Add new blist module - radix tree based bitmap allocator with
size hinting. Will be used by the new swapper.
This commit is contained in:
parent
eedc343625
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sys
928
sys/kern/subr_blist.c
Normal file
928
sys/kern/subr_blist.c
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@ -0,0 +1,928 @@
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/*
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* BLIST.C - Bitmap allocator/deallocator, using a radix tree with hinting
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*
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* (c)Copyright 1998, Matthew Dillon. Terms for use and redistribution
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* are covered by the BSD Copyright as found in /usr/src/COPYRIGHT.
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*
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* This module implements a general bitmap allocator/deallocator. The
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* allocator eats around 2 bits per 'block'. The module does not
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* try to interpret the meaning of a 'block' other then to return
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* SWAPBLK_NONE on an allocation failure.
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*
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* A radix tree is used to maintain the bitmap. Two radix constants are
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* involved: One for the bitmaps contained in the leaf nodes (typically
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* 32), and one for the meta nodes (typically 16). Both meta and leaf
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* nodes have a hint field. This field gives us a hint as to the largest
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* free contiguous range of blocks under the node. It may contain a
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* value that is too high, but will never contain a value that is too
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* low. When the radix tree is searched, allocation failures in subtrees
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* update the hint.
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*
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* The radix tree also implements two collapsed states for meta nodes:
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* the ALL-ALLOCATED state and the ALL-FREE state. If a meta node is
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* in either of these two states, all information contained underneath
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* the node is considered stale. These states are used to optimize
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* allocation and freeing operations.
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*
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* The hinting greatly increases code efficiency for allocations while
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* the general radix structure optimizes both allocations and frees. The
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* radix tree should be able to operate well no matter how much
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* fragmentation there is and no matter how large a bitmap is used.
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*
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* Unlike the rlist code, the blist code wires all necessary memory at
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* creation time. Neither allocations nor frees require interaction with
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* the memory subsystem. In contrast, the rlist code may allocate memory
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* on an rlist_free() call. The non-blocking features of the blist code
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* are used to great advantage in the swap code (vm/nswap_pager.c). The
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* rlist code uses a little less overall memory then the blist code (but
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* due to swap interleaving not all that much less), but the blist code
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* scales much, much better.
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*
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* LAYOUT: The radix tree is layed out recursively using a
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* linear array. Each meta node is immediately followed (layed out
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* sequentially in memory) by BLIST_META_RADIX lower level nodes. This
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* is a recursive structure but one that can be easily scanned through
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* a very simple 'skip' calculation. In order to support large radixes,
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* portions of the tree may reside outside our memory allocation. We
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* handle this with an early-termination optimization (when bighint is
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* set to -1) on the scan. The memory allocation is only large enough
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* to cover the number of blocks requested at creation time even if it
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* must be encompassed in larger root-node radix.
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*
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* NOTE: the allocator cannot currently allocate more then
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* BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too
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* large' if you try. This is an area that could use improvement. The
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* radix is large enough that this restriction does not effect the swap
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* system, though. Currently only the allocation code is effected by
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* this algorithmic unfeature. The freeing code can handle arbitrary
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* ranges.
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*
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* This code can be compiled stand-alone for debugging.
