Re: 6cec93da46c4 - main - Revert "radix_trie: have vm_radix use pctrie code"

Because jenkins reported failures on most of the non-amd64 
architectures, and leaving 'main' broken while I figured out the problem 
was not a sensible choice.

Doug

On 9/11/23 12:21, Ravi Pokala wrote:
> Hi Doug,
>
>> Revert "radix_trie: have vm_radix use pctrie code"
> That's "what", not "why". Why are you reverting the change?
>
> Thanks,
>
> Ravi (rpokala@)
>
> -----Original Message-----
> From: <owner-src-committers@freebsd.org <mailto:owner-src-committers@freebsd.org>> on behalf of Doug Moore <dougm@FreeBSD.org <mailto:dougm@FreeBSD.org>>
> Date: Monday, September 11, 2023 at 01:35
> To: <src-committers@FreeBSD.org <mailto:src-committers@FreeBSD.org>>, <dev-commits-src-all@FreeBSD.org <mailto:dev-commits-src-all@FreeBSD.org>>, <dev-commits-src-main@FreeBSD.org <mailto:dev-commits-src-main@FreeBSD.org>>
> Subject: git: 6cec93da46c4 - main - Revert "radix_trie: have vm_radix use pctrie code"
>
>
> The branch main has been updated by dougm:
>
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=6cec93da46c4a91a042b0be488844052c0f8985a <https://cgit.FreeBSD.org/src/commit/?id=6cec93da46c4a91a042b0be488844052c0f8985a>
>
>
> commit 6cec93da46c4a91a042b0be488844052c0f8985a
> Author: Doug Moore <dougm@FreeBSD.org <mailto:dougm@FreeBSD.org>>
> AuthorDate: 2023-09-11 08:34:46 +0000
> Commit: Doug Moore <dougm@FreeBSD.org <mailto:dougm@FreeBSD.org>>
> CommitDate: 2023-09-11 08:35:36 +0000
>
>
> Revert "radix_trie: have vm_radix use pctrie code"
>
>
> This reverts commit a494d30465f21e8cb014a5c788a43001397325d7.
> ---
> sys/vm/_vm_radix.h | 9 +-
> sys/vm/vm_radix.c | 696 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
> sys/vm/vm_radix.h | 113 ++-------
> 3 files changed, 709 insertions(+), 109 deletions(-)
>
>
> diff --git a/sys/vm/_vm_radix.h b/sys/vm/_vm_radix.h
> index 2d9b05c7b52a..01eb25a9dccf 100644
> --- a/sys/vm/_vm_radix.h
> +++ b/sys/vm/_vm_radix.h
> @@ -31,13 +31,16 @@
> #ifndef __VM_RADIX_H_
> #define __VM_RADIX_H_
>
>
> -#include <sys/_pctrie.h>
> +/*
> + * Radix tree node.
> + */
> +struct vm_radix_node;
>
>
> /*
> - * Radix tree
> + * Radix tree root.
> */
> struct vm_radix {
> - struct pctrie rt_trie;
> + struct vm_radix_node *rt_root;
> };
>
>
> #endif /* !__VM_RADIX_H_ */
> diff --git a/sys/vm/vm_radix.c b/sys/vm/vm_radix.c
> index b8c693eca66f..768a56ed76f7 100644
> --- a/sys/vm/vm_radix.c
> +++ b/sys/vm/vm_radix.c
> @@ -54,26 +54,302 @@
> #include "opt_ddb.h"
>
>
> #include <sys/param.h>
> -#include <sys/pctrie.h>
> +#include <sys/systm.h>
> +#include <sys/kernel.h>
> +#include <sys/libkern.h>
> +#include <sys/proc.h>
> +#include <sys/vmmeter.h>
> +#include <sys/smr.h>
> +#include <sys/smr_types.h>
>
>
> #include <vm/uma.h>
> #include <vm/vm.h>
> +#include <vm/vm_param.h>
> +#include <vm/vm_object.h>
> #include <vm/vm_page.h>
> #include <vm/vm_radix.h>
>
>
> +#ifdef DDB
> +#include <ddb/ddb.h>
> +#endif
> +
> +/*
> + * These widths should allow the pointers to a node's children to fit within
> + * a single cache line. The extra levels from a narrow width should not be
> + * a problem thanks to path compression.
