sys/vm/vm_reserv.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2002-2006 Rice University
   5  * Copyright (c) 2007-2011 Alan L. Cox <alc@cs.rice.edu>
   6  * All rights reserved.
   7  *
   8  * This software was developed for the FreeBSD Project by Alan L. Cox,
   9  * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
  24  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
  30  * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /*
  35  *      Superpage reservation management module
  36  *
  37  * Any external functions defined by this module are only to be used by the
  38  * virtual memory system.
  39  */
  40
  41 #include <sys/cdefs.h>
  42 #include "opt_vm.h"
  43
  44 #include <sys/param.h>
  45 #include <sys/kernel.h>
  46 #include <sys/lock.h>
  47 #include <sys/malloc.h>
  48 #include <sys/mutex.h>
  49 #include <sys/queue.h>
  50 #include <sys/rwlock.h>
  51 #include <sys/sbuf.h>
  52 #include <sys/sysctl.h>
  53 #include <sys/systm.h>
  54 #include <sys/bitstring.h>
  55 #include <sys/counter.h>
  56 #include <sys/ktr.h>
  57 #include <sys/vmmeter.h>
  58 #include <sys/smp.h>
  59
  60 #include <vm/vm.h>
  61 #include <vm/vm_extern.h>
  62 #include <vm/vm_param.h>
  63 #include <vm/vm_object.h>
  64 #include <vm/vm_page.h>
  65 #include <vm/vm_pageout.h>
  66 #include <vm/vm_pagequeue.h>
  67 #include <vm/vm_phys.h>
  68 #include <vm/vm_radix.h>
  69 #include <vm/vm_reserv.h>
  70
  71 /*
  72  * The reservation system supports the speculative allocation of large physical
  73  * pages ("superpages").  Speculative allocation enables the fully automatic
  74  * utilization of superpages by the virtual memory system.  In other words, no
  75  * programmatic directives are required to use superpages.
  76  */
  77
  78 #if VM_NRESERVLEVEL > 0
  79
  80 #ifndef VM_LEVEL_0_ORDER_MAX
  81 #define VM_LEVEL_0_ORDER_MAX    VM_LEVEL_0_ORDER
  82 #endif
  83
  84 /*
  85  * The number of small pages that are contained in a level 0 reservation
  86  */
  87 #define VM_LEVEL_0_NPAGES       (1 << VM_LEVEL_0_ORDER)
  88 #define VM_LEVEL_0_NPAGES_MAX   (1 << VM_LEVEL_0_ORDER_MAX)
  89
  90 /*
  91  * The number of bits by which a physical address is shifted to obtain the
  92  * reservation number
  93  */
  94 #define VM_LEVEL_0_SHIFT        (VM_LEVEL_0_ORDER + PAGE_SHIFT)
  95
  96 /*
  97  * The size of a level 0 reservation in bytes
  98  */
  99 #define VM_LEVEL_0_SIZE         (1 << VM_LEVEL_0_SHIFT)
 100
 101 /*
 102  * Computes the index of the small page underlying the given (object, pindex)
 103  * within the reservation's array of small pages.
 104  */
 105 #define VM_RESERV_INDEX(object, pindex) \
 106     (((object)->pg_color + (pindex)) & (VM_LEVEL_0_NPAGES - 1))
 107
 108 /*
 109  * Number of elapsed ticks before we update the LRU queue position.  Used
 110  * to reduce contention and churn on the list.
 111  */
 112 #define PARTPOPSLOP     1
 113
 114 /*
 115  * The reservation structure
 116  *
 117  * A reservation structure is constructed whenever a large physical page is
 118  * speculatively allocated to an object.  The reservation provides the small
 119  * physical pages for the range [pindex, pindex + VM_LEVEL_0_NPAGES) of offsets
 120  * within that object.  The reservation's "popcnt" tracks the number of these
 121  * small physical pages that are in use at any given time.  When and if the
 122  * reservation is not fully utilized, it appears in the queue of partially
 123  * populated reservations.  The reservation always appears on the containing
 124  * object's list of reservations.
 125  *
 126  * A partially populated reservation can be broken and reclaimed at any time.
 127  *
 128  * c - constant after boot
 129  * d - vm_reserv_domain_lock
 130  * o - vm_reserv_object_lock
 131  * r - vm_reserv_lock
 132  * s - vm_reserv_domain_scan_lock
 133  */
 134 struct vm_reserv {
 135         struct mtx      lock;                   /* reservation lock. */
 136         TAILQ_ENTRY(vm_reserv) partpopq;        /* (d, r) per-domain queue. */
 137         LIST_ENTRY(vm_reserv) objq;             /* (o, r) object queue */
 138         vm_object_t     object;                 /* (o, r) containing object */
 139         vm_pindex_t     pindex;                 /* (o, r) offset in object */
 140         vm_page_t       pages;                  /* (c) first page  */
 141         uint16_t        popcnt;                 /* (r) # of pages in use */
 142         uint8_t         domain;                 /* (c) NUMA domain. */
 143         char            inpartpopq;             /* (d, r) */
 144         int             lasttick;               /* (r) last pop update tick. */
 145         bitstr_t        bit_decl(popmap, VM_LEVEL_0_NPAGES_MAX);
 146                                                 /* (r) bit vector, used pages */
 147 };
 148
 149 TAILQ_HEAD(vm_reserv_queue, vm_reserv);
 150
 151 #define vm_reserv_lockptr(rv)           (&(rv)->lock)
 152 #define vm_reserv_assert_locked(rv)                                     \
 153             mtx_assert(vm_reserv_lockptr(rv), MA_OWNED)
 154 #define vm_reserv_lock(rv)              mtx_lock(vm_reserv_lockptr(rv))
 155 #define vm_reserv_trylock(rv)           mtx_trylock(vm_reserv_lockptr(rv))
 156 #define vm_reserv_unlock(rv)            mtx_unlock(vm_reserv_lockptr(rv))
 157
 158 /*
 159  * The reservation array
 160  *
 161  * This array is analoguous in function to vm_page_array.  It differs in the
 162  * respect that it may contain a greater number of useful reservation
 163  * structures than there are (physical) superpages.  These "invalid"
 164  * reservation structures exist to trade-off space for time in the
 165  * implementation of vm_reserv_from_page().  Invalid reservation structures are
 166  * distinguishable from "valid" reservation structures by inspecting the
 167  * reservation's "pages" field.  Invalid reservation structures have a NULL
 168  * "pages" field.
 169  *
 170  * vm_reserv_from_page() maps a small (physical) page to an element of this
 171  * array by computing a physical reservation number from the page's physical
 172  * address.  The physical reservation number is used as the array index.
 173  *
 174  * An "active" reservation is a valid reservation structure that has a non-NULL
 175  * "object" field and a non-zero "popcnt" field.  In other words, every active
 176  * reservation belongs to a particular object.  Moreover, every active
 177  * reservation has an entry in the containing object's list of reservations.
 178  */
 179 static vm_reserv_t vm_reserv_array;
 180
 181 /*
 182  * The per-domain partially populated reservation queues
 183  *
 184  * These queues enable the fast recovery of an unused free small page from a
 185  * partially populated reservation.  The reservation at the head of a queue
 186  * is the least recently changed, partially populated reservation.
