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NetBSD/sys/kern/subr_pool.c

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/* $NetBSD: subr_pool.c,v 1.76 2002/03/13 10:57:18 simonb Exp $ */
/*-
* Copyright (c) 1997, 1999, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg; by Jason R. Thorpe of the Numerical Aerospace
* Simulation Facility, NASA Ames Research Center.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.76 2002/03/13 10:57:18 simonb Exp $");
#include "opt_pool.h"
#include "opt_poollog.h"
#include "opt_lockdebug.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/pool.h>
#include <sys/syslog.h>
#include <uvm/uvm.h>
/*
* Pool resource management utility.
*
* Memory is allocated in pages which are split into pieces according
* to the pool item size. Each page is kept on a list headed by `pr_pagelist'
* in the pool structure and the individual pool items are on a linked list
* headed by `ph_itemlist' in each page header. The memory for building
* the page list is either taken from the allocated pages themselves (for
* small pool items) or taken from an internal pool of page headers (`phpool').
*/
/* List of all pools */
TAILQ_HEAD(,pool) pool_head = TAILQ_HEAD_INITIALIZER(pool_head);
/* Private pool for page header structures */
static struct pool phpool;
#ifdef POOL_SUBPAGE
/* Pool of subpages for use by normal pools. */
static struct pool psppool;
#endif
/* # of seconds to retain page after last use */
int pool_inactive_time = 10;
/* Next candidate for drainage (see pool_drain()) */
static struct pool *drainpp;
/* This spin lock protects both pool_head and drainpp. */
struct simplelock pool_head_slock = SIMPLELOCK_INITIALIZER;
struct pool_item_header {
/* Page headers */
TAILQ_ENTRY(pool_item_header)
ph_pagelist; /* pool page list */
TAILQ_HEAD(,pool_item) ph_itemlist; /* chunk list for this page */
LIST_ENTRY(pool_item_header)
ph_hashlist; /* Off-page page headers */
int ph_nmissing; /* # of chunks in use */
caddr_t ph_page; /* this page's address */
struct timeval ph_time; /* last referenced */
};
TAILQ_HEAD(pool_pagelist,pool_item_header);
struct pool_item {
#ifdef DIAGNOSTIC
int pi_magic;
#endif
#define PI_MAGIC 0xdeadbeef
/* Other entries use only this list entry */
TAILQ_ENTRY(pool_item) pi_list;
};
#define PR_HASH_INDEX(pp,addr) \
(((u_long)(addr) >> (pp)->pr_alloc->pa_pageshift) & \
(PR_HASHTABSIZE - 1))
#define POOL_NEEDS_CATCHUP(pp) \
((pp)->pr_nitems < (pp)->pr_minitems)
/*
* Pool cache management.
*
* Pool caches provide a way for constructed objects to be cached by the
* pool subsystem. This can lead to performance improvements by avoiding
* needless object construction/destruction; it is deferred until absolutely
* necessary.
*
* Caches are grouped into cache groups. Each cache group references
* up to 16 constructed objects. When a cache allocates an object
* from the pool, it calls the object's constructor and places it into
* a cache group. When a cache group frees an object back to the pool,
* it first calls the object's destructor. This allows the object to
* persist in constructed form while freed to the cache.
*
* Multiple caches may exist for each pool. This allows a single
* object type to have multiple constructed forms. The pool references
* each cache, so that when a pool is drained by the pagedaemon, it can
* drain each individual cache as well. Each time a cache is drained,
* the most idle cache group is freed to the pool in its entirety.
*
* Pool caches are layed on top of pools. By layering them, we can avoid
* the complexity of cache management for pools which would not benefit
* from it.
*/
/* The cache group pool. */
static struct pool pcgpool;
static void pool_cache_reclaim(struct pool_cache *);
static int pool_catchup(struct pool *);
static void pool_prime_page(struct pool *, caddr_t,
struct pool_item_header *);
void *pool_allocator_alloc(struct pool *, int);
void pool_allocator_free(struct pool *, void *);
static void pool_print1(struct pool *, const char *,
void (*)(const char *, ...));
/*
* Pool log entry. An array of these is allocated in pool_init().
*/
struct pool_log {
const char *pl_file;
long pl_line;
int pl_action;
#define PRLOG_GET 1
#define PRLOG_PUT 2
void *pl_addr;
};
/* Number of entries in pool log buffers */
#ifndef POOL_LOGSIZE
#define POOL_LOGSIZE 10
#endif
int pool_logsize = POOL_LOGSIZE;
#ifdef POOL_DIAGNOSTIC
static __inline void
pr_log(struct pool *pp, void *v, int action, const char *file, long line)
{
int n = pp->pr_curlogentry;
struct pool_log *pl;
if ((pp->pr_roflags & PR_LOGGING) == 0)
return;
/*
* Fill in the current entry. Wrap around and overwrite
* the oldest entry if necessary.
*/
pl = &pp->pr_log[n];
pl->pl_file = file;
pl->pl_line = line;
pl->pl_action = action;
pl->pl_addr = v;
if (++n >= pp->pr_logsize)
n = 0;
pp->pr_curlogentry = n;
}
static void
pr_printlog(struct pool *pp, struct pool_item *pi,
void (*pr)(const char *, ...))
{
int i = pp->pr_logsize;
int n = pp->pr_curlogentry;
if ((pp->pr_roflags & PR_LOGGING) == 0)
return;
/*
* Print all entries in this pool's log.
*/
while (i-- > 0) {
struct pool_log *pl = &pp->pr_log[n];
if (pl->pl_action != 0) {
if (pi == NULL || pi == pl->pl_addr) {
(*pr)("\tlog entry %d:\n", i);
(*pr)("\t\taction = %s, addr = %p\n",
pl->pl_action == PRLOG_GET ? "get" : "put",
pl->pl_addr);
(*pr)("\t\tfile: %s at line %lu\n",
pl->pl_file, pl->pl_line);
}
}
if (++n >= pp->pr_logsize)
n = 0;
}
}
static __inline void
pr_enter(struct pool *pp, const char *file, long line)
{
if (__predict_false(pp->pr_entered_file != NULL)) {
printf("pool %s: reentrancy at file %s line %ld\n",
pp->pr_wchan, file, line);
printf(" previous entry at file %s line %ld\n",
pp->pr_entered_file, pp->pr_entered_line);
panic("pr_enter");
}
pp->pr_entered_file = file;
pp->pr_entered_line = line;
}
static __inline void
pr_leave(struct pool *pp)
{
if (__predict_false(pp->pr_entered_file == NULL)) {
printf("pool %s not entered?\n", pp->pr_wchan);
panic("pr_leave");
}
pp->pr_entered_file = NULL;
pp->pr_entered_line = 0;
}
static __inline void
pr_enter_check(struct pool *pp, void (*pr)(const char *, ...))
{
if (pp->pr_entered_file != NULL)
(*pr)("\n\tcurrently entered from file %s line %ld\n",
pp->pr_entered_file, pp->pr_entered_line);
}
#else
#define pr_log(pp, v, action, file, line)
#define pr_printlog(pp, pi, pr)
#define pr_enter(pp, file, line)
#define pr_leave(pp)
#define pr_enter_check(pp, pr)
#endif /* POOL_DIAGNOSTIC */
/*
* Return the pool page header based on page address.