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*/
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#ifdef KERNEL
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/kernel.h>
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#include <sys/blist.h>
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#include <sys/malloc.h>
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#include <vm/vm.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_page.h>
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#else
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#ifndef BLIST_NO_DEBUG
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#define BLIST_DEBUG
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#endif
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#define SWAPBLK_NONE ((daddr_t)-1)
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#include <sys/types.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#define malloc(a,b,c) malloc(a)
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#define free(a,b) free(a)
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typedef unsigned int u_daddr_t;
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#include <sys/blist.h>
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void panic(const char *ctl, ...);
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#endif
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/*
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* static support functions
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*/
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static daddr_t blst_leaf_alloc(blmeta_t *scan, daddr_t blk, int count);
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static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk,
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daddr_t count, daddr_t radix, int skip);
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static void blst_leaf_free(blmeta_t *scan, daddr_t relblk, int count);
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static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count,
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daddr_t radix, int skip, daddr_t blk);
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static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
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daddr_t skip, blist_t dest, daddr_t count);
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static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix,
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int skip, daddr_t count);
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#ifndef KERNEL
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static void blst_radix_print(blmeta_t *scan, daddr_t blk,
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daddr_t radix, int skip, int tab);
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#endif
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#ifdef KERNEL
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static MALLOC_DEFINE(M_SWAP, "SWAP", "Swap space");
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#endif
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/*
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* blist_create() - create a blist capable of handling up to the specified
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* number of blocks
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*
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* blocks must be greater then 0
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*
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* The smallest blist consists of a single leaf node capable of
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* managing BLIST_BMAP_RADIX blocks.
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*/
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blist_t
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blist_create(daddr_t blocks)
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{
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blist_t bl;
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int radix;
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int skip = 0;
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/*
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* Calculate radix and skip field used for scanning.
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*/
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radix = BLIST_BMAP_RADIX;
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while (radix < blocks) {
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radix <<= BLIST_META_RADIX_SHIFT;
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skip = (skip + 1) << BLIST_META_RADIX_SHIFT;
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}
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bl = malloc(sizeof(struct blist), M_SWAP, M_WAITOK);
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bzero(bl, sizeof(*bl));
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bl->bl_blocks = blocks;
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bl->bl_radix = radix;
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bl->bl_skip = skip;
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bl->bl_rootblks = 1 +
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blst_radix_init(NULL, bl->bl_radix, bl->bl_skip, blocks);
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bl->bl_root = malloc(sizeof(blmeta_t) * bl->bl_rootblks, M_SWAP, M_WAITOK);
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#if defined(BLIST_DEBUG)
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printf(
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"BLIST representing %d blocks (%d MB of swap)"
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", requiring %dK of ram\n",
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bl->bl_blocks,
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bl->bl_blocks * 4 / 1024,
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(bl->bl_rootblks * sizeof(blmeta_t) + 1023) / 1024
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);
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printf("BLIST raw radix tree contains %d records\n", bl->bl_rootblks);
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#endif
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blst_radix_init(bl->bl_root, bl->bl_radix, bl->bl_skip, blocks);
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return(bl);
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}
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void
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blist_destroy(blist_t bl)
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{
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free(bl->bl_root, M_SWAP);
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free(bl, M_SWAP);
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}
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/*
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* blist_alloc() - reserve space in the block bitmap. Return the base
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* of a contiguous region or SWAPBLK_NONE if space could
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* not be allocated.
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*/
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daddr_t
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blist_alloc(blist_t bl, daddr_t count)
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{
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daddr_t blk = SWAPBLK_NONE;
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if (bl) {
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if (bl->bl_radix == BLIST_BMAP_RADIX)
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blk = blst_leaf_alloc(bl->bl_root, 0, count);
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else
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blk = blst_meta_alloc(bl->bl_root, 0, count, bl->bl_radix, bl->bl_skip);
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if (blk != SWAPBLK_NONE)
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bl->bl_free -= count;
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}
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return(blk);
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}
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/*
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* blist_free() - free up space in the block bitmap. Return the base
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* of a contiguous region. Panic if an inconsistancy is
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* found.
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*/
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void
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blist_free(blist_t bl, daddr_t blkno, daddr_t count)
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{
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if (bl) {
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if (bl->bl_radix == BLIST_BMAP_RADIX)
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blst_leaf_free(bl->bl_root, blkno, count);
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else
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blst_meta_free(bl->bl_root, blkno, count, bl->bl_radix, bl->bl_skip, 0);
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bl->bl_free += count;
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}
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}
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/*
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* blist_resize() - resize an existing radix tree to handle the
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* specified number of blocks. This will reallocate
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* the tree and transfer the previous bitmap to the new
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* one. When extending the tree you can specify whether
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* the new blocks are to left allocated or freed.