 187  *
 188  * Access to this queue is synchronized by the per-domain reservation lock.
 189  * Threads reclaiming free pages from the queue must hold the per-domain scan
 190  * lock.
 191  */
 192 struct vm_reserv_domain {
 193         struct mtx              lock;
 194         struct vm_reserv_queue  partpop;        /* (d) */
 195         struct vm_reserv        marker;         /* (d, s) scan marker/lock */
 196 } __aligned(CACHE_LINE_SIZE);
 197
 198 static struct vm_reserv_domain vm_rvd[MAXMEMDOM];
 199
 200 #define vm_reserv_domain_lockptr(d)     (&vm_rvd[(d)].lock)
 201 #define vm_reserv_domain_assert_locked(d)       \
 202         mtx_assert(vm_reserv_domain_lockptr(d), MA_OWNED)
 203 #define vm_reserv_domain_lock(d)        mtx_lock(vm_reserv_domain_lockptr(d))
 204 #define vm_reserv_domain_unlock(d)      mtx_unlock(vm_reserv_domain_lockptr(d))
 205
 206 #define vm_reserv_domain_scan_lock(d)   mtx_lock(&vm_rvd[(d)].marker.lock)
 207 #define vm_reserv_domain_scan_unlock(d) mtx_unlock(&vm_rvd[(d)].marker.lock)
 208
 209 static SYSCTL_NODE(_vm, OID_AUTO, reserv, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
 210     "Reservation Info");
 211
 212 static COUNTER_U64_DEFINE_EARLY(vm_reserv_broken);
 213 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, broken, CTLFLAG_RD,
 214     &vm_reserv_broken, "Cumulative number of broken reservations");
 215
 216 static COUNTER_U64_DEFINE_EARLY(vm_reserv_freed);
 217 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, freed, CTLFLAG_RD,
 218     &vm_reserv_freed, "Cumulative number of freed reservations");
 219
 220 static int sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS);
 221
 222 SYSCTL_PROC(_vm_reserv, OID_AUTO, fullpop, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RD,
 223     NULL, 0, sysctl_vm_reserv_fullpop, "I", "Current number of full reservations");
 224
 225 static int sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS);
 226
 227 SYSCTL_OID(_vm_reserv, OID_AUTO, partpopq,
 228     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
 229     sysctl_vm_reserv_partpopq, "A",
 230     "Partially populated reservation queues");
 231
 232 static COUNTER_U64_DEFINE_EARLY(vm_reserv_reclaimed);
 233 SYSCTL_COUNTER_U64(_vm_reserv, OID_AUTO, reclaimed, CTLFLAG_RD,
 234     &vm_reserv_reclaimed, "Cumulative number of reclaimed reservations");
 235
 236 /*
 237  * The object lock pool is used to synchronize the rvq.  We can not use a
 238  * pool mutex because it is required before malloc works.
 239  *
 240  * The "hash" function could be made faster without divide and modulo.
 241  */
 242 #define VM_RESERV_OBJ_LOCK_COUNT        MAXCPU
 243
 244 struct mtx_padalign vm_reserv_object_mtx[VM_RESERV_OBJ_LOCK_COUNT];
 245
 246 #define vm_reserv_object_lock_idx(object)                       \
 247             (((uintptr_t)object / sizeof(*object)) % VM_RESERV_OBJ_LOCK_COUNT)
 248 #define vm_reserv_object_lock_ptr(object)                       \
 249             &vm_reserv_object_mtx[vm_reserv_object_lock_idx((object))]
 250 #define vm_reserv_object_lock(object)                           \
 251             mtx_lock(vm_reserv_object_lock_ptr((object)))
 252 #define vm_reserv_object_unlock(object)                         \
 253             mtx_unlock(vm_reserv_object_lock_ptr((object)))
 254
 255 static void             vm_reserv_break(vm_reserv_t rv);
 256 static void             vm_reserv_depopulate(vm_reserv_t rv, int index);
 257 static vm_reserv_t      vm_reserv_from_page(vm_page_t m);
 258 static boolean_t        vm_reserv_has_pindex(vm_reserv_t rv,
 259                             vm_pindex_t pindex);
 260 static void             vm_reserv_populate(vm_reserv_t rv, int index);
 261 static void             vm_reserv_reclaim(vm_reserv_t rv);
 262
 263 /*
 264  * Returns the current number of full reservations.
 265  *
 266  * Since the number of full reservations is computed without acquiring any
 267  * locks, the returned value is inexact.
 268  */
 269 static int
 270 sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS)
 271 {
 272         vm_paddr_t paddr;
 273         struct vm_phys_seg *seg;
 274         vm_reserv_t rv;
 275         int fullpop, segind;
 276
 277         fullpop = 0;
 278         for (segind = 0; segind < vm_phys_nsegs; segind++) {
 279                 seg = &vm_phys_segs[segind];
 280                 paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
 281 #ifdef VM_PHYSSEG_SPARSE
 282                 rv = seg->first_reserv + (paddr >> VM_LEVEL_0_SHIFT) -
 283                     (seg->start >> VM_LEVEL_0_SHIFT);
 284 #else
 285                 rv = &vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT];
 286 #endif
 287                 while (paddr + VM_LEVEL_0_SIZE > paddr && paddr +
 288                     VM_LEVEL_0_SIZE <= seg->end) {
 289                         fullpop += rv->popcnt == VM_LEVEL_0_NPAGES;
 290                         paddr += VM_LEVEL_0_SIZE;
 291                         rv++;
 292                 }
 293         }
 294         return (sysctl_handle_int(oidp, &fullpop, 0, req));
 295 }
 296
 297 /*
 298  * Describes the current state of the partially populated reservation queue.
 299  */
 300 static int
 301 sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS)
 302 {
 303         struct sbuf sbuf;
 304         vm_reserv_t rv;
 305         int counter, error, domain, level, unused_pages;
 306
 307         error = sysctl_wire_old_buffer(req, 0);
 308         if (error != 0)
 309                 return (error);
 310         sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
 311         sbuf_printf(&sbuf, "\nDOMAIN    LEVEL     SIZE  NUMBER\n\n");
 312         for (domain = 0; domain < vm_ndomains; domain++) {
 313                 for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) {
 314                         counter = 0;
 315                         unused_pages = 0;
 316                         vm_reserv_domain_lock(domain);
 317                         TAILQ_FOREACH(rv, &vm_rvd[domain].partpop, partpopq) {
 318                                 if (rv == &vm_rvd[domain].marker)
 319                                         continue;
 320                                 counter++;
 321                                 unused_pages += VM_LEVEL_0_NPAGES - rv->popcnt;
 322                         }
 323                         vm_reserv_domain_unlock(domain);
 324                         sbuf_printf(&sbuf, "%6d, %7d, %6dK, %6d\n",
 325                             domain, level,
 326                             unused_pages * ((int)PAGE_SIZE / 1024), counter);
 327                 }
 328         }
 329         error = sbuf_finish(&sbuf);
 330         sbuf_delete(&sbuf);
 331         return (error);
 332 }
 333
 334 /*
 335  * Remove a reservation from the object's objq.