> + */
> +#ifdef __LP64__
> +#define VM_RADIX_WIDTH 4
> +#else
> +#define VM_RADIX_WIDTH 3
> +#endif
> +
> +#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH)
> +#define VM_RADIX_MASK (VM_RADIX_COUNT - 1)
> +#define VM_RADIX_LIMIT \
> + (howmany(sizeof(vm_pindex_t) * NBBY, VM_RADIX_WIDTH) - 1)
> +
> +#if VM_RADIX_WIDTH == 3
> +typedef uint8_t rn_popmap_t;
> +#elif VM_RADIX_WIDTH == 4
> +typedef uint16_t rn_popmap_t;
> +#elif VM_RADIX_WIDTH == 5
> +typedef uint32_t rn_popmap_t;
> +#else
> +#error Unsupported width
> +#endif
> +_Static_assert(sizeof(rn_popmap_t) <= sizeof(int),
> + "rn_popmap_t too wide");
> +
> +/* Set of all flag bits stored in node pointers. */
> +#define VM_RADIX_FLAGS (VM_RADIX_ISLEAF)
> +#define VM_RADIX_PAD VM_RADIX_FLAGS
> +
> +enum vm_radix_access { SMR, LOCKED, UNSERIALIZED };
> +
> +struct vm_radix_node;
> +typedef SMR_POINTER(struct vm_radix_node *) smrnode_t;
> +
> +struct vm_radix_node {
> + vm_pindex_t rn_owner; /* Owner of record. */
> + rn_popmap_t rn_popmap; /* Valid children. */
> + uint8_t rn_clev; /* Level * WIDTH. */
> + smrnode_t rn_child[VM_RADIX_COUNT]; /* Child nodes. */
> +};
> +
> static uma_zone_t vm_radix_node_zone;
> -smr_t vm_radix_smr;
> +static smr_t vm_radix_smr;
> +
> +static void vm_radix_node_store(smrnode_t *p, struct vm_radix_node *v,
> + enum vm_radix_access access);
>
>
> -void *
> -vm_radix_node_alloc(struct pctrie *ptree)
> +/*
> + * Map index to an array position for the children of rnode,
> + */
> +static __inline int
> +vm_radix_slot(struct vm_radix_node *rnode, vm_pindex_t index)
> {
> - return (uma_zalloc_smr(vm_radix_node_zone, M_NOWAIT));
> + return ((index >> rnode->rn_clev) & VM_RADIX_MASK);
> }
>
>
> -void
> -vm_radix_node_free(struct pctrie *ptree, void *node)
> +/*
> + * Returns true if index does not belong to the specified rnode. Otherwise,
> + * sets slot value, and returns false.
> + */
> +static __inline bool
> +vm_radix_keybarr(struct vm_radix_node *rnode, vm_pindex_t index, int *slot)
> +{
> + index = (index - rnode->rn_owner) >> rnode->rn_clev;
> + if (index >= VM_RADIX_COUNT)
> + return (true);
> + *slot = index;
> + return (false);
> +}
> +
> +/*
> + * Allocate a radix node.
> + */
> +static struct vm_radix_node *
> +vm_radix_node_get(vm_pindex_t index, vm_pindex_t newind)
> +{
> + struct vm_radix_node *rnode;
> +
> + rnode = uma_zalloc_smr(vm_radix_node_zone, M_NOWAIT);
> + if (rnode == NULL)
> + return (NULL);
> +
> + /*
> + * We want to clear the last child pointer after the final section
> + * has exited so lookup can not return false negatives. It is done
> + * here because it will be cache-cold in the dtor callback.
> + */
> + if (rnode->rn_popmap != 0) {
> + vm_radix_node_store(&rnode->rn_child[ffs(rnode->rn_popmap) - 1],
> + VM_RADIX_NULL, UNSERIALIZED);
> + rnode->rn_popmap = 0;
> + }
> +
> + /*
> + * From the highest-order bit where the indexes differ,
> + * compute the highest level in the trie where they differ. Then,
> + * compute the least index of this subtrie.