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*/
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void
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blist_resize(blist_t *pbl, daddr_t count, int freenew)
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{
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blist_t newbl = blist_create(count);
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blist_t save = *pbl;
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*pbl = newbl;
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if (count > save->bl_blocks)
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count = save->bl_blocks;
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blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count);
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/*
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* If resizing upwards, should we free the new space or not?
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*/
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if (freenew && count < newbl->bl_blocks) {
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blist_free(newbl, count, newbl->bl_blocks - count);
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}
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blist_destroy(save);
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}
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#ifdef BLIST_DEBUG
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/*
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* blist_print() - dump radix tree
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*/
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void
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blist_print(blist_t bl)
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{
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printf("BLIST {\n");
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blst_radix_print(bl->bl_root, 0, bl->bl_radix, bl->bl_skip, 4);
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printf("}\n");
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}
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#endif
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/************************************************************************
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* ALLOCATION SUPPORT FUNCTIONS *
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************************************************************************
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*
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* These support functions do all the actual work. They may seem
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* rather longish, but that's because I've commented them up. The
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* actual code is straight forward.
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*
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*/
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/*
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* blist_leaf_alloc() - allocate at a leaf in the radix tree (a bitmap).
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*
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* This is the core of the allocator and is optimized for the 1 block
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* and the BLIST_BMAP_RADIX block allocation cases. Other cases are
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* somewhat slower. The 1 block allocation case is log2 and extremely
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* quick.
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*/
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static daddr_t
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blst_leaf_alloc(
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blmeta_t *scan,
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daddr_t blk,
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int count
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) {
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u_daddr_t orig = scan->u.bmu_bitmap;
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if (orig == 0) {
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/*
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* Optimize bitmap all-allocated case. Also, count = 1
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* case assumes at least 1 bit is free in the bitmap, so
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* we have to take care of this case here.
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*/
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scan->bm_bighint = 0;
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return(SWAPBLK_NONE);
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}
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if (count == 1) {
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/*
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* Optimized code to allocate one bit out of the bitmap
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*/
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u_daddr_t mask;
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int j = BLIST_BMAP_RADIX/2;
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int r = 0;
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mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX/2);
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while (j) {
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if ((orig & mask) == 0) {
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r += j;
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orig >>= j;
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}
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j >>= 1;
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mask >>= j;
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}
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scan->u.bmu_bitmap &= ~(1 << r);
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return(blk + r);
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}
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if (count <= BLIST_BMAP_RADIX) {
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/*
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* non-optimized code to allocate N bits out of the bitmap.
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* The more bits, the faster the code runs. It will run
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* the slowest allocating 2 bits, but since there aren't any
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* memory ops in the core loop (or shouldn't be, anyway),
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* you probably won't notice the difference.
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*/
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int j;
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int n = BLIST_BMAP_RADIX - count;
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u_daddr_t mask;
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mask = (u_daddr_t)-1 >> n;
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for (j = 0; j <= n; ++j) {
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if ((orig & mask) == mask) {
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scan->u.bmu_bitmap &= ~mask;
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return(blk + j);
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}
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mask = (mask << 1);
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}
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}
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/*
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* We couldn't allocate count in this subtree, update bighint.
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*/
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scan->bm_bighint = count - 1;
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return(SWAPBLK_NONE);
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}
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/*
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* blist_meta_alloc() - allocate at a meta in the radix tree.
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*
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* Attempt to allocate at a meta node. If we can't, we update
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* bighint and return a failure. Updating bighint optimize future
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* calls that hit this node. We have to check for our collapse cases
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* and we have a few optimizations strewn in as well.
