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- Add a new general purpose path-compressed radix trie which can be used

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with any structure containing a uint64_t index.  The tree code
   auto-generates type safe wrappers.
 - Eliminate the buf splay and replace it with pctrie.  This is not only
   significantly faster with large files but also allows for the possibility
   of shared locking.

Reviewed by:    alc, attilio
Sponsored by:   EMC / Isilon Storage Division
This commit is contained in:
jeff 2013-05-12 04:05:01 +00:00
parent fb8ceacf96
commit 1cfa4a3bc4
7 changed files with 933 additions and 115 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/conf/files
View File

@ -2760,6 +2760,7 @@ kern/subr_module.c standard
kern/subr_msgbuf.c standard kern/subr_msgbuf.c standard
kern/subr_param.c standard kern/subr_param.c standard
kern/subr_pcpu.c standard kern/subr_pcpu.c standard
kern/subr_pctrie.c standard
kern/subr_power.c standard kern/subr_power.c standard
kern/subr_prf.c standard kern/subr_prf.c standard
kern/subr_prof.c standard kern/subr_prof.c standard

705
sys/kern/subr_pctrie.c Normal file
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@ -0,0 +1,705 @@
/*
* Copyright (c) 2013 EMC Corp.
* Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
* Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*
* Path-compressed radix trie implementation.
*
* The implementation takes into account the following rationale:
* - Size of the nodes should be as small as possible but still big enough
* to avoid a large maximum depth for the trie. This is a balance
* between the necessity to not wire too much physical memory for the nodes
* and the necessity to avoid too much cache pollution during the trie
* operations.
* - There is not a huge bias toward the number of lookup operations over
* the number of insert and remove operations. This basically implies
* that optimizations supposedly helping one operation but hurting the
* other might be carefully evaluated.
* - On average not many nodes are expected to be fully populated, hence
* level compression may just complicate things.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/pctrie.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 PCTRIE_WIDTH 4
#else
#define PCTRIE_WIDTH 3
#endif
#define PCTRIE_COUNT (1 << PCTRIE_WIDTH)
#define PCTRIE_MASK (PCTRIE_COUNT - 1)
#define PCTRIE_LIMIT (howmany((sizeof(uint64_t) * NBBY), PCTRIE_WIDTH) - 1)
/* Flag bits stored in node pointers. */
#define PCTRIE_ISLEAF 0x1
#define PCTRIE_FLAGS 0x1
#define PCTRIE_PAD PCTRIE_FLAGS
/* Returns one unit associated with specified level. */
#define PCTRIE_UNITLEVEL(lev) \
((uint64_t)1 << ((lev) * PCTRIE_WIDTH))
struct pctrie_node {
uint64_t pn_owner; /* Owner of record. */
uint16_t pn_count; /* Valid children. */
uint16_t pn_clev; /* Current level. */
void *pn_child[PCTRIE_COUNT]; /* Child nodes. */
};
/*
* Allocate a node. Pre-allocation should ensure that the request
* will always be satisfied.
*/
static __inline struct pctrie_node *
pctrie_node_get(struct pctrie *ptree, pctrie_alloc_t allocfn, uint64_t owner,
uint16_t count, uint16_t clevel)
{
struct pctrie_node *node;
node = allocfn(ptree);
if (node == NULL)
return (NULL);
node->pn_owner = owner;
node->pn_count = count;
node->pn_clev = clevel;
return (node);
}
/*
* Free radix node.
*/
static __inline void
pctrie_node_put(struct pctrie *ptree, struct pctrie_node *node,
pctrie_free_t freefn)
{
#ifdef INVARIANTS
int slot;
KASSERT(node->pn_count == 0,
("pctrie_node_put: node %p has %d children", node,
node->pn_count));
for (slot = 0; slot < PCTRIE_COUNT; slot++)
KASSERT(node->pn_child[slot] == NULL,
("pctrie_node_put: node %p has a child", node));
#endif
freefn(ptree, node);
}
/*
* Return the position in the array for a given level.