 336  */
 337 static void
 338 vm_reserv_remove(vm_reserv_t rv)
 339 {
 340         vm_object_t object;
 341
 342         vm_reserv_assert_locked(rv);
 343         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
 344             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
 345         KASSERT(rv->object != NULL,
 346             ("vm_reserv_remove: reserv %p is free", rv));
 347         KASSERT(!rv->inpartpopq,
 348             ("vm_reserv_remove: reserv %p's inpartpopq is TRUE", rv));
 349         object = rv->object;
 350         vm_reserv_object_lock(object);
 351         LIST_REMOVE(rv, objq);
 352         rv->object = NULL;
 353         vm_reserv_object_unlock(object);
 354 }
 355
 356 /*
 357  * Insert a new reservation into the object's objq.
 358  */
 359 static void
 360 vm_reserv_insert(vm_reserv_t rv, vm_object_t object, vm_pindex_t pindex)
 361 {
 362
 363         vm_reserv_assert_locked(rv);
 364         CTR6(KTR_VM,
 365             "%s: rv %p(%p) object %p new %p popcnt %d",
 366             __FUNCTION__, rv, rv->pages, rv->object, object,
 367            rv->popcnt);
 368         KASSERT(rv->object == NULL,
 369             ("vm_reserv_insert: reserv %p isn't free", rv));
 370         KASSERT(rv->popcnt == 0,
 371             ("vm_reserv_insert: reserv %p's popcnt is corrupted", rv));
 372         KASSERT(!rv->inpartpopq,
 373             ("vm_reserv_insert: reserv %p's inpartpopq is TRUE", rv));
 374         KASSERT(bit_ntest(rv->popmap, 0, VM_LEVEL_0_NPAGES - 1, 0),
 375             ("vm_reserv_insert: reserv %p's popmap is corrupted", rv));
 376         vm_reserv_object_lock(object);
 377         rv->pindex = pindex;
 378         rv->object = object;
 379         rv->lasttick = ticks;
 380         LIST_INSERT_HEAD(&object->rvq, rv, objq);
 381         vm_reserv_object_unlock(object);
 382 }
 383
 384 /*
 385  * Reduces the given reservation's population count.  If the population count
 386  * becomes zero, the reservation is destroyed.  Additionally, moves the
 387  * reservation to the tail of the partially populated reservation queue if the
 388  * population count is non-zero.
 389  */
 390 static void
 391 vm_reserv_depopulate(vm_reserv_t rv, int index)
 392 {
 393         struct vm_domain *vmd;
 394
 395         vm_reserv_assert_locked(rv);
 396         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
 397             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
 398         KASSERT(rv->object != NULL,
 399             ("vm_reserv_depopulate: reserv %p is free", rv));
 400         KASSERT(bit_test(rv->popmap, index),
 401             ("vm_reserv_depopulate: reserv %p's popmap[%d] is clear", rv,
 402             index));
 403         KASSERT(rv->popcnt > 0,
 404             ("vm_reserv_depopulate: reserv %p's popcnt is corrupted", rv));
 405         KASSERT(rv->domain < vm_ndomains,
 406             ("vm_reserv_depopulate: reserv %p's domain is corrupted %d",
 407             rv, rv->domain));
 408         if (rv->popcnt == VM_LEVEL_0_NPAGES) {
 409                 KASSERT(rv->pages->psind == 1,
 410                     ("vm_reserv_depopulate: reserv %p is already demoted",
 411                     rv));
 412                 rv->pages->psind = 0;
 413         }
 414         bit_clear(rv->popmap, index);
 415         rv->popcnt--;
 416         if ((unsigned)(ticks - rv->lasttick) >= PARTPOPSLOP ||
 417             rv->popcnt == 0) {
 418                 vm_reserv_domain_lock(rv->domain);
 419                 if (rv->inpartpopq) {
 420                         TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq);
 421                         rv->inpartpopq = FALSE;
 422                 }
 423                 if (rv->popcnt != 0) {
 424                         rv->inpartpopq = TRUE;
 425                         TAILQ_INSERT_TAIL(&vm_rvd[rv->domain].partpop, rv,
 426                             partpopq);
 427                 }
 428                 vm_reserv_domain_unlock(rv->domain);
 429                 rv->lasttick = ticks;
 430         }
 431         vmd = VM_DOMAIN(rv->domain);
 432         if (rv->popcnt == 0) {
 433                 vm_reserv_remove(rv);
 434                 vm_domain_free_lock(vmd);
 435                 vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER);
 436                 vm_domain_free_unlock(vmd);
 437                 counter_u64_add(vm_reserv_freed, 1);
 438         }
 439         vm_domain_freecnt_inc(vmd, 1);
 440 }
 441
 442 /*
 443  * Returns the reservation to which the given page might belong.
 444  */
 445 static __inline vm_reserv_t
 446 vm_reserv_from_page(vm_page_t m)
 447 {
 448 #ifdef VM_PHYSSEG_SPARSE
 449         struct vm_phys_seg *seg;
 450
 451         seg = &vm_phys_segs[m->segind];
 452         return (seg->first_reserv + (VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT) -
 453             (seg->start >> VM_LEVEL_0_SHIFT));
 454 #else
 455         return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]);
 456 #endif
 457 }
 458
 459 /*
 460  * Returns an existing reservation or NULL and initialized successor pointer.
 461  */
 462 static vm_reserv_t
 463 vm_reserv_from_object(vm_object_t object, vm_pindex_t pindex,
 464     vm_page_t mpred, vm_page_t *msuccp)
 465 {
 466         vm_reserv_t rv;
 467         vm_page_t msucc;
 468
 469         msucc = NULL;
 470         if (mpred != NULL) {
 471                 KASSERT(mpred->object == object,
 472                     ("vm_reserv_from_object: object doesn't contain mpred"));
 473                 KASSERT(mpred->pindex < pindex,
 474                     ("vm_reserv_from_object: mpred doesn't precede pindex"));
 475                 rv = vm_reserv_from_page(mpred);
 476                 if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
 477                         goto found;
 478                 msucc = TAILQ_NEXT(mpred, listq);
 479         } else
 480                 msucc = TAILQ_FIRST(&object->memq);
 481         if (msucc != NULL) {
 482                 KASSERT(msucc->pindex > pindex,
 483                     ("vm_reserv_from_object: msucc doesn't succeed pindex"));
 484                 rv = vm_reserv_from_page(msucc);
 485                 if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
 486                         goto found;
 487         }
 488         rv = NULL;
 489
 490 found:
 491         *msuccp = msucc;
 492
 493         return (rv);
 494 }
 495
 496 /*
 497  * Returns TRUE if the given reservation contains the given page index and
 498  * FALSE otherwise.
 499  */
 500 static __inline boolean_t
 501 vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex)
 502 {
 503
 504         return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0);
 505 }
 506
 507 /*
 508  * Increases the given reservation's population count.  Moves the reservation
 509  * to the tail of the partially populated reservation queue.
