OpenBSD-4.6/sys/kern/subr_pool.c
/* $OpenBSD: subr_pool.c,v 1.85 2009/06/24 11:23:33 deraadt Exp $ */
/* $NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs 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.
*
* 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/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/syslog.h>
#include <sys/sysctl.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 one of three lists in the
* pool structure: `pr_emptypages', `pr_fullpages' and `pr_partpages',
* for empty, full and partially-full pages respectively. 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').
*/
/* #define POOL_DEBUG */
/* List of all pools */
TAILQ_HEAD(,pool) pool_head = TAILQ_HEAD_INITIALIZER(pool_head);
/* Private pool for page header structures */
struct pool phpool;
struct pool_item_header {
/* Page headers */
LIST_ENTRY(pool_item_header)
ph_pagelist; /* pool page list */
TAILQ_HEAD(,pool_item) ph_itemlist; /* chunk list for this page */
SPLAY_ENTRY(pool_item_header)
ph_node; /* Off-page page headers */
int ph_nmissing; /* # of chunks in use */
caddr_t ph_page; /* this page's address */
caddr_t ph_colored; /* page's colored address */
int ph_pagesize;
};
struct pool_item {
#ifdef DIAGNOSTIC
u_int32_t pi_magic;
#endif
/* Other entries use only this list entry */
TAILQ_ENTRY(pool_item) pi_list;
};
#ifdef DEADBEEF1
#define PI_MAGIC DEADBEEF1
#else
#define PI_MAGIC 0xdeafbeef
#endif
#define POOL_NEEDS_CATCHUP(pp) \
((pp)->pr_nitems < (pp)->pr_minitems)
/*
* Every pool gets a unique serial number assigned to it. If this counter
* wraps, we're screwed, but we shouldn't create so many pools anyway.
*/
unsigned int pool_serial;
int pool_catchup(struct pool *);
void pool_prime_page(struct pool *, caddr_t, struct pool_item_header *);
void pool_update_curpage(struct pool *);
void *pool_do_get(struct pool *, int);
void pool_do_put(struct pool *, void *);
void pr_rmpage(struct pool *, struct pool_item_header *,
struct pool_pagelist *);
int pool_chk_page(struct pool *, const char *, struct pool_item_header *);
struct pool_item_header *pool_alloc_item_header(struct pool *, caddr_t , int);
void *pool_allocator_alloc(struct pool *, int, int *);
void pool_allocator_free(struct pool *, void *);
/*
* XXX - quick hack. For pools with large items we want to use a special
* allocator. For now, instead of having the allocator figure out
* the allocation size from the pool (which can be done trivially
* with round_page(pr_itemsperpage * pr_size)) which would require
* lots of changes everywhere, we just create allocators for each
* size. We limit those to 128 pages.
*/
#define POOL_LARGE_MAXPAGES 128
struct pool_allocator pool_allocator_large[POOL_LARGE_MAXPAGES];
struct pool_allocator pool_allocator_large_ni[POOL_LARGE_MAXPAGES];
void *pool_large_alloc(struct pool *, int, int *);
void pool_large_free(struct pool *, void *);
void *pool_large_alloc_ni(struct pool *, int, int *);
void pool_large_free_ni(struct pool *, void *);
#ifdef DDB
void pool_print_pagelist(struct pool_pagelist *,
int (*)(const char *, ...));
void pool_print1(struct pool *, const char *, int (*)(const char *, ...));
#endif
#define pool_sleep(pl) msleep(pl, &pl->pr_mtx, PSWP, pl->pr_wchan, 0)
static __inline int
phtree_compare(struct pool_item_header *a, struct pool_item_header *b)
{
long diff = (vaddr_t)a->ph_page - (vaddr_t)b->ph_page;
if (diff < 0)
return -(-diff >= a->ph_pagesize);
else if (diff > 0)
return (diff >= b->ph_pagesize);
else
return (0);
}
SPLAY_PROTOTYPE(phtree, pool_item_header, ph_node, phtree_compare);
SPLAY_GENERATE(phtree, pool_item_header, ph_node, phtree_compare);
/*
* Return the pool page header based on page address.
