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NetBSD/sys/kern/subr_pool.c

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/* $NetBSD: subr_pool.c,v 1.23 1999/04/06 23:32:44 thorpej Exp $ */
/*-
* Copyright (c) 1997, 1999 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/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 <vm/vm.h>
#include <vm/vm_kern.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;
/* # 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 */
};
struct pool_item {
#ifdef DIAGNOSTIC
int pi_magic;
#define PI_MAGIC 0xdeadbeef
#endif
/* Other entries use only this list entry */
TAILQ_ENTRY(pool_item) pi_list;
};
#define PR_HASH_INDEX(pp,addr) \
(((u_long)(addr) >> (pp)->pr_pageshift) & (PR_HASHTABSIZE - 1))
static struct pool_item_header
*pr_find_pagehead __P((struct pool *, caddr_t));
static void pr_rmpage __P((struct pool *, struct pool_item_header *));
static int pool_catchup __P((struct pool *));
static void pool_prime_page __P((struct pool *, caddr_t));
static void *pool_page_alloc __P((unsigned long, int, int));
static void pool_page_free __P((void *, unsigned long, int));
#if defined(POOL_DIAGNOSTIC) || defined(DEBUG)
static void pool_print1 __P((struct pool *, const char *));
#endif
#ifdef POOL_DIAGNOSTIC
/*
* Pool log entry. An array of these is allocated in pool_create().
*/
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;
static void pr_log __P((struct pool *, void *, int, const char *, long));
static void pr_printlog __P((struct pool *));
static __inline__ void
pr_log(pp, v, action, file, line)
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(pp)
struct pool *pp;
{
int i = pp->pr_logsize;
int n = pp->pr_curlogentry;
if ((pp->pr_roflags & PR_LOGGING) == 0)
return;
pool_print1(pp, "printlog");
/*
* Print all entries in this pool's log.
*/
while (i-- > 0) {
struct pool_log *pl = &pp->pr_log[n];
if (pl->pl_action != 0) {
printf("log entry %d:\n", i);
printf("\taction = %s, addr = %p\n",
pl->pl_action == PRLOG_GET ? "get" : "put",
pl->pl_addr);
printf("\tfile: %s at line %lu\n",
pl->pl_file, pl->pl_line);
}
if (++n >= pp->pr_logsize)
n = 0;
}
}
#else
#define pr_log(pp, v, action, file, line)
#define pr_printlog(pp)
#endif
/*
* Return the pool page header based on page address.
*/
static __inline__ struct pool_item_header *
pr_find_pagehead(pp, page)
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(pp, ph)
struct pool *pp;
struct pool_item_header *ph;
{
/*
* 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.
*/
TAILQ_REMOVE(&pp->pr_pagelist, ph, ph_pagelist);
(*pp->pr_free)(ph->ph_page, pp->pr_pagesz, pp->pr_mtype);
pp->pr_npages--;
pp->pr_npagefree++;
if ((pp->pr_roflags & PR_PHINPAGE) == 0) {
LIST_REMOVE(ph, ph_hashlist);
pool_put(&phpool, ph);
}
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.
*/
for (ph = TAILQ_FIRST(&pp->pr_pagelist); ph != NULL;
ph = TAILQ_NEXT(ph, ph_pagelist))
if (TAILQ_FIRST(&ph->ph_itemlist) != NULL)
break;
pp->pr_curpage = ph;
}
}
/*
* Allocate and initialize a pool.
