Module: xenomai-3
Branch: wip/heap-bitmap
Commit: 8f3d0b1a0aac47b7b2a5f1b3b6e307a2aab9643c
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=8f3d0b1a0aac47b7b2a5f1b3b6e307a2aab9643c
Author: Philippe Gerum <r...@xenomai.org>
Date: Fri Jun 3 10:00:38 2016 +0200
copperplate/heapobj-pshared: introduce allocation bitmap
Using a free list leads to pathological execution times when releasing
blocks obtained from huge heaps (i.e. hundreds of megabytes). Rework
the core to use an allocation bitmap instead.
---
lib/copperplate/heapobj-pshared.c | 411 +++++++++++++++++++++----------------
lib/copperplate/internal.h | 18 +-
2 files changed, 251 insertions(+), 178 deletions(-)
diff --git a/lib/copperplate/heapobj-pshared.c
b/lib/copperplate/heapobj-pshared.c
index 8c5dac6..8b8156b 100644
--- a/lib/copperplate/heapobj-pshared.c
+++ b/lib/copperplate/heapobj-pshared.c
@@ -28,6 +28,7 @@
#include <assert.h>
#include <errno.h>
#include <stdio.h>
+#include <stdint.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
@@ -43,15 +44,7 @@
#include "xenomai/init.h"
#include "internal.h"
-#define HOBJ_PAGE_SHIFT 9 /* 2^9 => 512 bytes */
-#define HOBJ_PAGE_SIZE (1U << HOBJ_PAGE_SHIFT)
-#define HOBJ_PAGE_MASK (~(HOBJ_PAGE_SIZE-1))
-#define HOBJ_PAGE_ALIGN(addr) (((addr)+HOBJ_PAGE_SIZE-1)&HOBJ_PAGE_MASK)
-
-#define HOBJ_MINALIGNSZ (1U << 4) /* i.e. 16 bytes */
-#define HOBJ_MAXEXTSZ (1U << 31) /* i.e. 2Gb */
-
-enum {
+enum { /* FIXME: page_free redundant with future
bitmap */
page_free =0,
page_cont =1,
page_list =2
@@ -66,8 +59,9 @@ struct shared_extent {
struct holder link;
memoff_t membase; /* Base offset of page array */
memoff_t memlim; /* Offset limit of page array */
- memoff_t freelist; /* Head of free page list */
- struct page_entry pagemap[1]; /* Start of page map */
+ memoff_t bitmap; /* Offset of allocation bitmap */
+ int bitwords; /* 32bit words in bitmap */
+ struct page_entry pagemap[0]; /* Start of page map */
};
/*
@@ -117,24 +111,38 @@ static inline size_t __align_to(size_t size, size_t al)
return ((size+al-1)&(~(al-1)));
}
-static inline size_t get_pagemap_size(size_t h)
+static inline size_t get_pagemap_size(size_t h,
+ memoff_t *bmapoff, int *bmapwords)
{
+ int nrpages = h >> HOBJ_PAGE_SHIFT, bitmapw;
+ size_t pagemapsz;
+
/*
* Return the size of the meta data required to map 'h' bytes
* of user memory in pages of HOBJ_PAGE_SIZE bytes. The meta
* data includes the length of the extent descriptor, plus the
- * length of the page mapping array. 'h' must be a multiple of
- * HOBJ_PAGE_SIZE on entry.
+ * length of the page mapping array followed by the allocation
+ * bitmap. 'h' must be a multiple of HOBJ_PAGE_SIZE on entry.
