The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_contig.c

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    1 /*-
    2  * Copyright (c) 1991 Regents of the University of California.
    3  * All rights reserved.
    4  *
    5  * This code is derived from software contributed to Berkeley by
    6  * The Mach Operating System project at Carnegie-Mellon University.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 4. Neither the name of the University nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  *
   32  *      from: @(#)vm_page.c     7.4 (Berkeley) 5/7/91
   33  */
   34 
   35 /*-
   36  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
   37  * All rights reserved.
   38  *
   39  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
   40  *
   41  * Permission to use, copy, modify and distribute this software and
   42  * its documentation is hereby granted, provided that both the copyright
   43  * notice and this permission notice appear in all copies of the
   44  * software, derivative works or modified versions, and any portions
   45  * thereof, and that both notices appear in supporting documentation.
   46  *
   47  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
   48  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
   49  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
   50  *
   51  * Carnegie Mellon requests users of this software to return to
   52  *
   53  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
   54  *  School of Computer Science
   55  *  Carnegie Mellon University
   56  *  Pittsburgh PA 15213-3890
   57  *
   58  * any improvements or extensions that they make and grant Carnegie the
   59  * rights to redistribute these changes.
   60  */
   61 
   62 #include <sys/cdefs.h>
   63 __FBSDID("$FreeBSD: releng/6.4/sys/vm/vm_contig.c 169086 2007-04-28 20:44:56Z alc $");
   64 
   65 #include <sys/param.h>
   66 #include <sys/systm.h>
   67 #include <sys/lock.h>
   68 #include <sys/malloc.h>
   69 #include <sys/mutex.h>
   70 #include <sys/proc.h>
   71 #include <sys/kernel.h>
   72 #include <sys/linker_set.h>
   73 #include <sys/sysctl.h>
   74 #include <sys/vmmeter.h>
   75 #include <sys/vnode.h>
   76 
   77 #include <vm/vm.h>
   78 #include <vm/vm_param.h>
   79 #include <vm/vm_kern.h>
   80 #include <vm/pmap.h>
   81 #include <vm/vm_map.h>
   82 #include <vm/vm_object.h>
   83 #include <vm/vm_page.h>
   84 #include <vm/vm_pageout.h>
   85 #include <vm/vm_pager.h>
   86 #include <vm/vm_extern.h>
   87 
   88 static int
   89 vm_contig_launder_page(vm_page_t m)
   90 {
   91         vm_object_t object;
   92         vm_page_t m_tmp;
   93         struct vnode *vp;
   94         struct mount *mp;
   95 
   96         object = m->object;
   97         if (!VM_OBJECT_TRYLOCK(object))
   98                 return (EAGAIN);
   99         if (vm_page_sleep_if_busy(m, TRUE, "vpctw0")) {
  100                 VM_OBJECT_UNLOCK(object);
  101                 vm_page_lock_queues();
  102                 return (EBUSY);
  103         }
  104         vm_page_test_dirty(m);
  105         if (m->dirty == 0 && m->hold_count == 0)
  106                 pmap_remove_all(m);
  107         if (m->dirty) {
  108                 if ((object->flags & OBJ_DEAD) != 0) {
  109                         VM_OBJECT_UNLOCK(object);
  110                         return (EAGAIN);
  111                 }
  112                 if (object->type == OBJT_VNODE) {
  113                         vm_page_unlock_queues();
  114                         vp = object->handle;
  115                         vm_object_reference_locked(object);
  116                         VM_OBJECT_UNLOCK(object);
  117                         (void) vn_start_write(vp, &mp, V_WAIT);
  118                         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
  119                         VM_OBJECT_LOCK(object);
  120                         vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
  121                         VM_OBJECT_UNLOCK(object);
  122                         VOP_UNLOCK(vp, 0, curthread);
  123                         vm_object_deallocate(object);
  124                         vn_finished_write(mp);
  125                         vm_page_lock_queues();
  126                         return (0);
  127                 } else if (object->type == OBJT_SWAP ||
  128                            object->type == OBJT_DEFAULT) {
  129                         m_tmp = m;
  130                         vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC);
  131                         VM_OBJECT_UNLOCK(object);
  132                         return (0);
  133                 }
  134         } else if (m->hold_count == 0)
  135                 vm_page_cache(m);
  136         VM_OBJECT_UNLOCK(object);
  137         return (0);
  138 }
  139 
  140 static int
  141 vm_contig_launder(int queue)
  142 {
  143         vm_page_t m, next;
  144         int error;
  145 
  146         for (m = TAILQ_FIRST(&vm_page_queues[queue].pl); m != NULL; m = next) {
  147                 next = TAILQ_NEXT(m, pageq);
  148 
  149                 /* Skip marker pages */
  150                 if ((m->flags & PG_MARKER) != 0)
  151                         continue;
  152 
  153                 KASSERT(m->queue == queue,
  154                     ("vm_contig_launder: page %p's queue is not %d", m, queue));
  155                 error = vm_contig_launder_page(m);
  156                 if (error == 0)
  157                         return (TRUE);
  158                 if (error == EBUSY)
  159                         return (FALSE);
  160         }
  161         return (FALSE);
  162 }
  163 
  164 /*
  165  * This interface is for merging with malloc() someday.
