* are covered by the BSD Copyright as found in /usr/src/COPYRIGHT.
*
* This module implements a general bitmap allocator/deallocator. The
- * allocator eats around 2 bits per 'block'. The module does not
- * try to interpret the meaning of a 'block' other then to return
+ * allocator eats around 2 bits per 'block'. The module does not
+ * try to interpret the meaning of a 'block' other then to return
* SWAPBLK_NONE on an allocation failure.
*
* A radix tree is used to maintain the bitmap. Two radix constants are
* 32), and one for the meta nodes (typically 16). Both meta and leaf
* nodes have a hint field. This field gives us a hint as to the largest
* free contiguous range of blocks under the node. It may contain a
- * value that is too high, but will never contain a value that is too
+ * value that is too high, but will never contain a value that is too
* low. When the radix tree is searched, allocation failures in subtrees
- * update the hint.
+ * update the hint.
*
* The radix tree also implements two collapsed states for meta nodes:
* the ALL-ALLOCATED state and the ALL-FREE state. If a meta node is
* the node is considered stale. These states are used to optimize
* allocation and freeing operations.
*
- * The hinting greatly increases code efficiency for allocations while
+ * The hinting greatly increases code efficiency for allocations while
* the general radix structure optimizes both allocations and frees. The
- * radix tree should be able to operate well no matter how much
+ * radix tree should be able to operate well no matter how much
* fragmentation there is and no matter how large a bitmap is used.
*
* Unlike the rlist code, the blist code wires all necessary memory at
* creation time. Neither allocations nor frees require interaction with
- * the memory subsystem. In contrast, the rlist code may allocate memory
+ * the memory subsystem. In contrast, the rlist code may allocate memory
* on an rlist_free() call. The non-blocking features of the blist code
* are used to great advantage in the swap code (vm/nswap_pager.c). The
* rlist code uses a little less overall memory then the blist code (but
- * due to swap interleaving not all that much less), but the blist code
+ * due to swap interleaving not all that much less), but the blist code
* scales much, much better.
*
* LAYOUT: The radix tree is layed out recursively using a
* linear array. Each meta node is immediately followed (layed out
* sequentially in memory) by BLIST_META_RADIX lower level nodes. This
* is a recursive structure but one that can be easily scanned through
- * a very simple 'skip' calculation. In order to support large radixes,
- * portions of the tree may reside outside our memory allocation. We
- * handle this with an early-termination optimization (when bighint is
- * set to -1) on the scan. The memory allocation is only large enough
+ * a very simple 'skip' calculation. In order to support large radixes,
+ * portions of the tree may reside outside our memory allocation. We
+ * handle this with an early-termination optimization (when bighint is
+ * set to -1) on the scan. The memory allocation is only large enough
* to cover the number of blocks requested at creation time even if it
* must be encompassed in larger root-node radix.
*
- * NOTE: the allocator cannot currently allocate more then
- * BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too
- * large' if you try. This is an area that could use improvement. The
- * radix is large enough that this restriction does not effect the swap
+ * NOTE: the allocator cannot currently allocate more then
+ * BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too
+ * large' if you try. This is an area that could use improvement. The
+ * radix is large enough that this restriction does not effect the swap
* system, though. Currently only the allocation code is effected by
* this algorithmic unfeature. The freeing code can handle arbitrary
* ranges.