*/
assert((h & ~HOBJ_PAGE_MASK) == 0);
- return __align_to((h >> HOBJ_PAGE_SHIFT) * sizeof(struct page_entry)
- + sizeof(struct shared_extent), HOBJ_MINALIGNSZ);
+ pagemapsz = __align_to(nrpages * sizeof(struct page_entry),
+ sizeof(uint32_t));
+ bitmapw =__align_to(nrpages, 32) / 32;
+ if (bmapoff)
+ *bmapoff = offsetof(struct shared_extent, pagemap) + pagemapsz;
+ if (bmapwords)
+ *bmapwords = bitmapw;
+
+ return __align_to(pagemapsz
+ + sizeof(struct shared_extent)
+ + bitmapw * sizeof(uint32_t),
+ HOBJ_MINALIGNSZ);
}
static void init_extent(void *base, struct shared_extent *extent)
{
- caddr_t freepage;
int n, lastpgnum;
+ uint32_t *p;
__holder_init_nocheck(base, &extent->link);
@@ -147,19 +155,20 @@ static void init_extent(void *base, struct shared_extent
*extent)
assert(lastpgnum >= 1);
/* Mark each page as free in the page map. */
- for (n = 0, freepage = __shref(base, extent->membase);
- n < lastpgnum; n++, freepage += HOBJ_PAGE_SIZE) {
- *((memoff_t *)freepage) = __shoff(base, freepage) +
HOBJ_PAGE_SIZE;
+ for (n = 0; n <= lastpgnum; n++) {
extent->pagemap[n].type = page_free;
extent->pagemap[n].bcount = 0;
}
- *((memoff_t *)freepage) = 0;
- extent->pagemap[lastpgnum].type = page_free;
- extent->pagemap[lastpgnum].bcount = 0;
-
- /* The first page starts the free list of a new extent. */
- extent->freelist = extent->membase;
+ /* Clear the allocation bitmap. */
+ p = __shref(base, extent->bitmap);
+ memset(p, 0, extent->bitwords * sizeof(uint32_t));
+ /*
+ * Mark the unused trailing bits (due to alignment) as busy,
+ * we don't want to pick them since they don't map any actual
+ * memory from the page pool.
+ */
+ p[lastpgnum / 32] |= ~(-1U >> (31 - (lastpgnum & 31)));
}
static int init_heap(struct shared_heap *heap, void *base,
@@ -168,7 +177,9 @@ static int init_heap(struct shared_heap *heap, void *base,
{
struct shared_extent *extent;
pthread_mutexattr_t mattr;
- int ret;
+ int ret, bmapwords;
+ memoff_t bmapoff;
+ size_t metasz;
namecpy(heap->name, name);
@@ -203,15 +214,20 @@ static int init_heap(struct shared_heap *heap, void *base,
* /...................\
* \....(page map)...../
* /...................\
+ * \.....(bitmap)....../
+ * /...................\
* +-------------------+ <= extent->membase
* | |
- * | (user memory) |
+ * | (page pool) |
* | |
* +-------------------+
* <= extent->memlim
*/
extent = mem;
- extent->membase = __shoff(base, mem) + get_pagemap_size(size);
+ metasz = get_pagemap_size(size, &bmapoff, &bmapwords);
+ extent->bitmap = __shoff(base, mem) + bmapoff;
+ extent->bitwords = bmapwords;
+ extent->membase = __shoff(base, mem) + metasz;
extent->memlim = extent->membase + size;
init_extent(base, extent);
__list_append(base, &extent->link, &heap->extents);
@@ -249,91 +265,124 @@ static int init_main_heap(struct session_heap *m_heap,
return 0;
}
+static inline void flip_page_range(uint32_t *p, int b, int nr)
+{
+ for (;;) {
+ *p ^= (1 << b);
+ if (--nr == 0)
+ return;
+ if (--b < 0) {
+ b = 31;
+ p--;
+ }
+ }
+}
+
+static int reserve_page_range(uint32_t *bitmap, int bitwords, int nrpages)
+{
+ int n, b, r, seq, beg, end;
+ uint32_t v = -1U;
+
+ for (n = 0, seq = 0; n < bitwords; n++) {
+ v = bitmap[n];
+ b = 0;
+ while (v != -1U) {
+ r = v ? __builtin_ctz(v) : 32;
+ if (r) {
+ seq += r;
+ if (seq >= nrpages) {
+ beg = n * 32 + b + r - seq;
+ end = beg + nrpages - 1;
+ flip_page_range(bitmap + end / 32,
+ end & 31, nrpages);
+ return beg;
+ }
+ } else {
+ seq = 0;
+ r = 1;
+ }
+ b += r;
+ v >>= r;
+ v |= -1U << (32 - r);
+ }
+ }
+
+ return -1;
+}
+
+static inline
+caddr_t get_page_addr(void *base,
+ struct shared_extent *extent, int pgnum)
+{
+ return __shref(base, extent->membase) + (pgnum << HOBJ_PAGE_SHIFT);
+}
+
static caddr_t get_free_range(struct shared_heap *heap, size_t bsize, int
log2size)
{
- caddr_t block, eblock, freepage, lastpage, headpage, freehead = NULL;
struct shared_extent *extent;
- size_t pnum, pcont, fcont;
void *base = main_base;
+ caddr_t block, eblock;
+ uint32_t *bitmap;
+ size_t areasz;
+ int pstart, n;
+
+ /*
+ * Scanning each extent, search for a range of contiguous
+ * pages in the extent's bitmap. The range must be at least
+ * 'bsize' long.