*/
struct pool *
pool_create(size, align, ioff, nitems, wchan, pagesz, alloc, release, mtype)
size_t size;
u_int align;
u_int ioff;
int nitems;
const char *wchan;
size_t pagesz;
void *(*alloc) __P((unsigned long, int, int));
void (*release) __P((void *, unsigned long, int));
int mtype;
{
struct pool *pp;
int flags;
pp = (struct pool *)malloc(sizeof(*pp), M_POOL, M_NOWAIT);
if (pp == NULL)
return (NULL);
flags = PR_FREEHEADER;
#ifdef POOL_DIAGNOSTIC
if (pool_logsize != 0)
flags |= PR_LOGGING;
#endif
pool_init(pp, size, align, ioff, flags, wchan, pagesz,
alloc, release, mtype);
if (nitems != 0) {
if (pool_prime(pp, nitems, NULL) != 0) {
pool_destroy(pp);
return (NULL);
}
}
return (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(pp, size, align, ioff, flags, wchan, pagesz, alloc, release, mtype)
struct pool *pp;
size_t size;
u_int align;
u_int ioff;
int flags;
const char *wchan;
size_t pagesz;
void *(*alloc) __P((unsigned long, int, int));
void (*release) __P((void *, unsigned long, int));
int mtype;
{
int off, slack, i;
/*
* Check arguments and construct default values.
*/
if (!powerof2(pagesz) || pagesz > PAGE_SIZE)
panic("pool_init: page size invalid (%lx)\n", (u_long)pagesz);
if (alloc == NULL && release == NULL) {
alloc = pool_page_alloc;
release = pool_page_free;
pagesz = PAGE_SIZE; /* Rounds to PAGE_SIZE anyhow. */
} else if ((alloc != NULL && release != NULL) == 0) {
/* If you specifiy one, must specify both. */
panic("pool_init: must specify alloc and release together");
}
if (pagesz == 0)
pagesz = PAGE_SIZE;
if (align == 0)
align = ALIGN(1);
if (size < sizeof(struct pool_item))
size = sizeof(struct pool_item);
/*
* Initialize the pool structure.
*/
TAILQ_INIT(&pp->pr_pagelist);
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 = ALIGN(size);
pp->pr_align = align;
pp->pr_wchan = wchan;
pp->pr_mtype = mtype;
pp->pr_alloc = alloc;
pp->pr_free = release;
pp->pr_pagesz = pagesz;
pp->pr_pagemask = ~(pagesz - 1);
pp->pr_pageshift = ffs(pagesz) - 1;
pp->pr_nitems = 0;
pp->pr_nout = 0;
pp->pr_hardlimit = UINT_MAX;
pp->pr_hardlimit_warning = NULL;
pp->pr_hardlimit_ratecap = 0;
memset(&pp->pr_hardlimit_warning_last, 0,
sizeof(pp->pr_hardlimit_warning_last));
/*
* 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 < pagesz/16) {
/* Use the end of the page for the page header */
pp->pr_roflags |= PR_PHINPAGE;
pp->pr_phoffset = off =
pagesz - ALIGN(sizeof(struct pool_item_header));
} else {
/* The page header will be taken from our page header pool */
pp->pr_phoffset = 0;
off = 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;
/*
* 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) != 0) {
pp->pr_log = malloc(pool_logsize * sizeof(struct pool_log),
M_TEMP, M_NOWAIT);
if (pp->pr_log == NULL)
pp->pr_roflags &= ~PR_LOGGING;
pp->pr_curlogentry = 0;
pp->pr_logsize = pool_logsize;
}
#endif
simple_lock_init(&pp->pr_slock);
/*
* Initialize private page header pool if we haven't done so yet.
* XXX LOCKING.
*/
if (phpool.pr_size == 0) {
pool_init(&phpool, sizeof(struct pool_item_header), 0, 0,
0, "phpool", 0, 0, 0, 0);
}
/* 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);
}
/*
* De-commision a pool resource.
