77b94e2841
Allocation explicitely initialized the 3 leading fields. The rest is an array which is supposed to be NULL-ed prior to deallocation. Delegate zeroing to the infrequently called object initializator. This gets rid of one of the most common memset consumers. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D15989
819 lines
21 KiB
C
819 lines
21 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2013 EMC Corp.
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* Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
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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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/*
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* Path-compressed radix trie implementation.
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* The following code is not generalized into a general purpose library
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* because there are way too many parameters embedded that should really
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* be decided by the library consumers. At the same time, consumers
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* of this code must achieve highest possible performance.
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*
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* The implementation takes into account the following rationale:
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* - Size of the nodes should be as small as possible but still big enough
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* to avoid a large maximum depth for the trie. This is a balance
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* between the necessity to not wire too much physical memory for the nodes
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* and the necessity to avoid too much cache pollution during the trie
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* operations.
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* - There is not a huge bias toward the number of lookup operations over
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* the number of insert and remove operations. This basically implies
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* that optimizations supposedly helping one operation but hurting the
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* other might be carefully evaluated.
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* - On average not many nodes are expected to be fully populated, hence
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* level compression may just complicate things.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_ddb.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/vmmeter.h>
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#include <vm/uma.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_page.h>
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#include <vm/vm_radix.h>
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#ifdef DDB
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#include <ddb/ddb.h>
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#endif
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/*
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* These widths should allow the pointers to a node's children to fit within
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* a single cache line. The extra levels from a narrow width should not be
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* a problem thanks to path compression.
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*/
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#ifdef __LP64__
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#define VM_RADIX_WIDTH 4
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#else
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#define VM_RADIX_WIDTH 3
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#endif
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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 \
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(howmany(sizeof(vm_pindex_t) * NBBY, VM_RADIX_WIDTH) - 1)
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/* Flag bits stored in node pointers. */
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#define VM_RADIX_ISLEAF 0x1
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#define VM_RADIX_FLAGS 0x1
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#define VM_RADIX_PAD VM_RADIX_FLAGS
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/* Returns one unit associated with specified level. */
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#define VM_RADIX_UNITLEVEL(lev) \
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((vm_pindex_t)1 << ((lev) * VM_RADIX_WIDTH))
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struct vm_radix_node {
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vm_pindex_t rn_owner; /* Owner of record. */
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uint16_t rn_count; /* Valid children. */
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uint16_t rn_clev; /* Current level. */
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void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */
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};
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static uma_zone_t vm_radix_node_zone;
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/*
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* Allocate a radix node.
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*/
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static __inline struct vm_radix_node *
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vm_radix_node_get(vm_pindex_t owner, uint16_t count, uint16_t clevel)
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{
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struct vm_radix_node *rnode;
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rnode = uma_zalloc(vm_radix_node_zone, M_NOWAIT);
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if (rnode == NULL)
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return (NULL);
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rnode->rn_owner = owner;
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rnode->rn_count = count;
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rnode->rn_clev = clevel;
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return (rnode);
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}
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/*
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* Free radix node.
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*/
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static __inline void
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vm_radix_node_put(struct vm_radix_node *rnode)
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{
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uma_zfree(vm_radix_node_zone, rnode);
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}
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/*
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* Return the position in the array for a given level.
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*/
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static __inline int
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vm_radix_slot(vm_pindex_t index, uint16_t level)
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{
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return ((index >> (level * VM_RADIX_WIDTH)) & VM_RADIX_MASK);
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}
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/* Trims the key after the specified level. */
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static __inline vm_pindex_t
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vm_radix_trimkey(vm_pindex_t index, uint16_t level)
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{
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vm_pindex_t ret;
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ret = index;
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if (level > 0) {
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ret >>= level * VM_RADIX_WIDTH;
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ret <<= level * VM_RADIX_WIDTH;
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}
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return (ret);
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}
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/*
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* Get the root node for a radix tree.
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*/
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static __inline struct vm_radix_node *
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vm_radix_getroot(struct vm_radix *rtree)
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{
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return ((struct vm_radix_node *)rtree->rt_root);
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}
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/*
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* Set the root node for a radix tree.
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*/
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static __inline void
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vm_radix_setroot(struct vm_radix *rtree, struct vm_radix_node *rnode)
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{
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rtree->rt_root = (uintptr_t)rnode;
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}
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/*
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* Returns TRUE if the specified radix node is a leaf and FALSE otherwise.