+ */
+ areasz =__align_to(bsize, HOBJ_PAGE_SIZE) >> HOBJ_PAGE_SHIFT;
__list_for_each_entry(base, extent, &heap->extents, link) {
- freepage = __shref_check(base, extent->freelist);
- while (freepage) {
- headpage = freepage;
- fcont = 0;
- /*
- * Search for a range of contiguous pages in
- * the free page list of the current
- * extent. The range must be 'bsize' long.
- */
- do {
- lastpage = freepage;
- freepage = __shref_check(base, *((memoff_t
*)freepage));
- fcont += HOBJ_PAGE_SIZE;
- } while (freepage == lastpage + HOBJ_PAGE_SIZE
- && fcont < bsize);
- if (fcont >= bsize) {
- /*
- * Ok, got it. Just update the free
- * page list, then proceed to the next
- * step.
- */
- if (__shoff(base, headpage) == extent->freelist)
- extent->freelist = *((memoff_t
*)lastpage);
- else
- *((memoff_t *)freehead) = *((memoff_t
*)lastpage);
-
- goto splitpage;
- }
- freehead = lastpage;
- }
+ bitmap = __shref(base, extent->bitmap);
+ pstart = reserve_page_range(bitmap, extent->bitwords, areasz);
+ if (pstart >= 0)
+ goto splitpage;
}
return NULL;
-splitpage:
-
+splitpage:
/*
- * At this point, headpage is valid and points to the first page
- * of a range of contiguous free pages larger or equal than
- * 'bsize'.
+ * pstart is the starting page number of a range of contiguous
+ * free pages larger or equal than 'bsize'.
*/
if (bsize < HOBJ_PAGE_SIZE) {
/*
- * If the allocation size is smaller than the standard page
- * size, split the page in smaller blocks of this size,
- * building a free list of free blocks.
+ * If the allocation size is smaller than the internal
+ * page size, split the page in smaller blocks of this
+ * size, building a free list of bucketed free blocks.
*/
- for (block = headpage, eblock =
- headpage + HOBJ_PAGE_SIZE - bsize; block < eblock;
- block += bsize)
+ for (block = get_page_addr(base, extent, pstart),
+ eblock = block + HOBJ_PAGE_SIZE - bsize;
+ block < eblock; block += bsize)
*((memoff_t *)block) = __shoff(base, block) + bsize;
*((memoff_t *)eblock) = 0;
- } else
- *((memoff_t *)headpage) = 0;
-
- pnum = (__shoff(base, headpage) - extent->membase) >> HOBJ_PAGE_SHIFT;
+ }
/*
* Update the page map. If log2size is non-zero (i.e. bsize
- * <= 2 * PAGESIZE), store it in the first page's slot to
- * record the exact block size (which is a power of
- * two). Otherwise, store the special marker page_list,
- * indicating the start of a block whose size is a multiple of
- * the standard page size, but not necessarily a power of two.