*/
void
pool_destroy(pp)
struct pool *pp;
{
struct pool_item_header *ph;
#ifdef DIAGNOSTIC
if (pp->pr_nout != 0) {
pr_printlog(pp);
panic("pool_destroy: pool busy: still out: %u\n",
pp->pr_nout);
}
#endif
/* Remove all pages */
if ((pp->pr_roflags & PR_STATIC) == 0)
while ((ph = pp->pr_pagelist.tqh_first) != NULL)
pr_rmpage(pp, ph);
/* Remove from global pool list */
simple_lock(&pool_head_slock);
TAILQ_REMOVE(&pool_head, pp, pr_poollist);
/* XXX Only clear this if we were drainpp? */
drainpp = NULL;
simple_unlock(&pool_head_slock);
#ifdef POOL_DIAGNOSTIC
if ((pp->pr_roflags & PR_LOGGING) != 0)
free(pp->pr_log, M_TEMP);
#endif
if (pp->pr_roflags & PR_FREEHEADER)
free(pp, M_POOL);
}
/*
* Grab an item from the pool; must be called at appropriate spl level
*/
#ifdef POOL_DIAGNOSTIC
void *
_pool_get(pp, flags, file, line)
struct pool *pp;
int flags;
const char *file;
long line;
#else
void *
pool_get(pp, flags)
struct pool *pp;
int flags;
#endif
{
void *v;
struct pool_item *pi;
struct pool_item_header *ph;
#ifdef DIAGNOSTIC
if ((pp->pr_roflags & PR_STATIC) && (flags & PR_MALLOCOK)) {
pr_printlog(pp);
panic("pool_get: static");
}
#endif
if (curproc == NULL && (flags & PR_WAITOK) != 0)
panic("pool_get: must have NOWAIT");
simple_lock(&pp->pr_slock);
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 (pp->pr_nout > pp->pr_hardlimit) {
simple_unlock(&pp->pr_slock);
panic("pool_get: %s: crossed hard limit", pp->pr_wchan);
}
#endif
if (pp->pr_nout == pp->pr_hardlimit) {
if (flags & PR_WAITOK) {
/*
* XXX: A warning isn't logged in this case. Should
* it be?
*/
pp->pr_flags |= PR_WANTED;
simple_unlock(&pp->pr_slock);
tsleep((caddr_t)pp, PSWP, pp->pr_wchan, 0);
simple_lock(&pp->pr_slock);
goto startover;
}
if (pp->pr_hardlimit_warning != NULL) {
/*
* Log a message that the hard limit has been hit.
*/
struct timeval curtime, logdiff;
int s = splclock();
curtime = mono_time;
splx(s);
timersub(&curtime, &pp->pr_hardlimit_warning_last,
&logdiff);
if (logdiff.tv_sec >= pp->pr_hardlimit_ratecap) {
pp->pr_hardlimit_warning_last = curtime;
log(LOG_ERR, "%s\n", pp->pr_hardlimit_warning);
}
}
if (flags & PR_URGENT)
panic("pool_get: urgent");
pp->pr_nfail++;
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) {
void *v;
#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.
*/
simple_unlock(&pp->pr_slock);
v = (*pp->pr_alloc)(pp->pr_pagesz, flags, pp->pr_mtype);
simple_lock(&pp->pr_slock);
if (v == NULL) {
/*
* We were unable to allocate a page, 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_URGENT)
panic("pool_get: urgent");
if ((flags & PR_WAITOK) == 0) {
pp->pr_nfail++;
simple_unlock(&pp->pr_slock);
return (NULL);
}
/*
* Wait for items to be returned to this pool.
*
* XXX: we actually want to wait just until
* the page allocator has memory again. Depending
* on this pool's usage, we might get stuck here
* for a long time.
*
* XXX: maybe we should wake up once a second and
* try again?