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*/
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static daddr_t
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blst_meta_alloc(
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blmeta_t *scan,
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daddr_t blk,
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daddr_t count,
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daddr_t radix,
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int skip
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) {
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int i;
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int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
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if (scan->u.bmu_avail == 0) {
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/*
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* ALL-ALLOCATED special case
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*/
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scan->bm_bighint = count;
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return(SWAPBLK_NONE);
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}
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if (scan->u.bmu_avail == radix) {
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radix >>= BLIST_META_RADIX_SHIFT;
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/*
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* ALL-FREE special case, initialize uninitialize
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* sublevel.
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*/
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for (i = 1; i <= skip; i += next_skip) {
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if (scan[i].bm_bighint == (daddr_t)-1)
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break;
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if (next_skip == 1) {
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scan[i].u.bmu_bitmap = (u_daddr_t)-1;
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scan[i].bm_bighint = BLIST_BMAP_RADIX;
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} else {
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scan[i].bm_bighint = radix;
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scan[i].u.bmu_avail = radix;
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}
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}
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} else {
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radix >>= BLIST_META_RADIX_SHIFT;
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}
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for (i = 1; i <= skip; i += next_skip) {
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if (count <= scan[i].bm_bighint) {
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/*
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* count fits in object
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*/
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daddr_t r;
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if (next_skip == 1) {
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r = blst_leaf_alloc(&scan[i], blk, count);
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} else {
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r = blst_meta_alloc(&scan[i], blk, count, radix, next_skip - 1);
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}
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if (r != SWAPBLK_NONE) {
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scan->u.bmu_avail -= count;
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if (scan->bm_bighint > scan->u.bmu_avail)
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scan->bm_bighint = scan->u.bmu_avail;
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return(r);
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}
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} else if (scan[i].bm_bighint == (daddr_t)-1) {
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/*
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* Terminator
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*/
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break;
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} else if (count > radix) {
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/*
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* count does not fit in object even if it were
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* complete free.
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*/
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panic("blist_meta_alloc: allocation too large");
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}
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blk += radix;
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}
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/*
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* We couldn't allocate count in this subtree, update bighint.
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*/
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if (scan->bm_bighint >= count)
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scan->bm_bighint = count - 1;
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return(SWAPBLK_NONE);
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}
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/*
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* BLST_LEAF_FREE() - free allocated block from leaf bitmap
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*
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*/
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static void
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blst_leaf_free(
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blmeta_t *scan,
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daddr_t blk,
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int count
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) {
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/*
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* free some data in this bitmap
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*
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* e.g.
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* 0000111111111110000
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* \_________/\__/
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* v n
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*/
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int n = blk & (BLIST_BMAP_RADIX - 1);
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u_daddr_t mask;
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mask = ((u_daddr_t)-1 << n) &
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((u_daddr_t)-1 >> (BLIST_BMAP_RADIX - count - n));
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if (scan->u.bmu_bitmap & mask)
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panic("blst_radix_free: freeing free block");
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scan->u.bmu_bitmap |= mask;
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/*
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* We could probably do a better job here. We are required to make
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* 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).
|
||||
*/
|
||||
scan->bm_bighint = BLIST_BMAP_RADIX;
|
||||
}
|
||||
|
||||
/*
|
||||
* BLST_META_FREE() - free allocated blocks from radix tree meta info
|
||||
*
|
||||
* This support routine frees a range of blocks from the bitmap.
|
||||
* The range must be entirely enclosed by this radix node. If a
|
||||
* meta node, we break the range down recursively to free blocks
|
||||
* in subnodes (which means that this code can free an arbitrary
|
||||
* range whereas the allocation code cannot allocate an arbitrary
|
||||
* range).
|
||||
*/
|
||||
|
||||
static void
|
||||
blst_meta_free(
|
||||
blmeta_t *scan,
|
||||
daddr_t freeBlk,
|
||||
daddr_t count,
|
||||
daddr_t radix,
|
||||
int skip,
|
||||
daddr_t blk
|
||||
) {
|
||||
int i;
|
||||
int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
|
||||
|
||||
#if 0
|
||||
printf("FREE (%x,%d) FROM (%x,%d)\n",
|
||||
freeBlk, count,
|
||||
blk, radix
|
||||
);
|
||||
#endif
|
||||
|
||||
if (scan->u.bmu_avail == 0) {
|
||||
/*
|
||||
* ALL-ALLOCATED special case, with possible
|
||||
* shortcut to ALL-FREE special case.