- * In any case, the following pages slots are marked as
- * 'continued' (page_cont).
+ * <= 2 * PAGESIZE), store it in the slot heading the page
+ * range to record the exact block size (which is a power of
+ * two).
+ *
+ * Otherwise, store the special marker page_list, indicating
+ * the start of a block which size is a multiple of the
+ * standard page size, but not necessarily a power of two.
+ *
+ * Page slots following the heading one bear the page_cont
+ * marker.
*/
- extent->pagemap[pnum].type = log2size ?: page_list;
- extent->pagemap[pnum].bcount = 1;
+ extent->pagemap[pstart].type = log2size ?: page_list;
+ extent->pagemap[pstart].bcount = 1;
- for (pcont = bsize >> HOBJ_PAGE_SHIFT; pcont > 1; pcont--) {
- extent->pagemap[pnum + pcont - 1].type = page_cont;
- extent->pagemap[pnum + pcont - 1].bcount = 0;
+ for (n = bsize >> HOBJ_PAGE_SHIFT; n > 1; n--) {
+ extent->pagemap[pstart + n - 1].type = page_cont;
+ extent->pagemap[pstart + n - 1].bcount = 0;
}
- return headpage;
+ return get_page_addr(base, extent, pstart);
}
static inline size_t __attribute__ ((always_inline))
@@ -353,8 +402,8 @@ static void *alloc_block(struct shared_heap *heap, size_t
size)
{
struct shared_extent *extent;
void *base = main_base;
+ size_t pgnum, bsize;
int log2size, ilog;
- size_t pnum, bsize;
caddr_t block;
if (size == 0)
@@ -362,22 +411,20 @@ static void *alloc_block(struct shared_heap *heap, size_t
size)
size = align_alloc_size(size);
/*
- * It becomes more space efficient to directly allocate pages from
- * the free page list whenever the requested size is greater than
- * 2 times the page size. Otherwise, use the bucketed memory
- * blocks.
+ * It becomes more space efficient to directly allocate pages
+ * from the free page pool whenever the requested size is
+ * greater than 2 times the page size. Otherwise, use the
+ * bucketed memory blocks.
*/
if (size <= HOBJ_PAGE_SIZE * 2) {
- /*
- * Find the first power of two greater or equal to the
- * rounded size. The log2 value of this size is also
- * computed.
- */
- for (bsize = (1 << HOBJ_MINLOG2), log2size = HOBJ_MINLOG2;
- bsize < size; bsize <<= 1, log2size++)
- ; /* Loop */
-
+ /* Find log2(size). */
+ log2size = 63 - __builtin_clzll(size);
+ if (size & (size - 1))
+ log2size++;
+ /* That is the actual block size we need. */
+ bsize = 1 << log2size;
ilog = log2size - HOBJ_MINLOG2;
+ assert(ilog < HOBJ_NBUCKETS);
write_lock_nocancel(&heap->lock);
@@ -400,8 +447,8 @@ static void *alloc_block(struct shared_heap *heap, size_t
size)
}
assert(0);
found:
- pnum = (__shoff(base, block) - extent->membase) >>
HOBJ_PAGE_SHIFT;
- ++extent->pagemap[pnum].bcount;
+ pgnum = (__shoff(base, block) - extent->membase) >>
HOBJ_PAGE_SHIFT;
+ ++extent->pagemap[pgnum].bcount;
}
heap->buckets[ilog].freelist = *((memoff_t *)block);
@@ -425,12 +472,14 @@ done:
static int free_block(struct shared_heap *heap, void *block)
{
- int log2size, ret = 0, nblocks, xpage, ilog, pagenr, maxpages;
- caddr_t freepage, lastpage, nextpage, tailpage, freeptr;
- size_t pnum, pcont, boffset, bsize;
+ int log2size, ret = 0, nblocks, xpage, ilog, pagenr,
+ maxpages, pghead, pgtail, n;
struct shared_extent *extent;
+ memoff_t *tailp, pgoff, boff;
+ caddr_t freep, startp, endp;