*/
pp->pr_flags |= PR_WANTED;
simple_unlock(&pp->pr_slock);
tsleep((caddr_t)pp, PSWP, pp->pr_wchan, 0);
simple_lock(&pp->pr_slock);
goto startover;
}
/* We have more memory; add it to the pool */
pp->pr_npagealloc++;
pool_prime_page(pp, v);
/* Start the allocation process over. */
goto startover;
}
if ((v = pi = TAILQ_FIRST(&ph->ph_itemlist)) == NULL) {
simple_unlock(&pp->pr_slock);
panic("pool_get: %s: page empty", pp->pr_wchan);
}
#ifdef DIAGNOSTIC
if (pp->pr_nitems == 0) {
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
pr_log(pp, v, PRLOG_GET, file, line);
#ifdef DIAGNOSTIC
if (pi->pi_magic != PI_MAGIC) {
pr_printlog(pp);
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 (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 (ph->ph_nmissing != pp->pr_itemsperpage) {
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);
for (ph = TAILQ_FIRST(&pp->pr_pagelist); ph != NULL;
ph = TAILQ_NEXT(ph, 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 (pp->pr_nitems < pp->pr_minitems && 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);
return (v);
}
/*
* Return resource to the pool; must be called at appropriate spl level
*/
#ifdef POOL_DIAGNOSTIC
void
_pool_put(pp, v, file, line)
struct pool *pp;
void *v;
const char *file;
long line;
#else
void
pool_put(pp, v)
struct pool *pp;
void *v;
#endif
{
struct pool_item *pi = v;
struct pool_item_header *ph;
caddr_t page;
int s;
page = (caddr_t)((u_long)v & pp->pr_pagemask);
simple_lock(&pp->pr_slock);
pr_log(pp, v, PRLOG_PUT, file, line);
if ((ph = pr_find_pagehead(pp, page)) == NULL) {
pr_printlog(pp);
panic("pool_put: %s: page header missing", pp->pr_wchan);
}
/*
* Return to item list.
*/
#ifdef DIAGNOSTIC
pi->pi_magic = 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++;
simple_unlock(&pp->pr_slock);
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) {
pr_rmpage(pp, ph);
} 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?
*/
for (ph = TAILQ_FIRST(&pp->pr_pagelist); ph != NULL;
ph = TAILQ_NEXT(ph, 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;
}
simple_unlock(&pp->pr_slock);
}
/*
* Add N items to the pool.
*/
int
pool_prime(pp, n, storage)
struct pool *pp;
int n;
caddr_t storage;
{
caddr_t cp;
int newnitems, newpages;
#ifdef DIAGNOSTIC
if (storage && !(pp->pr_roflags & PR_STATIC))
panic("pool_prime: static");
/* !storage && static caught below */
#endif
simple_lock(&pp->pr_slock);
newnitems = pp->pr_minitems + n;
newpages =
roundup(newnitems, pp->pr_itemsperpage) / pp->pr_itemsperpage
- pp->pr_minpages;
while (newpages-- > 0) {
if (pp->pr_roflags & PR_STATIC) {
cp = storage;
storage += pp->pr_pagesz;
} else {
simple_unlock(&pp->pr_slock);
cp = (*pp->pr_alloc)(pp->pr_pagesz, 0, pp->pr_mtype);
simple_lock(&pp->pr_slock);
}
if (cp == NULL) {
simple_unlock(&pp->pr_slock);
return (ENOMEM);
}
pool_prime_page(pp, cp);
pp->pr_minpages++;
}
pp->pr_minitems = newnitems;
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(pp, storage)
struct pool *pp;
caddr_t storage;
{
struct pool_item *pi;
struct pool_item_header *ph;
caddr_t cp = storage;
unsigned int align = pp->pr_align;
unsigned int ioff = pp->pr_itemoffset;
int n;
if ((pp->pr_roflags & PR_PHINPAGE) != 0) {
ph = (struct pool_item_header *)(cp + pp->pr_phoffset);
} else {
ph = pool_get(&phpool, PR_URGENT);
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;
}
/*
* Like pool_prime(), except this is 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, this doesn't work with static pools.
*
* Note 3, we must be called with the pool already locked, and we return
* with it locked.
*/
static int
pool_catchup(pp)
struct pool *pp;
{
caddr_t cp;
int error = 0;
if (pp->pr_roflags & PR_STATIC) {
/*
* We dropped below the low water mark, and this is not a
* good thing. Log a warning.
*
* XXX: rate-limit this?
