9e2e6a2980
Black nodes support standard active pages and red nodes support cached pages. Red nodes may be removed without the object lock but will not collapse unused tree nodes. Red nodes may not be directly inserted, instead a new function is supplied to convert between black and red. - Handle cached pages and active pages in the same loop in vm_object_split, vm_object_backing_scan, and vm_object_terminate. - Retire the splay page handling as the ifdefs are too difficult to maintain. - Slightly optimize the vm_radix_lookupn() function.
98 lines
3.6 KiB
C
98 lines
3.6 KiB
C
/*
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* Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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#ifndef _VM_RADIX_H_
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#define _VM_RADIX_H_
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#include <sys/queue.h>
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/* Default values of the tree parameters */
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#define VM_RADIX_WIDTH 5
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#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH)
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#define VM_RADIX_MASK (VM_RADIX_COUNT - 1)
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#define VM_RADIX_LIMIT howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH)
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#define VM_RADIX_FLAGS 0x3 /* Flag bits stored in node pointers. */
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#define VM_RADIX_BLACK 0x1 /* Black node. (leaf only) */
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#define VM_RADIX_RED 0x2 /* Red node. (leaf only) */
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#define VM_RADIX_ANY (VM_RADIX_RED | VM_RADIX_BLACK)
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#define VM_RADIX_EMPTY 0x1 /* Empty hint. (internal only) */
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#define VM_RADIX_HEIGHT 0xf /* Bits of height in root */
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#define VM_RADIX_STACK 8 /* Nodes to store on stack. */
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CTASSERT(VM_RADIX_HEIGHT >= VM_RADIX_LIMIT);
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/* Calculates maximum value for a tree of height h. */
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#define VM_RADIX_MAX(h) \
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((h) == VM_RADIX_LIMIT ? ((vm_pindex_t)-1) : \
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(((vm_pindex_t)1 << ((h) * VM_RADIX_WIDTH)) - 1))
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struct vm_radix_node {
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void *rn_child[VM_RADIX_COUNT]; /* child nodes. */
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uint16_t rn_count; /* Valid children. */
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};
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/*
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* Radix tree root. The height and pointer are set together to permit
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* coherent lookups while the root is modified.
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*/
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struct vm_radix {
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uintptr_t rt_root; /* root + height */
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};
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void vm_radix_init(void);
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/*
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* Functions which only work with black nodes. (object lock)
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*/
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int vm_radix_insert(struct vm_radix *, vm_pindex_t, void *);
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void vm_radix_shrink(struct vm_radix *);
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/*
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* Functions which work on specified colors. (object, vm_page_queue_free locks)
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*/
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void *vm_radix_color(struct vm_radix *, vm_pindex_t, int color);
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void *vm_radix_lookup(struct vm_radix *, vm_pindex_t, int color);
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int vm_radix_lookupn(struct vm_radix *rtree, vm_pindex_t start,
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vm_pindex_t end, int color, void **out, int cnt, vm_pindex_t *next);
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void *vm_radix_lookup_le(struct vm_radix *, vm_pindex_t, int color);
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void *vm_radix_remove(struct vm_radix *, vm_pindex_t, int color);
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/*
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* Look up any entry at a position greater or equal to index.
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*/
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static inline void *
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vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index, int color)
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{
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void *val;
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if (vm_radix_lookupn(rtree, index, 0, color, &val, 1, &index))
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return (val);
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return (NULL);
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}
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#endif /* !_VM_RADIX_H_ */
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