void *base = main_base;
- memoff_t *tailptr;
+ uint32_t *bitmap;
+ size_t bsize;
write_lock_nocancel(&heap->lock);
@@ -448,11 +497,11 @@ static int free_block(struct shared_heap *heap, void
*block)
goto out;
found:
/* Compute the heading page number in the page map. */
- pnum = (__shoff(base, block) - extent->membase) >> HOBJ_PAGE_SHIFT;
- boffset = (__shoff(base, block) -
- (extent->membase + (pnum << HOBJ_PAGE_SHIFT)));
+ pgoff = __shoff(base, block) - extent->membase;
+ pghead = pgoff >> HOBJ_PAGE_SHIFT;
+ boff = pgoff & ~HOBJ_PAGE_MASK;
- switch (extent->pagemap[pnum].type) {
+ switch (extent->pagemap[pghead].type) {
case page_free: /* Unallocated page? */
case page_cont: /* Not a range heading page? */
ret = -EINVAL;
@@ -462,76 +511,73 @@ found:
pagenr = 1;
maxpages = (extent->memlim - extent->membase) >>
HOBJ_PAGE_SHIFT;
while (pagenr < maxpages &&
- extent->pagemap[pnum + pagenr].type == page_cont)
+ extent->pagemap[pghead + pagenr].type == page_cont)
pagenr++;
bsize = pagenr * HOBJ_PAGE_SIZE;
- free_page_list:
- /* Link all freed pages in a single sub-list. */
- for (freepage = (caddr_t)block,
- tailpage = (caddr_t)block + bsize - HOBJ_PAGE_SIZE;
- freepage < tailpage; freepage += HOBJ_PAGE_SIZE)
- *((memoff_t *)freepage) = __shoff(base, freepage) +
HOBJ_PAGE_SIZE;
-
free_pages:
/* Mark the released pages as free in the extent's page map. */
- for (pcont = 0; pcont < pagenr; pcont++)
- extent->pagemap[pnum + pcont].type = page_free;
+ for (n = 0; n < pagenr; n++)
+ extent->pagemap[pghead + n].type = page_free;
+
+ /* Likewise for the allocation bitmap. */
+ bitmap = __shref(base, extent->bitmap);
+ pgtail = pghead + pagenr - 1;
/*
- * Return the sub-list to the free page list, keeping
- * an increasing address order to favor coalescence.
+ * Mark the released page(s) as free in the
+ * bitmap. Caution: this is a reverse scan from the
+ * end of the bitfield mapping the area.
*/
- for (nextpage = __shref_check(base, extent->freelist), lastpage
= NULL;
- nextpage && nextpage < (caddr_t)block;
- lastpage = nextpage, nextpage = __shref_check(base,
*((memoff_t *)nextpage)))
- ; /* Loop */
-
- *((memoff_t *)tailpage) = __shoff_check(base, nextpage);
- if (lastpage)
- *((memoff_t *)lastpage) = __shoff(base, block);
- else
- extent->freelist = __shoff(base, block);
+ flip_page_range(bitmap + pgtail / 32, pgtail & 31, pagenr);
break;
default:
-
- log2size = extent->pagemap[pnum].type;
+ log2size = extent->pagemap[pghead].type;
bsize = (1 << log2size);
- if ((boffset & (bsize - 1)) != 0) { /* Not a block start? */
+ if ((boff & (bsize - 1)) != 0) { /* Not at block start? */
ret = -EINVAL;
goto out;
}
/*
- * Return the page to the free list if we've just
+ * Return the page to the free pool if we've just
* freed its last busy block. Pages from multi-page
- * blocks are always pushed to the free list (bcount
+ * blocks are always pushed to the free pool (bcount
* value for the heading page is always 1).
*/
ilog = log2size - HOBJ_MINLOG2;
- if (--extent->pagemap[pnum].bcount > 0) {
- /* Return the block to the bucketed memory space. */
+ if (--extent->pagemap[pghead].bcount > 0) {
+ /*
+ * Page is still busy after release, return
+ * the block to the free list then bail out.