* $FreeBSD: src/sys/kern/subr_blist.c,v 1.5.2.1 2000/03/17 10:47:29 ps Exp $
*/
-#if !defined(__APPLE__)
-#ifdef _KERNEL
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/lock.h>
-#include <sys/kernel.h>
-#include <sys/blist.h>
-#include <sys/malloc.h>
-#include <vm/vm.h>
-#include <vm/vm_object.h>
-#include <vm/vm_kern.h>
-#include <vm/vm_extern.h>
-#include <vm/vm_page.h>
-
-#else
-
-#ifndef BLIST_NO_DEBUG
-#define BLIST_DEBUG
-#endif
-
-#define SWAPBLK_NONE ((daddr_t)-1)
-
-#include <sys/types.h>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdarg.h>
-
-#define malloc(a,b,c) malloc(a)
-#define free(a,b) free(a)
-
-typedef unsigned int u_daddr_t;
-
-#include <sys/blist.h>
-
-void panic(const char *ctl, ...);
-
-#endif
-#else /* is MacOS X */
-#ifdef KERNEL
-#ifndef _KERNEL
-#define _KERNEL /* Solaris vs. Darwin */
-#endif
-#endif
-
typedef unsigned int u_daddr_t;
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/kernel.h>
-/* #include <sys/blist.h> */
#include "blist.h"
#include <sys/malloc.h>
#define free _FREE
#define M_SWAP M_TEMP
-#endif /* __APPLE__ */
-
/*
* static support functions
*/
static daddr_t blst_leaf_alloc(blmeta_t *scan, daddr_t blk, int count);
-static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk,
- daddr_t count, daddr_t radix, int skip);
+static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk,
+ daddr_t count, daddr_t radix, int skip);
static void blst_leaf_free(blmeta_t *scan, daddr_t relblk, int count);
-static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count,
- daddr_t radix, int skip, daddr_t blk);
-static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
- daddr_t skip, blist_t dest, daddr_t count);
-static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix,
- int skip, daddr_t count);
-#ifndef _KERNEL
-static void blst_radix_print(blmeta_t *scan, daddr_t blk,
- daddr_t radix, int skip, int tab);
-#endif
-
-#if !defined(__APPLE__)
-#ifdef _KERNEL
-static MALLOC_DEFINE(M_SWAP, "SWAP", "Swap space");
-#endif
-#endif /* __APPLE__ */
+static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count,
+ daddr_t radix, int skip, daddr_t blk);
+static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
+ daddr_t skip, blist_t dest, daddr_t count);
+static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix,
+ int skip, daddr_t count);
/*
* blist_create() - create a blist capable of handling up to the specified
*
* blocks must be greater then 0
*
- * The smallest blist consists of a single leaf node capable of
+ * The smallest blist consists of a single leaf node capable of
* managing BLIST_BMAP_RADIX blocks.
*/
-blist_t
+blist_t
blist_create(daddr_t blocks)
{
blist_t bl;
bl->bl_blocks,
bl->bl_blocks * 4 / 1024,
(bl->bl_rootblks * sizeof(blmeta_t) + 1023) / 1024
- );
+ );
printf("BLIST raw radix tree contains %d records\n", bl->bl_rootblks);
#endif
blst_radix_init(bl->bl_root, bl->bl_radix, bl->bl_skip, blocks);
- return(bl);
+ return bl;
}
-void
+void
blist_destroy(blist_t bl)
{
free(bl->bl_root, M_SWAP);
* not be allocated.
*/
-daddr_t
+daddr_t
blist_alloc(blist_t bl, daddr_t count)
{
daddr_t blk = SWAPBLK_NONE;
if (bl) {
- if (bl->bl_radix == BLIST_BMAP_RADIX)
+ if (bl->bl_radix == BLIST_BMAP_RADIX) {
blk = blst_leaf_alloc(bl->bl_root, 0, count);
- else
+ } else {
blk = blst_meta_alloc(bl->bl_root, 0, count,
- bl->bl_radix, bl->bl_skip);
- if (blk != SWAPBLK_NONE)
+ bl->bl_radix, bl->bl_skip);
+ }
+ if (blk != SWAPBLK_NONE) {
bl->bl_free -= count;
+ }
}
- return(blk);
+ return blk;
}
/*
* blist_free() - free up space in the block bitmap. Return the base
- * of a contiguous region. Panic if an inconsistancy is
+ * of a contiguous region. Panic if an inconsistancy is
* found.
*/
-void
+void
blist_free(blist_t bl, daddr_t blkno, daddr_t count)
{
if (bl) {
- if (bl->bl_radix == BLIST_BMAP_RADIX)
+ if (bl->bl_radix == BLIST_BMAP_RADIX) {
blst_leaf_free(bl->bl_root, blkno, count);
- else
+ } else {
blst_meta_free(bl->bl_root, blkno, count,
- bl->bl_radix, bl->bl_skip, 0);
+ bl->bl_radix, bl->bl_skip, 0);
+ }
bl->bl_free += count;
}
}
void
blist_resize(blist_t *pbl, daddr_t count, int freenew)
{
- blist_t newbl = blist_create(count);
- blist_t save = *pbl;
-
- *pbl = newbl;
- if (count > save->bl_blocks)
- count = save->bl_blocks;
- blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count);
-
- /*
- * If resizing upwards, should we free the new space or not?
- */
- if (freenew && count < newbl->bl_blocks)
- blist_free(newbl, count, newbl->bl_blocks - count);
- blist_destroy(save);
+ blist_t newbl = blist_create(count);
+ blist_t save = *pbl;
+
+ *pbl = newbl;
+ if (count > save->bl_blocks) {
+ count = save->bl_blocks;
+ }
+ blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count);
+
+ /*
+ * If resizing upwards, should we free the new space or not?