*/
static __inline struct pool_item_header *
pr_find_pagehead(struct pool *pp, caddr_t page)
{
struct pool_item_header *ph;
if ((pp->pr_roflags & PR_PHINPAGE) != 0)
return ((struct pool_item_header *)(page + pp->pr_phoffset));
for (ph = LIST_FIRST(&pp->pr_hashtab[PR_HASH_INDEX(pp, page)]);
ph != NULL;
ph = LIST_NEXT(ph, ph_hashlist)) {
if (ph->ph_page == page)
return (ph);
}
return (NULL);
}
/*
* Remove a page from the pool.
*/
static __inline void
pr_rmpage(struct pool *pp, struct pool_item_header *ph,
struct pool_pagelist *pq)
{
int s;
/*
* If the page was idle, decrement the idle page count.
*/
if (ph->ph_nmissing == 0) {
#ifdef DIAGNOSTIC
if (pp->pr_nidle == 0)
panic("pr_rmpage: nidle inconsistent");
if (pp->pr_nitems < pp->pr_itemsperpage)
panic("pr_rmpage: nitems inconsistent");
#endif
pp->pr_nidle--;
}
pp->pr_nitems -= pp->pr_itemsperpage;
/*
* Unlink a page from the pool and release it (or queue it for release).
*/
TAILQ_REMOVE(&pp->pr_pagelist, ph, ph_pagelist);
if (pq) {
TAILQ_INSERT_HEAD(pq, ph, ph_pagelist);
} else {
pool_allocator_free(pp, ph->ph_page);
if ((pp->pr_roflags & PR_PHINPAGE) == 0) {
LIST_REMOVE(ph, ph_hashlist);
s = splhigh();
pool_put(&phpool, ph);
splx(s);
}
}
pp->pr_npages--;
pp->pr_npagefree++;
if (pp->pr_curpage == ph) {
/*
* Find a new non-empty page header, if any.
* Start search from the page head, to increase the
* chance for "high water" pages to be freed.
*/
TAILQ_FOREACH(ph, &pp->pr_pagelist, ph_pagelist)
if (TAILQ_FIRST(&ph->ph_itemlist) != NULL)
break;
pp->pr_curpage = ph;
}
}
/*
* Initialize the given pool resource structure.
*
* We export this routine to allow other kernel parts to declare
* static pools that must be initialized before malloc() is available.
*/
void
pool_init(struct pool *pp, size_t size, u_int align, u_int ioff, int flags,
const char *wchan, struct pool_allocator *palloc)
{
int off, slack, i;
#ifdef POOL_DIAGNOSTIC
/*
* Always log if POOL_DIAGNOSTIC is defined.
*/
if (pool_logsize != 0)
flags |= PR_LOGGING;
#endif
#ifdef POOL_SUBPAGE
/*
* XXX We don't provide a real `nointr' back-end
* yet; all sub-pages come from a kmem back-end.
* maybe some day...
*/
if (palloc == NULL) {
extern struct pool_allocator pool_allocator_kmem_subpage;
palloc = &pool_allocator_kmem_subpage;
}
/*
* We'll assume any user-specified back-end allocator
* will deal with sub-pages, or simply don't care.
*/
#else
if (palloc == NULL)
palloc = &pool_allocator_kmem;
#endif /* POOL_SUBPAGE */
if ((palloc->pa_flags & PA_INITIALIZED) == 0) {
if (palloc->pa_pagesz == 0) {
#ifdef POOL_SUBPAGE
if (palloc == &pool_allocator_kmem)
palloc->pa_pagesz = PAGE_SIZE;
else
palloc->pa_pagesz = POOL_SUBPAGE;
#else
palloc->pa_pagesz = PAGE_SIZE;
#endif /* POOL_SUBPAGE */
}
TAILQ_INIT(&palloc->pa_list);
simple_lock_init(&palloc->pa_slock);
palloc->pa_pagemask = ~(palloc->pa_pagesz - 1);
palloc->pa_pageshift = ffs(palloc->pa_pagesz) - 1;
palloc->pa_flags |= PA_INITIALIZED;
}
if (align == 0)
align = ALIGN(1);
if (size < sizeof(struct pool_item))
size = sizeof(struct pool_item);
size = ALIGN(size);
#ifdef DIAGNOSTIC
if (size > palloc->pa_pagesz)
panic("pool_init: pool item size (%lu) too large",
(u_long)size);
#endif
/*
* Initialize the pool structure.
*/
TAILQ_INIT(&pp->pr_pagelist);
TAILQ_INIT(&pp->pr_cachelist);
pp->pr_curpage = NULL;
pp->pr_npages = 0;
pp->pr_minitems = 0;
pp->pr_minpages = 0;
pp->pr_maxpages = UINT_MAX;
pp->pr_roflags = flags;
pp->pr_flags = 0;
pp->pr_size = size;
pp->pr_align = align;
pp->pr_wchan = wchan;
pp->pr_alloc = palloc;
pp->pr_nitems = 0;
pp->pr_nout = 0;
pp->pr_hardlimit = UINT_MAX;
pp->pr_hardlimit_warning = NULL;
pp->pr_hardlimit_ratecap.tv_sec = 0;
pp->pr_hardlimit_ratecap.tv_usec = 0;
pp->pr_hardlimit_warning_last.tv_sec = 0;
pp->pr_hardlimit_warning_last.tv_usec = 0;
pp->pr_drain_hook = NULL;
pp->pr_drain_hook_arg = NULL;
/*
* Decide whether to put the page header off page to avoid
* wasting too large a part of the page. Off-page page headers
* go on a hash table, so we can match a returned item
* with its header based on the page address.
* We use 1/16 of the page size as the threshold (XXX: tune)
*/
if (pp->pr_size < palloc->pa_pagesz/16) {
/* Use the end of the page for the page header */
pp->pr_roflags |= PR_PHINPAGE;
pp->pr_phoffset = off = palloc->pa_pagesz -
ALIGN(sizeof(struct pool_item_header));
} else {
/* The page header will be taken from our page header pool */
pp->pr_phoffset = 0;
off = palloc->pa_pagesz;
for (i = 0; i < PR_HASHTABSIZE; i++) {
LIST_INIT(&pp->pr_hashtab[i]);
}
}
/*
* Alignment is to take place at `ioff' within the item. This means
* we must reserve up to `align - 1' bytes on the page to allow
* appropriate positioning of each item.
*
* Silently enforce `0 <= ioff < align'.
*/
pp->pr_itemoffset = ioff = ioff % align;
pp->pr_itemsperpage = (off - ((align - ioff) % align)) / pp->pr_size;
KASSERT(pp->pr_itemsperpage != 0);
/*
* Use the slack between the chunks and the page header
* for "cache coloring".
*/
slack = off - pp->pr_itemsperpage * pp->pr_size;
pp->pr_maxcolor = (slack / align) * align;
pp->pr_curcolor = 0;
pp->pr_nget = 0;
pp->pr_nfail = 0;
pp->pr_nput = 0;
pp->pr_npagealloc = 0;
pp->pr_npagefree = 0;
pp->pr_hiwat = 0;
pp->pr_nidle = 0;
#ifdef POOL_DIAGNOSTIC
if (flags & PR_LOGGING) {
if (kmem_map == NULL ||
(pp->pr_log = malloc(pool_logsize * sizeof(struct pool_log),
M_TEMP, M_NOWAIT)) == NULL)
pp->pr_roflags &= ~PR_LOGGING;
pp->pr_curlogentry = 0;
pp->pr_logsize = pool_logsize;
}
#endif
pp->pr_entered_file = NULL;
pp->pr_entered_line = 0;
simple_lock_init(&pp->pr_slock);
/*
* Initialize private page header pool and cache magazine pool if we
* haven't done so yet.