> + */
> + KASSERT(index != newind, ("%s: passing the same key value %jx",
> + __func__, (uintmax_t)index));
> + _Static_assert(sizeof(long long) >= sizeof(vm_pindex_t),
> + "vm_pindex_t too wide");
> + _Static_assert(sizeof(vm_pindex_t) * NBBY <=
> + (1 << (sizeof(rnode->rn_clev) * NBBY)), "rn_clev too narrow");
> + rnode->rn_clev = rounddown(flsll(index ^ newind) - 1, VM_RADIX_WIDTH);
> + rnode->rn_owner = VM_RADIX_COUNT;
> + rnode->rn_owner = index & -(rnode->rn_owner << rnode->rn_clev);
> + return (rnode);
> +}
> +
> +/*
> + * Free radix node.
> + */
> +static __inline void
> +vm_radix_node_put(struct vm_radix_node *rnode)
> +{
> +#ifdef INVARIANTS
> + int slot;
> +
> + KASSERT(powerof2(rnode->rn_popmap),
> + ("vm_radix_node_put: rnode %p has too many children %04x", rnode,
> + rnode->rn_popmap));
> + for (slot = 0; slot < VM_RADIX_COUNT; slot++) {
> + if ((rnode->rn_popmap & (1 << slot)) != 0)
> + continue;
> + KASSERT(smr_unserialized_load(&rnode->rn_child[slot], true) ==
> + VM_RADIX_NULL,
> + ("vm_radix_node_put: rnode %p has a child", rnode));
> + }
> +#endif
> + uma_zfree_smr(vm_radix_node_zone, rnode);
> +}
> +
> +/*
> + * Fetch a node pointer from a slot in another node.
> + */
> +static __inline struct vm_radix_node *
> +vm_radix_node_load(smrnode_t *p, enum vm_radix_access access)
> +{
> +
> + switch (access) {
> + case UNSERIALIZED:
> + return (smr_unserialized_load(p, true));
> + case LOCKED:
> + return (smr_serialized_load(p, true));
> + case SMR:
> + return (smr_entered_load(p, vm_radix_smr));
> + }
> + __assert_unreachable();
> +}
> +
> +static __inline void
> +vm_radix_node_store(smrnode_t *p, struct vm_radix_node *v,
> + enum vm_radix_access access)
> +{
> +
> + switch (access) {
> + case UNSERIALIZED:
> + smr_unserialized_store(p, v, true);
> + break;
> + case LOCKED:
> + smr_serialized_store(p, v, true);
> + break;
> + case SMR:
> + panic("vm_radix_node_store: Not supported in smr section.");
> + }
> +}
> +
> +/*
> + * Get the root node for a radix tree.
> + */
> +static __inline struct vm_radix_node *
> +vm_radix_root_load(struct vm_radix *rtree, enum vm_radix_access access)
> +{
> +
> + return (vm_radix_node_load((smrnode_t *)&rtree->rt_root, access));
> +}
> +
> +/*
> + * Set the root node for a radix tree.
> + */
> +static __inline void
> +vm_radix_root_store(struct vm_radix *rtree, struct vm_radix_node *rnode,
> + enum vm_radix_access access)
> +{
> +
> + vm_radix_node_store((smrnode_t *)&rtree->rt_root, rnode, access);
> +}
> +
> +/*
> + * Returns TRUE if the specified radix node is a leaf and FALSE otherwise.
> + */
> +static __inline bool
> +vm_radix_isleaf(struct vm_radix_node *rnode)
> +{
> +
> + return (((uintptr_t)rnode & VM_RADIX_ISLEAF) != 0);
> +}
> +
> +/*
> + * Returns page cast to radix node with leaf bit set.
> + */
> +static __inline struct vm_radix_node *
> +vm_radix_toleaf(vm_page_t page)
> +{
> + return ((struct vm_radix_node *)((uintptr_t)page | VM_RADIX_ISLEAF));
> +}
> +
> +/*
> + * Returns the associated page extracted from rnode.
> + */
> +static __inline vm_page_t
> +vm_radix_topage(struct vm_radix_node *rnode)
> +{
> +
> + return ((vm_page_t)((uintptr_t)rnode & ~VM_RADIX_FLAGS));
> +}
> +
> +/*
> + * Make 'child' a child of 'rnode'.