*/
static __inline int
pctrie_slot(uint64_t index, uint16_t level)
{
return ((index >> (level * PCTRIE_WIDTH)) & PCTRIE_MASK);
}
/* Trims the key after the specified level. */
static __inline uint64_t
pctrie_trimkey(uint64_t index, uint16_t level)
{
uint64_t ret;
ret = index;
if (level > 0) {
ret >>= level * PCTRIE_WIDTH;
ret <<= level * PCTRIE_WIDTH;
}
return (ret);
}
/*
* Get the root node for a tree.
*/
static __inline struct pctrie_node *
pctrie_getroot(struct pctrie *ptree)
{
return ((struct pctrie_node *)ptree->pt_root);
}
/*
* Set the root node for a tree.
*/
static __inline void
pctrie_setroot(struct pctrie *ptree, struct pctrie_node *node)
{
ptree->pt_root = (uintptr_t)node;
}
/*
* Returns TRUE if the specified node is a leaf and FALSE otherwise.
*/
static __inline boolean_t
pctrie_isleaf(struct pctrie_node *node)
{
return (((uintptr_t)node & PCTRIE_ISLEAF) != 0);
}
/*
* Returns the associated val extracted from node.
*/
static __inline uint64_t *
pctrie_toval(struct pctrie_node *node)
{
return ((uint64_t *)((uintptr_t)node & ~PCTRIE_FLAGS));
}
/*
* Adds the val as a child of the provided node.
*/
static __inline void
pctrie_addval(struct pctrie_node *node, uint64_t index, uint16_t clev,
uint64_t *val)
{
int slot;
slot = pctrie_slot(index, clev);
node->pn_child[slot] = (void *)((uintptr_t)val | PCTRIE_ISLEAF);
}
/*
* Returns the slot where two keys differ.
* It cannot accept 2 equal keys.
*/
static __inline uint16_t
pctrie_keydiff(uint64_t index1, uint64_t index2)
{
uint16_t clev;
KASSERT(index1 != index2, ("%s: passing the same key value %jx",
__func__, (uintmax_t)index1));
index1 ^= index2;
for (clev = PCTRIE_LIMIT;; clev--)
if (pctrie_slot(index1, clev) != 0)
return (clev);
}
/*
* Returns TRUE if it can be determined that key does not belong to the
* specified node. Otherwise, returns FALSE.
*/
static __inline boolean_t
pctrie_keybarr(struct pctrie_node *node, uint64_t idx)
{
if (node->pn_clev < PCTRIE_LIMIT) {
idx = pctrie_trimkey(idx, node->pn_clev + 1);
return (idx != node->pn_owner);
}
return (FALSE);
}
/*
* Internal helper for pctrie_reclaim_allnodes().
* This function is recursive.
*/
static void
pctrie_reclaim_allnodes_int(struct pctrie *ptree, struct pctrie_node *node,
pctrie_free_t freefn)
{
int slot;
KASSERT(node->pn_count <= PCTRIE_COUNT,
("pctrie_reclaim_allnodes_int: bad count in node %p", node));
for (slot = 0; node->pn_count != 0; slot++) {
if (node->pn_child[slot] == NULL)
continue;
if (!pctrie_isleaf(node->pn_child[slot]))
pctrie_reclaim_allnodes_int(ptree,
node->pn_child[slot], freefn);
node->pn_child[slot] = NULL;
node->pn_count--;
}
pctrie_node_put(ptree, node, freefn);
}
/*
* pctrie node zone initializer.
*/
int
pctrie_zone_init(void *mem, int size __unused, int flags __unused)
{
struct pctrie_node *node;
node = mem;
memset(node->pn_child, 0, sizeof(node->pn_child));
return (0);
}
size_t
pctrie_node_size(void)
{
return (sizeof(struct pctrie_node));
}
/*
* Inserts the key-value pair into the trie.