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*/
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static __inline boolean_t
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vm_radix_isleaf(struct vm_radix_node *rnode)
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{
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return (((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0);
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}
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/*
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* Returns the associated page extracted from rnode.
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*/
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static __inline vm_page_t
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vm_radix_topage(struct vm_radix_node *rnode)
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{
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return ((vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS));
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}
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/*
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* Adds the page as a child of the provided node.
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*/
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static __inline void
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vm_radix_addpage(struct vm_radix_node *rnode, vm_pindex_t index, uint16_t clev,
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vm_page_t page)
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{
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int slot;
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slot = vm_radix_slot(index, clev);
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rnode->rn_child[slot] = (void *)((uintptr_t)page | VM_RADIX_ISLEAF);
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}
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/*
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* Returns the slot where two keys differ.
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* It cannot accept 2 equal keys.
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*/
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static __inline uint16_t
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vm_radix_keydiff(vm_pindex_t index1, vm_pindex_t index2)
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{
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uint16_t clev;
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KASSERT(index1 != index2, ("%s: passing the same key value %jx",
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__func__, (uintmax_t)index1));
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index1 ^= index2;
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for (clev = VM_RADIX_LIMIT;; clev--)
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if (vm_radix_slot(index1, clev) != 0)
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return (clev);
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}
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/*
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* Returns TRUE if it can be determined that key does not belong to the
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* specified rnode. Otherwise, returns FALSE.
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*/
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static __inline boolean_t
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vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t idx)
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{
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if (rnode->rn_clev < VM_RADIX_LIMIT) {
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idx = vm_radix_trimkey(idx, rnode->rn_clev + 1);
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return (idx != rnode->rn_owner);
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}
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return (FALSE);
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}
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/*
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* Internal helper for vm_radix_reclaim_allnodes().
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* This function is recursive.
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*/
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static void
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vm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode)
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{
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int slot;
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KASSERT(rnode->rn_count <= VM_RADIX_COUNT,
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("vm_radix_reclaim_allnodes_int: bad count in rnode %p", rnode));
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for (slot = 0; rnode->rn_count != 0; slot++) {
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if (rnode->rn_child[slot] == NULL)
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continue;
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if (!vm_radix_isleaf(rnode->rn_child[slot]))
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vm_radix_reclaim_allnodes_int(rnode->rn_child[slot]);
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rnode->rn_child[slot] = NULL;
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rnode->rn_count--;
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}
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vm_radix_node_put(rnode);
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}
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#ifdef INVARIANTS
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/*
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* Radix node zone destructor.
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*/
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static void
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vm_radix_node_zone_dtor(void *mem, int size __unused, void *arg __unused)
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{
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struct vm_radix_node *rnode;
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int slot;
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rnode = mem;
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KASSERT(rnode->rn_count == 0,
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("vm_radix_node_put: rnode %p has %d children", rnode,
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rnode->rn_count));
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for (slot = 0; slot < VM_RADIX_COUNT; slot++)
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KASSERT(rnode->rn_child[slot] == NULL,
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("vm_radix_node_put: rnode %p has a child", rnode));
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}
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#endif
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static int
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vm_radix_node_zone_init(void *mem, int size __unused, int flags __unused)
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{
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struct vm_radix_node *rnode;
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rnode = mem;
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bzero(rnode, sizeof(*rnode));
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return (0);
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}
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#ifndef UMA_MD_SMALL_ALLOC
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void vm_radix_reserve_kva(void);
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/*
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* Reserve the KVA necessary to satisfy the node allocation.
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* This is mandatory in architectures not supporting direct
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* mapping as they will need otherwise to carve into the kernel maps for
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* every node allocation, resulting into deadlocks for consumers already
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* working with kernel maps.
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*/
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void
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vm_radix_reserve_kva(void)
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{
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/*
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* Calculate the number of reserved nodes, discounting the pages that
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* are needed to store them.
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*/
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if (!uma_zone_reserve_kva(vm_radix_node_zone,
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((vm_paddr_t)vm_cnt.v_page_count * PAGE_SIZE) / (PAGE_SIZE +
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sizeof(struct vm_radix_node))))
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panic("%s: unable to reserve KVA", __func__);
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}
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#endif
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/*
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* Initialize the UMA slab zone.