> + */
> +static __inline void
> +vm_radix_addnode(struct vm_radix_node *rnode, vm_pindex_t index,
> + struct vm_radix_node *child, enum vm_radix_access access)
> +{
> + int slot;
> +
> + slot = vm_radix_slot(rnode, index);
> + vm_radix_node_store(&rnode->rn_child[slot], child, access);
> + rnode->rn_popmap ^= 1 << slot;
> + KASSERT((rnode->rn_popmap & (1 << slot)) != 0,
> + ("%s: bad popmap slot %d in rnode %p", __func__, slot, rnode));
> +}
> +
> +/*
> + * Internal helper for vm_radix_reclaim_allnodes().
> + * This function is recursive.
> + */
> +static void
> +vm_radix_reclaim_allnodes_int(struct vm_radix_node *rnode)
> +{
> + struct vm_radix_node *child;
> + int slot;
> +
> + while (rnode->rn_popmap != 0) {
> + slot = ffs(rnode->rn_popmap) - 1;
> + child = vm_radix_node_load(&rnode->rn_child[slot],
> + UNSERIALIZED);
> + KASSERT(child != VM_RADIX_NULL,
> + ("%s: bad popmap slot %d in rnode %p",
> + __func__, slot, rnode));
> + if (!vm_radix_isleaf(child))
> + vm_radix_reclaim_allnodes_int(child);
> + rnode->rn_popmap ^= 1 << slot;
> + vm_radix_node_store(&rnode->rn_child[slot], VM_RADIX_NULL,
> + UNSERIALIZED);
> + }
> + vm_radix_node_put(rnode);
> +}
> +
> +/*
> + * radix node zone initializer.
> + */
> +static int
> +vm_radix_zone_init(void *mem, int size, int flags)
> {
> - uma_zfree_smr(vm_radix_node_zone, node);
> + struct vm_radix_node *rnode;
> +
> + rnode = mem;
> + rnode->rn_popmap = 0;
> + for (int i = 0; i < nitems(rnode->rn_child); i++)
> + vm_radix_node_store(&rnode->rn_child[i], VM_RADIX_NULL,
> + UNSERIALIZED);
> + return (0);
> }
>
>
> #ifndef UMA_MD_SMALL_ALLOC
> @@ -107,14 +383,412 @@ void
> vm_radix_zinit(void)
> {
>
>
> - vm_radix_node_zone = uma_zcreate("RADIX NODE", pctrie_node_size(),
> - NULL, NULL, pctrie_zone_init, NULL,
> - PCTRIE_PAD, UMA_ZONE_VM | UMA_ZONE_SMR);
> + vm_radix_node_zone = uma_zcreate("RADIX NODE",
> + sizeof(struct vm_radix_node), NULL, NULL, vm_radix_zone_init, NULL,
> + VM_RADIX_PAD, UMA_ZONE_VM | UMA_ZONE_SMR);
> vm_radix_smr = uma_zone_get_smr(vm_radix_node_zone);
> }
>
>
> +/*
> + * Inserts the key-value pair into the trie.
> + * Panics if the key already exists.
> + */
> +int
> +vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
> +{
> + vm_pindex_t index, newind;
> + struct vm_radix_node *leaf, *parent, *rnode;
> + smrnode_t *parentp;
> + int slot;
> +
> + index = page->pindex;
> + leaf = vm_radix_toleaf(page);
> +
> + /*
> + * The owner of record for root is not really important because it
> + * will never be used.
> + */
> + rnode = vm_radix_root_load(rtree, LOCKED);
> + parent = NULL;
> + for (;;) {
> + if (vm_radix_isleaf(rnode)) {
> + if (rnode == VM_RADIX_NULL) {
> + if (parent == NULL)
> + rtree->rt_root = leaf;
> + else
> + vm_radix_addnode(parent, index, leaf,
> + LOCKED);
> + return (0);
> + }
> + newind = vm_radix_topage(rnode)->pindex;
> + if (newind == index)
> + panic("%s: key %jx is already present",
> + __func__, (uintmax_t)index);
> + break;
> + }
> + if (vm_radix_keybarr(rnode, index, &slot)) {
> + newind = rnode->rn_owner;
> + break;
> + }
> + parent = rnode;
> + rnode = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + }
> +
> + /*
> + * A new node is needed because the right insertion level is reached.