* XXX LOCKING.
*/
if (phpool.pr_size == 0) {
#ifdef POOL_SUBPAGE
pool_init(&phpool, sizeof(struct pool_item_header), 0, 0, 0,
"phpool", &pool_allocator_kmem);
pool_init(&psppool, POOL_SUBPAGE, POOL_SUBPAGE, 0,
PR_RECURSIVE, "psppool", &pool_allocator_kmem);
#else
pool_init(&phpool, sizeof(struct pool_item_header), 0, 0,
0, "phpool", NULL);
#endif
pool_init(&pcgpool, sizeof(struct pool_cache_group), 0, 0,
0, "pcgpool", NULL);
}
/* Insert into the list of all pools. */
simple_lock(&pool_head_slock);
TAILQ_INSERT_TAIL(&pool_head, pp, pr_poollist);
simple_unlock(&pool_head_slock);
/* Insert this into the list of pools using this allocator. */
simple_lock(&palloc->pa_slock);
TAILQ_INSERT_TAIL(&palloc->pa_list, pp, pr_alloc_list);
simple_unlock(&palloc->pa_slock);
}
/*
* De-commision a pool resource.
*/
void
pool_destroy(struct pool *pp)
{
struct pool_item_header *ph;
struct pool_cache *pc;
/* Locking order: pool_allocator -> pool */
simple_lock(&pp->pr_alloc->pa_slock);
TAILQ_REMOVE(&pp->pr_alloc->pa_list, pp, pr_alloc_list);
simple_unlock(&pp->pr_alloc->pa_slock);
/* Destroy all caches for this pool. */
while ((pc = TAILQ_FIRST(&pp->pr_cachelist)) != NULL)
pool_cache_destroy(pc);
#ifdef DIAGNOSTIC
if (pp->pr_nout != 0) {
pr_printlog(pp, NULL, printf);
panic("pool_destroy: pool busy: still out: %u\n",
pp->pr_nout);
}
#endif
/* Remove all pages */
while ((ph = TAILQ_FIRST(&pp->pr_pagelist)) != NULL)
pr_rmpage(pp, ph, NULL);
/* Remove from global pool list */
simple_lock(&pool_head_slock);
TAILQ_REMOVE(&pool_head, pp, pr_poollist);
if (drainpp == pp) {
drainpp = NULL;
}
simple_unlock(&pool_head_slock);
#ifdef POOL_DIAGNOSTIC
if ((pp->pr_roflags & PR_LOGGING) != 0)
free(pp->pr_log, M_TEMP);
#endif
}
void
pool_set_drain_hook(struct pool *pp, void (*fn)(void *, int), void *arg)
{
/* XXX no locking -- must be used just after pool_init() */
#ifdef DIAGNOSTIC
if (pp->pr_drain_hook != NULL)
panic("pool_set_drain_hook(%s): already set", pp->pr_wchan);
#endif
pp->pr_drain_hook = fn;
pp->pr_drain_hook_arg = arg;
}
static __inline struct pool_item_header *
pool_alloc_item_header(struct pool *pp, caddr_t storage, int flags)
{
struct pool_item_header *ph;
int s;
LOCK_ASSERT(simple_lock_held(&pp->pr_slock) == 0);
if ((pp->pr_roflags & PR_PHINPAGE) != 0)
ph = (struct pool_item_header *) (storage + pp->pr_phoffset);
else {
s = splhigh();
ph = pool_get(&phpool, flags);
splx(s);
}
return (ph);
}
/*
* Grab an item from the pool; must be called at appropriate spl level
*/
void *
#ifdef POOL_DIAGNOSTIC
_pool_get(struct pool *pp, int flags, const char *file, long line)
#else
pool_get(struct pool *pp, int flags)
#endif
{
struct pool_item *pi;
struct pool_item_header *ph;
void *v;
#ifdef DIAGNOSTIC
if (__predict_false(curproc == NULL && doing_shutdown == 0 &&
(flags & PR_WAITOK) != 0))
panic("pool_get: must have NOWAIT");
#ifdef LOCKDEBUG
if (flags & PR_WAITOK)
simple_lock_only_held(NULL, "pool_get(PR_WAITOK)");
#endif
#endif /* DIAGNOSTIC */
simple_lock(&pp->pr_slock);
pr_enter(pp, file, line);
startover:
/*
* Check to see if we've reached the hard limit. If we have,
* and we can wait, then wait until an item has been returned to
* the pool.
*/
#ifdef DIAGNOSTIC
if (__predict_false(pp->pr_nout > pp->pr_hardlimit)) {
pr_leave(pp);
simple_unlock(&pp->pr_slock);
panic("pool_get: %s: crossed hard limit", pp->pr_wchan);
}
#endif
if (__predict_false(pp->pr_nout == pp->pr_hardlimit)) {
if (pp->pr_drain_hook != NULL) {
/*
* Since the drain hook is going to free things
* back to the pool, unlock, call the hook, re-lock,
* and check the hardlimit condition again.
*/
pr_leave(pp);
simple_unlock(&pp->pr_slock);
(*pp->pr_drain_hook)(pp->pr_drain_hook_arg, flags);
simple_lock(&pp->pr_slock);
pr_enter(pp, file, line);
if (pp->pr_nout < pp->pr_hardlimit)
goto startover;
}
if ((flags & PR_WAITOK) && !(flags & PR_LIMITFAIL)) {
/*
* XXX: A warning isn't logged in this case. Should
* it be?
*/
pp->pr_flags |= PR_WANTED;
pr_leave(pp);
ltsleep(pp, PSWP, pp->pr_wchan, 0, &pp->pr_slock);
pr_enter(pp, file, line);
goto startover;
}
/*
* Log a message that the hard limit has been hit.
*/
if (pp->pr_hardlimit_warning != NULL &&
ratecheck(&pp->pr_hardlimit_warning_last,
&pp->pr_hardlimit_ratecap))
log(LOG_ERR, "%s\n", pp->pr_hardlimit_warning);
pp->pr_nfail++;
pr_leave(pp);
simple_unlock(&pp->pr_slock);
return (NULL);
}
/*
* The convention we use is that if `curpage' is not NULL, then
* it points at a non-empty bucket. In particular, `curpage'
* never points at a page header which has PR_PHINPAGE set and
* has no items in its bucket.
*/
if ((ph = pp->pr_curpage) == NULL) {
#ifdef DIAGNOSTIC
if (pp->pr_nitems != 0) {
simple_unlock(&pp->pr_slock);
printf("pool_get: %s: curpage NULL, nitems %u\n",
pp->pr_wchan, pp->pr_nitems);
panic("pool_get: nitems inconsistent\n");
}
#endif
/*
* Call the back-end page allocator for more memory.
* Release the pool lock, as the back-end page allocator
* may block.
*/
pr_leave(pp);
simple_unlock(&pp->pr_slock);
v = pool_allocator_alloc(pp, flags);
if (__predict_true(v != NULL))
ph = pool_alloc_item_header(pp, v, flags);
simple_lock(&pp->pr_slock);
pr_enter(pp, file, line);
if (__predict_false(v == NULL || ph == NULL)) {
if (v != NULL)
pool_allocator_free(pp, v);
/*
* We were unable to allocate a page or item
* header, but we released the lock during
* allocation, so perhaps items were freed
* back to the pool. Check for this case.