*/
static __inline struct pool_item_header *
pr_find_pagehead(struct pool *pp, void *v)
{
struct pool_item_header *ph, tmp;
if ((pp->pr_roflags & PR_PHINPAGE) != 0) {
caddr_t page;
page = (caddr_t)((vaddr_t)v & pp->pr_alloc->pa_pagemask);
return ((struct pool_item_header *)(page + pp->pr_phoffset));
}
/*
* The trick we're using in the tree compare function is to compare
* two elements equal when they overlap. We want to return the
* page header that belongs to the element just before this address.
* We don't want this element to compare equal to the next element,
* so the compare function takes the pagesize from the lower element.
* If this header is the lower, its pagesize is zero, so it can't
* overlap with the next header. But if the header we're looking for
* is lower, we'll use its pagesize and it will overlap and return
* equal.
*/
tmp.ph_page = v;
tmp.ph_pagesize = 0;
ph = SPLAY_FIND(phtree, &pp->pr_phtree, &tmp);
if (ph) {
KASSERT(ph->ph_page <= (caddr_t)v);
KASSERT(ph->ph_page + ph->ph_pagesize > (caddr_t)v);
}
return ph;
}
/*
* Remove a page from the pool.
*/
void
pr_rmpage(struct pool *pp, struct pool_item_header *ph,
struct pool_pagelist *pq)
{
/*
* 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).
*/
LIST_REMOVE(ph, ph_pagelist);
if ((pp->pr_roflags & PR_PHINPAGE) == 0)
SPLAY_REMOVE(phtree, &pp->pr_phtree, ph);
if (pq) {
LIST_INSERT_HEAD(pq, ph, ph_pagelist);
} else {
pool_allocator_free(pp, ph->ph_page);
if ((pp->pr_roflags & PR_PHINPAGE) == 0)
pool_put(&phpool, ph);
}
pp->pr_npages--;
pp->pr_npagefree++;
pool_update_curpage(pp);
}
/*
* 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;
#ifdef MALLOC_DEBUG
if ((flags & PR_DEBUG) && (ioff != 0 || align != 0))
flags &= ~PR_DEBUG;
#endif
/*
* Check arguments and construct default values.
*/
if (palloc == NULL) {
if (size > PAGE_SIZE) {
int psize;
/*
* XXX - should take align into account as well.
*/
if (size == round_page(size))
psize = size / PAGE_SIZE;
else
psize = PAGE_SIZE / roundup(size % PAGE_SIZE,
1024);
if (psize > POOL_LARGE_MAXPAGES)
psize = POOL_LARGE_MAXPAGES;
if (flags & PR_WAITOK)
palloc = &pool_allocator_large_ni[psize-1];
else
palloc = &pool_allocator_large[psize-1];
if (palloc->pa_pagesz == 0) {
palloc->pa_pagesz = psize * PAGE_SIZE;
if (flags & PR_WAITOK) {
palloc->pa_alloc = pool_large_alloc_ni;
palloc->pa_free = pool_large_free_ni;
} else {
palloc->pa_alloc = pool_large_alloc;
palloc->pa_free = pool_large_free;
}
}
} else {
palloc = &pool_allocator_nointr;
}
}
if (palloc->pa_pagesz == 0) {
palloc->pa_pagesz = PAGE_SIZE;
}
if (palloc->pa_pagemask == 0) {
palloc->pa_pagemask = ~(palloc->pa_pagesz - 1);
palloc->pa_pageshift = ffs(palloc->pa_pagesz) - 1;
}
if (align == 0)
align = ALIGN(1);
if (size < sizeof(struct pool_item))
size = sizeof(struct pool_item);
size = roundup(size, align);
#ifdef DIAGNOSTIC
if (size > palloc->pa_pagesz)
panic("pool_init: pool item size (%lu) too large",
(u_long)size);
#endif
/*
* Initialize the pool structure.