 510  */
 511 static void
 512 vm_reserv_populate(vm_reserv_t rv, int index)
 513 {
 514
 515         vm_reserv_assert_locked(rv);
 516         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
 517             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
 518         KASSERT(rv->object != NULL,
 519             ("vm_reserv_populate: reserv %p is free", rv));
 520         KASSERT(!bit_test(rv->popmap, index),
 521             ("vm_reserv_populate: reserv %p's popmap[%d] is set", rv,
 522             index));
 523         KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES,
 524             ("vm_reserv_populate: reserv %p is already full", rv));
 525         KASSERT(rv->pages->psind == 0,
 526             ("vm_reserv_populate: reserv %p is already promoted", rv));
 527         KASSERT(rv->domain < vm_ndomains,
 528             ("vm_reserv_populate: reserv %p's domain is corrupted %d",
 529             rv, rv->domain));
 530         bit_set(rv->popmap, index);
 531         rv->popcnt++;
 532         if ((unsigned)(ticks - rv->lasttick) < PARTPOPSLOP &&
 533             rv->inpartpopq && rv->popcnt != VM_LEVEL_0_NPAGES)
 534                 return;
 535         rv->lasttick = ticks;
 536         vm_reserv_domain_lock(rv->domain);
 537         if (rv->inpartpopq) {
 538                 TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq);
 539                 rv->inpartpopq = FALSE;
 540         }
 541         if (rv->popcnt < VM_LEVEL_0_NPAGES) {
 542                 rv->inpartpopq = TRUE;
 543                 TAILQ_INSERT_TAIL(&vm_rvd[rv->domain].partpop, rv, partpopq);
 544         } else {
 545                 KASSERT(rv->pages->psind == 0,
 546                     ("vm_reserv_populate: reserv %p is already promoted",
 547                     rv));
 548                 rv->pages->psind = 1;
 549         }
 550         vm_reserv_domain_unlock(rv->domain);
 551 }
 552
 553 /*
 554  * Allocates a contiguous set of physical pages of the given size "npages"
 555  * from existing or newly created reservations.  All of the physical pages
 556  * must be at or above the given physical address "low" and below the given
 557  * physical address "high".  The given value "alignment" determines the
 558  * alignment of the first physical page in the set.  If the given value
 559  * "boundary" is non-zero, then the set of physical pages cannot cross any
 560  * physical address boundary that is a multiple of that value.  Both
 561  * "alignment" and "boundary" must be a power of two.
 562  *
 563  * The page "mpred" must immediately precede the offset "pindex" within the
 564  * specified object.
 565  *
 566  * The object must be locked.
 567  */
 568 vm_page_t
 569 vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, int domain,
 570     int req, vm_page_t mpred, u_long npages, vm_paddr_t low, vm_paddr_t high,
 571     u_long alignment, vm_paddr_t boundary)
 572 {
 573         struct vm_domain *vmd;
 574         vm_paddr_t pa, size;
 575         vm_page_t m, m_ret, msucc;
 576         vm_pindex_t first, leftcap, rightcap;
 577         vm_reserv_t rv;
 578         u_long allocpages, maxpages, minpages;
 579         int i, index, n;
 580
 581         VM_OBJECT_ASSERT_WLOCKED(object);
 582         KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0"));
 583
 584         /*
 585          * Is a reservation fundamentally impossible?
 586          */
 587         if (pindex < VM_RESERV_INDEX(object, pindex) ||
 588             pindex + npages > object->size)
 589                 return (NULL);
 590
 591         /*
 592          * All reservations of a particular size have the same alignment.
 593          * Assuming that the first page is allocated from a reservation, the
 594          * least significant bits of its physical address can be determined
 595          * from its offset from the beginning of the reservation and the size
 596          * of the reservation.
 597          *
 598          * Could the specified index within a reservation of the smallest
 599          * possible size satisfy the alignment and boundary requirements?
 600          */
 601         pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT;
 602         size = npages << PAGE_SHIFT;
 603         if (!vm_addr_ok(pa, size, alignment, boundary))
 604                 return (NULL);
 605
 606         /*
 607          * Look for an existing reservation.
 608          */
 609         rv = vm_reserv_from_object(object, pindex, mpred, &msucc);
 610         if (rv != NULL) {
 611                 KASSERT(object != kernel_object || rv->domain == domain,
 612                     ("vm_reserv_alloc_contig: domain mismatch"));
 613                 index = VM_RESERV_INDEX(object, pindex);
 614                 /* Does the allocation fit within the reservation? */
 615                 if (index + npages > VM_LEVEL_0_NPAGES)
 616                         return (NULL);
 617                 domain = rv->domain;
 618                 vmd = VM_DOMAIN(domain);
 619                 vm_reserv_lock(rv);
 620                 /* Handle reclaim race. */
 621                 if (rv->object != object)
 622                         goto out;
 623                 m = &rv->pages[index];
 624                 pa = VM_PAGE_TO_PHYS(m);
 625                 if (pa < low || pa + size > high ||
 626                     !vm_addr_ok(pa, size, alignment, boundary))
 627                         goto out;
 628                 /* Handle vm_page_rename(m, new_object, ...). */
 629                 if (!bit_ntest(rv->popmap, index, index + npages - 1, 0))
 630                         goto out;
 631                 if (!vm_domain_allocate(vmd, req, npages))
 632                         goto out;
 633                 for (i = 0; i < npages; i++)
 634                         vm_reserv_populate(rv, index + i);
 635                 vm_reserv_unlock(rv);
 636                 return (m);
 637 out:
 638                 vm_reserv_unlock(rv);
 639                 return (NULL);
 640         }
 641
 642         /*
 643          * Could at least one reservation fit between the first index to the
 644          * left that can be used ("leftcap") and the first index to the right
 645          * that cannot be used ("rightcap")?
 646          *
 647          * We must synchronize with the reserv object lock to protect the
 648          * pindex/object of the resulting reservations against rename while
 649          * we are inspecting.
 650          */
 651         first = pindex - VM_RESERV_INDEX(object, pindex);
 652         minpages = VM_RESERV_INDEX(object, pindex) + npages;
 653         maxpages = roundup2(minpages, VM_LEVEL_0_NPAGES);
 654         allocpages = maxpages;
 655         vm_reserv_object_lock(object);
 656         if (mpred != NULL) {
 657                 if ((rv = vm_reserv_from_page(mpred))->object != object)
 658                         leftcap = mpred->pindex + 1;
 659                 else
 660                         leftcap = rv->pindex + VM_LEVEL_0_NPAGES;
 661                 if (leftcap > first) {
 662                         vm_reserv_object_unlock(object);
 663                         return (NULL);
 664                 }
 665         }
 666         if (msucc != NULL) {
 667                 if ((rv = vm_reserv_from_page(msucc))->object != object)
 668                         rightcap = msucc->pindex;
 669                 else
 670                         rightcap = rv->pindex;
 671                 if (first + maxpages > rightcap) {
 672                         if (maxpages == VM_LEVEL_0_NPAGES) {
 673                                 vm_reserv_object_unlock(object);
 674                                 return (NULL);
 675                         }
 676
 677                         /*
 678                          * At least one reservation will fit between "leftcap"
 679                          * and "rightcap".  However, a reservation for the
 680                          * last of the requested pages will not fit.  Reduce
 681                          * the size of the upcoming allocation accordingly.
 682                          */
 683                         allocpages = minpages;
 684                 }
 685         }
 686         vm_reserv_object_unlock(object);
 687
 688         /*
 689          * Would the last new reservation extend past the end of the object?
 690          *
 691          * If the object is unlikely to grow don't allocate a reservation for
 692          * the tail.