|
||||
*/
|
||||
scan->u.bmu_avail = count;
|
||||
scan->bm_bighint = count;
|
||||
|
||||
if (count != radix) {
|
||||
for (i = 1; i <= skip; i += next_skip) {
|
||||
if (scan[i].bm_bighint == (daddr_t)-1)
|
||||
break;
|
||||
scan[i].bm_bighint = 0;
|
||||
if (next_skip == 1) {
|
||||
scan[i].u.bmu_bitmap = 0;
|
||||
} else {
|
||||
scan[i].u.bmu_avail = 0;
|
||||
}
|
||||
}
|
||||
/* fall through */
|
||||
}
|
||||
} else {
|
||||
scan->u.bmu_avail += count;
|
||||
/* scan->bm_bighint = radix; */
|
||||
}
|
||||
|
||||
/*
|
||||
* ALL-FREE special case.
|
||||
*/
|
||||
|
||||
if (scan->u.bmu_avail == radix)
|
||||
return;
|
||||
#if !defined(MAX_PERF)
|
||||
if (scan->u.bmu_avail > radix)
|
||||
panic("blst_meta_free: freeing already free blocks (%d) %d/%d", count, scan->u.bmu_avail, radix);
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Break the free down into its components
|
||||
*/
|
||||
|
||||
radix >>= BLIST_META_RADIX_SHIFT;
|
||||
|
||||
i = (freeBlk - blk) / radix;
|
||||
blk += i * radix;
|
||||
i = i * next_skip + 1;
|
||||
|
||||
while (i <= skip && blk < freeBlk + count) {
|
||||
daddr_t v;
|
||||
|
||||
v = blk + radix - freeBlk;
|
||||
if (v > count)
|
||||
v = count;
|
||||
|
||||
if (scan->bm_bighint == (daddr_t)-1)
|
||||
panic("blst_meta_free: freeing unexpected range");
|
||||
|
||||
if (next_skip == 1) {
|
||||
blst_leaf_free(&scan[i], freeBlk, v);
|
||||
} 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;
|
||||
count -= v;
|
||||
freeBlk += v;
|
||||
blk += radix;
|
||||
i += next_skip;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* BLIST_RADIX_COPY() - copy one radix tree to another
|
||||
*
|
||||
* Locates free space in the source tree and frees it in the destination
|
||||
* 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
|
||||
) {
|
||||
int next_skip;
|
||||
int i;
|
||||
|
||||
/*
|
||||
* Leaf node
|
||||
*/
|
||||
|
||||
if (radix == BLIST_BMAP_RADIX) {
|
||||
u_daddr_t v = scan->u.bmu_bitmap;
|
||||
|
||||
if (v == (u_daddr_t)-1) {
|
||||
blist_free(dest, blk, count);
|
||||
} else if (v != 0) {
|
||||
int i;
|
||||
|
||||
for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
|
||||
if (v & (1 << i))
|
||||
blist_free(dest, blk + i, 1);
|
||||
}
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Meta node
|
||||
*/
|
||||
|
||||
if (scan->u.bmu_avail == 0) {
|
||||
/*
|
||||
* Source all allocated, leave dest allocated
|
||||
*/
|
||||
return;
|
||||
}
|
||||
if (scan->u.bmu_avail == radix) {
|
||||
/*
|
||||
* Source all free, free entire dest
|
||||
*/
|
||||
if (count < radix)
|
||||
blist_free(dest, blk, count);
|
||||
else
|
||||
blist_free(dest, blk, radix);
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
radix >>= BLIST_META_RADIX_SHIFT;
|
||||
next_skip = (skip >> BLIST_META_RADIX_SHIFT);
|
||||
|
||||
for (i = 1; count && i <= skip; i += next_skip) {
|
||||
if (scan[i].bm_bighint == (daddr_t)-1)
|
||||
break;
|
||||
|
||||
if (count >= radix) {
|
||||
blst_copy(
|
||||
&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
|
||||
);
|
||||
}
|
||||
count = 0;
|
||||
}
|
||||
blk += radix;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* BLST_RADIX_INIT() - initialize radix tree
|
||||
*
|
||||
* Initialize our meta structures and bitmaps and calculate the exact
|
||||
* amount of space required to manage 'count' blocks - this space may
|
||||
* be considerably less then the calculated radix due to the large
|
||||
* RADIX values we use.