*/
LIST_INIT(&pp->pr_emptypages);
LIST_INIT(&pp->pr_fullpages);
LIST_INIT(&pp->pr_partpages);
pp->pr_curpage = NULL;
pp->pr_npages = 0;
pp->pr_minitems = 0;
pp->pr_minpages = 0;
pp->pr_maxpages = 8;
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_serial = ++pool_serial;
if (pool_serial == 0)
panic("pool_init: too much uptime");
/* constructor, destructor, and arg */
pp->pr_ctor = NULL;
pp->pr_dtor = NULL;
pp->pr_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 && pp->pr_size < PAGE_SIZE) {
/* 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;
SPLAY_INIT(&pp->pr_phtree);
}
/*
* 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;
pp->pr_ipl = -1;
mtx_init(&pp->pr_mtx, IPL_NONE);
if (phpool.pr_size == 0) {
pool_init(&phpool, sizeof(struct pool_item_header), 0, 0,
0, "phpool", NULL);
pool_setipl(&phpool, IPL_HIGH);
}
/* Insert this into the list of all pools. */
TAILQ_INSERT_HEAD(&pool_head, pp, pr_poollist);
}
void
pool_setipl(struct pool *pp, int ipl)
{
pp->pr_ipl = ipl;
mtx_init(&pp->pr_mtx, ipl);
}
/*
* Decommission a pool resource.
*/
void
pool_destroy(struct pool *pp)
{
struct pool_item_header *ph;
#ifdef DIAGNOSTIC
if (pp->pr_nout != 0)
panic("pool_destroy: pool busy: still out: %u", pp->pr_nout);
#endif
/* Remove all pages */
while ((ph = LIST_FIRST(&pp->pr_emptypages)) != NULL)
pr_rmpage(pp, ph, NULL);
KASSERT(LIST_EMPTY(&pp->pr_fullpages));
KASSERT(LIST_EMPTY(&pp->pr_partpages));
/* Remove from global pool list */
TAILQ_REMOVE(&pool_head, pp, pr_poollist);
}
struct pool_item_header *
pool_alloc_item_header(struct pool *pp, caddr_t storage, int flags)
{
struct pool_item_header *ph;
if ((pp->pr_roflags & PR_PHINPAGE) != 0)
ph = (struct pool_item_header *)(storage + pp->pr_phoffset);
else {
ph = pool_get(&phpool, flags);
}
return (ph);
}
/*
* Grab an item from the pool; must be called at appropriate spl level
*/
void *
pool_get(struct pool *pp, int flags)
{
void *v;
#ifdef DIAGNOSTIC
if ((flags & PR_WAITOK) != 0)
splassert(IPL_NONE);
#endif /* DIAGNOSTIC */
mtx_enter(&pp->pr_mtx);
v = pool_do_get(pp, flags);
mtx_leave(&pp->pr_mtx);
if (v == NULL)
return (v);
if (pp->pr_ctor) {
if (flags & PR_ZERO)
panic("pool_get: PR_ZERO when ctor set");
if (pp->pr_ctor(pp->pr_arg, v, flags)) {
mtx_enter(&pp->pr_mtx);
pool_do_put(pp, v);
mtx_leave(&pp->pr_mtx);
v = NULL;
}
} else {
if (flags & PR_ZERO)
memset(v, 0, pp->pr_size);
}
if (v != NULL)
pp->pr_nget++;
return (v);
}
void *
pool_do_get(struct pool *pp, int flags)
{
struct pool_item *pi;
struct pool_item_header *ph;
void *v;
int slowdown = 0;
#if defined(DIAGNOSTIC) && defined(POOL_DEBUG)
int i, *ip;
#endif
#ifdef MALLOC_DEBUG
if (pp->pr_roflags & PR_DEBUG) {
void *addr;
addr = NULL;
debug_malloc(pp->pr_size, M_DEBUG,
(flags & PR_WAITOK) ? M_WAITOK : M_NOWAIT, &addr);
return (addr);
}
#endif
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))
panic("pool_do_get: %s: crossed hard limit", pp->pr_wchan);
#endif
if (__predict_false(pp->pr_nout == pp->pr_hardlimit)) {
if ((flags & PR_WAITOK) && !(flags & PR_LIMITFAIL)) {
/*
* XXX: A warning isn't logged in this case. Should
* it be?
*/
pp->pr_flags |= PR_WANTED;
pool_sleep(pp);
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++;
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) {
printf("pool_do_get: %s: curpage NULL, nitems %u\n",
pp->pr_wchan, pp->pr_nitems);
panic("pool_do_get: nitems inconsistent");
}
#endif
/*
* Call the back-end page allocator for more memory.