+ */
+ if (freenew && count < newbl->bl_blocks) {
+ blist_free(newbl, count, newbl->bl_blocks - count);
+ }
+ blist_destroy(save);
}
#ifdef BLIST_DEBUG
* ALLOCATION SUPPORT FUNCTIONS *
************************************************************************
*
- * These support functions do all the actual work. They may seem
+ * These support functions do all the actual work. They may seem
* rather longish, but that's because I've commented them up. The
* actual code is straight forward.
*
* we have to take care of this case here.
*/
scan->bm_bighint = 0;
- return(SWAPBLK_NONE);
+ return SWAPBLK_NONE;
}
if (count == 1) {
/*
* Optimized code to allocate one bit out of the bitmap
*/
u_daddr_t mask;
- int j = BLIST_BMAP_RADIX/2;
+ int j = BLIST_BMAP_RADIX / 2;
int r = 0;
- mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX/2);
+ mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX / 2);
while (j) {
if ((orig & mask) == 0) {
- r += j;
- orig >>= j;
+ r += j;
+ orig >>= j;
}
j >>= 1;
mask >>= j;
}
scan->u.bmu_bitmap &= ~(1 << r);
- return(blk + r);
+ return blk + r;
}
#if !defined(__APPLE__)
if (count <= BLIST_BMAP_RADIX) {
for (j = 0; j <= n; ++j) {
if ((orig & mask) == mask) {
scan->u.bmu_bitmap &= ~mask;
- return(blk + j);
+ return blk + j;
}
mask = (mask << 1);
}
* We couldn't allocate count in this subtree, update bighint.
*/
scan->bm_bighint = count - 1;
- return(SWAPBLK_NONE);
+ return SWAPBLK_NONE;
}
/*
static daddr_t
blst_meta_alloc(blmeta_t *scan, daddr_t blk, daddr_t count, daddr_t radix,
- int skip)
+ int skip)
{
int i;
int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
- if (scan->u.bmu_avail == 0) {
+ if (scan->u.bmu_avail == 0) {
/*
* ALL-ALLOCATED special case
*/
scan->bm_bighint = count;
- return(SWAPBLK_NONE);
+ return SWAPBLK_NONE;
}
if (scan->u.bmu_avail == radix) {
* sublevel.
*/
for (i = 1; i <= skip; i += next_skip) {
- if (scan[i].bm_bighint == (daddr_t)-1)
+ if (scan[i].bm_bighint == (daddr_t)-1) {
break;
+ }
if (next_skip == 1) {
scan[i].u.bmu_bitmap = (u_daddr_t)-1;
scan[i].bm_bighint = BLIST_BMAP_RADIX;
* count fits in object
*/
daddr_t r;
- if (next_skip == 1)
+ if (next_skip == 1) {
r = blst_leaf_alloc(&scan[i], blk, count);
- else
+ } else {
r = blst_meta_alloc(&scan[i], blk, count,
- radix, next_skip - 1);
+ radix, next_skip - 1);
+ }
if (r != SWAPBLK_NONE) {
scan->u.bmu_avail -= count;
- if (scan->bm_bighint > scan->u.bmu_avail)
+ if (scan->bm_bighint > scan->u.bmu_avail) {
scan->bm_bighint = scan->u.bmu_avail;
+ }
return r;
}
} else if (scan[i].bm_bighint == (daddr_t)-1) {
/*
* We couldn't allocate count in this subtree, update bighint.
*/
- if (scan->bm_bighint >= count)
+ if (scan->bm_bighint >= count) {
scan->bm_bighint = count - 1;
- return(SWAPBLK_NONE);
+ }
+ return SWAPBLK_NONE;
}
/*
mask = ((u_daddr_t)-1 << n) &
((u_daddr_t)-1 >> (BLIST_BMAP_RADIX - count - n));
- if (scan->u.bmu_bitmap & mask)
+ if (scan->u.bmu_bitmap & mask) {
panic("blst_radix_free: freeing free block");
+ }
scan->u.bmu_bitmap |= mask;
/*
* We could probably do a better job here. We are required to make
- * bighint at least as large as the biggest contiguous block of
+ * bighint at least as large as the biggest contiguous block of
* data. If we just shoehorn it, a little extra overhead will
* be incured on the next allocation (but only that one typically).
*/
* range).