  166  * Even if we never implement compaction so that contiguous allocation
  167  * works after initialization time, malloc()'s data structures are good
  168  * for statistics and for allocations of less than a page.
  169  */
  170 static void *
  171 contigmalloc1(
  172         unsigned long size,     /* should be size_t here and for malloc() */
  173         struct malloc_type *type,
  174         int flags,
  175         vm_paddr_t low,
  176         vm_paddr_t high,
  177         unsigned long alignment,
  178         unsigned long boundary,
  179         vm_map_t map)
  180 {
  181         int i, start;
  182         vm_paddr_t phys;
  183         vm_object_t object;
  184         vm_offset_t addr, tmp_addr;
  185         int pass, pqtype;
  186         int inactl, actl, inactmax, actmax;
  187         vm_page_t pga = vm_page_array;
  188 
  189         size = round_page(size);
  190         if (size == 0)
  191                 panic("contigmalloc1: size must not be 0");
  192         if ((alignment & (alignment - 1)) != 0)
  193                 panic("contigmalloc1: alignment must be a power of 2");
  194         if ((boundary & (boundary - 1)) != 0)
  195                 panic("contigmalloc1: boundary must be a power of 2");
  196 
  197         start = 0;
  198         for (pass = 2; pass >= 0; pass--) {
  199                 vm_page_lock_queues();
  200 again0:
  201                 mtx_lock_spin(&vm_page_queue_free_mtx);
  202 again:
  203                 /*
  204                  * Find first page in array that is free, within range,
  205                  * aligned, and such that the boundary won't be crossed.
  206                  */
  207                 for (i = start; i < cnt.v_page_count; i++) {
  208                         phys = VM_PAGE_TO_PHYS(&pga[i]);
  209                         pqtype = pga[i].queue - pga[i].pc;
  210                         if (((pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) &&
  211                             (phys >= low) && (phys < high) &&
  212                             ((phys & (alignment - 1)) == 0) &&
  213                             (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0))
  214                                 break;
  215                 }
  216 
  217                 /*
  218                  * If the above failed or we will exceed the upper bound, fail.
  219                  */
  220                 if ((i == cnt.v_page_count) ||
  221                         ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) {
  222                         mtx_unlock_spin(&vm_page_queue_free_mtx);
  223                         /*
  224                          * Instead of racing to empty the inactive/active
  225                          * queues, give up, even with more left to free,
  226                          * if we try more than the initial amount of pages.
  227                          *
  228                          * There's no point attempting this on the last pass.
  229                          */
  230                         if (pass > 0) {
  231                                 inactl = actl = 0;
  232                                 inactmax = vm_page_queues[PQ_INACTIVE].lcnt;
  233                                 actmax = vm_page_queues[PQ_ACTIVE].lcnt;
  234 again1:
  235                                 if (inactl < inactmax &&
  236                                     vm_contig_launder(PQ_INACTIVE)) {
  237                                         inactl++;
  238                                         goto again1;
  239                                 }
  240                                 if (actl < actmax &&
  241                                     vm_contig_launder(PQ_ACTIVE)) {
  242                                         actl++;
  243                                         goto again1;
  244                                 }
  245                         }
  246                         vm_page_unlock_queues();
  247                         continue;
  248                 }
  249                 start = i;
  250 
  251                 /*
  252                  * Check successive pages for contiguous and free.