> + * Setup the new intermediate node and add the 2 children: the
> + * new object and the older edge or object.
> + */
> + parentp = (parent != NULL) ? &parent->rn_child[slot]:
> + (smrnode_t *)&rtree->rt_root;
> + parent = vm_radix_node_get(index, newind);
> + if (parent == NULL)
> + return (ENOMEM);
> + /* These writes are not yet visible due to ordering. */
> + vm_radix_addnode(parent, index, leaf, UNSERIALIZED);
> + vm_radix_addnode(parent, newind, rnode, UNSERIALIZED);
> + /* Serializing write to make the above visible. */
> + vm_radix_node_store(parentp, parent, LOCKED);
> + return (0);
> +}
> +
> +/*
> + * Returns the value stored at the index. If the index is not present,
> + * NULL is returned.
> + */
> +static __always_inline vm_page_t
> +_vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index,
> + enum vm_radix_access access)
> +{
> + struct vm_radix_node *rnode;
> + vm_page_t m;
> + int slot;
> +
> + rnode = vm_radix_root_load(rtree, access);
> + for (;;) {
> + if (vm_radix_isleaf(rnode)) {
> + if ((m = vm_radix_topage(rnode)) != NULL &&
> + m->pindex == index)
> + return (m);
> + break;
> + }
> + if (vm_radix_keybarr(rnode, index, &slot))
> + break;
> + rnode = vm_radix_node_load(&rnode->rn_child[slot], access);
> + }
> + return (NULL);
> +}
> +
> +/*
> + * Returns the value stored at the index assuming there is an external lock.
> + *
> + * If the index is not present, NULL is returned.
> + */
> +vm_page_t
> +vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index)
> +{
> +
> + return _vm_radix_lookup(rtree, index, LOCKED);
> +}
> +
> +/*
> + * Returns the value stored at the index without requiring an external lock.
> + *
> + * If the index is not present, NULL is returned.
> + */
> +vm_page_t
> +vm_radix_lookup_unlocked(struct vm_radix *rtree, vm_pindex_t index)
> +{
> + vm_page_t m;
> +
> + smr_enter(vm_radix_smr);
> + m = _vm_radix_lookup(rtree, index, SMR);
> + smr_exit(vm_radix_smr);
> +
> + return (m);
> +}
> +
> +/*
> + * Returns the page with the least pindex that is greater than or equal to the
> + * specified pindex, or NULL if there are no such pages.
> + *
> + * Requires that access be externally synchronized by a lock.
> + */
> +vm_page_t
> +vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index)
> +{
> + struct vm_radix_node *rnode, *succ;
> + vm_page_t m;
> + int slot;
> +
> + /*
> + * Descend the trie as if performing an ordinary lookup for the page
> + * with the specified pindex. However, unlike an ordinary lookup, as we
> + * descend the trie, we use "succ" to remember the last branching-off
> + * point, that is, the interior node under which the page with the least
> + * pindex that is both outside our current path down the trie and more
> + * than the specified pindex resides. (The node's popmap makes it fast
> + * and easy to recognize a branching-off point.) If our ordinary lookup
> + * fails to yield a page with a pindex that is greater than or equal to
> + * the specified pindex, then we will exit this loop and perform a
> + * lookup starting from "succ". If "succ" is not NULL, then that lookup
> + * is guaranteed to succeed.
> + */
> + rnode = vm_radix_root_load(rtree, LOCKED);
> + succ = NULL;
> + for (;;) {
> + if (vm_radix_isleaf(rnode)) {
> + if ((m = vm_radix_topage(rnode)) != NULL &&
> + m->pindex >= index)
> + return (m);
> + break;
> + }
> + if (vm_radix_keybarr(rnode, index, &slot)) {
> + /*
> + * If all pages in this subtree have pindex > index,
> + * then the page in this subtree with the least pindex
> + * is the answer.
> + */
> + if (rnode->rn_owner > index)
> + succ = rnode;
> + break;
> + }
> +
> + /*
> + * Just in case the next search step leads to a subtree of all
> + * pages with pindex < index, check popmap to see if a next
> + * bigger step, to a subtree of all pages with pindex > index,
> + * is available. If so, remember to restart the search here.