*/
if (pp->pr_curpage != NULL)
goto startover;
if ((flags & PR_WAITOK) == 0) {
pp->pr_nfail++;
pr_leave(pp);
simple_unlock(&pp->pr_slock);
return (NULL);
}
/*
* Wait for items to be returned to this pool.
*
* XXX: maybe we should wake up once a second and
* try again?
*/
pp->pr_flags |= PR_WANTED;
/* PA_WANTED is already set on the allocator. */
pr_leave(pp);
ltsleep(pp, PSWP, pp->pr_wchan, 0, &pp->pr_slock);
pr_enter(pp, file, line);
goto startover;
}
/* We have more memory; add it to the pool */
pool_prime_page(pp, v, ph);
pp->pr_npagealloc++;
/* Start the allocation process over. */
goto startover;
}
if (__predict_false((v = pi = TAILQ_FIRST(&ph->ph_itemlist)) == NULL)) {
pr_leave(pp);
simple_unlock(&pp->pr_slock);
panic("pool_get: %s: page empty", pp->pr_wchan);
}
#ifdef DIAGNOSTIC
if (__predict_false(pp->pr_nitems == 0)) {
pr_leave(pp);
simple_unlock(&pp->pr_slock);
printf("pool_get: %s: items on itemlist, nitems %u\n",
pp->pr_wchan, pp->pr_nitems);
panic("pool_get: nitems inconsistent\n");
}
#endif
#ifdef POOL_DIAGNOSTIC
pr_log(pp, v, PRLOG_GET, file, line);
#endif
#ifdef DIAGNOSTIC
if (__predict_false(pi->pi_magic != PI_MAGIC)) {
pr_printlog(pp, pi, printf);
panic("pool_get(%s): free list modified: magic=%x; page %p;"
" item addr %p\n",
pp->pr_wchan, pi->pi_magic, ph->ph_page, pi);
}
#endif
/*
* Remove from item list.
*/
TAILQ_REMOVE(&ph->ph_itemlist, pi, pi_list);
pp->pr_nitems--;
pp->pr_nout++;
if (ph->ph_nmissing == 0) {
#ifdef DIAGNOSTIC
if (__predict_false(pp->pr_nidle == 0))
panic("pool_get: nidle inconsistent");
#endif
pp->pr_nidle--;
}
ph->ph_nmissing++;
if (TAILQ_FIRST(&ph->ph_itemlist) == NULL) {
#ifdef DIAGNOSTIC
if (__predict_false(ph->ph_nmissing != pp->pr_itemsperpage)) {
pr_leave(pp);
simple_unlock(&pp->pr_slock);
panic("pool_get: %s: nmissing inconsistent",
pp->pr_wchan);
}
#endif
/*
* Find a new non-empty page header, if any.
* Start search from the page head, to increase
* the chance for "high water" pages to be freed.
*
* Migrate empty pages to the end of the list. This
* will speed the update of curpage as pages become
* idle. Empty pages intermingled with idle pages
* is no big deal. As soon as a page becomes un-empty,
* it will move back to the head of the list.
*/
TAILQ_REMOVE(&pp->pr_pagelist, ph, ph_pagelist);
TAILQ_INSERT_TAIL(&pp->pr_pagelist, ph, ph_pagelist);
TAILQ_FOREACH(ph, &pp->pr_pagelist, ph_pagelist)
if (TAILQ_FIRST(&ph->ph_itemlist) != NULL)
break;
pp->pr_curpage = ph;
}
pp->pr_nget++;
/*
* If we have a low water mark and we are now below that low
* water mark, add more items to the pool.
*/
if (POOL_NEEDS_CATCHUP(pp) && pool_catchup(pp) != 0) {
/*
* XXX: Should we log a warning? Should we set up a timeout
* to try again in a second or so? The latter could break
* a caller's assumptions about interrupt protection, etc.
*/
}
pr_leave(pp);
simple_unlock(&pp->pr_slock);
return (v);
}
/*
* Internal version of pool_put(). Pool is already locked/entered.
*/
static void
pool_do_put(struct pool *pp, void *v)
{
struct pool_item *pi = v;
struct pool_item_header *ph;
caddr_t page;
int s;
LOCK_ASSERT(simple_lock_held(&pp->pr_slock));
page = (caddr_t)((u_long)v & pp->pr_alloc->pa_pagemask);
#ifdef DIAGNOSTIC
if (__predict_false(pp->pr_nout == 0)) {
printf("pool %s: putting with none out\n",
pp->pr_wchan);
panic("pool_put");
}
#endif
if (__predict_false((ph = pr_find_pagehead(pp, page)) == NULL)) {
pr_printlog(pp, NULL, printf);
panic("pool_put: %s: page header missing", pp->pr_wchan);
}
#ifdef LOCKDEBUG
/*
* Check if we're freeing a locked simple lock.
*/
simple_lock_freecheck((caddr_t)pi, ((caddr_t)pi) + pp->pr_size);
#endif
/*
* Return to item list.
*/
#ifdef DIAGNOSTIC
pi->pi_magic = PI_MAGIC;
#endif
#ifdef DEBUG
{
int i, *ip = v;
for (i = 0; i < pp->pr_size / sizeof(int); i++) {
*ip++ = PI_MAGIC;
}
}
#endif
TAILQ_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list);
ph->ph_nmissing--;
pp->pr_nput++;
pp->pr_nitems++;
pp->pr_nout--;
/* Cancel "pool empty" condition if it exists */
if (pp->pr_curpage == NULL)
pp->pr_curpage = ph;
if (pp->pr_flags & PR_WANTED) {
pp->pr_flags &= ~PR_WANTED;
if (ph->ph_nmissing == 0)
pp->pr_nidle++;
wakeup((caddr_t)pp);
return;
}
/*
* If this page is now complete, do one of two things:
*
* (1) If we have more pages than the page high water
* mark, free the page back to the system.
*
* (2) Move it to the end of the page list, so that
* we minimize our chances of fragmenting the
* pool. Idle pages migrate to the end (along with
* completely empty pages, so that we find un-empty
* pages more quickly when we update curpage) of the
* list so they can be more easily swept up by
* the pagedaemon when pages are scarce.
*/
if (ph->ph_nmissing == 0) {
pp->pr_nidle++;
if (pp->pr_npages > pp->pr_maxpages ||
(pp->pr_alloc->pa_flags & PA_WANT) != 0) {
pr_rmpage(pp, ph, NULL);
} else {
TAILQ_REMOVE(&pp->pr_pagelist, ph, ph_pagelist);
TAILQ_INSERT_TAIL(&pp->pr_pagelist, ph, ph_pagelist);
/*
* Update the timestamp on the page. A page must
* be idle for some period of time before it can
* be reclaimed by the pagedaemon. This minimizes
* ping-pong'ing for memory.
*/
s = splclock();
ph->ph_time = mono_time;
splx(s);
/*
* Update the current page pointer. Just look for
* the first page with any free items.
*
* XXX: Maybe we want an option to look for the
* page with the fewest available items, to minimize
* fragmentation?
*/
TAILQ_FOREACH(ph, &pp->pr_pagelist, ph_pagelist)
if (TAILQ_FIRST(&ph->ph_itemlist) != NULL)
break;
pp->pr_curpage = ph;
}
}
/*
* If the page has just become un-empty, move it to the head of
* the list, and make it the current page. The next allocation
* will get the item from this page, instead of further fragmenting
* the pool.