* Panics if the key already exists.
*/
int
pctrie_insert(struct pctrie *ptree, uint64_t *val, pctrie_alloc_t allocfn)
{
uint64_t index, newind;
void **parentp;
struct pctrie_node *node, *tmp;
uint64_t *m;
int slot;
uint16_t clev;
index = *val;
/*
* The owner of record for root is not really important because it
* will never be used.
*/
node = pctrie_getroot(ptree);
if (node == NULL) {
ptree->pt_root = (uintptr_t)val | PCTRIE_ISLEAF;
return (0);
}
parentp = (void **)&ptree->pt_root;
for (;;) {
if (pctrie_isleaf(node)) {
m = pctrie_toval(node);
if (*m == index)
panic("%s: key %jx is already present",
__func__, (uintmax_t)index);
clev = pctrie_keydiff(*m, index);
tmp = pctrie_node_get(ptree, allocfn,
pctrie_trimkey(index, clev + 1), 2, clev);
if (tmp == NULL)
return (ENOMEM);
*parentp = tmp;
pctrie_addval(tmp, index, clev, val);
pctrie_addval(tmp, *m, clev, m);
return (0);
} else if (pctrie_keybarr(node, index))
break;
slot = pctrie_slot(index, node->pn_clev);
if (node->pn_child[slot] == NULL) {
node->pn_count++;
pctrie_addval(node, index, node->pn_clev, val);
return (0);
}
parentp = &node->pn_child[slot];
node = node->pn_child[slot];
}
/*
* 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.
*/
newind = node->pn_owner;
clev = pctrie_keydiff(newind, index);
tmp = pctrie_node_get(ptree, allocfn,
pctrie_trimkey(index, clev + 1), 2, clev);
if (tmp == NULL)
return (ENOMEM);
*parentp = tmp;
pctrie_addval(tmp, index, clev, val);
slot = pctrie_slot(newind, clev);
tmp->pn_child[slot] = node;
return (0);
}
/*
* Returns the value stored at the index. If the index is not present,
* NULL is returned.
*/
uint64_t *
pctrie_lookup(struct pctrie *ptree, uint64_t index)
{
struct pctrie_node *node;
uint64_t *m;
int slot;
node = pctrie_getroot(ptree);
while (node != NULL) {
if (pctrie_isleaf(node)) {
m = pctrie_toval(node);
if (*m == index)
return (m);
else
break;
} else if (pctrie_keybarr(node, index))
break;
slot = pctrie_slot(index, node->pn_clev);
node = node->pn_child[slot];
}
return (NULL);
}
/*
* Look up the nearest entry at a position bigger than or equal to index.
*/
uint64_t *
pctrie_lookup_ge(struct pctrie *ptree, uint64_t index)
{
struct pctrie_node *stack[PCTRIE_LIMIT];
uint64_t inc;
uint64_t *m;
struct pctrie_node *child, *node;
#ifdef INVARIANTS
int loops = 0;
#endif
int slot, tos;
node = pctrie_getroot(ptree);
if (node == NULL)
return (NULL);
else if (pctrie_isleaf(node)) {
m = pctrie_toval(node);
if (*m >= 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
* search key).
*/
if (pctrie_keybarr(node, index)) {
if (index > node->pn_owner) {
ascend:
KASSERT(++loops < 1000,
("pctrie_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);
node = stack[--tos];
} while (pctrie_slot(index,
node->pn_clev) == (PCTRIE_COUNT - 1));
/*
* The following computation cannot overflow
* because index's slot at the current level
* is less than PCTRIE_COUNT - 1.
*/
index = pctrie_trimkey(index,
node->pn_clev);
index += PCTRIE_UNITLEVEL(node->pn_clev);
} else
index = node->pn_owner;
KASSERT(!pctrie_keybarr(node, index),
("pctrie_lookup_ge: keybarr failed"));
}
slot = pctrie_slot(index, node->pn_clev);
child = node->pn_child[slot];
if (pctrie_isleaf(child)) {
m = pctrie_toval(child);
if (*m >= index)
return (m);
} else if (child != NULL)
goto descend;
/*
* Look for an available edge or val within the current
* bisection node.
