uvm_page.c revision 1.52
1/* $OpenBSD: uvm_page.c,v 1.52 2006/04/27 15:21:19 mickey Exp $ */ 2/* $NetBSD: uvm_page.c,v 1.44 2000/11/27 08:40:04 chs Exp $ */ 3 4/* 5 * Copyright (c) 1997 Charles D. Cranor and Washington University. 6 * Copyright (c) 1991, 1993, The Regents of the University of California. 7 * 8 * All rights reserved. 9 * 10 * This code is derived from software contributed to Berkeley by 11 * The Mach Operating System project at Carnegie-Mellon University. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by Charles D. Cranor, 24 * Washington University, the University of California, Berkeley and 25 * its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 43 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp 44 * 45 * 46 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 47 * All rights reserved. 48 * 49 * Permission to use, copy, modify and distribute this software and 50 * its documentation is hereby granted, provided that both the copyright 51 * notice and this permission notice appear in all copies of the 52 * software, derivative works or modified versions, and any portions 53 * thereof, and that both notices appear in supporting documentation. 54 * 55 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 56 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 57 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 58 * 59 * Carnegie Mellon requests users of this software to return to 60 * 61 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 62 * School of Computer Science 63 * Carnegie Mellon University 64 * Pittsburgh PA 15213-3890 65 * 66 * any improvements or extensions that they make and grant Carnegie the 67 * rights to redistribute these changes. 68 */ 69 70/* 71 * uvm_page.c: page ops. 72 */ 73 74#define UVM_PAGE /* pull in uvm_page.h functions */ 75#include <sys/param.h> 76#include <sys/systm.h> 77#include <sys/malloc.h> 78#include <sys/sched.h> 79#include <sys/kernel.h> 80#include <sys/vnode.h> 81 82#include <uvm/uvm.h> 83 84/* 85 * global vars... XXXCDC: move to uvm. structure. 86 */ 87 88/* 89 * physical memory config is stored in vm_physmem. 90 */ 91 92struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 93int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 94 95/* 96 * Some supported CPUs in a given architecture don't support all 97 * of the things necessary to do idle page zero'ing efficiently. 98 * We therefore provide a way to disable it from machdep code here. 99 */ 100 101/* 102 * XXX disabled until we can find a way to do this without causing 103 * problems for either cpu caches or DMA latency. 104 */ 105boolean_t vm_page_zero_enable = FALSE; 106 107/* 108 * local variables 109 */ 110 111/* 112 * these variables record the values returned by vm_page_bootstrap, 113 * for debugging purposes. The implementation of uvm_pageboot_alloc 114 * and pmap_startup here also uses them internally. 115 */ 116 117static vaddr_t virtual_space_start; 118static vaddr_t virtual_space_end; 119 120/* 121 * we use a hash table with only one bucket during bootup. we will 122 * later rehash (resize) the hash table once the allocator is ready. 123 * we static allocate the one bootstrap bucket below... 124 */ 125 126static struct pglist uvm_bootbucket; 127 128/* 129 * History 130 */ 131UVMHIST_DECL(pghist); 132 133/* 134 * local prototypes 135 */ 136 137static void uvm_pageinsert(struct vm_page *); 138static void uvm_pageremove(struct vm_page *); 139 140/* 141 * inline functions 142 */ 143 144/* 145 * uvm_pageinsert: insert a page in the object and the hash table 146 * 147 * => caller must lock object 148 * => caller must lock page queues 149 * => call should have already set pg's object and offset pointers 150 * and bumped the version counter 151 */ 152 153__inline static void 154uvm_pageinsert(pg) 155 struct vm_page *pg; 156{ 157 struct pglist *buck; 158 int s; 159 UVMHIST_FUNC("uvm_pageinsert"); UVMHIST_CALLED(pghist); 160 161 KASSERT((pg->flags & PG_TABLED) == 0); 162 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 163 s = splvm(); 164 simple_lock(&uvm.hashlock); 165 TAILQ_INSERT_TAIL(buck, pg, hashq); /* put in hash */ 166 simple_unlock(&uvm.hashlock); 167 splx(s); 168 169 TAILQ_INSERT_TAIL(&pg->uobject->memq, pg, listq); /* put in object */ 170 pg->flags |= PG_TABLED; 171 pg->uobject->uo_npages++; 172} 173 174/* 175 * uvm_page_remove: remove page from object and hash 176 * 177 * => caller must lock object 178 * => caller must lock page queues 179 */ 180 181static __inline void 182uvm_pageremove(pg) 183 struct vm_page *pg; 184{ 185 struct pglist *buck; 186 int s; 187 UVMHIST_FUNC("uvm_pageremove"); UVMHIST_CALLED(pghist); 188 189 KASSERT(pg->flags & PG_TABLED); 190 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 191 s = splvm(); 192 simple_lock(&uvm.hashlock); 193 TAILQ_REMOVE(buck, pg, hashq); 194 simple_unlock(&uvm.hashlock); 195 splx(s); 196 197#ifdef UBC 198 if (pg->uobject->pgops == &uvm_vnodeops) { 199 uvm_pgcnt_vnode--; 200 } 201#endif 202 203 /* object should be locked */ 204 TAILQ_REMOVE(&pg->uobject->memq, pg, listq); 205 206 pg->flags &= ~PG_TABLED; 207 pg->uobject->uo_npages--; 208 pg->uobject = NULL; 209 pg->version++; 210} 211 212/* 213 * uvm_page_init: init the page system. called from uvm_init(). 214 * 215 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 216 */ 217 218void 219uvm_page_init(kvm_startp, kvm_endp) 220 vaddr_t *kvm_startp, *kvm_endp; 221{ 222 vsize_t freepages, pagecount, n; 223 vm_page_t pagearray; 224 int lcv, i; 225 paddr_t paddr; 226#if defined(UVMHIST) 227 static struct uvm_history_ent pghistbuf[100]; 228#endif 229 230 UVMHIST_FUNC("uvm_page_init"); 231 UVMHIST_INIT_STATIC(pghist, pghistbuf); 232 UVMHIST_CALLED(pghist); 233 234 /* 235 * init the page queues and page queue locks 236 */ 237 238 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 239 for (i = 0; i < PGFL_NQUEUES; i++) 240 TAILQ_INIT(&uvm.page_free[lcv].pgfl_queues[i]); 241 } 242 TAILQ_INIT(&uvm.page_active); 243 TAILQ_INIT(&uvm.page_inactive_swp); 244 TAILQ_INIT(&uvm.page_inactive_obj); 245 simple_lock_init(&uvm.pageqlock); 246 simple_lock_init(&uvm.fpageqlock); 247 248 /* 249 * init the <obj,offset> => <page> hash table. for now 250 * we just have one bucket (the bootstrap bucket). later on we 251 * will allocate new buckets as we dynamically resize the hash table. 252 */ 253 254 uvm.page_nhash = 1; /* 1 bucket */ 255 uvm.page_hashmask = 0; /* mask for hash function */ 256 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 257 TAILQ_INIT(uvm.page_hash); /* init hash table */ 258 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 259 260 /* 261 * allocate vm_page structures. 262 */ 263 264 /* 265 * sanity check: 266 * before calling this function the MD code is expected to register 267 * some free RAM with the uvm_page_physload() function. our job 268 * now is to allocate vm_page structures for this memory. 269 */ 270 271 if (vm_nphysseg == 0) 272 panic("uvm_page_bootstrap: no memory pre-allocated"); 273 274 /* 275 * first calculate the number of free pages... 276 * 277 * note that we use start/end rather than avail_start/avail_end. 278 * this allows us to allocate extra vm_page structures in case we 279 * want to return some memory to the pool after booting. 280 */ 281 282 freepages = 0; 283 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 284 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 285 286 /* 287 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 288 * use. for each page of memory we use we need a vm_page structure. 289 * thus, the total number of pages we can use is the total size of 290 * the memory divided by the PAGE_SIZE plus the size of the vm_page 291 * structure. we add one to freepages as a fudge factor to avoid 292 * truncation errors (since we can only allocate in terms of whole 293 * pages). 