*/
else if (ph->ph_nmissing == (pp->pr_itemsperpage - 1)) {
TAILQ_REMOVE(&pp->pr_pagelist, ph, ph_pagelist);
TAILQ_INSERT_HEAD(&pp->pr_pagelist, ph, ph_pagelist);
pp->pr_curpage = ph;
}
}
/*
* Return resource to the pool; must be called at appropriate spl level
*/
#ifdef POOL_DIAGNOSTIC
void
_pool_put(struct pool *pp, void *v, const char *file, long line)
{
simple_lock(&pp->pr_slock);
pr_enter(pp, file, line);
pr_log(pp, v, PRLOG_PUT, file, line);
pool_do_put(pp, v);
pr_leave(pp);
simple_unlock(&pp->pr_slock);
}
#undef pool_put
#endif /* POOL_DIAGNOSTIC */
void
pool_put(struct pool *pp, void *v)
{
simple_lock(&pp->pr_slock);
pool_do_put(pp, v);
simple_unlock(&pp->pr_slock);
}
#ifdef POOL_DIAGNOSTIC
#define pool_put(h, v) _pool_put((h), (v), __FILE__, __LINE__)
#endif
/*
* Add N items to the pool.
*/
int
pool_prime(struct pool *pp, int n)
{
struct pool_item_header *ph;
caddr_t cp;
int newpages;
simple_lock(&pp->pr_slock);
newpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
while (newpages-- > 0) {
simple_unlock(&pp->pr_slock);
cp = pool_allocator_alloc(pp, PR_NOWAIT);
if (__predict_true(cp != NULL))
ph = pool_alloc_item_header(pp, cp, PR_NOWAIT);
simple_lock(&pp->pr_slock);
if (__predict_false(cp == NULL || ph == NULL)) {
if (cp != NULL)
pool_allocator_free(pp, cp);
break;
}
pool_prime_page(pp, cp, ph);
pp->pr_npagealloc++;
pp->pr_minpages++;
}
if (pp->pr_minpages >= pp->pr_maxpages)
pp->pr_maxpages = pp->pr_minpages + 1; /* XXX */
simple_unlock(&pp->pr_slock);
return (0);
}
/*
* Add a page worth of items to the pool.
*
* Note, we must be called with the pool descriptor LOCKED.
*/
static void
pool_prime_page(struct pool *pp, caddr_t storage, struct pool_item_header *ph)
{
struct pool_item *pi;
caddr_t cp = storage;
unsigned int align = pp->pr_align;
unsigned int ioff = pp->pr_itemoffset;
int n;
#ifdef DIAGNOSTIC
if (((u_long)cp & (pp->pr_alloc->pa_pagesz - 1)) != 0)
panic("pool_prime_page: %s: unaligned page", pp->pr_wchan);
#endif
if ((pp->pr_roflags & PR_PHINPAGE) == 0)
LIST_INSERT_HEAD(&pp->pr_hashtab[PR_HASH_INDEX(pp, cp)],
ph, ph_hashlist);
/*
* Insert page header.
*/
TAILQ_INSERT_HEAD(&pp->pr_pagelist, ph, ph_pagelist);
TAILQ_INIT(&ph->ph_itemlist);
ph->ph_page = storage;
ph->ph_nmissing = 0;
memset(&ph->ph_time, 0, sizeof(ph->ph_time));
pp->pr_nidle++;
/*
* Color this page.
*/
cp = (caddr_t)(cp + pp->pr_curcolor);
if ((pp->pr_curcolor += align) > pp->pr_maxcolor)
pp->pr_curcolor = 0;
/*
* Adjust storage to apply aligment to `pr_itemoffset' in each item.
*/
if (ioff != 0)
cp = (caddr_t)(cp + (align - ioff));
/*
* Insert remaining chunks on the bucket list.
*/
n = pp->pr_itemsperpage;
pp->pr_nitems += n;
while (n--) {
pi = (struct pool_item *)cp;
/* Insert on page list */
TAILQ_INSERT_TAIL(&ph->ph_itemlist, pi, pi_list);
#ifdef DIAGNOSTIC
pi->pi_magic = PI_MAGIC;
#endif
cp = (caddr_t)(cp + pp->pr_size);
}
/*
* If the pool was depleted, point at the new page.
*/
if (pp->pr_curpage == NULL)
pp->pr_curpage = ph;
if (++pp->pr_npages > pp->pr_hiwat)
pp->pr_hiwat = pp->pr_npages;
}
/*
* Used by pool_get() when nitems drops below the low water mark. This
* is used to catch up nitmes with the low water mark.
*
* Note 1, we never wait for memory here, we let the caller decide what to do.
*
* Note 2, we must be called with the pool already locked, and we return
* with it locked.
*/
static int
pool_catchup(struct pool *pp)
{
struct pool_item_header *ph;
caddr_t cp;
int error = 0;
while (POOL_NEEDS_CATCHUP(pp)) {
/*
* Call the page back-end allocator for more memory.
*
* XXX: We never wait, so should we bother unlocking
* the pool descriptor?
*/
simple_unlock(&pp->pr_slock);
cp = pool_allocator_alloc(pp, PR_NOWAIT);
if (__predict_true(cp != NULL))
ph = pool_alloc_item_header(pp, cp, PR_NOWAIT);
simple_lock(&pp->pr_slock);
if (__predict_false(cp == NULL || ph == NULL)) {
if (cp != NULL)
pool_allocator_free(pp, cp);
error = ENOMEM;
break;
}
pool_prime_page(pp, cp, ph);
pp->pr_npagealloc++;
}
return (error);
}
void
pool_setlowat(struct pool *pp, int n)
{
simple_lock(&pp->pr_slock);
pp->pr_minitems = n;
pp->pr_minpages = (n == 0)
? 0
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
/* Make sure we're caught up with the newly-set low water mark. */
if (POOL_NEEDS_CATCHUP(pp) && pool_catchup(pp) != 0) {
/*
* XXX: Should we log a warning? Should we set up a timeout
* to try again in a second or so? The latter could break
* a caller's assumptions about interrupt protection, etc.
*/
}
simple_unlock(&pp->pr_slock);
}
void
pool_sethiwat(struct pool *pp, int n)
{
simple_lock(&pp->pr_slock);
pp->pr_maxpages = (n == 0)
? 0
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
simple_unlock(&pp->pr_slock);
}
void
pool_sethardlimit(struct pool *pp, int n, const char *warnmess, int ratecap)
{
simple_lock(&pp->pr_slock);
pp->pr_hardlimit = n;
pp->pr_hardlimit_warning = warnmess;
pp->pr_hardlimit_ratecap.tv_sec = ratecap;
pp->pr_hardlimit_warning_last.tv_sec = 0;
pp->pr_hardlimit_warning_last.tv_usec = 0;
/*
* In-line version of pool_sethiwat(), because we don't want to
* release the lock.
*/
pp->pr_maxpages = (n == 0)
? 0
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
simple_unlock(&pp->pr_slock);
}
/*
* Release all complete pages that have not been used recently.
*/
int
#ifdef POOL_DIAGNOSTIC
_pool_reclaim(struct pool *pp, const char *file, long line)
#else
pool_reclaim(struct pool *pp)
#endif
{
struct pool_item_header *ph, *phnext;
struct pool_cache *pc;
struct timeval curtime;
struct pool_pagelist pq;
int s;
if (pp->pr_drain_hook != NULL) {
/*
* The drain hook must be called with the pool unlocked.