*/
if (slot < (PCTRIE_COUNT - 1)) {
inc = PCTRIE_UNITLEVEL(node->pn_clev);
index = pctrie_trimkey(index, node->pn_clev);
do {
index += inc;
slot++;
child = node->pn_child[slot];
if (pctrie_isleaf(child)) {
m = pctrie_toval(child);
if (*m >= index)
return (m);
} else if (child != NULL)
goto descend;
} while (slot < (PCTRIE_COUNT - 1));
}
KASSERT(child == NULL || pctrie_isleaf(child),
("pctrie_lookup_ge: child is radix node"));
/*
* If a value 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(node->pn_clev > 0,
("pctrie_lookup_ge: pushing leaf's parent"));
KASSERT(tos < PCTRIE_LIMIT,
("pctrie_lookup_ge: stack overflow"));
stack[tos++] = node;
node = child;
}
}
/*
* Look up the nearest entry at a position less than or equal to index.
*/
uint64_t *
pctrie_lookup_le(struct pctrie *ptree, uint64_t index)
{
struct pctrie_node *stack[PCTRIE_LIMIT];
uint64_t inc;
uint64_t *m;
struct pctrie_node *child, *node;
#ifdef INVARIANTS
int loops = 0;
#endif
int slot, tos;
node = pctrie_getroot(ptree);
if (node == NULL)
return (NULL);
else if (pctrie_isleaf(node)) {
m = pctrie_toval(node);
if (*m <= 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 (pctrie_keybarr(node, index)) {
if (index > node->pn_owner) {
index = node->pn_owner + PCTRIE_COUNT *
PCTRIE_UNITLEVEL(node->pn_clev);
} else {
ascend:
KASSERT(++loops < 1000,
("pctrie_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);
node = stack[--tos];
} while (pctrie_slot(index,
node->pn_clev) == 0);
/*
* The following computation cannot overflow
* because index's slot at the current level
* is greater than 0.
*/
index = pctrie_trimkey(index,
node->pn_clev);
}
index--;
KASSERT(!pctrie_keybarr(node, index),
("pctrie_lookup_le: keybarr failed"));
}
slot = pctrie_slot(index, node->pn_clev);
child = node->pn_child[slot];
if (pctrie_isleaf(child)) {
m = pctrie_toval(child);
if (*m <= index)
return (m);
} else if (child != NULL)
goto descend;
/*
* Look for an available edge or value within the current
* bisection node.
*/
if (slot > 0) {
inc = PCTRIE_UNITLEVEL(node->pn_clev);
index |= inc - 1;
do {
index -= inc;
slot--;
child = node->pn_child[slot];
if (pctrie_isleaf(child)) {
m = pctrie_toval(child);
if (*m <= index)
return (m);
} else if (child != NULL)
goto descend;
} while (slot > 0);
}
KASSERT(child == NULL || pctrie_isleaf(child),
("pctrie_lookup_le: child is radix node"));
/*
* If a value 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(node->pn_clev > 0,
("pctrie_lookup_le: pushing leaf's parent"));
KASSERT(tos < PCTRIE_LIMIT,
("pctrie_lookup_le: stack overflow"));
stack[tos++] = node;
node = child;
}
}
/*
* Remove the specified index from the tree.
* Panics if the key is not present.