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*/
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void
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vm_radix_zinit(void)
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{
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vm_radix_node_zone = uma_zcreate("RADIX NODE",
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sizeof(struct vm_radix_node), NULL,
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#ifdef INVARIANTS
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vm_radix_node_zone_dtor,
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#else
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NULL,
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#endif
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vm_radix_node_zone_init, NULL, VM_RADIX_PAD, UMA_ZONE_VM);
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}
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/*
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* Inserts the key-value pair into the trie.
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* Panics if the key already exists.
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*/
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int
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vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
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{
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vm_pindex_t index, newind;
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void **parentp;
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struct vm_radix_node *rnode, *tmp;
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vm_page_t m;
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int slot;
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uint16_t clev;
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index = page->pindex;
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/*
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* The owner of record for root is not really important because it
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* will never be used.
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*/
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rnode = vm_radix_getroot(rtree);
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if (rnode == NULL) {
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rtree->rt_root = (uintptr_t)page | VM_RADIX_ISLEAF;
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return (0);
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}
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parentp = (void **)&rtree->rt_root;
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for (;;) {
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if (vm_radix_isleaf(rnode)) {
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m = vm_radix_topage(rnode);
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if (m->pindex == index)
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panic("%s: key %jx is already present",
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__func__, (uintmax_t)index);
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clev = vm_radix_keydiff(m->pindex, index);
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tmp = vm_radix_node_get(vm_radix_trimkey(index,
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clev + 1), 2, clev);
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if (tmp == NULL)
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return (ENOMEM);
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*parentp = tmp;
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vm_radix_addpage(tmp, index, clev, page);
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vm_radix_addpage(tmp, m->pindex, clev, m);
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return (0);
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} else if (vm_radix_keybarr(rnode, index))
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break;
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slot = vm_radix_slot(index, rnode->rn_clev);
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if (rnode->rn_child[slot] == NULL) {
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rnode->rn_count++;
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vm_radix_addpage(rnode, index, rnode->rn_clev, page);
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return (0);
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}
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parentp = &rnode->rn_child[slot];
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rnode = rnode->rn_child[slot];
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}
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/*
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* A new node is needed because the right insertion level is reached.
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* Setup the new intermediate node and add the 2 children: the
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* new object and the older edge.
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*/
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newind = rnode->rn_owner;
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clev = vm_radix_keydiff(newind, index);
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tmp = vm_radix_node_get(vm_radix_trimkey(index, clev + 1), 2, clev);
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if (tmp == NULL)
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return (ENOMEM);
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*parentp = tmp;
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vm_radix_addpage(tmp, index, clev, page);
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slot = vm_radix_slot(newind, clev);
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tmp->rn_child[slot] = rnode;
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return (0);
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}
|
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|
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/*
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* Returns TRUE if the specified radix tree contains a single leaf and FALSE
|
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* otherwise.
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*/
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boolean_t
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vm_radix_is_singleton(struct vm_radix *rtree)
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{
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struct vm_radix_node *rnode;
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|
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rnode = vm_radix_getroot(rtree);
|
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if (rnode == NULL)
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return (FALSE);
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return (vm_radix_isleaf(rnode));
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}
|
|
|
|
/*
|
|
* Returns the value stored at the index. If the index is not present,
|
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* NULL is returned.
|
|
*/
|
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vm_page_t
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vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index)
|
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{
|
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struct vm_radix_node *rnode;
|
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vm_page_t m;
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int slot;
|
|
|
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rnode = vm_radix_getroot(rtree);
|
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while (rnode != NULL) {
|
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if (vm_radix_isleaf(rnode)) {
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m = vm_radix_topage(rnode);
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if (m->pindex == index)
|
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return (m);
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else
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break;
|
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} else if (vm_radix_keybarr(rnode, index))
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break;
|
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slot = vm_radix_slot(index, rnode->rn_clev);
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rnode = rnode->rn_child[slot];
|
|
}
|
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return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Look up the nearest entry at a position bigger than or equal to index.
|
|
*/
|
|
vm_page_t
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vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index)
|
|
{
|
|
struct vm_radix_node *stack[VM_RADIX_LIMIT];
|
|
vm_pindex_t inc;
|
|
vm_page_t m;
|
|
struct vm_radix_node *child, *rnode;
|
|
#ifdef INVARIANTS
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|
int loops = 0;
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#endif
|
|
int slot, tos;
|
|
|
|
rnode = vm_radix_getroot(rtree);
|
|
if (rnode == NULL)
|
|
return (NULL);
|
|
else if (vm_radix_isleaf(rnode)) {
|
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m = vm_radix_topage(rnode);
|
|
if (m->pindex >= index)
|
|
return (m);
|
|
else
|
|
return (NULL);
|
|
}
|
|
tos = 0;
|
|
for (;;) {
|
|
/*
|
|
* If the keys differ before the current bisection node,
|
|
* then the search key might rollback to the earliest
|
|
* available bisection node or to the smallest key
|
|
* in the current node (if the owner is bigger than the
|
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* search key).
