/* $NetBSD: subr_pool.c,v 1.30 1999/08/29 00:26:01 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 "opt_pool.h" #include "opt_poollog.h" #include "opt_lockdebug.h" #include #include #include #include #include #include #include #include #include #include #include #include /* * 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)); static void pool_print1 __P((struct pool *, const char *, void (*)(const char *, ...))); /* * 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; #ifdef DIAGNOSTIC static void pr_log __P((struct pool *, void *, int, const char *, long)); static void pr_printlog __P((struct pool *, struct pool_item *, void (*)(const char *, ...))); static void pr_enter __P((struct pool *, const char *, long)); static void pr_leave __P((struct pool *)); static void pr_enter_check __P((struct pool *, void (*)(const char *, ...))); 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, pi, pr) struct pool *pp; struct pool_item *pi; void (*pr) __P((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(pp, file, line) struct pool *pp; const char *file; long line; { if (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(pp) struct pool *pp; { if (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(pp, pr) struct pool *pp; void (*pr) __P((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 /* DIAGNOSTIC */ /* * 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) { int s; LIST_REMOVE(ph, ph_hashlist); s = splhigh(); pool_put(&phpool, ph); splx(s); } 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; 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; #ifdef POOL_DIAGNOSTIC /* * Always log if POOL_DIAGNOSTIC is defined. */ if (pool_logsize != 0) flags |= PR_LOGGING; #endif /* * 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; 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; } pp->pr_entered_file = NULL; pp->pr_entered_line = 0; 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, NULL, printf); 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); if ((pp->pr_roflags & PR_LOGGING) != 0) free(pp->pr_log, M_TEMP); if (pp->pr_roflags & PR_FREEHEADER) free(pp, M_POOL); } /* * Grab an item from the pool; must be called at appropriate spl level */ void * _pool_get(pp, flags, file, line) struct pool *pp; int flags; const char *file; long line; { 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, NULL, printf); panic("pool_get: static"); } #endif if (curproc == NULL && (flags & PR_WAITOK) != 0) panic("pool_get: must have NOWAIT"); 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 (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 (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; pr_leave(pp); simple_unlock(&pp->pr_slock); tsleep((caddr_t)pp, PSWP, pp->pr_wchan, 0); simple_lock(&pp->pr_slock); pr_enter(pp, file, line); 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++; 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) { 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. */ pr_leave(pp); simple_unlock(&pp->pr_slock); v = (*pp->pr_alloc)(pp->pr_pagesz, flags, pp->pr_mtype); simple_lock(&pp->pr_slock); pr_enter(pp, file, line); 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++; pr_leave(pp); 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; pr_leave(pp); simple_unlock(&pp->pr_slock); tsleep((caddr_t)pp, PSWP, pp->pr_wchan, 0); simple_lock(&pp->pr_slock); pr_enter(pp, file, line); 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) { pr_leave(pp); simple_unlock(&pp->pr_slock); panic("pool_get: %s: page empty", pp->pr_wchan); } #ifdef DIAGNOSTIC if (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 pr_log(pp, v, PRLOG_GET, file, line); #ifdef DIAGNOSTIC if (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 (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) { 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); 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. */ } pr_leave(pp); simple_unlock(&pp->pr_slock); return (v); } /* * Return resource to the pool; must be called at appropriate spl level */ void _pool_put(pp, v, file, line) struct pool *pp; void *v; const char *file; long line; { 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_enter(pp, file, line); #ifdef DIAGNOSTIC if (pp->pr_nout == 0) { printf("pool %s: putting with none out\n", pp->pr_wchan); panic("pool_put"); } #endif pr_log(pp, v, PRLOG_PUT, file, line); if ((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 /* XXX Should fill the item. */ 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++; pr_leave(pp); 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; } pr_leave(pp); 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); } pp->pr_npagealloc++; 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 s, n; if ((pp->pr_roflags & PR_PHINPAGE) != 0) { ph = (struct pool_item_header *)(cp + pp->pr_phoffset); } else { s = splhigh(); ph = pool_get(&phpool, PR_URGENT); splx(s); 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; } pp->pr_npagealloc++; 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, file, line) pool_handle_t pp; const char *file; long line; { 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; pr_enter(pp, file, line); 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); } } pr_leave(pp); 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); } /* * Diagnostic helpers. */ void pool_print(pp, modif) struct pool *pp; const char *modif; { int s; s = splimp(); 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(pp, modif, pr) struct pool *pp; const char *modif; void (*pr) __P((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(pp, modif, pr) struct pool *pp; const char *modif; void (*pr) __P((const char *, ...)); { struct pool_item_header *ph; #ifdef DIAGNOSTIC struct pool_item *pi; #endif int print_log = 0, print_pagelist = 0; char c; while ((c = *modif++) != '\0') { if (c == 'l') print_log = 1; 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)("\tpagesz %u, mtype %d\n", pp->pr_pagesz, pp->pr_mtype); (*pr)("\talloc %p, release %p\n", pp->pr_alloc, pp->pr_free); (*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 for (pi = TAILQ_FIRST(&ph->ph_itemlist); pi != NULL; pi = TAILQ_NEXT(pi, 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: pr_enter_check(pp, pr); } 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); }