138 lines
4.8 KiB
C
138 lines
4.8 KiB
C
/* $OpenBSD: blist.h,v 1.2 2022/08/06 13:44:04 semarie Exp $ */
|
|
/* DragonFlyBSD:7b80531f545c7d3c51c1660130c71d01f6bccbe0:/sys/sys/blist.h */
|
|
/*
|
|
* Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The DragonFly Project
|
|
* by Matthew Dillon <dillon@backplane.com>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name of The DragonFly Project nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific, prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* Implements bitmap resource lists.
|
|
*
|
|
* Usage:
|
|
* blist = blist_create(blocks)
|
|
* (void) blist_destroy(blist)
|
|
* blkno = blist_alloc(blist, count)
|
|
* (void) blist_free(blist, blkno, count)
|
|
* nblks = blist_fill(blist, blkno, count)
|
|
* (void) blist_resize(&blist, count, freeextra)
|
|
*
|
|
*
|
|
* Notes:
|
|
* on creation, the entire list is marked reserved. You should
|
|
* first blist_free() the sections you want to make available
|
|
* for allocation before doing general blist_alloc()/free()
|
|
* ops.
|
|
*
|
|
* SWAPBLK_NONE is returned on failure. This module is typically
|
|
* capable of managing up to (2^31) blocks per blist, though
|
|
* the memory utilization would be insane if you actually did
|
|
* that. Managing something like 512MB worth of 4K blocks
|
|
* eats around 32 KBytes of memory.
|
|
*
|
|
* $FreeBSD: src/sys/sys/blist.h,v 1.2.2.1 2003/01/12 09:23:12 dillon Exp $
|
|
*/
|
|
|
|
#ifndef _SYS_BLIST_H_
|
|
#define _SYS_BLIST_H_
|
|
|
|
#ifndef _SYS_TYPES_H_
|
|
#include <sys/types.h>
|
|
#endif
|
|
|
|
typedef u_long swblk_t;
|
|
typedef u_int64_t u_swblk_t;
|
|
|
|
/*
|
|
* note: currently use SWAPBLK_NONE as an absolute value rather then
|
|
* a flag bit.
|
|
*/
|
|
#define SWAPBLK_NONE ((swblk_t)-1)
|
|
|
|
/*
|
|
* blmeta and bl_bitmap_t MUST be a power of 2 in size.
|
|
*/
|
|
|
|
typedef struct blmeta {
|
|
union {
|
|
swblk_t bmu_avail; /* space available under us */
|
|
u_swblk_t bmu_bitmap; /* bitmap if we are a leaf */
|
|
} u;
|
|
swblk_t bm_bighint; /* biggest contiguous block hint*/
|
|
} blmeta_t;
|
|
|
|
typedef struct blist {
|
|
swblk_t bl_blocks; /* area of coverage */
|
|
/* XXX int64_t bl_radix */
|
|
swblk_t bl_radix; /* coverage radix */
|
|
swblk_t bl_skip; /* starting skip */
|
|
swblk_t bl_free; /* number of free blocks */
|
|
blmeta_t *bl_root; /* root of radix tree */
|
|
swblk_t bl_rootblks; /* swblk_t blks allocated for tree */
|
|
} *blist_t;
|
|
|
|
#define BLIST_META_RADIX (sizeof(u_swblk_t)*8/2) /* 2 bits per */
|
|
#define BLIST_BMAP_RADIX (sizeof(u_swblk_t)*8) /* 1 bit per */
|
|
|
|
/*
|
|
* The radix may exceed the size of a 64 bit signed (or unsigned) int
|
|
* when the maximal number of blocks is allocated. With a 32-bit swblk_t
|
|
* this corresponds to ~1G x PAGE_SIZE = 4096GB. The swap code usually
|
|
* divides this by 4, leaving us with a capability of up to four 1TB swap
|
|
* devices.
|
|
*
|
|
* With a 64-bit swblk_t the limitation is some insane number.
|
|
*
|
|
* NOTE: For now I don't trust that we overflow-detect properly so we divide
|
|
* out to ensure that no overflow occurs.
|
|
*/
|
|
|
|
#if defined(_LP64)
|
|
/* swblk_t 64bits */
|
|
#define BLIST_MAXBLKS (0x4000000000000000LL / \
|
|
(BLIST_BMAP_RADIX / BLIST_META_RADIX))
|
|
#else
|
|
#define BLIST_MAXBLKS (0x40000000 / \
|
|
(BLIST_BMAP_RADIX / BLIST_META_RADIX))
|
|
#endif
|
|
|
|
#define BLIST_MAX_ALLOC BLIST_BMAP_RADIX
|
|
|
|
blist_t blist_create(swblk_t);
|
|
void blist_destroy(blist_t);
|
|
swblk_t blist_alloc(blist_t, swblk_t);
|
|
swblk_t blist_allocat(blist_t, swblk_t, swblk_t);
|
|
void blist_free(blist_t, swblk_t, swblk_t);
|
|
swblk_t blist_fill(blist_t, swblk_t, swblk_t);
|
|
void blist_print(blist_t);
|
|
void blist_resize(blist_t *, swblk_t, int);
|
|
void blist_gapfind(blist_t, swblk_t *, swblk_t *);
|
|
|
|
#endif /* _SYS_BLIST_H_ */
|