*/
void
pctrie_remove(struct pctrie *ptree, uint64_t index, pctrie_free_t freefn)
{
struct pctrie_node *node, *parent;
uint64_t *m;
int i, slot;
node = pctrie_getroot(ptree);
if (pctrie_isleaf(node)) {
m = pctrie_toval(node);
if (*m != index)
panic("%s: invalid key found", __func__);
pctrie_setroot(ptree, NULL);
return;
}
parent = NULL;
for (;;) {
if (node == NULL)
panic("pctrie_remove: impossible to locate the key");
slot = pctrie_slot(index, node->pn_clev);
if (pctrie_isleaf(node->pn_child[slot])) {
m = pctrie_toval(node->pn_child[slot]);
if (*m != index)
panic("%s: invalid key found", __func__);
node->pn_child[slot] = NULL;
node->pn_count--;
if (node->pn_count > 1)
break;
for (i = 0; i < PCTRIE_COUNT; i++)
if (node->pn_child[i] != NULL)
break;
KASSERT(i != PCTRIE_COUNT,
("%s: invalid node configuration", __func__));
if (parent == NULL)
pctrie_setroot(ptree, node->pn_child[i]);
else {
slot = pctrie_slot(index, parent->pn_clev);
KASSERT(parent->pn_child[slot] == node,
("%s: invalid child value", __func__));
parent->pn_child[slot] = node->pn_child[i];
}
node->pn_count--;
node->pn_child[i] = NULL;
pctrie_node_put(ptree, node, freefn);
break;
}
parent = node;
node = node->pn_child[slot];
}
}
/*
* Remove and free all the nodes from the tree.
* This function is recursive but there is a tight control on it as the
* maximum depth of the tree is fixed.
*/
void
pctrie_reclaim_allnodes(struct pctrie *ptree, pctrie_free_t freefn)
{
struct pctrie_node *root;
root = pctrie_getroot(ptree);
if (root == NULL)
return;
pctrie_setroot(ptree, NULL);
if (!pctrie_isleaf(root))
pctrie_reclaim_allnodes_int(ptree, root, freefn);
}
#ifdef DDB
/*
* Show details about the given node.
*/
DB_SHOW_COMMAND(pctrienode, db_show_pctrienode)
{
struct pctrie_node *node;
int i;
if (!have_addr)
return;
node = (struct pctrie_node *)addr;
db_printf("node %p, owner %jx, children count %u, level %u:\n",
(void *)node, (uintmax_t)node->pn_owner, node->pn_count,
node->pn_clev);
for (i = 0; i < PCTRIE_COUNT; i++)
if (node->pn_child[i] != NULL)
db_printf("slot: %d, val: %p, value: %p, clev: %d\n",
i, (void *)node->pn_child[i],
pctrie_isleaf(node->pn_child[i]) ?
pctrie_toval(node->pn_child[i]) : NULL,
node->pn_clev);
}
#endif /* DDB */

167
sys/kern/vfs_subr.c
View File

@ -65,6 +65,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h> #include <sys/malloc.h>
#include <sys/mount.h> #include <sys/mount.h>
#include <sys/namei.h> #include <sys/namei.h>
#include <sys/pctrie.h>
#include <sys/priv.h> #include <sys/priv.h>
#include <sys/reboot.h> #include <sys/reboot.h>
#include <sys/rwlock.h> #include <sys/rwlock.h>
@ -184,6 +185,8 @@ static struct mtx vnode_free_list_mtx;
/* Publicly exported FS */ /* Publicly exported FS */
struct nfs_public nfs_pub; struct nfs_public nfs_pub;
static uma_zone_t buf_trie_zone;
/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
static uma_zone_t vnode_zone; static uma_zone_t vnode_zone;
static uma_zone_t vnodepoll_zone; static uma_zone_t vnodepoll_zone;
@ -283,6 +286,24 @@ SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
/* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
static int vnsz2log; static int vnsz2log;
/*
* Support for the bufobj clean & dirty pctrie.
*/
static void *
buf_trie_alloc(struct pctrie *ptree)
{
return uma_zalloc(buf_trie_zone, M_NOWAIT);
}
static void
buf_trie_free(struct pctrie *ptree, void *node)
{
uma_zfree(buf_trie_zone, node);
}
PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
/* /*
* Initialize the vnode management data structures. * Initialize the vnode management data structures.