294 */ 295 296 pagecount = (((paddr_t)freepages + 1) << PAGE_SHIFT) / 297 (PAGE_SIZE + sizeof(struct vm_page)); 298 pagearray = (vm_page_t)uvm_pageboot_alloc(pagecount * 299 sizeof(struct vm_page)); 300 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 301 302 /* 303 * init the vm_page structures and put them in the correct place. 304 */ 305 306 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 307 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 308 if (n > pagecount) { 309 printf("uvm_page_init: lost %ld page(s) in init\n", 310 (long)(n - pagecount)); 311 panic("uvm_page_init"); /* XXXCDC: shouldn't happen? */ 312 /* n = pagecount; */ 313 } 314 315 /* set up page array pointers */ 316 vm_physmem[lcv].pgs = pagearray; 317 pagearray += n; 318 pagecount -= n; 319 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 320 321 /* init and free vm_pages (we've already zeroed them) */ 322 paddr = ptoa(vm_physmem[lcv].start); 323 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 324 vm_physmem[lcv].pgs[i].phys_addr = paddr; 325#ifdef __HAVE_VM_PAGE_MD 326 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 327#endif 328 if (atop(paddr) >= vm_physmem[lcv].avail_start && 329 atop(paddr) <= vm_physmem[lcv].avail_end) { 330 uvmexp.npages++; 331 /* add page to free pool */ 332 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 333 } 334 } 335 } 336 337 /* 338 * pass up the values of virtual_space_start and 339 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 340 * layers of the VM. 341 */ 342 343 *kvm_startp = round_page(virtual_space_start); 344 *kvm_endp = trunc_page(virtual_space_end); 345 346 /* 347 * init locks for kernel threads 348 */ 349 350 simple_lock_init(&uvm.pagedaemon_lock); 351 simple_lock_init(&uvm.aiodoned_lock); 352 353 /* 354 * init reserve thresholds 355 * XXXCDC - values may need adjusting 356 */ 357 uvmexp.reserve_pagedaemon = 4; 358 uvmexp.reserve_kernel = 6; 359 uvmexp.anonminpct = 10; 360 uvmexp.vnodeminpct = 10; 361 uvmexp.vtextminpct = 5; 362 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 363 uvmexp.vnodemin = uvmexp.vnodeminpct * 256 / 100; 364 uvmexp.vtextmin = uvmexp.vtextminpct * 256 / 100; 365 366 /* 367 * determine if we should zero pages in the idle loop. 368 */ 369 370 uvm.page_idle_zero = vm_page_zero_enable; 371 372 /* 373 * done! 374 */ 375 376 uvm.page_init_done = TRUE; 377} 378 379/* 380 * uvm_setpagesize: set the page size 381 * 382 * => sets page_shift and page_mask from uvmexp.pagesize. 383 */ 384 385void 386uvm_setpagesize() 387{ 388 if (uvmexp.pagesize == 0) 389 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 390 uvmexp.pagemask = uvmexp.pagesize - 1; 391 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 392 panic("uvm_setpagesize: page size not a power of two"); 393 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 394 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 395 break; 396} 397 398/* 399 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 400 */ 401 402vaddr_t 403uvm_pageboot_alloc(size) 404 vsize_t size; 405{ 406#if defined(PMAP_STEAL_MEMORY) 407 vaddr_t addr; 408 409 /* 410 * defer bootstrap allocation to MD code (it may want to allocate 411 * from a direct-mapped segment). pmap_steal_memory should round 412 * off virtual_space_start/virtual_space_end. 413 */ 414 415 addr = pmap_steal_memory(size, &virtual_space_start, 416 &virtual_space_end); 417 418 return(addr); 419 420#else /* !PMAP_STEAL_MEMORY */ 421 422 static boolean_t initialized = FALSE; 423 vaddr_t addr, vaddr; 424 paddr_t paddr; 425 426 /* round to page size */ 427 size = round_page(size); 428 429 /* 430 * on first call to this function, initialize ourselves. 