> + */
> + if ((rnode->rn_popmap >> slot) > 1)
> + succ = rnode;
> + rnode = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + }
> +
> + /*
> + * Restart the search from the last place visited in the subtree that
> + * included some pages with pindex > index, if there was such a place.
> + */
> + if (succ == NULL)
> + return (NULL);
> + if (succ != rnode) {
> + /*
> + * Take a step to the next bigger sibling of the node chosen
> + * last time. In that subtree, all pages have pindex > index.
> + */
> + slot = vm_radix_slot(succ, index) + 1;
> + KASSERT((succ->rn_popmap >> slot) != 0,
> + ("%s: no popmap siblings past slot %d in node %p",
> + __func__, slot, succ));
> + slot += ffs(succ->rn_popmap >> slot) - 1;
> + succ = vm_radix_node_load(&succ->rn_child[slot], LOCKED);
> + }
> +
> + /*
> + * Find the page in the subtree rooted at "succ" with the least pindex.
> + */
> + while (!vm_radix_isleaf(succ)) {
> + KASSERT(succ->rn_popmap != 0,
> + ("%s: no popmap children in node %p", __func__, succ));
> + slot = ffs(succ->rn_popmap) - 1;
> + succ = vm_radix_node_load(&succ->rn_child[slot], LOCKED);
> + }
> + return (vm_radix_topage(succ));
> +}
> +
> +/*
> + * Returns the page with the greatest pindex that is less than or equal to the
> + * specified pindex, or NULL if there are no such pages.
> + *
> + * Requires that access be externally synchronized by a lock.
> + */
> +vm_page_t
> +vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index)
> +{
> + struct vm_radix_node *pred, *rnode;
> + vm_page_t m;
> + int slot;
> +
> + /*
> + * Mirror the implementation of vm_radix_lookup_ge, described above.
> + */
> + rnode = vm_radix_root_load(rtree, LOCKED);
> + pred = NULL;
> + for (;;) {
> + if (vm_radix_isleaf(rnode)) {
> + if ((m = vm_radix_topage(rnode)) != NULL &&
> + m->pindex <= index)
> + return (m);
> + break;
> + }
> + if (vm_radix_keybarr(rnode, index, &slot)) {
> + if (rnode->rn_owner < index)
> + pred = rnode;
> + break;
> + }
> + if ((rnode->rn_popmap & ((1 << slot) - 1)) != 0)
> + pred = rnode;
> + rnode = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + }
> + if (pred == NULL)
> + return (NULL);
> + if (pred != rnode) {
> + slot = vm_radix_slot(pred, index);
> + KASSERT((pred->rn_popmap & ((1 << slot) - 1)) != 0,
> + ("%s: no popmap siblings before slot %d in node %p",
> + __func__, slot, pred));
> + slot = fls(pred->rn_popmap & ((1 << slot) - 1)) - 1;
> + pred = vm_radix_node_load(&pred->rn_child[slot], LOCKED);
> + }
> + while (!vm_radix_isleaf(pred)) {
> + KASSERT(pred->rn_popmap != 0,
> + ("%s: no popmap children in node %p", __func__, pred));
> + slot = fls(pred->rn_popmap) - 1;
> + pred = vm_radix_node_load(&pred->rn_child[slot], LOCKED);
> + }
> + return (vm_radix_topage(pred));
> +}
> +
> +/*
> + * 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 *child, *parent, *rnode;
> + vm_page_t m;
> + int slot;
> +
> + rnode = NULL;
> + child = vm_radix_root_load(rtree, LOCKED);
> + for (;;) {
> + if (vm_radix_isleaf(child))
> + break;
> + parent = rnode;
> + rnode = child;
> + slot = vm_radix_slot(rnode, index);
> + child = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + }
> + if ((m = vm_radix_topage(child)) == NULL || m->pindex != index)
> + return (NULL);
> + if (rnode == NULL) {
> + vm_radix_root_store(rtree, VM_RADIX_NULL, LOCKED);
> + return (m);
> + }
> + KASSERT((rnode->rn_popmap & (1 << slot)) != 0,
> + ("%s: bad popmap slot %d in rnode %p", __func__, slot, rnode));
> + rnode->rn_popmap ^= 1 << slot;
> + vm_radix_node_store(&rnode->rn_child[slot], VM_RADIX_NULL, LOCKED);
> + if (!powerof2(rnode->rn_popmap))
> + return (m);
> + KASSERT(rnode->rn_popmap != 0, ("%s: bad popmap all zeroes", __func__));
> + slot = ffs(rnode->rn_popmap) - 1;
> + child = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + KASSERT(child != VM_RADIX_NULL,
> + ("%s: bad popmap slot %d in rnode %p", __func__, slot, rnode));
> + if (parent == NULL)
> + vm_radix_root_store(rtree, child, LOCKED);
> + else {
> + slot = vm_radix_slot(parent, index);
> + KASSERT(rnode ==
> + vm_radix_node_load(&parent->rn_child[slot], LOCKED),
> + ("%s: invalid child value", __func__));
> + vm_radix_node_store(&parent->rn_child[slot], child, LOCKED);
> + }
> + /*
> + * The child is still valid and we can not zero the
> + * pointer until all smr references are gone.