|
||||
*/
|
||||
|
||||
static daddr_t
|
||||
blst_radix_init(blmeta_t *scan, daddr_t radix, int skip, daddr_t count)
|
||||
{
|
||||
int i;
|
||||
int next_skip;
|
||||
daddr_t memindex = 0;
|
||||
|
||||
/*
|
||||
* Leaf node
|
||||
*/
|
||||
|
||||
if (radix == BLIST_BMAP_RADIX) {
|
||||
if (scan) {
|
||||
scan->bm_bighint = 0;
|
||||
scan->u.bmu_bitmap = 0;
|
||||
}
|
||||
return(memindex);
|
||||
}
|
||||
|
||||
/*
|
||||
* Meta node. If allocating the entire object we can special
|
||||
* case it. However, we need to figure out how much memory
|
||||
* is required to manage 'count' blocks, so we continue on anyway.
|
||||
*/
|
||||
|
||||
if (scan) {
|
||||
scan->bm_bighint = 0;
|
||||
scan->u.bmu_avail = 0;
|
||||
}
|
||||
|
||||
radix >>= BLIST_META_RADIX_SHIFT;
|
||||
next_skip = (skip >> BLIST_META_RADIX_SHIFT);
|
||||
|
||||
for (i = 1; i <= skip; i += next_skip) {
|
||||
if (count >= radix) {
|
||||
/*
|
||||
* Allocate the entire object
|
||||
*/
|
||||
memindex = i + blst_radix_init(
|
||||
((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
|
||||
);
|
||||
count = 0;
|
||||
} else {
|
||||
/*
|
||||
* Add terminator and break out
|
||||
*/
|
||||
if (scan)
|
||||
scan[i].bm_bighint = (daddr_t)-1;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (memindex < i)
|
||||
memindex = i;
|
||||
return(memindex);
|
||||
}
|
||||
|
||||
#ifdef BLIST_DEBUG
|
||||
|
||||
static void
|
||||
blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int skip, int tab)
|
||||
{
|
||||
int i;
|
||||
int next_skip;
|
||||
int lastState = 0;
|
||||
|
||||
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
|
||||
);
|
||||
return;
|
||||
}
|
||||
|
||||
if (scan->u.bmu_avail == 0) {
|
||||
printf(
|
||||
"%*.*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
|
||||
);
|
||||
return;
|
||||
}
|
||||
|
||||
printf(
|
||||
"%*.*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);
|
||||
tab += 4;
|
||||
|
||||
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
|
||||
);
|
||||
lastState = 0;
|
||||
break;
|
||||
}
|
||||
blst_radix_print(
|
||||
&scan[i],
|
||||
blk,
|
||||
radix,
|
||||
next_skip - 1,
|
||||
tab
|
||||
);
|
||||
blk += radix;
|
||||
}
|
||||
tab -= 4;
|
||||
|
||||
printf(
|
||||
"%*.*s}\n",
|
||||
tab, tab, ""
|
||||
);