431 */ 432 if (initialized == FALSE) { 433 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 434 435 /* round it the way we like it */ 436 virtual_space_start = round_page(virtual_space_start); 437 virtual_space_end = trunc_page(virtual_space_end); 438 439 initialized = TRUE; 440 } 441 442 /* 443 * allocate virtual memory for this request 444 */ 445 if (virtual_space_start == virtual_space_end || 446 (virtual_space_end - virtual_space_start) < size) 447 panic("uvm_pageboot_alloc: out of virtual space"); 448 449 addr = virtual_space_start; 450 451#ifdef PMAP_GROWKERNEL 452 /* 453 * If the kernel pmap can't map the requested space, 454 * then allocate more resources for it. 455 */ 456 if (uvm_maxkaddr < (addr + size)) { 457 uvm_maxkaddr = pmap_growkernel(addr + size); 458 if (uvm_maxkaddr < (addr + size)) 459 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 460 } 461#endif 462 463 virtual_space_start += size; 464 465 /* 466 * allocate and mapin physical pages to back new virtual pages 467 */ 468 469 for (vaddr = round_page(addr) ; vaddr < addr + size ; 470 vaddr += PAGE_SIZE) { 471 472 if (!uvm_page_physget(&paddr)) 473 panic("uvm_pageboot_alloc: out of memory"); 474 475 /* 476 * Note this memory is no longer managed, so using 477 * pmap_kenter is safe. 478 */ 479 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 480 } 481 pmap_update(pmap_kernel()); 482 return(addr); 483#endif /* PMAP_STEAL_MEMORY */ 484} 485 486#if !defined(PMAP_STEAL_MEMORY) 487/* 488 * uvm_page_physget: "steal" one page from the vm_physmem structure. 489 * 490 * => attempt to allocate it off the end of a segment in which the "avail" 491 * values match the start/end values. if we can't do that, then we 492 * will advance both values (making them equal, and removing some 493 * vm_page structures from the non-avail area). 494 * => return false if out of memory. 495 */ 496 497/* subroutine: try to allocate from memory chunks on the specified freelist */ 498static boolean_t uvm_page_physget_freelist(paddr_t *, int); 499 500static boolean_t 501uvm_page_physget_freelist(paddrp, freelist) 502 paddr_t *paddrp; 503 int freelist; 504{ 505 int lcv, x; 506 UVMHIST_FUNC("uvm_page_physget_freelist"); UVMHIST_CALLED(pghist); 507 508 /* pass 1: try allocating from a matching end */ 509#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \ 510 (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 511 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 512#else 513 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 514#endif 515 { 516 517 if (uvm.page_init_done == TRUE) 518 panic("uvm_page_physget: called _after_ bootstrap"); 519 520 if (vm_physmem[lcv].free_list != freelist) 521 continue; 522 523 /* try from front */ 524 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 525 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 526 *paddrp = ptoa(vm_physmem[lcv].avail_start); 527 vm_physmem[lcv].avail_start++; 528 vm_physmem[lcv].start++; 529 /* nothing left? nuke it */ 530 if (vm_physmem[lcv].avail_start == 531 vm_physmem[lcv].end) { 532 if (vm_nphysseg == 1) 533 panic("uvm_page_physget: out of memory!"); 534 vm_nphysseg--; 535 for (x = lcv ; x < vm_nphysseg ; x++) 536 /* structure copy */ 537 vm_physmem[x] = vm_physmem[x+1]; 538 } 539 return (TRUE); 540 } 541 542 /* try from rear */ 543 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 544 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 545 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 546 vm_physmem[lcv].avail_end--; 547 vm_physmem[lcv].end--; 548 /* nothing left? nuke it */ 549 if (vm_physmem[lcv].avail_end == 550 vm_physmem[lcv].start) { 551 if (vm_nphysseg == 1) 552 panic("uvm_page_physget: out of memory!"); 553 vm_nphysseg--; 554 for (x = lcv ; x < vm_nphysseg ; x++) 555 /* structure copy */ 556 vm_physmem[x] = vm_physmem[x+1]; 557 } 558 return (TRUE); 559 } 560 } 561 562 /* pass2: forget about matching ends, just allocate something */ 563#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \ 564 (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 565 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 566#else 567 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 568#endif 569 { 570 571 /* any room in this bank? */ 572 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 573 