+ */
*((memoff_t *)block) = heap->buckets[ilog].freelist;
heap->buckets[ilog].freelist = __shoff(base, block);
++heap->buckets[ilog].fcount;
break;
}
+ /*
+ * The page the block was sitting on is idle, return
+ * it to the pool.
+ */
pagenr = bsize >> HOBJ_PAGE_SHIFT;
+ /*
+ * In the simplest case, we only have a single block
+ * to deal with, which spans multiple consecutive
+ * pages: release it as a range of pages.
+ */
if (pagenr > 1)
- /*
- * The simplest case: we only have a single
- * block to deal with, which spans multiple
- * pages. We just need to release it as a list
- * of pages, without caring about the
- * consistency of the bucket.
- */
- goto free_page_list;
+ goto free_pages;
- freepage = __shref(base, extent->membase) + (pnum <<
HOBJ_PAGE_SHIFT);
- block = freepage;
- tailpage = freepage;
- nextpage = freepage + HOBJ_PAGE_SIZE;
+ pagenr = 1;
nblocks = HOBJ_PAGE_SIZE >> log2size;
+ /*
+ * Decrease the free bucket count by the number of
+ * blocks that the empty page we are returning to the
+ * pool may contain. The block we are releasing can't
+ * be part of the free list by definition, hence
+ * nblocks - 1.
+ */
heap->buckets[ilog].fcount -= (nblocks - 1);
assert(heap->buckets[ilog].fcount >= 0);
@@ -553,22 +599,25 @@ found:
* traversed, or we hit the end of list, whichever
* comes first.
*/
- for (tailptr = &heap->buckets[ilog].freelist,
- freeptr = __shref_check(base, *tailptr), xpage = 1;
- freeptr && nblocks > 0;
- freeptr = __shref_check(base, *((memoff_t *)freeptr))) {
- if (freeptr < freepage || freeptr >= nextpage) {
+ startp = get_page_addr(base, extent, pghead);
+ endp = startp + HOBJ_PAGE_SIZE;
+ for (tailp = &heap->buckets[ilog].freelist,
+ freep = __shref_check(base, *tailp), xpage = 1;
+ freep && nblocks > 0;
+ freep = __shref_check(base, *((memoff_t *)freep))) {
+ if (freep < startp || freep >= endp) {
if (xpage) { /* Limit random writes */
- *tailptr = __shoff(base, freeptr);
+ *tailp = __shoff(base, freep);
xpage = 0;
}
- tailptr = (memoff_t *)freeptr;
+ tailp = (memoff_t *)freep;
} else {
--nblocks;
xpage = 1;
}
}
- *tailptr = __shoff_check(base, freeptr);
+ *tailp = __shoff_check(base, freep);
+
goto free_pages;
}
@@ -581,10 +630,10 @@ out:
static size_t check_block(struct shared_heap *heap, void *block)
{
- size_t pnum, boffset, bsize, ret = 0;
+ size_t pgnum, pgoff, boff, bsize, ret = 0;
struct shared_extent *extent;
+ int ptype, maxpages, pagenr;
void *base = main_base;
- int ptype;
read_lock_nocancel(&heap->lock);
@@ -599,16 +648,25 @@ static size_t check_block(struct shared_heap *heap, void
*block)
goto out;
found:
/* Compute the heading page number in the page map. */
- pnum = (__shoff(base, block) - extent->membase) >> HOBJ_PAGE_SHIFT;
- ptype = extent->pagemap[pnum].type;
+ pgoff = __shoff(base, block) - extent->membase;
+ pgnum = pgoff >> HOBJ_PAGE_SHIFT;
+ ptype = extent->pagemap[pgnum].type;
if (ptype == page_free || ptype == page_cont)