* *
@ -328,6 +349,15 @@ vntblinit(void *dummy __unused)
NULL, NULL, UMA_ALIGN_PTR, 0); NULL, NULL, UMA_ALIGN_PTR, 0);
vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
/*
* Preallocate enough nodes to support one-per buf so that
* we can not fail an insert. reassignbuf() callers can not
* tolerate the insertion failure.
*/
buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
UMA_ZONE_NOFREE | UMA_ZONE_VM);
uma_prealloc(buf_trie_zone, nbuf);
/* /*
* Initialize the filesystem syncer. * Initialize the filesystem syncer.
*/ */
@ -1476,75 +1506,9 @@ vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize)
return (0); return (0);
} }
/*
* buf_splay() - splay tree core for the clean/dirty list of buffers in
* a vnode.
*
* NOTE: We have to deal with the special case of a background bitmap
* buffer, a situation where two buffers will have the same logical
* block offset. We want (1) only the foreground buffer to be accessed
* in a lookup and (2) must differentiate between the foreground and
* background buffer in the splay tree algorithm because the splay
* tree cannot normally handle multiple entities with the same 'index'.
* We accomplish this by adding differentiating flags to the splay tree's
* numerical domain.
*/
static
struct buf *
buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
{
struct buf dummy;
struct buf *lefttreemax, *righttreemin, *y;
if (root == NULL)
return (NULL);
lefttreemax = righttreemin = &dummy;
for (;;) {
if (lblkno < root->b_lblkno) {
if ((y = root->b_left) == NULL)
break;
if (lblkno < y->b_lblkno) {
/* Rotate right. */
root->b_left = y->b_right;
y->b_right = root;
root = y;
if ((y = root->b_left) == NULL)
break;
}
/* Link into the new root's right tree. */
righttreemin->b_left = root;
righttreemin = root;
} else if (lblkno > root->b_lblkno) {
if ((y = root->b_right) == NULL)
break;
if (lblkno > y->b_lblkno) {
/* Rotate left. */
root->b_right = y->b_left;
y->b_left = root;
root = y;
if ((y = root->b_right) == NULL)
break;
}
/* Link into the new root's left tree. */
lefttreemax->b_right = root;
lefttreemax = root;
} else {
break;
}
root = y;
}
/* Assemble the new root. */
lefttreemax->b_right = root->b_left;
righttreemin->b_left = root->b_right;
root->b_left = dummy.b_right;
root->b_right = dummy.b_left;
return (root);
}
static void static void
buf_vlist_remove(struct buf *bp) buf_vlist_remove(struct buf *bp)
{ {
struct buf *root;
struct bufv *bv; struct bufv *bv;
KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
@ -1556,33 +1520,23 @@ buf_vlist_remove(struct buf *bp)
bv = &bp->b_bufobj->bo_dirty; bv = &bp->b_bufobj->bo_dirty;
else else
bv = &bp->b_bufobj->bo_clean; bv = &bp->b_bufobj->bo_clean;
if (bp != bv->bv_root) { BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
KASSERT(root == bp, ("splay lookup failed in remove"));
}
if (bp->b_left == NULL) {
root = bp->b_right;
} else {
root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
root->b_right = bp->b_right;
}
bv->bv_root = root;
TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
bv->bv_cnt--; bv->bv_cnt--;
bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
} }
/* /*
* Add the buffer to the sorted clean or dirty block list using a * Add the buffer to the sorted clean or dirty block list.
* splay tree algorithm.
* *
* NOTE: xflags is passed as a constant, optimizing this inline function! * NOTE: xflags is passed as a constant, optimizing this inline function!