  253                  */
  254                 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) {
  255                         pqtype = pga[i].queue - pga[i].pc;
  256                         if ((VM_PAGE_TO_PHYS(&pga[i]) !=
  257                             (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) ||
  258                             ((pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) {
  259                                 start++;
  260                                 goto again;
  261                         }
  262                 }
  263                 mtx_unlock_spin(&vm_page_queue_free_mtx);
  264                 for (i = start; i < (start + size / PAGE_SIZE); i++) {
  265                         vm_page_t m = &pga[i];
  266 
  267                         if ((m->queue - m->pc) == PQ_CACHE) {
  268                                 if (m->hold_count != 0) {
  269                                         start++;
  270                                         goto again0;
  271                                 }
  272                                 object = m->object;
  273                                 if (!VM_OBJECT_TRYLOCK(object)) {
  274                                         start++;
  275                                         goto again0;
  276                                 }
  277                                 if ((m->flags & PG_BUSY) || m->busy != 0) {
  278                                         VM_OBJECT_UNLOCK(object);
  279                                         start++;
  280                                         goto again0;
  281                                 }
  282                                 vm_page_free(m);
  283                                 VM_OBJECT_UNLOCK(object);
  284                         }
  285                 }
  286                 mtx_lock_spin(&vm_page_queue_free_mtx);
  287                 for (i = start; i < (start + size / PAGE_SIZE); i++) {
  288                         pqtype = pga[i].queue - pga[i].pc;
  289                         if (pqtype != PQ_FREE) {
  290                                 start++;
  291                                 goto again;
  292                         }
  293                 }
  294                 for (i = start; i < (start + size / PAGE_SIZE); i++) {
  295                         vm_page_t m = &pga[i];
  296                         vm_pageq_remove_nowakeup(m);
  297                         m->valid = VM_PAGE_BITS_ALL;
  298                         if (m->flags & PG_ZERO)
  299                                 vm_page_zero_count--;
  300                         /* Don't clear the PG_ZERO flag, we'll need it later. */
  301                         m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
  302                         KASSERT(m->dirty == 0,
  303                             ("contigmalloc1: page %p was dirty", m));
  304                         m->wire_count = 0;
  305                         m->busy = 0;
  306                 }
  307                 mtx_unlock_spin(&vm_page_queue_free_mtx);
  308                 vm_page_unlock_queues();
  309                 /*
  310                  * We've found a contiguous chunk that meets are requirements.
  311                  * Allocate kernel VM, unfree and assign the physical pages to
  312                  * it and return kernel VM pointer.
  313                  */
  314                 vm_map_lock(map);
  315                 if (vm_map_findspace(map, vm_map_min(map), size, &addr) !=
  316                     KERN_SUCCESS) {
  317                         /*
  318                          * XXX We almost never run out of kernel virtual
  319                          * space, so we don't make the allocated memory
  320                          * above available.
  321                          */
  322                         vm_map_unlock(map);
  323                         return (NULL);
  324                 }
  325                 vm_object_reference(kernel_object);
  326                 vm_map_insert(map, kernel_object, addr - VM_MIN_KERNEL_ADDRESS,
  327                     addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
  328                 vm_map_unlock(map);
  329 
  330                 tmp_addr = addr;
  331                 VM_OBJECT_LOCK(kernel_object);
  332                 for (i = start; i < (start + size / PAGE_SIZE); i++) {
  333                         vm_page_t m = &pga[i];
  334                         vm_page_insert(m, kernel_object,
  335                                 OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
  336                         if ((flags & M_ZERO) && !(m->flags & PG_ZERO))
  337                                 pmap_zero_page(m);
  338                         tmp_addr += PAGE_SIZE;
  339                 }
  340                 VM_OBJECT_UNLOCK(kernel_object);
  341                 vm_map_wire(map, addr, addr + size,
  342                     VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
  343 
  344                 return ((void *)addr);
  345         }
  346         return (NULL);
  347 }
  348 
  349 static void
  350 vm_page_release_contigl(vm_page_t m, vm_pindex_t count)
  351 {
  352         while (count--) {
  353                 vm_page_free_toq(m);
  354                 m++;
  355         }
  356 }
  357 
  358 void
  359 vm_page_release_contig(vm_page_t m, vm_pindex_t count)
  360 {
  361         vm_page_lock_queues();
  362         vm_page_release_contigl(m, count);
  363         vm_page_unlock_queues();
  364 }
  365 
  366 static int
  367 vm_contig_unqueue_free(vm_page_t m)
  368 {
  369         int error = 0;
  370 
  371         mtx_lock_spin(&vm_page_queue_free_mtx);
  372         if ((m->queue - m->pc) == PQ_FREE)
  373                 vm_pageq_remove_nowakeup(m);
  374         else
  375                 error = EAGAIN;
  376         mtx_unlock_spin(&vm_page_queue_free_mtx);
  377         if (error)
  378                 return (error);
  379         m->valid = VM_PAGE_BITS_ALL;
  380         if (m->flags & PG_ZERO)
  381                 vm_page_zero_count--;
  382         /* Don't clear the PG_ZERO flag; we'll need it later. */
  383         m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
  384         KASSERT(m->dirty == 0,
  385             ("contigmalloc2: page %p was dirty", m));
  386         m->wire_count = 0;
  387         m->busy = 0;