*/
printf("WARNING: static pool `%s' dropped below low water "
"mark\n", pp->pr_wchan);
return (0);
}
while (pp->pr_nitems < pp->pr_minitems) {
/*
* 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 = (*pp->pr_alloc)(pp->pr_pagesz, 0, pp->pr_mtype);
simple_lock(&pp->pr_slock);
if (cp == NULL) {
error = ENOMEM;
break;
}
pool_prime_page(pp, cp);
}
return (error);
}
void
pool_setlowat(pp, n)
pool_handle_t pp;
int n;
{
int error;
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 ((error = 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(pp, n)
pool_handle_t 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(pp, n, warnmess, ratecap)
pool_handle_t 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 = ratecap;
memset(&pp->pr_hardlimit_warning_last, 0,
sizeof(pp->pr_hardlimit_warning_last));
/*
* 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);
}
/*
* Default page allocator.
*/
static void *
pool_page_alloc(sz, flags, mtype)
unsigned long sz;
int flags;
int mtype;
{
boolean_t waitok = (flags & PR_WAITOK) ? TRUE : FALSE;
return ((void *)uvm_km_alloc_poolpage(waitok));
}
static void
pool_page_free(v, sz, mtype)
void *v;
unsigned long sz;
int mtype;
{
uvm_km_free_poolpage((vaddr_t)v);
}
/*
* Alternate pool page allocator for pools that know they will
* never be accessed in interrupt context.
*/
void *
pool_page_alloc_nointr(sz, flags, mtype)
unsigned long sz;
int flags;
int mtype;
{
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(v, sz, mtype)
void *v;
unsigned long sz;
int mtype;
{
uvm_km_free_poolpage1(kernel_map, (vaddr_t)v);
}
/*
* Release all complete pages that have not been used recently.
*/
void
pool_reclaim(pp)
pool_handle_t pp;
{
struct pool_item_header *ph, *phnext;
struct timeval curtime;
int s;
if (pp->pr_roflags & PR_STATIC)
return;
if (simple_lock_try(&pp->pr_slock) == 0)
return;
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);
}
}
simple_unlock(&pp->pr_slock);
}
/*
* Drain pools, one at a time.
*
* Note, we must never be called from an interrupt context.
*/
void
pool_drain(arg)
void *arg;
{
struct pool *pp;
int s;
s = splimp();
simple_lock(&pool_head_slock);
if (drainpp == NULL && (drainpp = TAILQ_FIRST(&pool_head)) == NULL)
goto out;
pp = drainpp;
drainpp = TAILQ_NEXT(pp, pr_poollist);
pool_reclaim(pp);
out:
simple_unlock(&pool_head_slock);
splx(s);
}
#if defined(POOL_DIAGNOSTIC) || defined(DEBUG)
/*
* Diagnostic helpers.
*/
void
pool_print(pp, label)
struct pool *pp;
const char *label;
{
int s;
s = splimp();
simple_lock(&pp->pr_slock);
pool_print1(pp, label);
simple_unlock(&pp->pr_slock);
splx(s);
}
static void
pool_print1(pp, label)
struct pool *pp;
const char *label;
{
if (label != NULL)
printf("%s: ", label);
printf("pool %s: nalloc %lu nfree %lu npagealloc %lu npagefree %lu\n"
" npages %u minitems %u itemsperpage %u itemoffset %u\n"
" nidle %lu\n",
pp->pr_wchan,
pp->pr_nget,
pp->pr_nput,
pp->pr_npagealloc,
pp->pr_npagefree,
pp->pr_npages,
pp->pr_minitems,
pp->pr_itemsperpage,
pp->pr_itemoffset,
pp->pr_nidle);
}
int
pool_chk(pp, label)
struct pool *pp;
char *label;
{
struct pool_item_header *ph;
int r = 0;
simple_lock(&pp->pr_slock);
for (ph = TAILQ_FIRST(&pp->pr_pagelist); ph != NULL;
ph = TAILQ_NEXT(ph, ph_pagelist)) {
struct pool_item *pi;
int n;
caddr_t page;
page = (caddr_t)((u_long)ph & pp->pr_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_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);
}
#endif /* POOL_DIAGNOSTIC || DEBUG */
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