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
#ifdef BLIST_DEBUG
|
||||
|
||||
int
|
||||
main(int ac, char **av)
|
||||
{
|
||||
int size = 1024;
|
||||
int i;
|
||||
blist_t bl;
|
||||
|
||||
for (i = 1; i < ac; ++i) {
|
||||
const char *ptr = av[i];
|
||||
if (*ptr != '-') {
|
||||
size = strtol(ptr, NULL, 0);
|
||||
continue;
|
||||
}
|
||||
ptr += 2;
|
||||
fprintf(stderr, "Bad option: %s\n", ptr - 2);
|
||||
exit(1);
|
||||
}
|
||||
bl = blist_create(size);
|
||||
blist_free(bl, 0, size);
|
||||
|
||||
for (;;) {
|
||||
char buf[1024];
|
||||
daddr_t da = 0;
|
||||
daddr_t count = 0;
|
||||
|
||||
|
||||
printf("%d/%d/%d> ", bl->bl_free, size, bl->bl_radix);
|
||||
fflush(stdout);
|
||||
if (fgets(buf, sizeof(buf), stdin) == NULL)
|
||||
break;
|
||||
switch(buf[0]) {
|
||||
case 'r':
|
||||
if (sscanf(buf + 1, "%d", &count) == 1) {
|
||||
blist_resize(&bl, count, 1);
|
||||
} else {
|
||||
printf("?\n");
|
||||
}
|
||||
case 'p':
|
||||
blist_print(bl);
|
||||
break;
|
||||
case 'a':
|
||||
if (sscanf(buf + 1, "%d", &count) == 1) {
|
||||
daddr_t blk = blist_alloc(bl, count);
|
||||
printf(" R=%04x\n", blk);
|
||||
} else {
|
||||
printf("?\n");
|
||||
}
|
||||
break;
|
||||
case 'f':
|
||||
if (sscanf(buf + 1, "%x %d", &da, &count) == 2) {
|
||||
blist_free(bl, da, count);
|
||||
} else {
|
||||
printf("?\n");
|
||||
}
|
||||
break;
|
||||
case '?':
|
||||
case 'h':
|
||||
puts(
|
||||
"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);
|
||||
}
|
||||
|
||||
void
|
||||
panic(const char *ctl, ...)
|
||||
{
|
||||
va_list va;
|
||||
|
||||
va_start(va, ctl);
|
||||
vfprintf(stderr, ctl, va);
|
||||
fprintf(stderr, "\n");
|
||||
va_end(va);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
#endif
|
||||
|
101
sys/sys/blist.h
Normal file
101
sys/sys/blist.h
Normal file
@ -0,0 +1,101 @@
|
||||
/*
|
||||
* Copyright (c) 1998 Matthew Dillon. Terms of use and redistribution in all
|
||||
* forms are covered by the BSD copyright in the file "/usr/src/COPYRIGHT".
|
||||
*
|
||||
* Implements bitmap resource lists.
|
||||
*
|
||||
* Usage:
|
||||
* blist = blist_create(blocks)
|
||||
* (void) blist_destroy(blist)
|
||||
* blkno = blist_alloc(blist, count)
|
||||
* (void) blist_free(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.