> + */
> + vm_radix_node_put(rnode);
> + return (m);
> +}
> +
> +/*
> + * 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_root_load(rtree, LOCKED);
> + if (root == VM_RADIX_NULL)
> + return;
> + vm_radix_root_store(rtree, VM_RADIX_NULL, UNSERIALIZED);
> + 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 *leaf, *parent, *rnode;
> + vm_page_t m;
> + vm_pindex_t index;
> + int slot;
> +
> + leaf = vm_radix_toleaf(newpage);
> + index = newpage->pindex;
> + rnode = vm_radix_root_load(rtree, LOCKED);
> + parent = NULL;
> + for (;;) {
> + if (vm_radix_isleaf(rnode)) {
> + if ((m = vm_radix_topage(rnode)) != NULL &&
> + m->pindex == index) {
> + if (parent == NULL)
> + rtree->rt_root = leaf;
> + else
> + vm_radix_node_store(
> + &parent->rn_child[slot], leaf,
> + LOCKED);
> + return (m);
> + }
> + break;
> + }
> + if (vm_radix_keybarr(rnode, index, &slot))
> + break;
> + parent = rnode;
> + rnode = vm_radix_node_load(&rnode->rn_child[slot], LOCKED);
> + }
> + 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, *tmp;
> + int slot;
> + rn_popmap_t popmap;
> +
> + if (!have_addr)
> + return;
> + rnode = (struct vm_radix_node *)addr;
> + db_printf("radixnode %p, owner %jx, children popmap %04x, level %u:\n",
> + (void *)rnode, (uintmax_t)rnode->rn_owner, rnode->rn_popmap,
> + rnode->rn_clev / VM_RADIX_WIDTH);
> + for (popmap = rnode->rn_popmap; popmap != 0; popmap ^= 1 << slot) {
> + slot = ffs(popmap) - 1;
> + tmp = vm_radix_node_load(&rnode->rn_child[slot], UNSERIALIZED);
> + db_printf("slot: %d, val: %p, page: %p, clev: %d\n",
> + slot, (void *)tmp,
> + vm_radix_isleaf(tmp) ? vm_radix_topage(tmp) : NULL,
> + rnode->rn_clev / VM_RADIX_WIDTH);
> + }
> +}
> +#endif /* DDB */
> diff --git a/sys/vm/vm_radix.h b/sys/vm/vm_radix.h
> index a332618fc0e6..231edda65102 100644
> --- a/sys/vm/vm_radix.h
> +++ b/sys/vm/vm_radix.h
> @@ -34,113 +34,36 @@
> #include <vm/_vm_radix.h>
>
>
> #ifdef _KERNEL
> -#include <sys/pctrie.h>
> -#include <vm/vm.h>
>
>
> +int vm_radix_insert(struct vm_radix *rtree, vm_page_t page);
> void vm_radix_wait(void);
> +vm_page_t vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index);
> +vm_page_t vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index);
> +vm_page_t vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index);
> +vm_page_t vm_radix_lookup_unlocked(struct vm_radix *rtree, vm_pindex_t index);
> +void vm_radix_reclaim_allnodes(struct vm_radix *rtree);
> +vm_page_t vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index);
> +vm_page_t vm_radix_replace(struct vm_radix *rtree, vm_page_t newpage);
> void vm_radix_zinit(void);
> -void *vm_radix_node_alloc(struct pctrie *ptree);
> -void vm_radix_node_free(struct pctrie *ptree, void *node);
> -extern smr_t vm_radix_smr;
> -
> -static __inline void
> -vm_radix_init(struct vm_radix *rtree)
> -{
> - pctrie_init(&rtree->rt_trie);
> -}
> -
> -static __inline bool
> -vm_radix_is_empty(struct vm_radix *rtree)
> -{
> - return (pctrie_is_empty(&rtree->rt_trie));
> -}
> -
> -PCTRIE_DEFINE_SMR(VM_RADIX, vm_page, pindex, vm_radix_node_alloc, vm_radix_node_free,
> - vm_radix_smr);
>
>
> /*
> - * Inserts the key-value pair into the trie.