*/
v = pool_allocator_alloc(pp, flags, &slowdown);
if (__predict_true(v != NULL))
ph = pool_alloc_item_header(pp, v, flags);
if (__predict_false(v == NULL || ph == NULL)) {
if (v != NULL)
pool_allocator_free(pp, v);
if ((flags & PR_WAITOK) == 0) {
pp->pr_nfail++;
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;
pool_sleep(pp);
goto startover;
}
/* We have more memory; add it to the pool */
pool_prime_page(pp, v, ph);
pp->pr_npagealloc++;
if (slowdown && (flags & PR_WAITOK)) {
mtx_leave(&pp->pr_mtx);
yield();
mtx_enter(&pp->pr_mtx);
}
/* Start the allocation process over. */
goto startover;
}
if (__predict_false((v = pi = TAILQ_FIRST(&ph->ph_itemlist)) == NULL)) {
panic("pool_do_get: %s: page empty", pp->pr_wchan);
}
#ifdef DIAGNOSTIC
if (__predict_false(pp->pr_nitems == 0)) {
printf("pool_do_get: %s: items on itemlist, nitems %u\n",
pp->pr_wchan, pp->pr_nitems);
panic("pool_do_get: nitems inconsistent");
}
#endif
#ifdef DIAGNOSTIC
if (__predict_false(pi->pi_magic != PI_MAGIC))
panic("pool_do_get(%s): free list modified: "
"page %p; item addr %p; offset 0x%x=0x%x",
pp->pr_wchan, ph->ph_page, pi, 0, pi->pi_magic);
#ifdef POOL_DEBUG
for (ip = (int *)pi, i = sizeof(*pi) / sizeof(int);
i < pp->pr_size / sizeof(int); i++) {
if (ip[i] != PI_MAGIC) {
panic("pool_do_get(%s): free list modified: "
"page %p; item addr %p; offset 0x%x=0x%x",
pp->pr_wchan, ph->ph_page, pi,
i * sizeof(int), ip[i]);
}
}
#endif /* POOL_DEBUG */
#endif /* DIAGNOSTIC */
/*
* 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_do_get: nidle inconsistent");
#endif
pp->pr_nidle--;
/*
* This page was previously empty. Move it to the list of
* partially-full pages. This page is already curpage.
*/
LIST_REMOVE(ph, ph_pagelist);
LIST_INSERT_HEAD(&pp->pr_partpages, ph, ph_pagelist);
}
ph->ph_nmissing++;
if (TAILQ_EMPTY(&ph->ph_itemlist)) {
#ifdef DIAGNOSTIC
if (__predict_false(ph->ph_nmissing != pp->pr_itemsperpage)) {
panic("pool_do_get: %s: nmissing inconsistent",
pp->pr_wchan);
}
#endif
/*
* This page is now full. Move it to the full list
* and select a new current page.
*/
LIST_REMOVE(ph, ph_pagelist);
LIST_INSERT_HEAD(&pp->pr_fullpages, ph, ph_pagelist);
pool_update_curpage(pp);
}
/*
* 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.
*/
}
return (v);
}
/*
* Return resource to the pool; must be called at appropriate spl level
*/
void
pool_put(struct pool *pp, void *v)
{
if (pp->pr_dtor)
pp->pr_dtor(pp->pr_arg, v);
mtx_enter(&pp->pr_mtx);
pool_do_put(pp, v);
mtx_leave(&pp->pr_mtx);
pp->pr_nput++;
}
/*
* Internal version of pool_put().
*/
void
pool_do_put(struct pool *pp, void *v)
{
struct pool_item *pi = v;
struct pool_item_header *ph;
#if defined(DIAGNOSTIC) && defined(POOL_DEBUG)
int i, *ip;
#endif
if (v == NULL)
panic("pool_put of NULL");
#ifdef MALLOC_DEBUG
if (pp->pr_roflags & PR_DEBUG) {
debug_free(v, M_DEBUG);
return;
}
#endif
#ifdef DIAGNOSTIC
if (pp->pr_ipl != -1)
splassert(pp->pr_ipl);
if (__predict_false(pp->pr_nout == 0)) {
printf("pool %s: putting with none out\n",
pp->pr_wchan);
panic("pool_do_put");
}
#endif
if (__predict_false((ph = pr_find_pagehead(pp, v)) == NULL)) {
panic("pool_do_put: %s: page header missing", pp->pr_wchan);
}
/*
* Return to item list.