|
||||
*
|
||||
* $Id: blist.h,v Exp $
|
||||
*/
|
||||
|
||||
#ifndef _SYS_BLIST_H_
|
||||
#define _SYS_BLIST_H_
|
||||
|
||||
#define LOG2(v) (((u_daddr_t)(v) >= 0x80000000U) ? 31 : \
|
||||
((u_daddr_t)(v) >= 0x40000000U) ? 30 : \
|
||||
((u_daddr_t)(v) >= 0x20000000U) ? 29 : \
|
||||
((u_daddr_t)(v) >= 0x10000000U) ? 28 : \
|
||||
((u_daddr_t)(v) >= 0x08000000U) ? 27 : \
|
||||
((u_daddr_t)(v) >= 0x04000000U) ? 26 : \
|
||||
((u_daddr_t)(v) >= 0x02000000U) ? 25 : \
|
||||
((u_daddr_t)(v) >= 0x01000000U) ? 24 : \
|
||||
((u_daddr_t)(v) >= 0x00800000U) ? 23 : \
|
||||
((u_daddr_t)(v) >= 0x00400000U) ? 22 : \
|
||||
((u_daddr_t)(v) >= 0x00200000U) ? 21 : \
|
||||
((u_daddr_t)(v) >= 0x00100000U) ? 20 : \
|
||||
((u_daddr_t)(v) >= 0x00080000U) ? 19 : \
|
||||
((u_daddr_t)(v) >= 0x00040000U) ? 18 : \
|
||||
((u_daddr_t)(v) >= 0x00020000U) ? 17 : \
|
||||
((u_daddr_t)(v) >= 0x00010000U) ? 16 : \
|
||||
((u_daddr_t)(v) >= 0x00008000U) ? 15 : \
|
||||
((u_daddr_t)(v) >= 0x00004000U) ? 14 : \
|
||||
((u_daddr_t)(v) >= 0x00002000U) ? 13 : \
|
||||
((u_daddr_t)(v) >= 0x00001000U) ? 12 : \
|
||||
((u_daddr_t)(v) >= 0x00000800U) ? 11 : \
|
||||
((u_daddr_t)(v) >= 0x00000400U) ? 10 : \
|
||||
((u_daddr_t)(v) >= 0x00000200U) ? 9 : \
|
||||
((u_daddr_t)(v) >= 0x00000100U) ? 8 : \
|
||||
((u_daddr_t)(v) >= 0x00000080U) ? 7 : \
|
||||
((u_daddr_t)(v) >= 0x00000040U) ? 6 : \
|
||||
((u_daddr_t)(v) >= 0x00000020U) ? 5 : \
|
||||
((u_daddr_t)(v) >= 0x00000010U) ? 4 : \
|
||||
((u_daddr_t)(v) >= 0x00000008U) ? 3 : \
|
||||
((u_daddr_t)(v) >= 0x00000004U) ? 2 : \
|
||||
((u_daddr_t)(v) >= 0x00000002U) ? 1 : 0)
|
||||
|
||||
/*
|
||||
* blmeta and bl_bitmap_t MUST be a power of 2 in size.
|
||||
*/
|
||||
|
||||
typedef struct blmeta {
|
||||
union {
|
||||
daddr_t bmu_avail; /* space available under us */
|
||||
u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */
|
||||
} u;
|
||||
daddr_t bm_bighint; /* biggest contiguous block hint*/
|
||||
} blmeta_t;
|
||||
|
||||
typedef struct blist {
|
||||
daddr_t bl_blocks; /* area of coverage */
|
||||
daddr_t bl_radix; /* coverage radix */
|
||||
daddr_t bl_skip; /* starting skip */
|
||||
daddr_t bl_free; /* number of free blocks */
|
||||
blmeta_t *bl_root; /* root of radix tree */
|
||||
daddr_t bl_rootblks; /* daddr_t blks allocated for tree */
|
||||
} *blist_t;
|
||||
|
||||
#define BLIST_META_RADIX 16
|
||||
#define BLIST_META_RADIX_SHIFT LOG2(BLIST_META_RADIX)
|
||||
#define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8)
|
||||
#define BLIST_BMAP_RADIX_SHIFT LOG2(BLIST_BMAP_RADIX)
|
||||
|
||||
#define BLIST_MAX_ALLOC BLIST_BMAP_RADIX
|
||||
|
||||
extern blist_t blist_create(daddr_t blocks);
|
||||
extern void blist_destroy(blist_t blist);
|
||||
extern daddr_t blist_alloc(blist_t blist, daddr_t count);
|
||||
extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count);
|
||||
extern void blist_print(blist_t blist);
|
||||
extern void blist_resize(blist_t *pblist, daddr_t count, int freenew);
|
||||
|
||||
#endif /* _SYS_BLIST_H_ */
|
||||
|
Loading…
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Reference in New Issue
Block a user