> - * Panics if the key already exists.
> + * Each search path in the trie terminates at a leaf, which is a pointer to a
> + * page marked with a set 1-bit. A leaf may be associated with a null pointer
> + * to indicate no page there.
> */
> -static __inline int
> -vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
> -{
> - return (VM_RADIX_PCTRIE_INSERT(&rtree->rt_trie, page));
> -}
> -
> -/*
> - * Returns the value stored at the index assuming there is an external lock.
> - *
> - * If the index is not present, NULL is returned.
> - */
> -static __inline vm_page_t
> -vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index)
> -{
> - return (VM_RADIX_PCTRIE_LOOKUP(&rtree->rt_trie, index));
> -}
> -
> -/*
> - * Returns the value stored at the index without requiring an external lock.
> - *
> - * If the index is not present, NULL is returned.
> - */
> -static __inline vm_page_t
> -vm_radix_lookup_unlocked(struct vm_radix *rtree, vm_pindex_t index)
> -{
> - return (VM_RADIX_PCTRIE_LOOKUP_UNLOCKED(&rtree->rt_trie, index));
> -}
> +#define VM_RADIX_ISLEAF 0x1
> +#define VM_RADIX_NULL (struct vm_radix_node *)VM_RADIX_ISLEAF
>
>
> -/*
> - * Returns the page with the least pindex that is greater than or equal to the
> - * specified pindex, or NULL if there are no such pages.
> - *
> - * Requires that access be externally synchronized by a lock.
> - */
> -static __inline vm_page_t
> -vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index)
> -{
> - return (VM_RADIX_PCTRIE_LOOKUP_GE(&rtree->rt_trie, index));
> -}
> -
> -/*
> - * Returns the page with the greatest pindex that is less than or equal to the
> - * specified pindex, or NULL if there are no such pages.
> - *
> - * Requires that access be externally synchronized by a lock.
> - */
> -static __inline vm_page_t
> -vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index)
> -{
> - return (VM_RADIX_PCTRIE_LOOKUP_LE(&rtree->rt_trie, index));
> -}
> -
> -/*
> - * Remove the specified index from the trie, and return the value stored at
> - * that index. If the index is not present, return NULL.
> - */
> -static __inline vm_page_t
> -vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
> -{
> - return (VM_RADIX_PCTRIE_REMOVE_LOOKUP(&rtree->rt_trie, index));
> -}
> -
> -/*
> - * Remove and free all the nodes from the radix tree.
> - */
> static __inline void
> -vm_radix_reclaim_allnodes(struct vm_radix *rtree)
> +vm_radix_init(struct vm_radix *rtree)
> {
> - VM_RADIX_PCTRIE_RECLAIM(&rtree->rt_trie);
> + rtree->rt_root = VM_RADIX_NULL;
> }
>
>
> -/*
> - * 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.
> - */
> -static __inline vm_page_t
> -vm_radix_replace(struct vm_radix *rtree, vm_page_t newpage)
> +static __inline bool
> +vm_radix_is_empty(struct vm_radix *rtree)
> {
> - return (VM_RADIX_PCTRIE_REPLACE(&rtree->rt_trie, newpage));
> + return (rtree->rt_root == VM_RADIX_NULL);
> }
>
>
> #endif /* _KERNEL */
>
>
>
>