*/
#ifdef DIAGNOSTIC
pi->pi_magic = PI_MAGIC;
#ifdef POOL_DEBUG
for (ip = (int *)pi, i = sizeof(*pi)/sizeof(int);
i < pp->pr_size / sizeof(int); i++)
ip[i] = PI_MAGIC;
#endif /* POOL_DEBUG */
#endif /* DIAGNOSTIC */
TAILQ_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list);
ph->ph_nmissing--;
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(pp);
return;
}
/*
* If this page is now empty, 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) Otherwise, move the page to the empty page list.
*
* Either way, select a new current page (so we use a partially-full
* page if one is available).
*/
if (ph->ph_nmissing == 0) {
pp->pr_nidle++;
if (pp->pr_nidle > pp->pr_maxpages) {
pr_rmpage(pp, ph, NULL);
} else {
LIST_REMOVE(ph, ph_pagelist);
LIST_INSERT_HEAD(&pp->pr_emptypages, ph, ph_pagelist);
}
pool_update_curpage(pp);
}
/*
* If the page was previously completely full, move it to the
* partially-full 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)) {
LIST_REMOVE(ph, ph_pagelist);
LIST_INSERT_HEAD(&pp->pr_partpages, ph, ph_pagelist);
pp->pr_curpage = ph;
}
}
/*
* Add N items to the pool.
*/
int
pool_prime(struct pool *pp, int n)
{
struct pool_item_header *ph;
caddr_t cp;
int newpages;
int slowdown;
mtx_enter(&pp->pr_mtx);
newpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
while (newpages-- > 0) {
cp = pool_allocator_alloc(pp, PR_NOWAIT, &slowdown);
if (__predict_true(cp != NULL))
ph = pool_alloc_item_header(pp, cp, PR_NOWAIT);
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 */
mtx_leave(&pp->pr_mtx);
return (0);
}
/*
* Add a page worth of items to the pool.
*
* Note, we must be called with the pool descriptor LOCKED.
*/
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;
#if defined(DIAGNOSTIC) && defined(POOL_DEBUG)
int i, *ip;
#endif
/*
* Insert page header.
*/
LIST_INSERT_HEAD(&pp->pr_emptypages, ph, ph_pagelist);
TAILQ_INIT(&ph->ph_itemlist);
ph->ph_page = storage;
ph->ph_pagesize = pp->pr_alloc->pa_pagesz;
ph->ph_nmissing = 0;
if ((pp->pr_roflags & PR_PHINPAGE) == 0)
SPLAY_INSERT(phtree, &pp->pr_phtree, ph);
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));
ph->ph_colored = cp;
/*
* Insert remaining chunks on the bucket list.
*/
n = pp->pr_itemsperpage;
pp->pr_nitems += n;
while (n--) {
pi = (struct pool_item *)cp;
KASSERT(((((vaddr_t)pi) + ioff) & (align - 1)) == 0);
/* Insert on page list */
TAILQ_INSERT_TAIL(&ph->ph_itemlist, pi, pi_list);
#ifdef DIAGNOSTIC
pi->pi_magic = PI_MAGIC;
#ifdef POOL_DEBUG
for (ip = (int *)pi, i = sizeof(*pi)/sizeof(int);
i < pp->pr_size / sizeof(int); i++)
ip[i] = PI_MAGIC;
#endif /* POOL_DEBUG */
#endif /* DIAGNOSTIC */
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 pr_nitems with the low water mark.
*
* Note we never wait for memory here, we let the caller decide what to do.
*/
int
pool_catchup(struct pool *pp)
{
struct pool_item_header *ph;
caddr_t cp;
int error = 0;
int slowdown;
while (POOL_NEEDS_CATCHUP(pp)) {
/*
* Call the page back-end allocator for more memory.
*/
cp = pool_allocator_alloc(pp, PR_NOWAIT, &slowdown);
if (__predict_true(cp != NULL))
ph = pool_alloc_item_header(pp, cp, PR_NOWAIT);
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_update_curpage(struct pool *pp)
{
pp->pr_curpage = LIST_FIRST(&pp->pr_partpages);
if (pp->pr_curpage == NULL) {
pp->pr_curpage = LIST_FIRST(&pp->pr_emptypages);
}
}
void
pool_setlowat(struct pool *pp, int n)
{
pp->pr_minitems = n;
pp->pr_minpages = (n == 0)
? 0
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
mtx_enter(&pp->pr_mtx);
/* 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.