|
|
*/
|
|
if (vm_radix_keybarr(rnode, index)) {
|
|
if (index > rnode->rn_owner) {
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ascend:
|
|
KASSERT(++loops < 1000,
|
|
("vm_radix_lookup_ge: too many loops"));
|
|
|
|
/*
|
|
* Pop nodes from the stack until either the
|
|
* stack is empty or a node that could have a
|
|
* matching descendant is found.
|
|
*/
|
|
do {
|
|
if (tos == 0)
|
|
return (NULL);
|
|
rnode = stack[--tos];
|
|
} while (vm_radix_slot(index,
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rnode->rn_clev) == (VM_RADIX_COUNT - 1));
|
|
|
|
/*
|
|
* The following computation cannot overflow
|
|
* because index's slot at the current level
|
|
* is less than VM_RADIX_COUNT - 1.
|
|
*/
|
|
index = vm_radix_trimkey(index,
|
|
rnode->rn_clev);
|
|
index += VM_RADIX_UNITLEVEL(rnode->rn_clev);
|
|
} else
|
|
index = rnode->rn_owner;
|
|
KASSERT(!vm_radix_keybarr(rnode, index),
|
|
("vm_radix_lookup_ge: keybarr failed"));
|
|
}
|
|
slot = vm_radix_slot(index, rnode->rn_clev);
|
|
child = rnode->rn_child[slot];
|
|
if (vm_radix_isleaf(child)) {
|
|
m = vm_radix_topage(child);
|
|
if (m->pindex >= index)
|
|
return (m);
|
|
} else if (child != NULL)
|
|
goto descend;
|
|
|
|
/*
|
|
* Look for an available edge or page within the current
|
|
* bisection node.
|
|
*/
|
|
if (slot < (VM_RADIX_COUNT - 1)) {
|
|
inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
|
|
index = vm_radix_trimkey(index, rnode->rn_clev);
|
|
do {
|
|
index += inc;
|
|
slot++;
|
|
child = rnode->rn_child[slot];
|
|
if (vm_radix_isleaf(child)) {
|
|
m = vm_radix_topage(child);
|
|
if (m->pindex >= index)
|
|
return (m);
|
|
} else if (child != NULL)
|
|
goto descend;
|
|
} while (slot < (VM_RADIX_COUNT - 1));
|
|
}
|
|
KASSERT(child == NULL || vm_radix_isleaf(child),
|
|
("vm_radix_lookup_ge: child is radix node"));
|
|
|
|
/*
|
|
* If a page or edge bigger than the search slot is not found
|
|
* in the current node, ascend to the next higher-level node.
|
|
*/
|
|
goto ascend;
|
|
descend:
|
|
KASSERT(rnode->rn_clev > 0,
|
|
("vm_radix_lookup_ge: pushing leaf's parent"));
|
|
KASSERT(tos < VM_RADIX_LIMIT,
|
|
("vm_radix_lookup_ge: stack overflow"));
|
|
stack[tos++] = rnode;
|
|
rnode = child;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Look up the nearest entry at a position less than or equal to index.
|
|
*/
|
|
vm_page_t
|
|
vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index)
|
|
{
|
|
struct vm_radix_node *stack[VM_RADIX_LIMIT];
|
|
vm_pindex_t inc;
|
|
vm_page_t m;
|
|
struct vm_radix_node *child, *rnode;
|
|
#ifdef INVARIANTS
|
|
int loops = 0;
|
|
#endif
|
|
int slot, tos;
|
|
|
|
rnode = vm_radix_getroot(rtree);
|
|
if (rnode == NULL)
|
|
return (NULL);
|
|
else if (vm_radix_isleaf(rnode)) {
|
|
m = vm_radix_topage(rnode);
|
|
if (m->pindex <= index)
|
|
return (m);
|
|
else
|
|
return (NULL);
|
|
}
|
|
tos = 0;
|
|
for (;;) {
|
|
/*
|
|
* If the keys differ before the current bisection node,
|
|
* then the search key might rollback to the earliest
|
|
* available bisection node or to the largest key
|
|
* in the current node (if the owner is smaller than the
|
|
* search key).