  388         return (error);
  389 }
  390 
  391 vm_page_t
  392 vm_page_alloc_contig(vm_pindex_t npages, vm_paddr_t low, vm_paddr_t high,
  393             vm_offset_t alignment, vm_offset_t boundary)
  394 {
  395         vm_object_t object;
  396         vm_offset_t size;
  397         vm_paddr_t phys;
  398         vm_page_t pga = vm_page_array;
  399         int i, pass, pqtype, start;
  400 
  401         size = npages << PAGE_SHIFT;
  402         if (size == 0)
  403                 panic("vm_page_alloc_contig: size must not be 0");
  404         if ((alignment & (alignment - 1)) != 0)
  405                 panic("vm_page_alloc_contig: alignment must be a power of 2");
  406         if ((boundary & (boundary - 1)) != 0)
  407                 panic("vm_page_alloc_contig: boundary must be a power of 2");
  408 
  409         for (pass = 0; pass < 2; pass++) {
  410                 if (atop(high) < vm_page_array_size)
  411                         start = atop(high) - npages + 1;
  412                 else
  413                         start = vm_page_array_size - npages + 1;
  414                 vm_page_lock_queues();
  415 retry:
  416                 start--;
  417                 /*
  418                  * Find last page in array that is free, within range,
  419                  * aligned, and such that the boundary won't be crossed.
  420                  */
  421                 for (i = start; i >= 0; i--) {
  422                         phys = VM_PAGE_TO_PHYS(&pga[i]);
  423                         pqtype = pga[i].queue - pga[i].pc;
  424                         if (pass == 0) {
  425                                 if (pqtype != PQ_FREE && pqtype != PQ_CACHE)
  426                                         continue;
  427                         } else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
  428                                     pga[i].queue != PQ_ACTIVE &&
  429                                     pga[i].queue != PQ_INACTIVE)
  430                                 continue;
  431                         if (phys >= low && phys + size <= high &&
  432                             ((phys & (alignment - 1)) == 0) &&
  433                             ((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)
  434                                 break;
  435                 }
  436                 /* There are no candidates at all. */
  437                 if (i < 0) {
  438                         vm_page_unlock_queues();
  439                         continue;
  440                 }
  441                 start = i;
  442                 /*
  443                  * Check successive pages for contiguous and free.
  444                  */
  445                 for (i = start + npages - 1; i > start; i--) {
  446                         pqtype = pga[i].queue - pga[i].pc;
  447                         if (VM_PAGE_TO_PHYS(&pga[i]) !=
  448                             VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE) {
  449                                 start = i - npages + 1;
  450                                 goto retry;
  451                         }
  452                         if (pass == 0) {
  453                                 if (pqtype != PQ_FREE && pqtype != PQ_CACHE) {
  454                                         start = i - npages + 1;
  455                                         goto retry;
  456                                 }
  457                         } else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
  458                                     pga[i].queue != PQ_ACTIVE &&
  459                                     pga[i].queue != PQ_INACTIVE) {
  460                                 start = i - npages + 1;
  461                                 goto retry;
  462                         }
  463                 }
  464                 for (i = start + npages - 1; i >= start; i--) {
  465                         vm_page_t m = &pga[i];
  466 
  467 retry_page:
  468                         pqtype = m->queue - m->pc;
  469                         if (pass != 0 && pqtype != PQ_FREE &&
  470                             pqtype != PQ_CACHE) {
  471                                 switch (m->queue) {
  472                                 case PQ_ACTIVE:
  473                                 case PQ_INACTIVE:
  474                                         if (vm_contig_launder_page(m) != 0)
  475                                                 goto cleanup_freed;
  476                                         pqtype = m->queue - m->pc;
  477                                         if (pqtype == PQ_FREE ||
  478                                             pqtype == PQ_CACHE)
  479                                                 break;
  480                                 default:
  481 cleanup_freed:
  482                                         vm_page_release_contigl(&pga[i + 1],
  483                                             start + npages - 1 - i);
  484                                         start = i - npages + 1;
  485                                         goto retry;
  486                                 }
  487                         }
  488                         if (pqtype == PQ_CACHE) {
  489                                 if (m->hold_count != 0) {
  490                                         start = i - npages + 1;
  491                                         goto retry;
  492                                 }
  493                                 object = m->object;
  494                                 if (!VM_OBJECT_TRYLOCK(object)) {
  495                                         start = i - npages + 1;
  496                                         goto retry;
  497                                 }
  498                                 if ((m->flags & PG_BUSY) || m->busy != 0) {
  499                                         VM_OBJECT_UNLOCK(object);
  500                                         start = i - npages + 1;
  501                                         goto retry;
  502                                 }
  503                                 vm_page_free(m);
  504                                 VM_OBJECT_UNLOCK(object);
  505                         }
  506                         /*
  507                          * There is no good API for freeing a page
  508                          * directly to PQ_NONE on our behalf, so spin.