*/
-static void
+static void
blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count, daddr_t radix,
- int skip, daddr_t blk)
+ int skip, daddr_t blk)
{
int i;
int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
printf("FREE (%x,%d) FROM (%x,%d)\n",
freeBlk, count,
blk, radix
- );
+ );
#endif
if (scan->u.bmu_avail == 0) {
scan->u.bmu_avail = count;
scan->bm_bighint = count;
- if (count != radix) {
+ if (count != radix) {
for (i = 1; i <= skip; i += next_skip) {
- if (scan[i].bm_bighint == (daddr_t)-1)
+ if (scan[i].bm_bighint == (daddr_t)-1) {
break;
+ }
scan[i].bm_bighint = 0;
- if (next_skip == 1)
+ if (next_skip == 1) {
scan[i].u.bmu_bitmap = 0;
- else
+ } else {
scan[i].u.bmu_avail = 0;
+ }
}
/* fall through */
}
* ALL-FREE special case.
*/
- if (scan->u.bmu_avail == radix)
+ if (scan->u.bmu_avail == radix) {
return;
- if (scan->u.bmu_avail > radix)
+ }
+ if (scan->u.bmu_avail > radix) {
panic("blst_meta_free: freeing already free blocks (%d) %d/%d", count, scan->u.bmu_avail, radix);
+ }
/*
* Break the free down into its components
daddr_t v;
v = blk + radix - freeBlk;
- if (v > count)
+ if (v > count) {
v = count;
+ }
- if (scan->bm_bighint == (daddr_t)-1)
+ if (scan->bm_bighint == (daddr_t)-1) {
panic("blst_meta_free: freeing unexpected range");
+ }
- if (next_skip == 1)
+ if (next_skip == 1) {
blst_leaf_free(&scan[i], freeBlk, v);
- else
+ } else {
blst_meta_free(&scan[i], freeBlk, v, radix,
- next_skip - 1, blk);
- if (scan->bm_bighint < scan[i].bm_bighint)
- scan->bm_bighint = scan[i].bm_bighint;
+ next_skip - 1, blk);
+ }
+ if (scan->bm_bighint < scan[i].bm_bighint) {
+ scan->bm_bighint = scan[i].bm_bighint;
+ }
count -= v;
freeBlk += v;
blk += radix;
* tree. The space may not already be free in the destination.
*/
-static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
- daddr_t skip, blist_t dest, daddr_t count)
+static void
+blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
+ daddr_t skip, blist_t dest, daddr_t count)
{
int next_skip;
int i;
#if !defined(__APPLE__)
int i;
- for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i)
- if (v & (1 << i))
+ for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
+ if (v & (1 << i)) {
blist_free(dest, blk + i, 1);
+ }
+ }
#else
int j; /* Avoid shadow warnings */
- for (j = 0; j < (int)BLIST_BMAP_RADIX && j < count; ++j)
- if (v & (1 << j))
+ for (j = 0; j < (int)BLIST_BMAP_RADIX && j < count; ++j) {
+ if (v & (1 << j)) {
blist_free(dest, blk + j, 1);
+ }
+ }
#endif /* __APPLE__ */
}
return;
/*
* Source all allocated, leave dest allocated
*/
- if (scan->u.bmu_avail == 0)
+ if (scan->u.bmu_avail == 0) {
return;
+ }
if (scan->u.bmu_avail == radix) {
/*
* Source all free, free entire dest
*/
- if (count < radix)
+ if (count < radix) {
blist_free(dest, blk, count);
- else
+ } else {
blist_free(dest, blk, radix);
+ }
return;
}
next_skip = (skip >> BLIST_META_RADIX_SHIFT);
for (i = 1; count && i <= skip; i += next_skip) {
- if (scan[i].bm_bighint == (daddr_t)-1)
+ if (scan[i].bm_bighint == (daddr_t)-1) {
break;
+ }
if (count >= radix) {
blst_copy(
- &scan[i],
- blk,
- radix,
- next_skip - 1,
- dest,
- radix
- );
+ &scan[i],
+ blk,
+ radix,
+ next_skip - 1,
+ dest,
+ radix
+ );
count -= radix;
} else {
if (count) {
blst_copy(
- &scan[i],
- blk,
- radix,
- next_skip - 1,
- dest,
- count
- );
+ &scan[i],
+ blk,
+ radix,
+ next_skip - 1,
+ dest,
+ count
+ );
}
count = 0;
}
* RADIX values we use.
