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Commit f033b4f3 authored by Rusty Russell's avatar Rusty Russell
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More cleanups where get_bit_pair should be used instead of 

get_page_state.
Combine alloc_get_pages and alloc_from_bitmap.
Fix error in alloc_init (valgrind found uninitialized mem)
parent e6737e85
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Inline Side-by-side
Showing with 58 additions and 78 deletions
alloc/alloc.c
View file @ f033b4f3
......@@ -143,14 +143,14 @@ void alloc_init(void *pool, unsigned long poolsize)
mh = first_mheader(pool, poolsize);
/* len covers all page states, plus the metaheader. */
len = (char *)(mh + 1) - (char *)pool;
/* Mark all page states FREE */
/* Mark all page states FREE, and all of metaheader bitmap which takes
* rest of first page. */
len = align_up(pool_offset(pool, mh + 1), getpagesize());
BUILD_ASSERT(FREE == 0);
memset(pool, 0, len);
/* metaheader len takes us up to next page boundary. */
mh->metalen = align_up(len, getpagesize()) - 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);
......@@ -158,9 +158,12 @@ void alloc_init(void *pool, unsigned long poolsize)
set_page_state(pool, i, TAKEN);
}
/* Two bits per element, representing page states. Returns -1 on fail. */
static long alloc_from_bitmap(uint8_t *bits, unsigned long elems,
unsigned long want, unsigned long align)
/* Two bits per element, representing page states. Returns 0 on fail.
* off is used to allocate from subpage bitmaps, which use the first 2
* bits as the type, so the real bitmap is offset by 1. */
static unsigned long alloc_from_bitmap(uint8_t *bits, unsigned long off,
unsigned long elems,
unsigned long want, unsigned long align)
{
long i;
unsigned long free;
......@@ -168,7 +171,7 @@ static long alloc_from_bitmap(uint8_t *bits, unsigned long elems,
free = 0;
/* We allocate from far end, to increase ability to expand metadata. */
for (i = elems - 1; i >= 0; i--) {
switch (get_bit_pair(bits, i)) {
switch (get_bit_pair(bits, off+i)) {
case FREE:
if (++free >= want) {
unsigned long j;
......@@ -177,10 +180,10 @@ static long alloc_from_bitmap(uint8_t *bits, unsigned long elems,
if (align && i % align)
continue;
set_bit_pair(bits, off+i, TAKEN_START);
for (j = i+1; j < i + want; j++)
set_bit_pair(bits, j, TAKEN);
set_bit_pair(bits, i, TAKEN_START);
return i;
set_bit_pair(bits, off+j, TAKEN);
return off+i;
}
break;
case SPECIAL:
......@@ -191,44 +194,14 @@ static long alloc_from_bitmap(uint8_t *bits, unsigned long elems,
}
}
return -1;
return 0;
}
static unsigned long alloc_get_pages(void *pool, unsigned long poolsize,
unsigned long pages, unsigned long align)
{
long i;
unsigned long free;
free = 0;
/* We allocate from far end, to increase ability to expand metadata. */
for (i = poolsize / getpagesize() - 1; i >= 0; i--) {
switch (get_page_state(pool, i)) {
case FREE:
if (++free >= pages) {
unsigned long j, addr;
addr = (unsigned long)pool + i * getpagesize();
/* They might ask for multi-page alignment. */
if (addr % align)
continue;
for (j = i+1; j < i + pages; j++)
set_page_state(pool, j, TAKEN);
set_page_state(pool, i, TAKEN_START);
return i;
}
break;
case SPECIAL:
case TAKEN_START:
case TAKEN:
free = 0;
break;
}
}
return 0;
return alloc_from_bitmap(pool, 0, poolsize / getpagesize(), pages,
align / getpagesize());
}
/* Offset to metadata is at end of page. */
......@@ -252,39 +225,43 @@ static unsigned long sub_page_alloc(void *pool, unsigned long page,
unsigned long size, unsigned long align)
{
uint8_t *bits = get_page_metadata(pool, page);
long i;
unsigned long i;
/* TAKEN at end means a bitwise alloc. */
assert(get_bit_pair(bits, getpagesize()/BITMAP_GRANULARITY-1) == TAKEN);
/* TAKEN at start means a bitwise alloc. */
assert(get_bit_pair(bits, 0) == BITMAP);
/* Our bits are the same as the page bits. */
i = alloc_from_bitmap(bits, SUBPAGE_METAOFF/BITMAP_GRANULARITY,
/* We use a standart bitmap, but offset because of that BITMAP
* header. */
i = alloc_from_bitmap(bits, 1, SUBPAGE_METAOFF/BITMAP_GRANULARITY,
div_up(size, BITMAP_GRANULARITY),
align / BITMAP_GRANULARITY);
/* Can't allocate? */
if (i < 0)
if (i == 0)
return 0;
return page*getpagesize() + i*BITMAP_GRANULARITY;
/* i-1 because of the header. */
return page*getpagesize() + (i-1)*BITMAP_GRANULARITY;
}
static uint8_t *alloc_metaspace(struct metaheader *mh, unsigned long bytes)
static uint8_t *alloc_metaspace(struct metaheader *mh, unsigned long bytes,
enum sub_metadata_type type)