 693          */
 694         if ((object->flags & OBJ_ANON) == 0 &&
 695             first + maxpages > object->size) {
 696                 if (maxpages == VM_LEVEL_0_NPAGES)
 697                         return (NULL);
 698                 allocpages = minpages;
 699         }
 700
 701         /*
 702          * Allocate the physical pages.  The alignment and boundary specified
 703          * for this allocation may be different from the alignment and
 704          * boundary specified for the requested pages.  For instance, the
 705          * specified index may not be the first page within the first new
 706          * reservation.
 707          */
 708         m = NULL;
 709         vmd = VM_DOMAIN(domain);
 710         if (vm_domain_allocate(vmd, req, npages)) {
 711                 vm_domain_free_lock(vmd);
 712                 m = vm_phys_alloc_contig(domain, allocpages, low, high,
 713                     ulmax(alignment, VM_LEVEL_0_SIZE),
 714                     boundary > VM_LEVEL_0_SIZE ? boundary : 0);
 715                 vm_domain_free_unlock(vmd);
 716                 if (m == NULL) {
 717                         vm_domain_freecnt_inc(vmd, npages);
 718                         return (NULL);
 719                 }
 720         } else
 721                 return (NULL);
 722         KASSERT(vm_page_domain(m) == domain,
 723             ("vm_reserv_alloc_contig: Page domain does not match requested."));
 724
 725         /*
 726          * The allocated physical pages always begin at a reservation
 727          * boundary, but they do not always end at a reservation boundary.
 728          * Initialize every reservation that is completely covered by the
 729          * allocated physical pages.
 730          */
 731         m_ret = NULL;
 732         index = VM_RESERV_INDEX(object, pindex);
 733         do {
 734                 rv = vm_reserv_from_page(m);
 735                 KASSERT(rv->pages == m,
 736                     ("vm_reserv_alloc_contig: reserv %p's pages is corrupted",
 737                     rv));
 738                 vm_reserv_lock(rv);
 739                 vm_reserv_insert(rv, object, first);
 740                 n = ulmin(VM_LEVEL_0_NPAGES - index, npages);
 741                 for (i = 0; i < n; i++)
 742                         vm_reserv_populate(rv, index + i);
 743                 npages -= n;
 744                 if (m_ret == NULL) {
 745                         m_ret = &rv->pages[index];
 746                         index = 0;
 747                 }
 748                 vm_reserv_unlock(rv);
 749                 m += VM_LEVEL_0_NPAGES;
 750                 first += VM_LEVEL_0_NPAGES;
 751                 allocpages -= VM_LEVEL_0_NPAGES;
 752         } while (allocpages >= VM_LEVEL_0_NPAGES);
 753         return (m_ret);
 754 }
 755
 756 /*
 757  * Allocate a physical page from an existing or newly created reservation.
 758  *
 759  * The page "mpred" must immediately precede the offset "pindex" within the
 760  * specified object.
 761  *
 762  * The object must be locked.
 763  */
 764 vm_page_t
 765 vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, int domain,
 766     int req, vm_page_t mpred)
 767 {
 768         struct vm_domain *vmd;
 769         vm_page_t m, msucc;
 770         vm_pindex_t first, leftcap, rightcap;
 771         vm_reserv_t rv;
 772         int index;
 773
 774         VM_OBJECT_ASSERT_WLOCKED(object);
 775
 776         /*
 777          * Is a reservation fundamentally impossible?
 778          */
 779         if (pindex < VM_RESERV_INDEX(object, pindex) ||
 780             pindex >= object->size)
 781                 return (NULL);
 782
 783         /*
 784          * Look for an existing reservation.
 785          */
 786         rv = vm_reserv_from_object(object, pindex, mpred, &msucc);
 787         if (rv != NULL) {
 788                 KASSERT(object != kernel_object || rv->domain == domain,
 789                     ("vm_reserv_alloc_page: domain mismatch"));
 790                 domain = rv->domain;
 791                 vmd = VM_DOMAIN(domain);
 792                 index = VM_RESERV_INDEX(object, pindex);
 793                 m = &rv->pages[index];
 794                 vm_reserv_lock(rv);
 795                 /* Handle reclaim race. */
 796                 if (rv->object != object ||
 797                     /* Handle vm_page_rename(m, new_object, ...). */
 798                     bit_test(rv->popmap, index)) {
 799                         m = NULL;
 800                         goto out;
 801                 }
 802                 if (vm_domain_allocate(vmd, req, 1) == 0)
 803                         m = NULL;
 804                 else
 805                         vm_reserv_populate(rv, index);
 806 out:
 807                 vm_reserv_unlock(rv);
 808                 return (m);
 809         }
 810
 811         /*
 812          * Could a reservation fit between the first index to the left that
 813          * can be used and the first index to the right that cannot be used?
 814          *
 815          * We must synchronize with the reserv object lock to protect the
 816          * pindex/object of the resulting reservations against rename while
 817          * we are inspecting.
 818          */
 819         first = pindex - VM_RESERV_INDEX(object, pindex);
 820         vm_reserv_object_lock(object);
 821         if (mpred != NULL) {
 822                 if ((rv = vm_reserv_from_page(mpred))->object != object)
 823                         leftcap = mpred->pindex + 1;
 824                 else
 825                         leftcap = rv->pindex + VM_LEVEL_0_NPAGES;
 826                 if (leftcap > first) {
 827                         vm_reserv_object_unlock(object);
 828                         return (NULL);
 829                 }
 830         }
 831         if (msucc != NULL) {
 832                 if ((rv = vm_reserv_from_page(msucc))->object != object)
 833                         rightcap = msucc->pindex;
 834                 else
 835                         rightcap = rv->pindex;
 836                 if (first + VM_LEVEL_0_NPAGES > rightcap) {
 837                         vm_reserv_object_unlock(object);
 838                         return (NULL);
 839                 }
 840         }
 841         vm_reserv_object_unlock(object);
 842
 843         /*
 844          * Would the last new reservation extend past the end of the object?
 845          *
 846          * If the object is unlikely to grow don't allocate a reservation for
 847          * the tail.
 848          */
 849         if ((object->flags & OBJ_ANON) == 0 &&
 850             first + VM_LEVEL_0_NPAGES > object->size)
 851                 return (NULL);
 852
 853         /*
 854          * Allocate and populate the new reservation.
 855          */
 856         m = NULL;
 857         vmd = VM_DOMAIN(domain);
 858         if (vm_domain_allocate(vmd, req, 1)) {
 859                 vm_domain_free_lock(vmd);
 860                 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT,
 861                     VM_LEVEL_0_ORDER);
 862                 vm_domain_free_unlock(vmd);
 863                 if (m == NULL) {
 864                         vm_domain_freecnt_inc(vmd, 1);
 865                         return (NULL);
 866                 }
 867         } else
 868                 return (NULL);
 869         rv = vm_reserv_from_page(m);
 870         vm_reserv_lock(rv);
 871         KASSERT(rv->pages == m,
 872             ("vm_reserv_alloc_page: reserv %p's pages is corrupted", rv));
 873         vm_reserv_insert(rv, object, first);
 874         index = VM_RESERV_INDEX(object, pindex);
 875         vm_reserv_populate(rv, index);
 876         vm_reserv_unlock(rv);
 877
 878         return (&rv->pages[index]);
 879 }
 880
 881 /*
 882  * Breaks the given reservation.  All free pages in the reservation
 883  * are returned to the physical memory allocator.  The reservation's
 884  * population count and map are reset to their initial state.