*/
}
mtx_leave(&pp->pr_mtx);
}
void
pool_sethiwat(struct pool *pp, int n)
{
pp->pr_maxpages = (n == 0)
? 0
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
}
int
pool_sethardlimit(struct pool *pp, u_int n, const char *warnmsg, int ratecap)
{
int error = 0;
if (n < pp->pr_nout) {
error = EINVAL;
goto done;
}
pp->pr_hardlimit = n;
pp->pr_hardlimit_warning = warnmsg;
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().
*/
pp->pr_maxpages = (n == 0 || n == UINT_MAX)
? n
: roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
done:
return (error);
}
void
pool_set_ctordtor(struct pool *pp, int (*ctor)(void *, void *, int),
void (*dtor)(void *, void *), void *arg)
{
pp->pr_ctor = ctor;
pp->pr_dtor = dtor;
pp->pr_arg = arg;
}
/*
* Release all complete pages that have not been used recently.
*
* Returns non-zero if any pages have been reclaimed.
*/
int
pool_reclaim(struct pool *pp)
{
struct pool_item_header *ph, *phnext;
struct pool_pagelist pq;
LIST_INIT(&pq);
mtx_enter(&pp->pr_mtx);
for (ph = LIST_FIRST(&pp->pr_emptypages); ph != NULL; ph = phnext) {
phnext = LIST_NEXT(ph, ph_pagelist);
/* Check our minimum page claim */
if (pp->pr_npages <= pp->pr_minpages)
break;
KASSERT(ph->ph_nmissing == 0);
/*
* 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);
}
mtx_leave(&pp->pr_mtx);
if (LIST_EMPTY(&pq))
return (0);
while ((ph = LIST_FIRST(&pq)) != NULL) {
LIST_REMOVE(ph, ph_pagelist);
pool_allocator_free(pp, ph->ph_page);
if (pp->pr_roflags & PR_PHINPAGE)
continue;
pool_put(&phpool, ph);
}
return (1);
}
#ifdef DDB
#include <machine/db_machdep.h>
#include <ddb/db_interface.h>
#include <ddb/db_output.h>
/*
* Diagnostic helpers.
*/
void
pool_printit(struct pool *pp, const char *modif, int (*pr)(const char *, ...))
{
pool_print1(pp, modif, pr);
}
void
pool_print_pagelist(struct pool_pagelist *pl, int (*pr)(const char *, ...))
{
struct pool_item_header *ph;
#ifdef DIAGNOSTIC
struct pool_item *pi;
#endif
LIST_FOREACH(ph, pl, ph_pagelist) {
(*pr)("\t\tpage %p, nmissing %d\n",
ph->ph_page, ph->ph_nmissing);
#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
}
}
void
pool_print1(struct pool *pp, const char *modif, int (*pr)(const char *, ...))
{
struct pool_item_header *ph;
int print_pagelist = 0;
char c;
while ((c = *modif++) != '\0') {
if (c == 'p')
print_pagelist = 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)
return;
if ((ph = LIST_FIRST(&pp->pr_emptypages)) != NULL)
(*pr)("\n\tempty page list:\n");
pool_print_pagelist(&pp->pr_emptypages, pr);
if ((ph = LIST_FIRST(&pp->pr_fullpages)) != NULL)
(*pr)("\n\tfull page list:\n");
pool_print_pagelist(&pp->pr_fullpages, pr);
if ((ph = LIST_FIRST(&pp->pr_partpages)) != NULL)
(*pr)("\n\tpartial-page list:\n");
pool_print_pagelist(&pp->pr_partpages, pr);
if (pp->pr_curpage == NULL)
(*pr)("\tno current page\n");
else
(*pr)("\tcurpage %p\n", pp->pr_curpage->ph_page);
}
void
db_show_all_pools(db_expr_t expr, int haddr, db_expr_t count, char *modif)
{
struct pool *pp;
char maxp[16];
int ovflw;
char mode;
mode = modif[0];
if (mode != '\0' && mode != 'a') {
db_printf("usage: show all pools [/a]\n");
return;
}
if (mode == '\0')