*/
-static daddr_t
+static daddr_t
blst_radix_init(blmeta_t *scan, daddr_t radix, int skip, daddr_t count)
{
int i;
scan->bm_bighint = 0;
scan->u.bmu_bitmap = 0;
}
- return(memindex);
+ return memindex;
}
/*
* Allocate the entire object
*/
memindex = i + blst_radix_init(
- ((scan) ? &scan[i] : NULL),
- radix,
- next_skip - 1,
- radix
- );
+ ((scan) ? &scan[i] : NULL),
+ radix,
+ next_skip - 1,
+ radix
+ );
count -= radix;
} else if (count > 0) {
/*
* Allocate a partial object
*/
memindex = i + blst_radix_init(
- ((scan) ? &scan[i] : NULL),
- radix,
- next_skip - 1,
- count
- );
+ ((scan) ? &scan[i] : NULL),
+ radix,
+ next_skip - 1,
+ count
+ );
count = 0;
} else {
/*
* Add terminator and break out
*/
- if (scan)
+ if (scan) {
scan[i].bm_bighint = (daddr_t)-1;
+ }
break;
}
}
- if (memindex < i)
+ if (memindex < i) {
memindex = i;
- return(memindex);
+ }
+ return memindex;
}
#ifdef BLIST_DEBUG
-static void
+static void
blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int skip, int tab)
{
int i;
if (radix == BLIST_BMAP_RADIX) {
printf(
- "%*.*s(%04x,%d): bitmap %08x big=%d\n",
- tab, tab, "",
- blk, radix,
- scan->u.bmu_bitmap,
- scan->bm_bighint
- );
+ "%*.*s(%04x,%d): bitmap %08x big=%d\n",
+ tab, tab, "",
+ blk, radix,
+ scan->u.bmu_bitmap,
+ scan->bm_bighint
+ );
return;
}
if (scan->u.bmu_avail == 0) {
printf(
- "%*.*s(%04x,%d) ALL ALLOCATED\n",
- tab, tab, "",
- blk,
- radix
- );
+ "%*.*s(%04x,%d) ALL ALLOCATED\n",
+ tab, tab, "",
+ blk,
+ radix
+ );
return;
}
if (scan->u.bmu_avail == radix) {
printf(
- "%*.*s(%04x,%d) ALL FREE\n",
- tab, tab, "",
- blk,
- radix
- );
+ "%*.*s(%04x,%d) ALL FREE\n",
+ tab, tab, "",
+ blk,
+ radix
+ );
return;
}
printf(
- "%*.*s(%04x,%d): subtree (%d/%d) big=%d {\n",
- tab, tab, "",
- blk, radix,
- scan->u.bmu_avail,
- radix,
- scan->bm_bighint
- );
+ "%*.*s(%04x,%d): subtree (%d/%d) big=%d {\n",
+ tab, tab, "",
+ blk, radix,
+ scan->u.bmu_avail,
+ radix,
+ scan->bm_bighint
+ );
radix >>= BLIST_META_RADIX_SHIFT;
next_skip = (skip >> BLIST_META_RADIX_SHIFT);
for (i = 1; i <= skip; i += next_skip) {
if (scan[i].bm_bighint == (daddr_t)-1) {
printf(
- "%*.*s(%04x,%d): Terminator\n",
- tab, tab, "",
- blk, radix
- );
+ "%*.*s(%04x,%d): Terminator\n",
+ tab, tab, "",
+ blk, radix
+ );
lastState = 0;
break;
}
blst_radix_print(
- &scan[i],
- blk,
- radix,
- next_skip - 1,
- tab
- );
+ &scan[i],
+ blk,
+ radix,
+ next_skip - 1,
+ tab
+ );
blk += radix;
}
tab -= 4;
printf(
- "%*.*s}\n",
- tab, tab, ""
- );
+ "%*.*s}\n",
+ tab, tab, ""
+ );
}
#endif
printf("%d/%d/%d> ", bl->bl_free, size, bl->bl_radix);
fflush(stdout);
- if (fgets(buf, sizeof(buf), stdin) == NULL)
+ if (fgets(buf, sizeof(buf), stdin) == NULL) {
break;
- switch(buf[0]) {
+ }
+ switch (buf[0]) {
case 'r':
if (sscanf(buf + 1, "%d", &count) == 1) {
blist_resize(&bl, count, 1);
case '?':
case 'h':
puts(
- "p -print\n"
- "a %d -allocate\n"
- "f %x %d -free\n"
- "r %d -resize\n"
- "h/? -help"
- );
+ "p -print\n"
+ "a %d -allocate\n"
+ "f %x %d -free\n"
+ "r %d -resize\n"
+ "h/? -help"
+ );
break;
default:
printf("?\n");
break;
}
}
- return(0);
+ return 0;
}
void
projects / apple / xnu.git / blobdiff