|
|
*/
|
|
if (vm_radix_keybarr(rnode, index)) {
|
|
if (index > rnode->rn_owner) {
|
|
index = rnode->rn_owner + VM_RADIX_COUNT *
|
|
VM_RADIX_UNITLEVEL(rnode->rn_clev);
|
|
} else {
|
|
ascend:
|
|
KASSERT(++loops < 1000,
|
|
("vm_radix_lookup_le: too many loops"));
|
|
|
|
/*
|
|
* Pop nodes from the stack until either the
|
|
* stack is empty or a node that could have a
|
|
* matching descendant is found.
|
|
*/
|
|
do {
|
|
if (tos == 0)
|
|
return (NULL);
|
|
rnode = stack[--tos];
|
|
} while (vm_radix_slot(index,
|
|
rnode->rn_clev) == 0);
|
|
|
|
/*
|
|
* The following computation cannot overflow
|
|
* because index's slot at the current level
|
|
* is greater than 0.
|
|
*/
|
|
index = vm_radix_trimkey(index,
|
|
rnode->rn_clev);
|
|
}
|
|
index--;
|
|
KASSERT(!vm_radix_keybarr(rnode, index),
|
|
("vm_radix_lookup_le: keybarr failed"));
|
|
}
|
|
slot = vm_radix_slot(index, rnode->rn_clev);
|
|
child = rnode->rn_child[slot];
|
|
if (vm_radix_isleaf(child)) {
|
|
m = vm_radix_topage(child);
|
|
if (m->pindex <= index)
|
|
return (m);
|
|
} else if (child != NULL)
|
|
goto descend;
|
|
|
|
/*
|
|
* Look for an available edge or page within the current
|
|
* bisection node.
|
|
*/
|
|
if (slot > 0) {
|
|
inc = VM_RADIX_UNITLEVEL(rnode->rn_clev);
|
|
index |= inc - 1;
|
|
do {
|
|
index -= inc;
|
|
slot--;
|
|
child = rnode->rn_child[slot];
|
|
if (vm_radix_isleaf(child)) {
|
|
m = vm_radix_topage(child);
|
|
if (m->pindex <= index)
|
|
return (m);
|
|
} else if (child != NULL)
|
|
goto descend;
|
|
} while (slot > 0);
|
|
}
|
|
KASSERT(child == NULL || vm_radix_isleaf(child),
|
|
("vm_radix_lookup_le: child is radix node"));
|
|
|
|
/*
|
|
* If a page or edge smaller than the search slot is not found
|
|
* in the current node, ascend to the next higher-level node.
|
|
*/
|
|
goto ascend;
|
|
descend:
|
|
KASSERT(rnode->rn_clev > 0,
|
|
("vm_radix_lookup_le: pushing leaf's parent"));
|
|
KASSERT(tos < VM_RADIX_LIMIT,
|
|
("vm_radix_lookup_le: stack overflow"));
|
|
stack[tos++] = rnode;
|
|
rnode = child;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove the specified index from the trie, and return the value stored at
|
|
* that index. If the index is not present, return NULL.
|
|
*/
|
|
vm_page_t
|
|
vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
|
|
{
|
|
struct vm_radix_node *rnode, *parent;
|
|
vm_page_t m;
|
|
int i, slot;
|
|
|
|
rnode = vm_radix_getroot(rtree);
|
|
if (vm_radix_isleaf(rnode)) {
|
|
m = vm_radix_topage(rnode);
|
|
if (m->pindex != index)
|
|
return (NULL);
|
|
vm_radix_setroot(rtree, NULL);
|
|
return (m);
|
|
}
|
|
parent = NULL;
|
|
for (;;) {
|
|
if (rnode == NULL)
|
|
return (NULL);
|
|
slot = vm_radix_slot(index, rnode->rn_clev);
|
|
if (vm_radix_isleaf(rnode->rn_child[slot])) {
|
|
m = vm_radix_topage(rnode->rn_child[slot]);
|
|
if (m->pindex != index)
|
|
return (NULL);
|
|
rnode->rn_child[slot] = NULL;
|
|
rnode->rn_count--;
|
|
if (rnode->rn_count > 1)
|
|
return (m);
|
|
for (i = 0; i < VM_RADIX_COUNT; i++)
|
|
if (rnode->rn_child[i] != NULL)
|
|
break;
|
|
KASSERT(i != VM_RADIX_COUNT,
|
|
("%s: invalid node configuration", __func__));
|
|
if (parent == NULL)
|
|
vm_radix_setroot(rtree, rnode->rn_child[i]);
|
|
else {
|
|
slot = vm_radix_slot(index, parent->rn_clev);
|
|
KASSERT(parent->rn_child[slot] == rnode,
|
|
("%s: invalid child value", __func__));
|
|
parent->rn_child[slot] = rnode->rn_child[i];
|
|
}
|
|
rnode->rn_count--;
|
|
rnode->rn_child[i] = NULL;
|
|
vm_radix_node_put(rnode);
|
|
return (m);
|
|
}
|
|
parent = rnode;
|
|
rnode = rnode->rn_child[slot];
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove and free all the nodes from the radix tree.
