) {
switch (get_bit_pair(meta, i)) {
case FREE:
len = 1;
unsigned long page;
for (mh = first_mheader(pool,poolsize); mh; mh = next_mheader(pool,mh)){
- uint8_t *meta = alloc_metaspace(mh, bytes, type);
+ uint8_t *meta = alloc_metaspace(pool, poolsize, mh, bytes,type);
if (meta)
return meta;
/* No room for metadata? Can we expand an existing one? */
for (mh = first_mheader(pool,poolsize); mh; mh = next_mheader(pool,mh)){
- /* It should end on a page boundary. */
unsigned long nextpage;
- nextpage = pool_offset(pool, (char *)(mh + 1) + mh->metalen);
- assert(nextpage % getpagesize() == 0);
+ /* We start on this page. */
+ nextpage = pool_offset(pool, (char *)(mh+1))/getpagesize();
+ /* Iterate through any other pages we own. */
+ while (get_page_state(pool, ++nextpage) == TAKEN)
/* Now, can we grab that page? */
- if (get_page_state(pool, nextpage / getpagesize()) != FREE)
+ if (get_page_state(pool, nextpage) != FREE)
continue;
/* OK, expand metadata, do it again. */
- set_page_state(pool, nextpage / getpagesize(), TAKEN);
+ set_page_state(pool, nextpage, TAKEN);
BUILD_ASSERT(FREE == 0);
- memset((char *)pool + nextpage, 0, getpagesize());
- mh->metalen += getpagesize();
- return alloc_metaspace(mh, bytes, type);
+ memset((char *)pool + nextpage*getpagesize(), 0, getpagesize());
+ return alloc_metaspace(pool, poolsize, mh, bytes, type);
}
/* No metadata left at all? */
return NULL;
newmh = (struct metaheader *)((char *)pool + page * getpagesize());
- newmh->metalen = getpagesize() - sizeof(*mh);
BUILD_ASSERT(FREE == 0);
- memset(newmh + 1, 0, newmh->metalen);
+ memset(newmh + 1, 0, getpagesize() - sizeof(*mh));
/* Sew it into linked list */
mh = first_mheader(pool,poolsize);
newmh->next = mh->next;
mh->next = pool_offset(pool, newmh);
- return alloc_metaspace(newmh, bytes, type);
+ return alloc_metaspace(pool, poolsize, newmh, bytes, type);
}
static void alloc_free_pages(void *pool, unsigned long pagenum)
for (mh = first_mheader(pool,poolsize); mh; mh = next_mheader(pool,mh)){
uint8_t *meta;
long i;
+ unsigned long metalen = get_metalen(pool, poolsize, mh);
meta = (uint8_t *)(mh + 1);
BUILD_ASSERT(FREE == 0);
- for (i = mh->metalen - 1; i > 0; i--)
+ for (i = metalen - 1; i > 0; i--)
if (meta[i] != 0)
break;
/* Completely empty? */
- if (prev_mh && i == mh->metalen) {
+ if (prev_mh && i == metalen) {
alloc_free_pages(pool,
pool_offset(pool, mh)/getpagesize());
prev_mh->next = mh->next;
uint8_t *p;
/* Some pages at end are free? */
- for (p = (uint8_t *)(mh+1)+mh->metalen - getpagesize();
+ for (p = (uint8_t *)(mh+1) + metalen - getpagesize();
p > meta + i;
p -= getpagesize()) {
set_page_state(pool,
assert(poolsize >= MIN_SIZE);
mh = first_mheader(pool, poolsize);
- assert((char *)free >= (char *)(mh + 1) + mh->metalen);
+ assert((char *)free >= (char *)(mh + 1));
assert((char *)pool + poolsize > (char *)free);
pagenum = pool_offset(pool, free) / getpagesize();
unsigned long start, end;
start = pool_offset(pool, mh);
- end = pool_offset(pool, (char *)(mh+1) + mh->metalen);
+ end = pool_offset(pool, (char *)(mh+1)
+ + get_metalen(pool, poolsize, mh));
if (page >= start/getpagesize() && page < end/getpagesize())
return true;
}
if (start + sizeof(*mh) > poolsize)
return false;
- end = pool_offset(pool, (char *)(mh+1) + mh->metalen);
+ end = pool_offset(pool, (char *)(mh+1)
+ + get_metalen(pool, poolsize, mh));
if (end > poolsize)
return false;
/* Now do each metadata page. */
for (; mh; mh = next_mheader(pool,mh)) {
- unsigned long free = 0, subpageblocks = 0, len = 0;
+ unsigned long free = 0, subpageblocks = 0, len = 0, metalen;
uint8_t *meta = (uint8_t *)(mh + 1);
- metadata_pages += (sizeof(*mh) + mh->metalen) / getpagesize();
+ metalen = get_metalen(pool, poolsize, mh);
+ metadata_pages += (sizeof(*mh) + metalen) / getpagesize();
- for (i = 0;
- i < mh->metalen * CHAR_BIT / BITS_PER_PAGE;
- i += len) {
+ for (i = 0; i < metalen * CHAR_BIT / BITS_PER_PAGE; i += len) {
switch (get_page_state(meta, i)) {
case FREE:
len = 1;
fprintf(out, "Metadata %lu-%lu: %lu free, %lu subpageblocks, %lu%% density\n",
pool_offset(pool, mh),
- pool_offset(pool, (char *)(mh+1) + mh->metalen),
+ pool_offset(pool, (char *)(mh+1) + metalen),
free, subpageblocks,
subpageblocks * BITMAP_METALEN * 100
/ (free + subpageblocks * BITMAP_METALEN));
projects / ccan / blobdiff