*/
(*pp->pr_drain_hook)(pp->pr_drain_hook_arg, PR_NOWAIT);
}
if (simple_lock_try(&pp->pr_slock) == 0)
return (0);
pr_enter(pp, file, line);
TAILQ_INIT(&pq);
/*
* Reclaim items from the pool's caches.
*/
TAILQ_FOREACH(pc, &pp->pr_cachelist, pc_poollist)
pool_cache_reclaim(pc);
s = splclock();
curtime = mono_time;
splx(s);
for (ph = TAILQ_FIRST(&pp->pr_pagelist); ph != NULL; ph = phnext) {
phnext = TAILQ_NEXT(ph, ph_pagelist);
/* Check our minimum page claim */
if (pp->pr_npages <= pp->pr_minpages)
break;
if (ph->ph_nmissing == 0) {
struct timeval diff;
timersub(&curtime, &ph->ph_time, &diff);
if (diff.tv_sec < pool_inactive_time)
continue;
/*
* If freeing this page would put us below
* the low water mark, stop now.
*/
if ((pp->pr_nitems - pp->pr_itemsperpage) <
pp->pr_minitems)
break;
pr_rmpage(pp, ph, &pq);
}
}
pr_leave(pp);
simple_unlock(&pp->pr_slock);
if (TAILQ_EMPTY(&pq))
return (0);
while ((ph = TAILQ_FIRST(&pq)) != NULL) {
TAILQ_REMOVE(&pq, ph, ph_pagelist);
pool_allocator_free(pp, ph->ph_page);
if (pp->pr_roflags & PR_PHINPAGE) {
continue;
}
LIST_REMOVE(ph, ph_hashlist);
s = splhigh();
pool_put(&phpool, ph);
splx(s);
}
return (1);
}
/*
* Drain pools, one at a time.
*
* Note, we must never be called from an interrupt context.
*/
void
pool_drain(void *arg)
{
struct pool *pp;
int s;
pp = NULL;
s = splvm();
simple_lock(&pool_head_slock);
if (drainpp == NULL) {
drainpp = TAILQ_FIRST(&pool_head);
}
if (drainpp) {
pp = drainpp;
drainpp = TAILQ_NEXT(pp, pr_poollist);
}
simple_unlock(&pool_head_slock);
pool_reclaim(pp);
splx(s);
}
/*
* Diagnostic helpers.
*/
void
pool_print(struct pool *pp, const char *modif)
{
int s;
s = splvm();
if (simple_lock_try(&pp->pr_slock) == 0) {
printf("pool %s is locked; try again later\n",
pp->pr_wchan);
splx(s);
return;
}
pool_print1(pp, modif, printf);
simple_unlock(&pp->pr_slock);
splx(s);
}
void
pool_printit(struct pool *pp, const char *modif, void (*pr)(const char *, ...))
{
int didlock = 0;
if (pp == NULL) {
(*pr)("Must specify a pool to print.\n");
return;
}
/*
* Called from DDB; interrupts should be blocked, and all
* other processors should be paused. We can skip locking
* the pool in this case.
*
* We do a simple_lock_try() just to print the lock
* status, however.
*/
if (simple_lock_try(&pp->pr_slock) == 0)
(*pr)("WARNING: pool %s is locked\n", pp->pr_wchan);
else
didlock = 1;
pool_print1(pp, modif, pr);
if (didlock)
simple_unlock(&pp->pr_slock);
}
static void
pool_print1(struct pool *pp, const char *modif, void (*pr)(const char *, ...))
{
struct pool_item_header *ph;
struct pool_cache *pc;
struct pool_cache_group *pcg;
#ifdef DIAGNOSTIC
struct pool_item *pi;
#endif
int i, print_log = 0, print_pagelist = 0, print_cache = 0;
char c;
while ((c = *modif++) != '\0') {
if (c == 'l')
print_log = 1;
if (c == 'p')
print_pagelist = 1;
if (c == 'c')
print_cache = 1;
modif++;
}
(*pr)("POOL %s: size %u, align %u, ioff %u, roflags 0x%08x\n",
pp->pr_wchan, pp->pr_size, pp->pr_align, pp->pr_itemoffset,
pp->pr_roflags);
(*pr)("\talloc %p\n", pp->pr_alloc);
(*pr)("\tminitems %u, minpages %u, maxpages %u, npages %u\n",
pp->pr_minitems, pp->pr_minpages, pp->pr_maxpages, pp->pr_npages);
(*pr)("\titemsperpage %u, nitems %u, nout %u, hardlimit %u\n",
pp->pr_itemsperpage, pp->pr_nitems, pp->pr_nout, pp->pr_hardlimit);
(*pr)("\n\tnget %lu, nfail %lu, nput %lu\n",
pp->pr_nget, pp->pr_nfail, pp->pr_nput);
(*pr)("\tnpagealloc %lu, npagefree %lu, hiwat %u, nidle %lu\n",
pp->pr_npagealloc, pp->pr_npagefree, pp->pr_hiwat, pp->pr_nidle);
if (print_pagelist == 0)
goto skip_pagelist;
if ((ph = TAILQ_FIRST(&pp->pr_pagelist)) != NULL)
(*pr)("\n\tpage list:\n");
for (; ph != NULL; ph = TAILQ_NEXT(ph, ph_pagelist)) {
(*pr)("\t\tpage %p, nmissing %d, time %lu,%lu\n",
ph->ph_page, ph->ph_nmissing,
(u_long)ph->ph_time.tv_sec,
(u_long)ph->ph_time.tv_usec);
#ifdef DIAGNOSTIC
TAILQ_FOREACH(pi, &ph->ph_itemlist, pi_list) {
if (pi->pi_magic != PI_MAGIC) {
(*pr)("\t\t\titem %p, magic 0x%x\n",
pi, pi->pi_magic);
}
}
#endif
}
if (pp->pr_curpage == NULL)
(*pr)("\tno current page\n");
else
(*pr)("\tcurpage %p\n", pp->pr_curpage->ph_page);
skip_pagelist:
if (print_log == 0)
goto skip_log;
(*pr)("\n");
if ((pp->pr_roflags & PR_LOGGING) == 0)
(*pr)("\tno log\n");
else
pr_printlog(pp, NULL, pr);
skip_log:
if (print_cache == 0)
goto skip_cache;
TAILQ_FOREACH(pc, &pp->pr_cachelist, pc_poollist) {
(*pr)("\tcache %p: allocfrom %p freeto %p\n", pc,
pc->pc_allocfrom, pc->pc_freeto);
(*pr)("\t hits %lu misses %lu ngroups %lu nitems %lu\n",
pc->pc_hits, pc->pc_misses, pc->pc_ngroups, pc->pc_nitems);
TAILQ_FOREACH(pcg, &pc->pc_grouplist, pcg_list) {
(*pr)("\t\tgroup %p: avail %d\n", pcg, pcg->pcg_avail);
for (i = 0; i < PCG_NOBJECTS; i++)
(*pr)("\t\t\t%p\n", pcg->pcg_objects[i]);
}
}
skip_cache:
pr_enter_check(pp, pr);
}
int
pool_chk(struct pool *pp, const char *label)
{
struct pool_item_header *ph;
int r = 0;
simple_lock(&pp->pr_slock);
TAILQ_FOREACH(ph, &pp->pr_pagelist, ph_pagelist) {
struct pool_item *pi;
int n;
caddr_t page;
page = (caddr_t)((u_long)ph & pp->pr_alloc->pa_pagemask);
if (page != ph->ph_page &&
(pp->pr_roflags & PR_PHINPAGE) != 0) {
if (label != NULL)
printf("%s: ", label);
printf("pool(%p:%s): page inconsistency: page %p;"
" at page head addr %p (p %p)\n", pp,
pp->pr_wchan, ph->ph_page,
ph, page);
r++;
goto out;
}
for (pi = TAILQ_FIRST(&ph->ph_itemlist), n = 0;
pi != NULL;
pi = TAILQ_NEXT(pi,pi_list), n++) {
#ifdef DIAGNOSTIC
if (pi->pi_magic != PI_MAGIC) {
if (label != NULL)
printf("%s: ", label);
printf("pool(%s): free list modified: magic=%x;"
" page %p; item ordinal %d;"
" addr %p (p %p)\n",
pp->pr_wchan, pi->pi_magic, ph->ph_page,
n, pi, page);
panic("pool");
}
#endif
page =
(caddr_t)((u_long)pi & pp->pr_alloc->pa_pagemask);
if (page == ph->ph_page)
continue;
if (label != NULL)
printf("%s: ", label);
printf("pool(%p:%s): page inconsistency: page %p;"
" item ordinal %d; addr %p (p %p)\n", pp,
pp->pr_wchan, ph->ph_page,
n, pi, page);
r++;
goto out;
}
}
out:
simple_unlock(&pp->pr_slock);
return (r);
}
/*
* pool_cache_init:
*
* Initialize a pool cache.