{
uint8_t *meta = (uint8_t *)(mh + 1);
unsigned long free = 0, len;
long i;
unsigned long i;
/* TAKEN tags end a subpage alloc. */
for (i = mh->metalen * CHAR_BIT / BITS_PER_PAGE - 1; i >= 0; i -= len) {
for (i = 0; i < mh->metalen * CHAR_BIT / BITS_PER_PAGE; i += len) {
switch (get_bit_pair(meta, i)) {
case FREE:
len = 1;
free++;
if (free == bytes * CHAR_BIT / BITS_PER_PAGE) {
/* TAKEN marks end of metablock. */
set_page_state(meta, i + free - 1, TAKEN);
return meta + i / (CHAR_BIT / BITS_PER_PAGE);
/* Mark this as a bitmap. */
set_bit_pair(meta, i - free + 1, type);
return meta + (i - free + 1)
/ (CHAR_BIT / BITS_PER_PAGE);
}
break;
case BITMAP:
......@@ -302,13 +279,13 @@ static uint8_t *alloc_metaspace(struct metaheader *mh, unsigned long bytes)
/* We need this many bytes of metadata. */
static uint8_t *new_metadata(void *pool, unsigned long poolsize,
unsigned long bytes)
unsigned long bytes, enum sub_metadata_type type)
{
struct metaheader *mh, *newmh;
unsigned long page;
for (mh = first_mheader(pool,poolsize); mh; mh = next_mheader(pool,mh)){
uint8_t *meta = alloc_metaspace(mh, bytes);
uint8_t *meta = alloc_metaspace(mh, bytes, type);
if (meta)
return meta;
......@@ -331,7 +308,7 @@ static uint8_t *new_metadata(void *pool, unsigned long poolsize,
BUILD_ASSERT(FREE == 0);
memset((char *)pool + nextpage, 0, getpagesize());
mh->metalen += getpagesize();
return alloc_metaspace(mh, bytes);
return alloc_metaspace(mh, bytes, type);
}
/* No metadata left at all? */
......@@ -349,7 +326,7 @@ static uint8_t *new_metadata(void *pool, unsigned long poolsize,
newmh->next = mh->next;
mh->next = pool_offset(pool, newmh);
return alloc_metaspace(newmh, bytes);
return alloc_metaspace(newmh, bytes, type);
}
static void alloc_free_pages(void *pool, unsigned long pagenum)
......@@ -383,7 +360,7 @@ static unsigned long alloc_sub_page(void *pool, unsigned long poolsize,
return 0;
/* Get metadata for page. */
metadata = new_metadata(pool, poolsize, BITMAP_METALEN);
metadata = new_metadata(pool, poolsize, BITMAP_METALEN, BITMAP);
if (!metadata) {
alloc_free_pages(pool, i);
return 0;
......@@ -412,12 +389,13 @@ static bool clean_empty_subpages(void *pool, unsigned long poolsize)
continue;
meta = get_page_metadata(pool, i);
for (j = 0; j < SUBPAGE_METAOFF/BITMAP_GRANULARITY; j++)
if (get_page_state(meta, j) != FREE)
/* Skip the header (first bit of metadata). */
for (j = 1; j < SUBPAGE_METAOFF/BITMAP_GRANULARITY+1; j++)
if (get_bit_pair(meta, j) != FREE)
break;
/* So, is this page totally empty? */
if (j == SUBPAGE_METAOFF/BITMAP_GRANULARITY) {
if (j == SUBPAGE_METAOFF/BITMAP_GRANULARITY+1) {
set_page_state(pool, i, FREE);
progress = true;
}
......@@ -518,10 +496,13 @@ static void subpage_free(void *pool, unsigned long pagenum, void *free)
off /= BITMAP_GRANULARITY;
set_page_state(metadata, off++, FREE);
/* Offset by one because first bit is used for header. */
off++;
set_bit_pair(metadata, off++, FREE);
while (off < SUBPAGE_METAOFF / BITMAP_GRANULARITY
&& get_page_state(metadata, off) == TAKEN)
set_page_state(metadata, off++, FREE);
&& get_bit_pair(metadata, off) == TAKEN)
set_bit_pair(metadata, off++, FREE);
}
void alloc_free(void *pool, unsigned long poolsize, void *free)
......@@ -581,15 +562,15 @@ static bool check_subpage(void *pool, unsigned long poolsize,
if (!is_metadata_page(pool, poolsize, *mhoff / getpagesize()))
return false;
/* Marker at end of subpage allocation is "taken" */
if (get_bit_pair((uint8_t *)pool + *mhoff,
getpagesize()/BITMAP_GRANULARITY - 1) != TAKEN)
/* Header at start of subpage allocation */
if (get_bit_pair((uint8_t *)pool + *mhoff, 0) != BITMAP)
return false;
for (i = 0; i < SUBPAGE_METAOFF / BITMAP_GRANULARITY; i++) {
enum alloc_state state;
state = get_bit_pair((uint8_t *)pool + *mhoff, i);
/* +1 because header is the first byte. */
state = get_bit_pair((uint8_t *)pool + *mhoff, i+1);
switch (state) {
case SPECIAL:
return false;
......@@ -700,16 +681,15 @@ void alloc_visualize(FILE *out, void *pool, unsigned long poolsize)
metadata_pages += (sizeof(*mh) + mh->metalen) / getpagesize();
/* TAKEN tags end a subpage alloc. */
for (i = mh->metalen * CHAR_BIT/BITS_PER_PAGE - 1;
i >= 0;
i -= len) {
for (i = 0;
i < mh->metalen * CHAR_BIT / BITS_PER_PAGE;
i += len) {
switch (get_page_state(meta, i)) {
case FREE:
len = 1;
free++;
break;
case TAKEN:
case BITMAP:
/* Skip over this allocated part. */
len = BITMAP_METALEN * CHAR_BIT;
subpageblocks++;
......
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