db_printf("%-10s%4s%9s%5s%9s%6s%6s%6s%6s%6s%6s%5s\n",
"Name",
"Size",
"Requests",
"Fail",
"Releases",
"Pgreq",
"Pgrel",
"Npage",
"Hiwat",
"Minpg",
"Maxpg",
"Idle");
else
db_printf("%-10s %18s %18s\n",
"Name", "Address", "Allocator");
TAILQ_FOREACH(pp, &pool_head, pr_poollist) {
if (mode == 'a') {
db_printf("%-10s %18p %18p\n", pp->pr_wchan, pp,
pp->pr_alloc);
continue;
}
if (!pp->pr_nget)
continue;
if (pp->pr_maxpages == UINT_MAX)
snprintf(maxp, sizeof maxp, "inf");
else
snprintf(maxp, sizeof maxp, "%u", pp->pr_maxpages);
#define PRWORD(ovflw, fmt, width, fixed, val) do { \
(ovflw) += db_printf((fmt), \
(width) - (fixed) - (ovflw) > 0 ? \
(width) - (fixed) - (ovflw) : 0, \
(val)) - (width); \
if ((ovflw) < 0) \
(ovflw) = 0; \
} while (/* CONSTCOND */0)
ovflw = 0;
PRWORD(ovflw, "%-*s", 10, 0, pp->pr_wchan);
PRWORD(ovflw, " %*u", 4, 1, pp->pr_size);
PRWORD(ovflw, " %*lu", 9, 1, pp->pr_nget);
PRWORD(ovflw, " %*lu", 5, 1, pp->pr_nfail);
PRWORD(ovflw, " %*lu", 9, 1, pp->pr_nput);
PRWORD(ovflw, " %*lu", 6, 1, pp->pr_npagealloc);
PRWORD(ovflw, " %*lu", 6, 1, pp->pr_npagefree);
PRWORD(ovflw, " %*d", 6, 1, pp->pr_npages);
PRWORD(ovflw, " %*d", 6, 1, pp->pr_hiwat);
PRWORD(ovflw, " %*d", 6, 1, pp->pr_minpages);
PRWORD(ovflw, " %*s", 6, 1, maxp);
PRWORD(ovflw, " %*lu\n", 5, 1, pp->pr_nidle);
pool_chk(pp, pp->pr_wchan);
}
}
int
pool_chk_page(struct pool *pp, const char *label, struct pool_item_header *ph)
{
struct pool_item *pi;
caddr_t page;
int n;
#if defined(DIAGNOSTIC) && defined(POOL_DEBUG)
int i, *ip;
#endif
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);
return 1;
}
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: "
"page %p; item ordinal %d; addr %p "
"(p %p); offset 0x%x=0x%x\n",
pp->pr_wchan, ph->ph_page, n, pi, page,
0, pi->pi_magic);
}
#ifdef POOL_DEBUG
for (ip = (int *)pi, i = sizeof(*pi) / sizeof(int);
i < pp->pr_size / sizeof(int); i++) {
if (ip[i] != PI_MAGIC) {
printf("pool(%s): free list modified: "
"page %p; item ordinal %d; addr %p "
"(p %p); offset 0x%x=0x%x\n",
pp->pr_wchan, ph->ph_page, n, pi,
page, i * sizeof(int), ip[i]);
}
}
#endif /* POOL_DEBUG */
#endif /* DIAGNOSTIC */
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);
return 1;
}
return 0;
}
int
pool_chk(struct pool *pp, const char *label)
{
struct pool_item_header *ph;
int r = 0;
LIST_FOREACH(ph, &pp->pr_emptypages, ph_pagelist)
r += pool_chk_page(pp, label, ph);
LIST_FOREACH(ph, &pp->pr_fullpages, ph_pagelist)
r += pool_chk_page(pp, label, ph);
LIST_FOREACH(ph, &pp->pr_partpages, ph_pagelist)
r += pool_chk_page(pp, label, ph);
return (r);
}
void
pool_walk(struct pool *pp, void (*func)(void *))
{
struct pool_item_header *ph;
struct pool_item *pi;
caddr_t cp;
int n;
LIST_FOREACH(ph, &pp->pr_fullpages, ph_pagelist) {
cp = ph->ph_colored;
n = ph->ph_nmissing;
while (n--) {
func(cp);
cp += pp->pr_size;
}
}
LIST_FOREACH(ph, &pp->pr_partpages, ph_pagelist) {
cp = ph->ph_colored;
n = ph->ph_nmissing;
do {
TAILQ_FOREACH(pi, &ph->ph_itemlist, pi_list) {
if (cp == (caddr_t)pi)
break;
}
if (cp != (caddr_t)pi) {
func(cp);
n--;
}
cp += pp->pr_size;
} while (n > 0);
}
}
#endif
/*
* We have three different sysctls.