continue; /* nope */ 574 575 *paddrp = ptoa(vm_physmem[lcv].avail_start); 576 vm_physmem[lcv].avail_start++; 577 /* truncate! */ 578 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 579 580 /* nothing left? nuke it */ 581 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 582 if (vm_nphysseg == 1) 583 panic("uvm_page_physget: out of memory!"); 584 vm_nphysseg--; 585 for (x = lcv ; x < vm_nphysseg ; x++) 586 /* structure copy */ 587 vm_physmem[x] = vm_physmem[x+1]; 588 } 589 return (TRUE); 590 } 591 592 return (FALSE); /* whoops! */ 593} 594 595boolean_t 596uvm_page_physget(paddrp) 597 paddr_t *paddrp; 598{ 599 int i; 600 UVMHIST_FUNC("uvm_page_physget"); UVMHIST_CALLED(pghist); 601 602 /* try in the order of freelist preference */ 603 for (i = 0; i < VM_NFREELIST; i++) 604 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 605 return (TRUE); 606 return (FALSE); 607} 608#endif /* PMAP_STEAL_MEMORY */ 609 610/* 611 * uvm_page_physload: load physical memory into VM system 612 * 613 * => all args are PFs 614 * => all pages in start/end get vm_page structures 615 * => areas marked by avail_start/avail_end get added to the free page pool 616 * => we are limited to VM_PHYSSEG_MAX physical memory segments 617 */ 618 619void 620uvm_page_physload(start, end, avail_start, avail_end, free_list) 621 paddr_t start, end, avail_start, avail_end; 622 int free_list; 623{ 624 int preload, lcv; 625 psize_t npages; 626 struct vm_page *pgs; 627 struct vm_physseg *ps; 628 629 if (uvmexp.pagesize == 0) 630 panic("uvm_page_physload: page size not set!"); 631 632 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 633 panic("uvm_page_physload: bad free list %d", free_list); 634 635 if (start >= end) 636 panic("uvm_page_physload: start >= end"); 637 638 /* 639 * do we have room? 640 */ 641 if (vm_nphysseg == VM_PHYSSEG_MAX) { 642 printf("uvm_page_physload: unable to load physical memory " 643 "segment\n"); 644 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 645 VM_PHYSSEG_MAX, (long long)start, (long long)end); 646 printf("\tincrease VM_PHYSSEG_MAX\n"); 647 return; 648 } 649 650 /* 651 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 652 * called yet, so malloc is not available). 653 */ 654 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 655 if (vm_physmem[lcv].pgs) 656 break; 657 } 658 preload = (lcv == vm_nphysseg); 659 660 /* 661 * if VM is already running, attempt to malloc() vm_page structures 662 */ 663 if (!preload) { 664#if defined(VM_PHYSSEG_NOADD) 665 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 666#else 667 /* XXXCDC: need some sort of lockout for this case */ 668 paddr_t paddr; 669 npages = end - start; /* # of pages */ 670 pgs = (vm_page *)uvm_km_alloc(kernel_map, 671 sizeof(struct vm_page) * npages); 672 if (pgs == NULL) { 673 printf("uvm_page_physload: can not malloc vm_page " 674 "structs for segment\n"); 675 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 676 return; 677 } 678 /* zero data, init phys_addr and free_list, and free pages */ 679 memset(pgs, 0, sizeof(struct vm_page) * npages); 680 for (lcv = 0, paddr = ptoa(start) ; 681 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 682 pgs[lcv].phys_addr = paddr; 683 pgs[lcv].free_list = free_list; 684 if (atop(paddr) >= avail_start && 685 atop(paddr) <= avail_end) 686 uvm_pagefree(&pgs[lcv]); 687 } 688 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 689 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 690#endif 691 } else { 692 693 /* gcc complains if these don't get init'd */ 694 pgs = NULL; 695 npages = 0; 696 697 } 698 699 /* 700 * now insert us in the proper place in vm_physmem[] 701 */ 702 703#if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 704 705 /* random: put it at the end (easy!) */ 706 ps = &vm_physmem[vm_nphysseg]; 707 708#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 709 710 { 711 int x; 712 /* sort by address for binary search */ 713 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 