  509                          */
  510                         if (vm_contig_unqueue_free(m) != 0)
  511                                 goto retry_page;
  512                 }
  513                 vm_page_unlock_queues();
  514                 /*
  515                  * We've found a contiguous chunk that meets are requirements.
  516                  */
  517                 return (&pga[start]);
  518         }
  519         return (NULL);
  520 }
  521 
  522 static void *
  523 contigmalloc2(vm_page_t m, vm_pindex_t npages, int flags)
  524 {
  525         vm_object_t object = kernel_object;
  526         vm_map_t map = kernel_map;
  527         vm_offset_t addr, tmp_addr;
  528         vm_pindex_t i;
  529  
  530         /*
  531          * Allocate kernel VM, unfree and assign the physical pages to
  532          * it and return kernel VM pointer.
  533          */
  534         vm_map_lock(map);
  535         if (vm_map_findspace(map, vm_map_min(map), npages << PAGE_SHIFT, &addr)
  536             != KERN_SUCCESS) {
  537                 vm_map_unlock(map);
  538                 return (NULL);
  539         }
  540         vm_object_reference(object);
  541         vm_map_insert(map, object, addr - VM_MIN_KERNEL_ADDRESS,
  542             addr, addr + (npages << PAGE_SHIFT), VM_PROT_ALL, VM_PROT_ALL, 0);
  543         vm_map_unlock(map);
  544         tmp_addr = addr;
  545         VM_OBJECT_LOCK(object);
  546         for (i = 0; i < npages; i++) {
  547                 vm_page_insert(&m[i], object,
  548                     OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
  549                 if ((flags & M_ZERO) && !(m[i].flags & PG_ZERO))
  550                         pmap_zero_page(&m[i]);
  551                 tmp_addr += PAGE_SIZE;
  552         }
  553         VM_OBJECT_UNLOCK(object);
  554         vm_map_wire(map, addr, addr + (npages << PAGE_SHIFT),
  555             VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
  556         return ((void *)addr);
  557 }
  558 
  559 static int vm_old_contigmalloc = 0;
  560 SYSCTL_INT(_vm, OID_AUTO, old_contigmalloc,
  561     CTLFLAG_RW, &vm_old_contigmalloc, 0, "Use the old contigmalloc algorithm");
  562 TUNABLE_INT("vm.old_contigmalloc", &vm_old_contigmalloc);
  563 
  564 void *
  565 contigmalloc(
  566         unsigned long size,     /* should be size_t here and for malloc() */
  567         struct malloc_type *type,
  568         int flags,
  569         vm_paddr_t low,
  570         vm_paddr_t high,
  571         unsigned long alignment,
  572         unsigned long boundary)
  573 {
  574         void * ret;
  575         vm_page_t pages;
  576         vm_pindex_t npgs;
  577 
  578         npgs = round_page(size) >> PAGE_SHIFT;
  579         mtx_lock(&Giant);
  580         if (vm_old_contigmalloc) {
  581                 ret = contigmalloc1(size, type, flags, low, high, alignment,
  582                     boundary, kernel_map);
  583         } else {
  584                 pages = vm_page_alloc_contig(npgs, low, high,
  585                     alignment, boundary);
  586                 if (pages == NULL) {
  587                         ret = NULL;
  588                 } else {
  589                         ret = contigmalloc2(pages, npgs, flags);
  590                         if (ret == NULL)
  591                                 vm_page_release_contig(pages, npgs);
  592                 }
  593                 
  594         }
  595         mtx_unlock(&Giant);
  596         malloc_type_allocated(type, ret == NULL ? 0 : npgs << PAGE_SHIFT);
  597         return (ret);
  598 }
  599 
  600 void
  601 contigfree(void *addr, unsigned long size, struct malloc_type *type)
  602 {
  603         vm_pindex_t npgs;
  604 
  605         npgs = round_page(size) >> PAGE_SHIFT;
  606         kmem_free(kernel_map, (vm_offset_t)addr, size);
  607         malloc_type_freed(type, npgs << PAGE_SHIFT);
  608 }

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