* kern.pool.npools - the number of pools.
* kern.pool.pool.<pool#> - the pool struct for the pool#.
* kern.pool.name.<pool#> - the name for pool#.
*/
int
sysctl_dopool(int *name, u_int namelen, char *where, size_t *sizep)
{
struct pool *pp, *foundpool = NULL;
size_t buflen = where != NULL ? *sizep : 0;
int npools = 0, s;
unsigned int lookfor;
size_t len;
switch (*name) {
case KERN_POOL_NPOOLS:
if (namelen != 1 || buflen != sizeof(int))
return (EINVAL);
lookfor = 0;
break;
case KERN_POOL_NAME:
if (namelen != 2 || buflen < 1)
return (EINVAL);
lookfor = name[1];
break;
case KERN_POOL_POOL:
if (namelen != 2 || buflen != sizeof(struct pool))
return (EINVAL);
lookfor = name[1];
break;
default:
return (EINVAL);
}
s = splvm();
TAILQ_FOREACH(pp, &pool_head, pr_poollist) {
npools++;
if (lookfor == pp->pr_serial) {
foundpool = pp;
break;
}
}
splx(s);
if (*name != KERN_POOL_NPOOLS && foundpool == NULL)
return (ENOENT);
switch (*name) {
case KERN_POOL_NPOOLS:
return copyout(&npools, where, buflen);
case KERN_POOL_NAME:
len = strlen(foundpool->pr_wchan) + 1;
if (*sizep < len)
return (ENOMEM);
*sizep = len;
return copyout(foundpool->pr_wchan, where, len);
case KERN_POOL_POOL:
return copyout(foundpool, where, buflen);
}
/* NOTREACHED */
return (0); /* XXX - Stupid gcc */
}
/*
* Pool backend allocators.
*
* Each pool has a backend allocator that handles allocation, deallocation
*/
void *pool_page_alloc(struct pool *, int, int *);
void pool_page_free(struct pool *, void *);
/*
* safe for interrupts, name preserved for compat this is the default
* allocator
*/
struct pool_allocator pool_allocator_nointr = {
pool_page_alloc, pool_page_free, 0,
};
/*
* XXX - 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, then 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 addresses, so we have to fake. The caller sleeps on
* the pool (so that we 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 wakeup all
* sleeping pools belonging to this allocator. (XXX - thundering herd).
* We also wake up the allocator in case someone without a pool (malloc)
* is sleeping waiting for this allocator.
*/
void *
pool_allocator_alloc(struct pool *pp, int flags, int *slowdown)
{
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
void *v;
if (waitok)
mtx_leave(&pp->pr_mtx);
v = pp->pr_alloc->pa_alloc(pp, flags, slowdown);
if (waitok)
mtx_enter(&pp->pr_mtx);
return (v);
}
void
pool_allocator_free(struct pool *pp, void *v)
{
struct pool_allocator *pa = pp->pr_alloc;
(*pa->pa_free)(pp, v);
}
void *
pool_page_alloc(struct pool *pp, int flags, int *slowdown)
{
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
return (uvm_km_getpage(waitok, slowdown));
}
void
pool_page_free(struct pool *pp, void *v)
{
uvm_km_putpage(v);
}
void *
pool_large_alloc(struct pool *pp, int flags, int *slowdown)
{
int kfl = (flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT;
vaddr_t va;
int s;
s = splvm();
va = uvm_km_kmemalloc(kmem_map, NULL, pp->pr_alloc->pa_pagesz, kfl);
splx(s);
return ((void *)va);
}
void
pool_large_free(struct pool *pp, void *v)
{
int s;
s = splvm();
uvm_km_free(kmem_map, (vaddr_t)v, pp->pr_alloc->pa_pagesz);
splx(s);
}
void *
pool_large_alloc_ni(struct pool *pp, int flags, int *slowdown)
{
int kfl = (flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT;
return ((void *)uvm_km_kmemalloc(kernel_map, uvm.kernel_object,
pp->pr_alloc->pa_pagesz, kfl));
}
void
pool_large_free_ni(struct pool *pp, void *v)
{
uvm_km_free(kernel_map, (vaddr_t)v, pp->pr_alloc->pa_pagesz);
}