714 if (start < vm_physmem[lcv].start) 715 break; 716 ps = &vm_physmem[lcv]; 717 /* move back other entries, if necessary ... */ 718 for (x = vm_nphysseg ; x > lcv ; x--) 719 /* structure copy */ 720 vm_physmem[x] = vm_physmem[x - 1]; 721 } 722 723#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 724 725 { 726 int x; 727 /* sort by largest segment first */ 728 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 729 if ((end - start) > 730 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 731 break; 732 ps = &vm_physmem[lcv]; 733 /* move back other entries, if necessary ... */ 734 for (x = vm_nphysseg ; x > lcv ; x--) 735 /* structure copy */ 736 vm_physmem[x] = vm_physmem[x - 1]; 737 } 738 739#else 740 741 panic("uvm_page_physload: unknown physseg strategy selected!"); 742 743#endif 744 745 ps->start = start; 746 ps->end = end; 747 ps->avail_start = avail_start; 748 ps->avail_end = avail_end; 749 if (preload) { 750 ps->pgs = NULL; 751 } else { 752 ps->pgs = pgs; 753 ps->lastpg = pgs + npages - 1; 754 } 755 ps->free_list = free_list; 756 vm_nphysseg++; 757 758 /* 759 * done! 760 */ 761 762 if (!preload) 763 uvm_page_rehash(); 764 765 return; 766} 767 768/* 769 * uvm_page_rehash: reallocate hash table based on number of free pages. 770 */ 771 772void 773uvm_page_rehash() 774{ 775 int freepages, lcv, bucketcount, s, oldcount; 776 struct pglist *newbuckets, *oldbuckets; 777 struct vm_page *pg; 778 size_t newsize, oldsize; 779 780 /* 781 * compute number of pages that can go in the free pool 782 */ 783 784 freepages = 0; 785 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 786 freepages += 787 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 788 789 /* 790 * compute number of buckets needed for this number of pages 791 */ 792 793 bucketcount = 1; 794 while (bucketcount < freepages) 795 bucketcount = bucketcount * 2; 796 797 /* 798 * compute the size of the current table and new table. 799 */ 800 801 oldbuckets = uvm.page_hash; 802 oldcount = uvm.page_nhash; 803 oldsize = round_page(sizeof(struct pglist) * oldcount); 804 newsize = round_page(sizeof(struct pglist) * bucketcount); 805 806 /* 807 * allocate the new buckets 808 */ 809 810 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 811 if (newbuckets == NULL) { 812 printf("uvm_page_physrehash: WARNING: could not grow page " 813 "hash table\n"); 814 return; 815 } 816 for (lcv = 0 ; lcv < bucketcount ; lcv++) 817 TAILQ_INIT(&newbuckets[lcv]); 818 819 /* 820 * now replace the old buckets with the new ones and rehash everything 821 */ 822 823 s = splvm(); 824 simple_lock(&uvm.hashlock); 825 uvm.page_hash = newbuckets; 826 uvm.page_nhash = bucketcount; 827 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 828 829 /* ... and rehash */ 830 for (lcv = 0 ; lcv < oldcount ; lcv++) { 831 while ((pg = TAILQ_FIRST(&oldbuckets[lcv])) != NULL) { 832 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 833 TAILQ_INSERT_TAIL( 834 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 835 pg, hashq); 836 } 837 } 838 simple_unlock(&uvm.hashlock); 839 splx(s); 840 841 /* 842 * free old bucket array if is not the boot-time table 843 */ 844 845 if (oldbuckets != &uvm_bootbucket) 846 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 847 848 /* 849 * done 850 */ 851 return; 852} 853 854 855#if 1 /* XXXCDC: TMP TMP TMP DEBUG DEBUG DEBUG */ 856 857void uvm_page_physdump(void); /* SHUT UP GCC */ 858 859/* call from DDB */ 860void 861uvm_page_physdump() 862{ 863 int lcv; 864 865 printf("rehash: physical memory config [segs=%d of %d]:\n", 866 vm_nphysseg, VM_PHYSSEG_MAX); 867 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 868 printf("0x%llx->0x%llx [0x%llx->0x%llx]\n", 869 (long long)vm_physmem[lcv].start, 870 (long long)vm_physmem[lcv].end, 871 (long long)vm_physmem[lcv].avail_start, 872 (long long)vm_physmem[lcv].avail_end); 873 printf("STRATEGY = "); 874 switch (VM_PHYSSEG_STRAT) { 875 case VM_PSTRAT_RANDOM: printf("RANDOM\n"); break; 876 case VM_PSTRAT_BSEARCH: printf("BSEARCH\n"); break; 877 case VM_PSTRAT_BIGFIRST: printf("BIGFIRST\n"); break; 878 default: printf("<<UNKNOWN>>!!!!