*
* NOTE: If the pool must be protected from interrupts, we expect
* to be called at the appropriate interrupt priority level.
*/
void
pool_cache_init(struct pool_cache *pc, struct pool *pp,
int (*ctor)(void *, void *, int),
void (*dtor)(void *, void *),
void *arg)
{
TAILQ_INIT(&pc->pc_grouplist);
simple_lock_init(&pc->pc_slock);
pc->pc_allocfrom = NULL;
pc->pc_freeto = NULL;
pc->pc_pool = pp;
pc->pc_ctor = ctor;
pc->pc_dtor = dtor;
pc->pc_arg = arg;
pc->pc_hits = 0;
pc->pc_misses = 0;
pc->pc_ngroups = 0;
pc->pc_nitems = 0;
simple_lock(&pp->pr_slock);
TAILQ_INSERT_TAIL(&pp->pr_cachelist, pc, pc_poollist);
simple_unlock(&pp->pr_slock);
}
/*
* pool_cache_destroy:
*
* Destroy a pool cache.
*/
void
pool_cache_destroy(struct pool_cache *pc)
{
struct pool *pp = pc->pc_pool;
/* First, invalidate the entire cache. */
pool_cache_invalidate(pc);
/* ...and remove it from the pool's cache list. */
simple_lock(&pp->pr_slock);
TAILQ_REMOVE(&pp->pr_cachelist, pc, pc_poollist);
simple_unlock(&pp->pr_slock);
}
static __inline void *
pcg_get(struct pool_cache_group *pcg)
{
void *object;
u_int idx;
KASSERT(pcg->pcg_avail <= PCG_NOBJECTS);
KASSERT(pcg->pcg_avail != 0);
idx = --pcg->pcg_avail;
KASSERT(pcg->pcg_objects[idx] != NULL);
object = pcg->pcg_objects[idx];
pcg->pcg_objects[idx] = NULL;
return (object);
}
static __inline void
pcg_put(struct pool_cache_group *pcg, void *object)
{
u_int idx;
KASSERT(pcg->pcg_avail < PCG_NOBJECTS);
idx = pcg->pcg_avail++;
KASSERT(pcg->pcg_objects[idx] == NULL);
pcg->pcg_objects[idx] = object;
}
/*
* pool_cache_get:
*
* Get an object from a pool cache.
*/
void *
pool_cache_get(struct pool_cache *pc, int flags)
{
struct pool_cache_group *pcg;
void *object;
#ifdef LOCKDEBUG
if (flags & PR_WAITOK)
simple_lock_only_held(NULL, "pool_cache_get(PR_WAITOK)");
#endif
simple_lock(&pc->pc_slock);
if ((pcg = pc->pc_allocfrom) == NULL) {
TAILQ_FOREACH(pcg, &pc->pc_grouplist, pcg_list) {
if (pcg->pcg_avail != 0) {
pc->pc_allocfrom = pcg;
goto have_group;
}
}
/*
* No groups with any available objects. Allocate
* a new object, construct it, and return it to
* the caller. We will allocate a group, if necessary,
* when the object is freed back to the cache.
*/
pc->pc_misses++;
simple_unlock(&pc->pc_slock);
object = pool_get(pc->pc_pool, flags);
if (object != NULL && pc->pc_ctor != NULL) {
if ((*pc->pc_ctor)(pc->pc_arg, object, flags) != 0) {
pool_put(pc->pc_pool, object);
return (NULL);
}
}
return (object);
}
have_group:
pc->pc_hits++;
pc->pc_nitems--;
object = pcg_get(pcg);
if (pcg->pcg_avail == 0)
pc->pc_allocfrom = NULL;
simple_unlock(&pc->pc_slock);
return (object);
}
/*
* pool_cache_put:
*
* Put an object back to the pool cache.
*/
void
pool_cache_put(struct pool_cache *pc, void *object)
{
struct pool_cache_group *pcg;
int s;
simple_lock(&pc->pc_slock);
if ((pcg = pc->pc_freeto) == NULL) {
TAILQ_FOREACH(pcg, &pc->pc_grouplist, pcg_list) {
if (pcg->pcg_avail != PCG_NOBJECTS) {
pc->pc_freeto = pcg;
goto have_group;
}
}
/*
* No empty groups to free the object to. Attempt to
* allocate one.
*/
simple_unlock(&pc->pc_slock);
s = splvm();
pcg = pool_get(&pcgpool, PR_NOWAIT);
splx(s);
if (pcg != NULL) {
memset(pcg, 0, sizeof(*pcg));
simple_lock(&pc->pc_slock);
pc->pc_ngroups++;
TAILQ_INSERT_TAIL(&pc->pc_grouplist, pcg, pcg_list);
if (pc->pc_freeto == NULL)
pc->pc_freeto = pcg;
goto have_group;
}
/*
* Unable to allocate a cache group; destruct the object
* and free it back to the pool.
*/
pool_cache_destruct_object(pc, object);
return;
}
have_group:
pc->pc_nitems++;
pcg_put(pcg, object);
if (pcg->pcg_avail == PCG_NOBJECTS)
pc->pc_freeto = NULL;
simple_unlock(&pc->pc_slock);
}
/*
* pool_cache_destruct_object:
*
* Force destruction of an object and its release back into
* the pool.
*/
void
pool_cache_destruct_object(struct pool_cache *pc, void *object)
{
if (pc->pc_dtor != NULL)
(*pc->pc_dtor)(pc->pc_arg, object);
pool_put(pc->pc_pool, object);
}
/*
* pool_cache_do_invalidate:
*
* This internal function implements pool_cache_invalidate() and
* pool_cache_reclaim().