|
|
* This function is recursive but there is a tight control on it as the
|
|
* maximum depth of the tree is fixed.
|
|
*/
|
|
void
|
|
vm_radix_reclaim_allnodes(struct vm_radix *rtree)
|
|
{
|
|
struct vm_radix_node *root;
|
|
|
|
root = vm_radix_getroot(rtree);
|
|
if (root == NULL)
|
|
return;
|
|
vm_radix_setroot(rtree, NULL);
|
|
if (!vm_radix_isleaf(root))
|
|
vm_radix_reclaim_allnodes_int(root);
|
|
}
|
|
|
|
/*
|
|
* Replace an existing page in the trie with another one.
|
|
* Panics if there is not an old page in the trie at the new page's index.
|
|
*/
|
|
vm_page_t
|
|
vm_radix_replace(struct vm_radix *rtree, vm_page_t newpage)
|
|
{
|
|
struct vm_radix_node *rnode;
|
|
vm_page_t m;
|
|
vm_pindex_t index;
|
|
int slot;
|
|
|
|
index = newpage->pindex;
|
|
rnode = vm_radix_getroot(rtree);
|
|
if (rnode == NULL)
|
|
panic("%s: replacing page on an empty trie", __func__);
|
|
if (vm_radix_isleaf(rnode)) {
|
|
m = vm_radix_topage(rnode);
|
|
if (m->pindex != index)
|
|
panic("%s: original replacing root key not found",
|
|
__func__);
|
|
rtree->rt_root = (uintptr_t)newpage | VM_RADIX_ISLEAF;
|
|
return (m);
|
|
}
|
|
for (;;) {
|
|
slot = vm_radix_slot(index, rnode->rn_clev);
|
|
if (vm_radix_isleaf(rnode->rn_child[slot])) {
|
|
m = vm_radix_topage(rnode->rn_child[slot]);
|
|
if (m->pindex == index) {
|
|
rnode->rn_child[slot] =
|
|
(void *)((uintptr_t)newpage |
|
|
VM_RADIX_ISLEAF);
|
|
return (m);
|
|
} else
|
|
break;
|
|
} else if (rnode->rn_child[slot] == NULL ||
|
|
vm_radix_keybarr(rnode->rn_child[slot], index))
|
|
break;
|
|
rnode = rnode->rn_child[slot];
|
|
}
|
|
panic("%s: original replacing page not found", __func__);
|
|
}
|
|
|
|
void
|
|
vm_radix_wait(void)
|
|
{
|
|
uma_zwait(vm_radix_node_zone);
|
|
}
|
|
|
|
#ifdef DDB
|
|
/*
|
|
* Show details about the given radix node.
|
|
*/
|
|
DB_SHOW_COMMAND(radixnode, db_show_radixnode)
|
|
{
|
|
struct vm_radix_node *rnode;
|
|
int i;
|
|
|
|
if (!have_addr)
|
|
return;
|
|
rnode = (struct vm_radix_node *)addr;
|
|
db_printf("radixnode %p, owner %jx, children count %u, level %u:\n",
|
|
(void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_count,
|
|
rnode->rn_clev);
|
|
for (i = 0; i < VM_RADIX_COUNT; i++)
|
|
if (rnode->rn_child[i] != NULL)
|
|
db_printf("slot: %d, val: %p, page: %p, clev: %d\n",
|
|
i, (void *)rnode->rn_child[i],
|
|
vm_radix_isleaf(rnode->rn_child[i]) ?
|
|
vm_radix_topage(rnode->rn_child[i]) : NULL,
|
|
rnode->rn_clev);
|
|
}
|
|
#endif /* DDB */
|