*/ */
static void static void
buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
{ {
struct buf *root;
struct bufv *bv; struct bufv *bv;
struct buf *n;
int error;
ASSERT_BO_LOCKED(bo); ASSERT_BO_LOCKED(bo);
KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
@ -1593,24 +1547,22 @@ buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
else else
bv = &bo->bo_clean; bv = &bo->bo_clean;
root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); /*
if (root == NULL) { * Keep the list ordered. Optimize empty list insertion. Assume
bp->b_left = NULL; * we tend to grow at the tail so lookup_le should usually be cheaper
bp->b_right = NULL; * than _ge.
*/
if (bv->bv_cnt == 0 ||
bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
} else if (bp->b_lblkno < root->b_lblkno) { else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
bp->b_left = root->b_left; TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
bp->b_right = root; else
root->b_left = NULL; TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
TAILQ_INSERT_BEFORE(root, bp, b_bobufs); error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
} else { if (error)
bp->b_right = root->b_right; panic("buf_vlist_add: Preallocated nodes insufficient.");
bp->b_left = root;
root->b_right = NULL;
TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
}
bv->bv_cnt++; bv->bv_cnt++;
bv->bv_root = bp;
} }
/* /*
@ -1631,21 +1583,10 @@ gbincore(struct bufobj *bo, daddr_t lblkno)
struct buf *bp; struct buf *bp;
ASSERT_BO_LOCKED(bo); ASSERT_BO_LOCKED(bo);
if ((bp = bo->bo_clean.bv_root) != NULL && bp->b_lblkno == lblkno) bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
if (bp != NULL)
return (bp); return (bp);
if ((bp = bo->bo_dirty.bv_root) != NULL && bp->b_lblkno == lblkno) return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
return (bp);
if ((bp = bo->bo_clean.bv_root) != NULL) {
bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
if (bp->b_lblkno == lblkno)
return (bp);
}
if ((bp = bo->bo_dirty.bv_root) != NULL) {
bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
if (bp->b_lblkno == lblkno)
return (bp);
}
return (NULL);
} }
/* /*
@ -2460,9 +2401,11 @@ vdropl(struct vnode *vp)
VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL")); VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
("clean blk trie not empty"));
VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL")); VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
("dirty blk trie not empty"));
VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));

51
sys/sys/_pctrie.h Normal file
View File

@ -0,0 +1,51 @@
/*
* Copyright (c) 2013 EMC Corp.
* Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
* Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef __SYS_PCTRIE_H_
#define __SYS_PCTRIE_H_
/*
* Radix tree root.
*/
struct pctrie {
uintptr_t pt_root;
};
#ifdef _KERNEL
static __inline boolean_t
pctrie_is_empty(struct pctrie *ptree)
{
return (ptree->pt_root == 0);
}
#endif /* _KERNEL */
#endif /* !__SYS_PCTRIE_H_ */

2
sys/sys/buf.h
View File

@ -106,8 +106,6 @@ struct buf {
daddr_t b_blkno; /* Underlying physical block number. */ daddr_t b_blkno; /* Underlying physical block number. */
off_t b_offset; /* Offset into file. */ off_t b_offset; /* Offset into file. */
TAILQ_ENTRY(buf) b_bobufs; /* (V) Buffer's associated vnode. */ TAILQ_ENTRY(buf) b_bobufs; /* (V) Buffer's associated vnode. */
struct buf *b_left; /* (V) splay tree link */
struct buf *b_right; /* (V) splay tree link */
uint32_t b_vflags; /* (V) BV_* flags */ uint32_t b_vflags; /* (V) BV_* flags */
TAILQ_ENTRY(buf) b_freelist; /* (Q) Free list position inactive. */ TAILQ_ENTRY(buf) b_freelist; /* (Q) Free list position inactive. */
unsigned short b_qindex; /* (Q) buffer queue index */ unsigned short b_qindex; /* (Q) buffer queue index */

3
sys/sys/bufobj.h
View File

@ -54,6 +54,7 @@
#include <sys/queue.h> #include <sys/queue.h>
#include <sys/_lock.h> #include <sys/_lock.h>
#include <sys/_mutex.h> #include <sys/_mutex.h>
#include <sys/_pctrie.h>
struct bufobj; struct bufobj;
struct buf_ops; struct buf_ops;
@ -65,7 +66,7 @@ TAILQ_HEAD(buflists, buf);
/* A Buffer splay list */ /* A Buffer splay list */
struct bufv { struct bufv {
struct buflists bv_hd; /* Sorted blocklist */ struct buflists bv_hd; /* Sorted blocklist */
struct buf *bv_root; /* Buf splay tree */ struct pctrie bv_root; /* Buf trie */
int bv_cnt; /* Number of buffers */ int bv_cnt; /* Number of buffers */
}; };

119
sys/sys/pctrie.h Normal file
View File

@ -0,0 +1,119 @@
/*
* Copyright (c) 2013 EMC Corp.
* Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
* Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_PCTRIE_H_
#define _SYS_PCTRIE_H_
#include <sys/_pctrie.h>
#ifdef _KERNEL
#define PCTRIE_DEFINE(name, type, field, allocfn, freefn) \
\
CTASSERT(sizeof(((struct type *)0)->field) == sizeof(uint64_t)); \
CTASSERT((__offsetof(struct type, field) & (sizeof(uint64_t) - 1)) == 0); \
\
static __inline struct type * \
name##_PCTRIE_VAL2PTR(uint64_t *val) \
{ \
\
if (val == NULL) \
return (NULL); \
return (struct type *) \
((uintptr_t)val - __offsetof(struct type, field)); \
} \
\
static __inline uint64_t * \
name##_PCTRIE_PTR2VAL(struct type *ptr) \
{ \
\
return &ptr->field; \
} \
\
static __inline int \
name##_PCTRIE_INSERT(struct pctrie *ptree, struct type *ptr) \
{ \
\
return pctrie_insert(ptree, name##_PCTRIE_PTR2VAL(ptr), \
allocfn); \
} \
\
static __inline struct type * \
name##_PCTRIE_LOOKUP(struct pctrie *ptree, uint64_t key) \
{ \
\
return name##_PCTRIE_VAL2PTR(pctrie_lookup(ptree, key)); \
} \
\
static __inline struct type * \
name##_PCTRIE_LOOKUP_LE(struct pctrie *ptree, uint64_t key) \
{ \
\
return name##_PCTRIE_VAL2PTR(pctrie_lookup_le(ptree, key)); \
} \
\
static __inline struct type * \
name##_PCTRIE_LOOKUP_GE(struct pctrie *ptree, uint64_t key) \
{ \
\
return name##_PCTRIE_VAL2PTR(pctrie_lookup_ge(ptree, key)); \
} \
\
static __inline void \
name##_PCTRIE_RECLAIM(struct pctrie *ptree) \
{ \
\
pctrie_reclaim_allnodes(ptree, freefn); \
} \
\
static __inline void \
name##_PCTRIE_REMOVE(struct pctrie *ptree, uint64_t key) \
{ \
\
pctrie_remove(ptree, key, freefn); \
}
typedef void *(*pctrie_alloc_t)(struct pctrie *ptree);
typedef void (*pctrie_free_t)(struct pctrie *ptree, void *node);
int pctrie_insert(struct pctrie *ptree, uint64_t *val,
pctrie_alloc_t allocfn);
uint64_t *pctrie_lookup(struct pctrie *ptree, uint64_t key);
uint64_t *pctrie_lookup_ge(struct pctrie *ptree, uint64_t key);
uint64_t *pctrie_lookup_le(struct pctrie *ptree, uint64_t key);
void pctrie_reclaim_allnodes(struct pctrie *ptree,
pctrie_free_t freefn);
void pctrie_remove(struct pctrie *ptree, uint64_t key,
pctrie_free_t freefn);
size_t pctrie_node_size(void);
int pctrie_zone_init(void *mem, int size, int flags);
#endif /* _KERNEL */
#endif /* !_SYS_PCTRIE_H_ */