goto out;
- bsize = (1 << ptype);
- boffset = (__shoff(base, block) -
- (extent->membase + (pnum << HOBJ_PAGE_SHIFT)));
- if ((boffset & (bsize - 1)) != 0) /* Not a block start? */
- goto out;
+ if (ptype == page_list) {
+ pagenr = 1;
+ maxpages = (extent->memlim - extent->membase) >>
HOBJ_PAGE_SHIFT;
+ while (pagenr < maxpages &&
+ extent->pagemap[pgnum + pagenr].type == page_cont)
+ pagenr++;
+ bsize = pagenr * HOBJ_PAGE_SIZE;
+ } else {
+ bsize = (1 << ptype);
+ boff = pgoff & ~HOBJ_PAGE_MASK;
+ if ((boff & (bsize - 1)) != 0) /* Not at block start? */
+ goto out;
+ }
ret = bsize;
out:
@@ -646,7 +704,7 @@ static int create_main_heap(pid_t *cnode_r)
size = HOBJ_PAGE_SIZE * 2;
len = size + sizeof(*m_heap);
- len += get_pagemap_size(size);
+ len += get_pagemap_size(size, NULL, NULL);
/*
* Bind to (and optionally create) the main session's heap:
@@ -885,7 +943,7 @@ int heapobj_init(struct heapobj *hobj, const char *name,
size_t size)
size = HOBJ_PAGE_SIZE * 2;
len = size + sizeof(*heap);
- len += get_pagemap_size(size);
+ len += get_pagemap_size(size, NULL, NULL);
/*
* Create a heap nested in the main shared heap to hold data
@@ -950,18 +1008,21 @@ int heapobj_extend(struct heapobj *hobj, size_t size,
void *unused)
{
struct shared_heap *heap = __mptr(hobj->pool_ref);
struct shared_extent *extent;
+ int state, bmapwords;
+ memoff_t bmapoff;
size_t metasz;
- int state;
if (hobj == &main_pool) /* Can't extend the main pool. */
return __bt(-EINVAL);
size = __align_to(size, HOBJ_PAGE_SIZE);
- metasz = get_pagemap_size(size);
+ metasz = get_pagemap_size(size, &bmapoff, &bmapwords);
extent = alloc_block(&main_heap.heap, size + metasz);
if (extent == NULL)
return __bt(-ENOMEM);
+ extent->bitmap = __shoff(main_base, extent) + bmapoff;
+ extent->bitwords = bmapwords;
extent->membase = __shoff(main_base, extent) + metasz;
extent->memlim = extent->membase + size;
init_extent(main_base, extent);
diff --git a/lib/copperplate/internal.h b/lib/copperplate/internal.h
index 23047b4..0d68ac9 100644
--- a/lib/copperplate/internal.h
+++ b/lib/copperplate/internal.h
@@ -38,9 +38,21 @@
#define DEFAULT_REGISTRY_ROOT NULL
#endif
-#define HOBJ_MINLOG2 3
-#define HOBJ_MAXLOG2 22 /* Must hold pagemap::bcount objects */
-#define HOBJ_NBUCKETS (HOBJ_MAXLOG2 - HOBJ_MINLOG2 + 2)
+#define HOBJ_PAGE_SHIFT 9 /* 2^9 => 512 bytes */
+#if HOBJ_PAGE_SHIFT > 21
+#error "page size is too large"
+#endif
+
+#define HOBJ_PAGE_SIZE (1UL << HOBJ_PAGE_SHIFT)
+#define HOBJ_PAGE_MASK (~(HOBJ_PAGE_SIZE-1))
+
+#define HOBJ_MINLOG2 4 /* 16 bytes */
+/* +1 for holding HOBJ_PAGE_SIZE < x <= HOBJ_PAGE_SIZE * 2 */
+#define HOBJ_MAXLOG2 (HOBJ_PAGE_SHIFT + 1)
+#define HOBJ_NBUCKETS (HOBJ_MAXLOG2 - HOBJ_MINLOG2 + 1)
+#define HOBJ_MINALIGNSZ (1U << HOBJ_MINLOG2)
+
+#define HOBJ_MAXEXTSZ (1U << 31) /* 2Gb */
/*
* The struct below has to live in shared memory; no direct reference
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