 885  *
 886  * The given reservation must not be in the partially populated reservation
 887  * queue.
 888  */
 889 static void
 890 vm_reserv_break(vm_reserv_t rv)
 891 {
 892         int hi, lo, pos;
 893
 894         vm_reserv_assert_locked(rv);
 895         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
 896             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
 897         vm_reserv_remove(rv);
 898         rv->pages->psind = 0;
 899         hi = lo = -1;
 900         pos = 0;
 901         for (;;) {
 902                 bit_ff_at(rv->popmap, pos, VM_LEVEL_0_NPAGES, lo != hi, &pos);
 903                 if (lo == hi) {
 904                         if (pos == -1)
 905                                 break;
 906                         lo = pos;
 907                         continue;
 908                 }
 909                 if (pos == -1)
 910                         pos = VM_LEVEL_0_NPAGES;
 911                 hi = pos;
 912                 vm_domain_free_lock(VM_DOMAIN(rv->domain));
 913                 vm_phys_enqueue_contig(&rv->pages[lo], hi - lo);
 914                 vm_domain_free_unlock(VM_DOMAIN(rv->domain));
 915                 lo = hi;
 916         }
 917         bit_nclear(rv->popmap, 0, VM_LEVEL_0_NPAGES - 1);
 918         rv->popcnt = 0;
 919         counter_u64_add(vm_reserv_broken, 1);
 920 }
 921
 922 /*
 923  * Breaks all reservations belonging to the given object.
 924  */
 925 void
 926 vm_reserv_break_all(vm_object_t object)
 927 {
 928         vm_reserv_t rv;
 929
 930         /*
 931          * This access of object->rvq is unsynchronized so that the
 932          * object rvq lock can nest after the domain_free lock.  We
 933          * must check for races in the results.  However, the object
 934          * lock prevents new additions, so we are guaranteed that when
 935          * it returns NULL the object is properly empty.
 936          */
 937         while ((rv = LIST_FIRST(&object->rvq)) != NULL) {
 938                 vm_reserv_lock(rv);
 939                 /* Reclaim race. */
 940                 if (rv->object != object) {
 941                         vm_reserv_unlock(rv);
 942                         continue;
 943                 }
 944                 vm_reserv_domain_lock(rv->domain);
 945                 if (rv->inpartpopq) {
 946                         TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq);
 947                         rv->inpartpopq = FALSE;
 948                 }
 949                 vm_reserv_domain_unlock(rv->domain);
 950                 vm_reserv_break(rv);
 951                 vm_reserv_unlock(rv);
 952         }
 953 }
 954
 955 /*
 956  * Frees the given page if it belongs to a reservation.  Returns TRUE if the
 957  * page is freed and FALSE otherwise.
 958  */
 959 boolean_t
 960 vm_reserv_free_page(vm_page_t m)
 961 {
 962         vm_reserv_t rv;
 963         boolean_t ret;
 964
 965         rv = vm_reserv_from_page(m);
 966         if (rv->object == NULL)
 967                 return (FALSE);
 968         vm_reserv_lock(rv);
 969         /* Re-validate after lock. */
 970         if (rv->object != NULL) {
 971                 vm_reserv_depopulate(rv, m - rv->pages);
 972                 ret = TRUE;
 973         } else
 974                 ret = FALSE;
 975         vm_reserv_unlock(rv);
 976
 977         return (ret);
 978 }
 979
 980 /*
 981  * Initializes the reservation management system.  Specifically, initializes
 982  * the reservation array.
 983  *
 984  * Requires that vm_page_array and first_page are initialized!
 985  */
 986 void
 987 vm_reserv_init(void)
 988 {
 989         vm_paddr_t paddr;
 990         struct vm_phys_seg *seg;
 991         struct vm_reserv *rv;
 992         struct vm_reserv_domain *rvd;
 993 #ifdef VM_PHYSSEG_SPARSE
 994         vm_pindex_t used;
 995 #endif
 996         int i, segind;
 997
 998         /*
 999          * Initialize the reservation array.  Specifically, initialize the
1000          * "pages" field for every element that has an underlying superpage.
1001          */
1002 #ifdef VM_PHYSSEG_SPARSE
1003         used = 0;
1004 #endif
1005         for (segind = 0; segind < vm_phys_nsegs; segind++) {
1006                 seg = &vm_phys_segs[segind];
1007 #ifdef VM_PHYSSEG_SPARSE
1008                 seg->first_reserv = &vm_reserv_array[used];
1009                 used += howmany(seg->end, VM_LEVEL_0_SIZE) -
1010                     seg->start / VM_LEVEL_0_SIZE;
1011 #else
1012                 seg->first_reserv =
1013                     &vm_reserv_array[seg->start >> VM_LEVEL_0_SHIFT];
1014 #endif
1015                 paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
1016                 rv = seg->first_reserv + (paddr >> VM_LEVEL_0_SHIFT) -
1017                     (seg->start >> VM_LEVEL_0_SHIFT);
1018                 while (paddr + VM_LEVEL_0_SIZE > paddr && paddr +
1019                     VM_LEVEL_0_SIZE <= seg->end) {
1020                         rv->pages = PHYS_TO_VM_PAGE(paddr);
1021                         rv->domain = seg->domain;
1022                         mtx_init(&rv->lock, "vm reserv", NULL, MTX_DEF);
1023                         paddr += VM_LEVEL_0_SIZE;
1024                         rv++;
1025                 }
1026         }
1027         for (i = 0; i < MAXMEMDOM; i++) {
1028                 rvd = &vm_rvd[i];
1029                 mtx_init(&rvd->lock, "vm reserv domain", NULL, MTX_DEF);
1030                 TAILQ_INIT(&rvd->partpop);
1031                 mtx_init(&rvd->marker.lock, "vm reserv marker", NULL, MTX_DEF);
1032
1033                 /*
1034                  * Fully populated reservations should never be present in the
1035                  * partially populated reservation queues.
1036                  */
1037                 rvd->marker.popcnt = VM_LEVEL_0_NPAGES;
1038                 bit_nset(rvd->marker.popmap, 0, VM_LEVEL_0_NPAGES - 1);
1039         }
1040
1041         for (i = 0; i < VM_RESERV_OBJ_LOCK_COUNT; i++)
1042                 mtx_init(&vm_reserv_object_mtx[i], "resv obj lock", NULL,
1043                     MTX_DEF);
1044 }
1045
1046 /*
1047  * Returns true if the given page belongs to a reservation and that page is
1048  * free.  Otherwise, returns false.
1049  */
1050 bool
1051 vm_reserv_is_page_free(vm_page_t m)
1052 {
1053         vm_reserv_t rv;
1054
1055         rv = vm_reserv_from_page(m);
1056         if (rv->object == NULL)
1057                 return (false);
1058         return (!bit_test(rv->popmap, m - rv->pages));
1059 }
1060
1061 /*
1062  * If the given page belongs to a reservation, returns the level of that
1063  * reservation.  Otherwise, returns -1.
1064  */
1065 int
1066 vm_reserv_level(vm_page_t m)
1067 {
1068         vm_reserv_t rv;
1069
1070         rv = vm_reserv_from_page(m);
1071         return (rv->object != NULL ? 0 : -1);
1072 }
1073
1074 /*
1075  * Returns a reservation level if the given page belongs to a fully populated
1076  * reservation and -1 otherwise.