*/
static void
pool_cache_do_invalidate(struct pool_cache *pc, int free_groups,
void (*putit)(struct pool *, void *))
{
struct pool_cache_group *pcg, *npcg;
void *object;
int s;
for (pcg = TAILQ_FIRST(&pc->pc_grouplist); pcg != NULL;
pcg = npcg) {
npcg = TAILQ_NEXT(pcg, pcg_list);
while (pcg->pcg_avail != 0) {
pc->pc_nitems--;
object = pcg_get(pcg);
if (pcg->pcg_avail == 0 && pc->pc_allocfrom == pcg)
pc->pc_allocfrom = NULL;
if (pc->pc_dtor != NULL)
(*pc->pc_dtor)(pc->pc_arg, object);
(*putit)(pc->pc_pool, object);
}
if (free_groups) {
pc->pc_ngroups--;
TAILQ_REMOVE(&pc->pc_grouplist, pcg, pcg_list);
if (pc->pc_freeto == pcg)
pc->pc_freeto = NULL;
s = splvm();
pool_put(&pcgpool, pcg);
splx(s);
}
}
}
/*
* pool_cache_invalidate:
*
* Invalidate a pool cache (destruct and release all of the
* cached objects).
*/
void
pool_cache_invalidate(struct pool_cache *pc)
{
simple_lock(&pc->pc_slock);
pool_cache_do_invalidate(pc, 0, pool_put);
simple_unlock(&pc->pc_slock);
}
/*
* pool_cache_reclaim:
*
* Reclaim a pool cache for pool_reclaim().
*/
static void
pool_cache_reclaim(struct pool_cache *pc)
{
simple_lock(&pc->pc_slock);
pool_cache_do_invalidate(pc, 1, pool_do_put);
simple_unlock(&pc->pc_slock);
}
/*
* Pool backend allocators.
*
* Each pool has a backend allocator that handles allocation, deallocation,
* and any additional draining that might be needed.
*
* We provide two standard allocators:
*
* pool_allocator_kmem - the default when no allocator is specified
*
* pool_allocator_nointr - used for pools that will not be accessed
* in interrupt context.
*/
void *pool_page_alloc(struct pool *, int);
void pool_page_free(struct pool *, void *);
struct pool_allocator pool_allocator_kmem = {
pool_page_alloc, pool_page_free, 0,
};
void *pool_page_alloc_nointr(struct pool *, int);
void pool_page_free_nointr(struct pool *, void *);
struct pool_allocator pool_allocator_nointr = {
pool_page_alloc_nointr, pool_page_free_nointr, 0,
};
#ifdef POOL_SUBPAGE
void *pool_subpage_alloc(struct pool *, int);
void pool_subpage_free(struct pool *, void *);
struct pool_allocator pool_allocator_kmem_subpage = {
pool_subpage_alloc, pool_subpage_free, 0,
};
#endif /* POOL_SUBPAGE */
/*
* We have at least three different resources for the same allocation and
* each resource can be depleted. First, we have the ready elements in the
* pool. Then we have the resource (typically a vm_map) for this allocator.
* Finally, we have physical memory. Waiting for any of these can be
* unnecessary when any other is freed, but the kernel doesn't support
* sleeping on multiple wait channels, so we have to employ another strategy.
*
* The caller sleeps on the pool (so that it can be awakened when an item
* is returned to the pool), but we set PA_WANT on the allocator. When a
* page is returned to the allocator and PA_WANT is set, pool_allocator_free
* will wake up all sleeping pools belonging to this allocator.
*
* XXX Thundering herd.
*/
void *
pool_allocator_alloc(struct pool *org, int flags)
{
struct pool_allocator *pa = org->pr_alloc;
struct pool *pp, *start;
int s, freed;
void *res;
do {
if ((res = (*pa->pa_alloc)(org, flags)) != NULL)
return (res);
if ((flags & PR_WAITOK) == 0) {
/*
* We only run the drain hookhere if PR_NOWAIT.
* In other cases, the hook will be run in
* pool_reclaim().
*/
if (org->pr_drain_hook != NULL) {
(*org->pr_drain_hook)(org->pr_drain_hook_arg,
flags);
if ((res = (*pa->pa_alloc)(org, flags)) != NULL)
return (res);
}
break;
}
/*
* Drain all pools, except "org", that use this
* allocator. We do this to reclaim VA space.
* pa_alloc is responsible for waiting for
* physical memory.
*
* XXX We risk looping forever if start if someone
* calls pool_destroy on "start". But there is no
* other way to have potentially sleeping pool_reclaim,
* non-sleeping locks on pool_allocator, and some
* stirring of drained pools in the allocator.
*
* XXX Maybe we should use pool_head_slock for locking
* the allocators?
*/
freed = 0;
s = splvm();
simple_lock(&pa->pa_slock);
pp = start = TAILQ_FIRST(&pa->pa_list);
do {
TAILQ_REMOVE(&pa->pa_list, pp, pr_alloc_list);
TAILQ_INSERT_TAIL(&pa->pa_list, pp, pr_alloc_list);
if (pp == org)
continue;
simple_unlock(&pa->pa_slock);
freed = pool_reclaim(pp);
simple_lock(&pa->pa_slock);
} while ((pp = TAILQ_FIRST(&pa->pa_list)) != start &&
freed == 0);
if (freed == 0) {
/*
* We set PA_WANT here, the caller will most likely
* sleep waiting for pages (if not, this won't hurt
* that much), and there is no way to set this in
* the caller without violating locking order.
*/
pa->pa_flags |= PA_WANT;
}
simple_unlock(&pa->pa_slock);
splx(s);
} while (freed);
return (NULL);
}
void
pool_allocator_free(struct pool *pp, void *v)
{
struct pool_allocator *pa = pp->pr_alloc;
int s;
(*pa->pa_free)(pp, v);
s = splvm();
simple_lock(&pa->pa_slock);
if ((pa->pa_flags & PA_WANT) == 0) {
simple_unlock(&pa->pa_slock);
splx(s);
return;
}
TAILQ_FOREACH(pp, &pa->pa_list, pr_alloc_list) {
simple_lock(&pp->pr_slock);
if ((pp->pr_flags & PR_WANTED) != 0) {
pp->pr_flags &= ~PR_WANTED;
wakeup(pp);
}
simple_unlock(&pp->pr_slock);
}
pa->pa_flags &= ~PA_WANT;
simple_unlock(&pa->pa_slock);
splx(s);
}
void *
pool_page_alloc(struct pool *pp, int flags)
{
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
return ((void *) uvm_km_alloc_poolpage(waitok));
}
void
pool_page_free(struct pool *pp, void *v)
{
uvm_km_free_poolpage((vaddr_t) v);
}
#ifdef POOL_SUBPAGE
/* Sub-page allocator, for machines with large hardware pages. */
void *
pool_subpage_alloc(struct pool *pp, int flags)
{
return (pool_get(&psppool, flags));
}
void
pool_subpage_free(struct pool *pp, void *v)
{
pool_put(&psppool, v);
}
/* We don't provide a real nointr allocator. Maybe later. */
void *
pool_page_alloc_nointr(struct pool *pp, int flags)
{
return (pool_subpage_alloc(pp, flags));
}
void
pool_page_free_nointr(struct pool *pp, void *v)
{
pool_subpage_free(pp, v);
}
#else
void *
pool_page_alloc_nointr(struct pool *pp, int flags)
{
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
return ((void *) uvm_km_alloc_poolpage1(kernel_map,
uvm.kernel_object, waitok));
}
void
pool_page_free_nointr(struct pool *pp, void *v)
{
uvm_km_free_poolpage1(kernel_map, (vaddr_t) v);
}
#endif /* POOL_SUBPAGE */
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