1077  */
1078 int
1079 vm_reserv_level_iffullpop(vm_page_t m)
1080 {
1081         vm_reserv_t rv;
1082
1083         rv = vm_reserv_from_page(m);
1084         return (rv->popcnt == VM_LEVEL_0_NPAGES ? 0 : -1);
1085 }
1086
1087 /*
1088  * Remove a partially populated reservation from the queue.
1089  */
1090 static void
1091 vm_reserv_dequeue(vm_reserv_t rv)
1092 {
1093
1094         vm_reserv_domain_assert_locked(rv->domain);
1095         vm_reserv_assert_locked(rv);
1096         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
1097             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
1098         KASSERT(rv->inpartpopq,
1099             ("vm_reserv_reclaim: reserv %p's inpartpopq is FALSE", rv));
1100
1101         TAILQ_REMOVE(&vm_rvd[rv->domain].partpop, rv, partpopq);
1102         rv->inpartpopq = FALSE;
1103 }
1104
1105 /*
1106  * Breaks the given partially populated reservation, releasing its free pages
1107  * to the physical memory allocator.
1108  */
1109 static void
1110 vm_reserv_reclaim(vm_reserv_t rv)
1111 {
1112
1113         vm_reserv_assert_locked(rv);
1114         CTR5(KTR_VM, "%s: rv %p object %p popcnt %d inpartpop %d",
1115             __FUNCTION__, rv, rv->object, rv->popcnt, rv->inpartpopq);
1116         if (rv->inpartpopq) {
1117                 vm_reserv_domain_lock(rv->domain);
1118                 vm_reserv_dequeue(rv);
1119                 vm_reserv_domain_unlock(rv->domain);
1120         }
1121         vm_reserv_break(rv);
1122         counter_u64_add(vm_reserv_reclaimed, 1);
1123 }
1124
1125 /*
1126  * Breaks a reservation near the head of the partially populated reservation
1127  * queue, releasing its free pages to the physical memory allocator.  Returns
1128  * TRUE if a reservation is broken and FALSE otherwise.
1129  */
1130 bool
1131 vm_reserv_reclaim_inactive(int domain)
1132 {
1133         vm_reserv_t rv;
1134
1135         vm_reserv_domain_lock(domain);
1136         TAILQ_FOREACH(rv, &vm_rvd[domain].partpop, partpopq) {
1137                 /*
1138                  * A locked reservation is likely being updated or reclaimed,
1139                  * so just skip ahead.
1140                  */
1141                 if (rv != &vm_rvd[domain].marker && vm_reserv_trylock(rv)) {
1142                         vm_reserv_dequeue(rv);
1143                         break;
1144                 }
1145         }
1146         vm_reserv_domain_unlock(domain);
1147         if (rv != NULL) {
1148                 vm_reserv_reclaim(rv);
1149                 vm_reserv_unlock(rv);
1150                 return (true);
1151         }
1152         return (false);
1153 }
1154
1155 /*
1156  * Determine whether this reservation has free pages that satisfy the given
1157  * request for contiguous physical memory.  Start searching from the lower
1158  * bound, defined by lo, and stop at the upper bound, hi.  Return the index
1159  * of the first satisfactory free page, or -1 if none is found.
1160  */
1161 static int
1162 vm_reserv_find_contig(vm_reserv_t rv, int npages, int lo,
1163     int hi, int ppn_align, int ppn_bound)
1164 {
1165
1166         vm_reserv_assert_locked(rv);
1167         KASSERT(npages <= VM_LEVEL_0_NPAGES - 1,
1168             ("%s: Too many pages", __func__));
1169         KASSERT(ppn_bound <= VM_LEVEL_0_NPAGES,
1170             ("%s: Too big a boundary for reservation size", __func__));
1171         KASSERT(npages <= ppn_bound,
1172             ("%s: Too many pages for given boundary", __func__));
1173         KASSERT(ppn_align != 0 && powerof2(ppn_align),
1174             ("ppn_align is not a positive power of 2"));
1175         KASSERT(ppn_bound != 0 && powerof2(ppn_bound),
1176             ("ppn_bound is not a positive power of 2"));
1177         while (bit_ffc_area_at(rv->popmap, lo, hi, npages, &lo), lo != -1) {
1178                 if (lo < roundup2(lo, ppn_align)) {
1179                         /* Skip to next aligned page. */
1180                         lo = roundup2(lo, ppn_align);
1181                 } else if (roundup2(lo + 1, ppn_bound) >= lo + npages)
1182                         return (lo);
1183                 if (roundup2(lo + 1, ppn_bound) < lo + npages) {
1184                         /* Skip to next boundary-matching page. */
1185                         lo = roundup2(lo + 1, ppn_bound);
1186                 }
1187         }
1188         return (-1);
1189 }
1190
1191 /*
1192  * Searches the partially populated reservation queue for the least recently
1193  * changed reservation with free pages that satisfy the given request for
1194  * contiguous physical memory.  If a satisfactory reservation is found, it is
1195  * broken.  Returns true if a reservation is broken and false otherwise.
1196  */
1197 vm_page_t
1198 vm_reserv_reclaim_contig(int domain, u_long npages, vm_paddr_t low,
1199     vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1200 {
1201         struct vm_reserv_queue *queue;
1202         vm_paddr_t pa, size;
1203         vm_page_t m_ret;
1204         vm_reserv_t marker, rv, rvn;
1205         int hi, lo, posn, ppn_align, ppn_bound;
1206
1207         KASSERT(npages > 0, ("npages is 0"));
1208         KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1209         KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1210         if (npages > VM_LEVEL_0_NPAGES - 1)
1211                 return (false);
1212         size = npages << PAGE_SHIFT;
1213         /*
1214          * Ensure that a free range starting at a boundary-multiple
1215          * doesn't include a boundary-multiple within it.  Otherwise,
1216          * no boundary-constrained allocation is possible.
1217          */
1218         if (!vm_addr_bound_ok(0, size, boundary))
1219                 return (NULL);
1220         marker = &vm_rvd[domain].marker;
1221         queue = &vm_rvd[domain].partpop;
1222         /*
1223          * Compute shifted alignment, boundary values for page-based
1224          * calculations.  Constrain to range [1, VM_LEVEL_0_NPAGES] to
1225          * avoid overflow.
1226          */
1227         ppn_align = (int)(ulmin(ulmax(PAGE_SIZE, alignment),
1228             VM_LEVEL_0_SIZE) >> PAGE_SHIFT);
1229         ppn_bound = boundary == 0 ? VM_LEVEL_0_NPAGES :
1230             (int)(MIN(MAX(PAGE_SIZE, boundary),
1231             VM_LEVEL_0_SIZE) >> PAGE_SHIFT);
1232
1233         vm_reserv_domain_scan_lock(domain);
1234         vm_reserv_domain_lock(domain);
1235         TAILQ_FOREACH_SAFE(rv, queue, partpopq, rvn) {
1236                 pa = VM_PAGE_TO_PHYS(&rv->pages[0]);
1237                 if (pa + VM_LEVEL_0_SIZE - size < low) {
1238                         /* This entire reservation is too low; go to next. */
1239                         continue;
1240                 }
1241                 if (pa + size > high) {
1242                         /* This entire reservation is too high; go to next. */
1243                         continue;
1244                 }
1245                 if (!vm_addr_align_ok(pa, alignment)) {
1246                         /* This entire reservation is unaligned; go to next. */
1247                         continue;
1248                 }
1249
1250                 if (vm_reserv_trylock(rv) == 0) {
1251                         TAILQ_INSERT_AFTER(queue, rv, marker, partpopq);
1252                         vm_reserv_domain_unlock(domain);
1253                         vm_reserv_lock(rv);
1254                         if (TAILQ_PREV(marker, vm_reserv_queue, partpopq) !=
1255                             rv) {
1256                                 vm_reserv_unlock(rv);
1257                                 vm_reserv_domain_lock(domain);
1258                                 rvn = TAILQ_NEXT(marker, partpopq);
1259                                 TAILQ_REMOVE(queue, marker, partpopq);
1260                                 continue;
1261                         }
1262                         vm_reserv_domain_lock(domain);
1263                         TAILQ_REMOVE(queue, marker, partpopq);
1264                 }
1265                 vm_reserv_domain_unlock(domain);
1266                 lo = (pa >= low) ? 0 :
1267                     (int)((low + PAGE_MASK - pa) >> PAGE_SHIFT);
1268                 hi = (pa + VM_LEVEL_0_SIZE <= high) ? VM_LEVEL_0_NPAGES :
1269                     (int)((high - pa) >> PAGE_SHIFT);
1270                 posn = vm_reserv_find_contig(rv, (int)npages, lo, hi,
1271                     ppn_align, ppn_bound);
1272                 if (posn >= 0) {
1273                         vm_reserv_domain_scan_unlock(domain);
1274                         /* Allocate requested space */
1275                         rv->popcnt += npages;
1276                         bit_nset(rv->popmap, posn, posn + npages - 1);
1277                         vm_reserv_reclaim(rv);
1278                         vm_reserv_unlock(rv);
1279                         m_ret = &rv->pages[posn];
1280                         pa = VM_PAGE_TO_PHYS(m_ret);
1281                         KASSERT(vm_addr_ok(pa, size, alignment, boundary),
1282                             ("%s: adjusted address not aligned/bounded to "
1283                              "%lx/%jx",
1284                              __func__, alignment, (uintmax_t)boundary));
1285                         return (m_ret);
1286                 }
1287                 vm_reserv_domain_lock(domain);
1288                 rvn = TAILQ_NEXT(rv, partpopq);
1289                 vm_reserv_unlock(rv);
1290         }
1291         vm_reserv_domain_unlock(domain);
1292         vm_reserv_domain_scan_unlock(domain);
1293         return (NULL);
1294 }
1295
1296 /*
1297  * Transfers the reservation underlying the given page to a new object.
1298  *
1299  * The object must be locked.
1300  */
1301 void
1302 vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object,
1303     vm_pindex_t old_object_offset)
1304 {
1305         vm_reserv_t rv;
1306
1307         VM_OBJECT_ASSERT_WLOCKED(new_object);
1308         rv = vm_reserv_from_page(m);
1309         if (rv->object == old_object) {
1310                 vm_reserv_lock(rv);
1311                 CTR6(KTR_VM,
1312                     "%s: rv %p object %p new %p popcnt %d inpartpop %d",
1313                     __FUNCTION__, rv, rv->object, new_object, rv->popcnt,
1314                     rv->inpartpopq);
1315                 if (rv->object == old_object) {
1316                         vm_reserv_object_lock(old_object);
1317                         rv->object = NULL;
1318                         LIST_REMOVE(rv, objq);
1319                         vm_reserv_object_unlock(old_object);
1320                         vm_reserv_object_lock(new_object);
1321                         rv->object = new_object;
1322                         rv->pindex -= old_object_offset;
1323                         LIST_INSERT_HEAD(&new_object->rvq, rv, objq);
1324                         vm_reserv_object_unlock(new_object);
1325                 }
1326                 vm_reserv_unlock(rv);
1327         }
1328 }
1329
1330 /*
1331  * Returns the size (in bytes) of a reservation of the specified level.
1332  */
1333 int
1334 vm_reserv_size(int level)
1335 {
1336
1337         switch (level) {
1338         case 0:
1339                 return (VM_LEVEL_0_SIZE);
1340         case -1:
1341                 return (PAGE_SIZE);
1342         default:
1343                 return (0);
1344         }
1345 }
1346
1347 /*
1348  * Allocates the virtual and physical memory required by the reservation
1349  * management system's data structures, in particular, the reservation array.
1350  */
1351 vm_paddr_t
1352 vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end)
1353 {
1354         vm_paddr_t new_end;
1355         vm_pindex_t count;
1356         size_t size;
1357         int i;
1358
1359         count = 0;
1360         for (i = 0; i < vm_phys_nsegs; i++) {
1361 #ifdef VM_PHYSSEG_SPARSE
1362                 count += howmany(vm_phys_segs[i].end, VM_LEVEL_0_SIZE) -
1363                     vm_phys_segs[i].start / VM_LEVEL_0_SIZE;
1364 #else
1365                 count = MAX(count,
1366                     howmany(vm_phys_segs[i].end, VM_LEVEL_0_SIZE));
1367 #endif
1368         }
1369
1370         for (i = 0; phys_avail[i + 1] != 0; i += 2) {
1371 #ifdef VM_PHYSSEG_SPARSE
1372                 count += howmany(phys_avail[i + 1], VM_LEVEL_0_SIZE) -
1373                     phys_avail[i] / VM_LEVEL_0_SIZE;
1374 #else
1375                 count = MAX(count,
1376                     howmany(phys_avail[i + 1], VM_LEVEL_0_SIZE));
1377 #endif
1378         }
1379
1380         /*
1381          * Calculate the size (in bytes) of the reservation array.  Rounding up
1382          * for partial superpages at boundaries, as every small page is mapped
1383          * to an element in the reservation array based on its physical address.
1384          * Thus, the number of elements in the reservation array can be greater
1385          * than the number of superpages.
1386          */
1387         size = count * sizeof(struct vm_reserv);
1388
1389         /*
1390          * Allocate and map the physical memory for the reservation array.  The
1391          * next available virtual address is returned by reference.
1392          */
1393         new_end = end - round_page(size);
1394         vm_reserv_array = (void *)(uintptr_t)pmap_map(vaddr, new_end, end,
1395             VM_PROT_READ | VM_PROT_WRITE);
1396         bzero(vm_reserv_array, size);
1397
1398         /*
1399          * Return the next available physical address.
1400          */
1401         return (new_end);
1402 }
1403
1404 /*
1405  * Returns the superpage containing the given page.
1406  */
1407 vm_page_t
1408 vm_reserv_to_superpage(vm_page_t m)
1409 {
1410         vm_reserv_t rv;
1411
1412         VM_OBJECT_ASSERT_LOCKED(m->object);
1413         rv = vm_reserv_from_page(m);
1414         if (rv->object == m->object && rv->popcnt == VM_LEVEL_0_NPAGES)
1415                 m = rv->pages;
1416         else
1417                 m = NULL;
1418
1419         return (m);
1420 }
1421
1422 #endif  /* VM_NRESERVLEVEL > 0 */