\n"); 879 } 880 printf("number of buckets = %d\n", uvm.page_nhash); 881} 882#endif 883 884/* 885 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 886 * 887 * => return null if no pages free 888 * => wake up pagedaemon if number of free pages drops below low water mark 889 * => if obj != NULL, obj must be locked (to put in hash) 890 * => if anon != NULL, anon must be locked (to put in anon) 891 * => only one of obj or anon can be non-null 892 * => caller must activate/deactivate page if it is not wired. 893 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 894 * => policy decision: it is more important to pull a page off of the 895 * appropriate priority free list than it is to get a zero'd or 896 * unknown contents page. This is because we live with the 897 * consequences of a bad free list decision for the entire 898 * lifetime of the page, e.g. if the page comes from memory that 899 * is slower to access. 900 */ 901 902struct vm_page * 903uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 904 struct uvm_object *obj; 905 voff_t off; 906 int flags; 907 struct vm_anon *anon; 908 int strat, free_list; 909{ 910 int lcv, try1, try2, s, zeroit = 0; 911 struct vm_page *pg; 912 struct pglist *freeq; 913 struct pgfreelist *pgfl; 914 boolean_t use_reserve; 915 UVMHIST_FUNC("uvm_pagealloc_strat"); UVMHIST_CALLED(pghist); 916 917 KASSERT(obj == NULL || anon == NULL); 918 KASSERT(off == trunc_page(off)); 919 s = uvm_lock_fpageq(); 920 921 /* 922 * check to see if we need to generate some free pages waking 923 * the pagedaemon. 924 */ 925 926#ifdef UBC 927 if (uvmexp.free + uvmexp.paging < uvmexp.freemin || 928 (uvmexp.free + uvmexp.paging < uvmexp.freetarg && 929 uvmexp.inactive < uvmexp.inactarg)) { 930 wakeup(&uvm.pagedaemon); 931 } 932#else 933 if (uvmexp.free < uvmexp.freemin || (uvmexp.free < uvmexp.freetarg && 934 uvmexp.inactive < uvmexp.inactarg)) 935 wakeup(&uvm.pagedaemon); 936#endif 937 938 /* 939 * fail if any of these conditions is true: 940 * [1] there really are no free pages, or 941 * [2] only kernel "reserved" pages remain and 942 * the page isn't being allocated to a kernel object. 943 * [3] only pagedaemon "reserved" pages remain and 944 * the requestor isn't the pagedaemon. 945 */ 946 947 use_reserve = (flags & UVM_PGA_USERESERVE) || 948 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 949 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 950 (uvmexp.free <= uvmexp.reserve_pagedaemon && 951 !(use_reserve && (curproc == uvm.pagedaemon_proc || 952 curproc == syncerproc)))) 953 goto fail; 954 955#if PGFL_NQUEUES != 2 956#error uvm_pagealloc_strat needs to be updated 957#endif 958 959 /* 960 * If we want a zero'd page, try the ZEROS queue first, otherwise 961 * we try the UNKNOWN queue first. 962 */ 963 if (flags & UVM_PGA_ZERO) { 964 try1 = PGFL_ZEROS; 965 try2 = PGFL_UNKNOWN; 966 } else { 967 try1 = PGFL_UNKNOWN; 968 try2 = PGFL_ZEROS; 969 } 970 971 UVMHIST_LOG(pghist, "obj=%p off=%llx anon=%x flags=%x", 972 obj, off, flags, anon); 973 UVMHIST_LOG(pghist, "strat=%d free_list=%d", strat, free_list, 0, 0); 974 again: 975 switch (strat) { 976 case UVM_PGA_STRAT_NORMAL: 977 /* Check all freelists in descending priority order. */ 978 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 979 pgfl = &uvm.page_free[lcv]; 980 if ((pg = TAILQ_FIRST((freeq = 981 &pgfl->pgfl_queues[try1]))) != NULL || 982 (pg = TAILQ_FIRST((freeq = 983 &pgfl->pgfl_queues[try2]))) != NULL) 984 goto gotit; 985 } 986 987 /* No pages free! */ 988 goto fail; 989 990 case UVM_PGA_STRAT_ONLY: 991 case UVM_PGA_STRAT_FALLBACK: 992 /* Attempt to allocate from the specified free list. */ 993 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 994 pgfl = &uvm.page_free[free_list]; 995 if ((pg = TAILQ_FIRST((freeq = 996 &pgfl->pgfl_queues[try1]))) != NULL || 997 (pg = TAILQ_FIRST((freeq = 998 &pgfl->pgfl_queues[try2]))) != NULL) 999 goto gotit; 1000 1001 /* Fall back, if possible. */ 1002 if (strat == UVM_PGA_STRAT_FALLBACK) { 1003 strat = UVM_PGA_STRAT_NORMAL; 1004 goto again; 1005 } 1006 1007 /* No pages free! */ 1008 goto fail; 1009 1010 default: 1011 panic("uvm_pagealloc_strat: bad strat %d", strat); 1012 /* NOTREACHED */ 1013 } 1014 1015 gotit: 1016 TAILQ_REMOVE(freeq, pg, pageq); 1017 uvmexp.free--; 1018 1019 /* update zero'd page count */ 1020 if (pg->flags & PG_ZERO) 1021 uvmexp.zeropages--; 1022 1023 /* 1024 * update allocation statistics and remember if we have to 1025 * zero the page 1026 */ 1027 if (flags & UVM_PGA_ZERO) { 1028 if (pg->flags & PG_ZERO) { 1029 uvmexp.pga_zerohit++; 1030 zeroit = 0; 1031 } else { 1032 uvmexp.pga_zeromiss++; 1033 zeroit = 1; 1034 } 1035 } 1036 1037 uvm_unlock_fpageq(s); /* unlock free page queue */ 1038 1039 pg->offset = off; 1040 pg->uobject = obj; 1041 pg->uanon = anon; 1042 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1043 pg->version++; 1044 if (anon) { 1045 anon->u.an_page = pg; 1046 pg->pqflags = PQ_ANON; 1047#ifdef UBC 1048 uvm_pgcnt_anon++; 1049#endif 1050 } else { 1051 if (obj) 1052 uvm_pageinsert(pg); 1053 pg->pqflags = 0; 1054 } 1055#if defined(UVM_PAGE_TRKOWN) 1056 pg->owner_tag = NULL; 1057#endif 1058 UVM_PAGE_OWN(pg, "new alloc"); 1059 1060 if (flags & UVM_PGA_ZERO) { 1061 /* 1062 * A zero'd page is not clean. If we got a page not already 1063 * zero'd, then we have to zero it ourselves. 1064 */ 1065 pg->flags &= ~PG_CLEAN; 1066 if (zeroit) 1067 pmap_zero_page(pg); 1068 } 1069 1070 UVMHIST_LOG(pghist, "allocated pg %p/%llx", pg, 1071 (long long)VM_PAGE_TO_PHYS(pg), 0, 0); 1072 return(pg); 1073 1074 fail: 1075 uvm_unlock_fpageq(s); 1076 UVMHIST_LOG(pghist, "failed!", 0, 0, 0, 0); 1077 return (NULL); 1078} 1079 1080/* 1081 * uvm_pagerealloc: reallocate a page from one object to another 1082 * 1083 * => both objects must be locked 1084 */ 1085 1086void 1087uvm_pagerealloc(pg, newobj, newoff) 1088 struct vm_page *pg; 1089 struct uvm_object *newobj; 1090 voff_t newoff; 1091{ 1092 1093 UVMHIST_FUNC("uvm_pagerealloc"); UVMHIST_CALLED(pghist); 1094 1095 /* 1096 * remove it from the old object 1097 */ 1098 1099 if (pg->uobject) { 1100 uvm_pageremove(pg); 1101 } 1102 1103 /* 1104 * put it in the new object 1105 */ 1106 1107 if (newobj) { 1108 pg->uobject = newobj; 1109 pg->offset = newoff; 1110 pg->version++; 1111 uvm_pageinsert(pg); 1112 } 1113} 1114 1115 1116/* 1117 * uvm_pagefree: free page 1118 * 1119 * => erase page's identity (i.e. remove from hash/object) 1120 * => put page on free list 1121 * => caller must lock owning object (either anon or uvm_object) 1122 * => caller must lock page queues 1123 * => assumes all valid mappings of pg are gone 1124 */ 1125 1126void 1127uvm_pagefree(pg) 1128 struct vm_page *pg; 1129{ 1130 int s; 1131 int saved_loan_count = pg->loan_count; 1132 UVMHIST_FUNC("uvm_pagefree"); UVMHIST_CALLED(pghist); 1133 1134#ifdef DEBUG 1135 if (pg->uobject == (void *)0xdeadbeef && 1136 pg->uanon == (void *)0xdeadbeef) { 1137 panic("uvm_pagefree: freeing free page %p", pg); 1138 } 1139#endif 1140 1141 UVMHIST_LOG(pghist, "freeing pg %p/%llx", pg, 1142 (long long)VM_PAGE_TO_PHYS(pg), 0, 0); 1143 1144 /* 1145 * if the page was an object page (and thus "TABLED"), remove it 1146 * from the object. 1147 */ 1148 1149 if (pg->flags & PG_TABLED) { 1150 1151 /* 1152 * if the object page is on loan we are going to drop ownership. 1153 * it is possible that an anon will take over as owner for this 1154 * page later on. the anon will want a !PG_CLEAN page so that 1155 * it knows it needs to allocate swap if it wants to page the 1156 * page out. 1157 */ 1158 1159 if (saved_loan_count) 1160 pg->flags &= ~PG_CLEAN; /* in case an anon takes over */ 1161 uvm_pageremove(pg); 1162 1163 /* 1164 * if our page was on loan, then we just lost control over it 1165 * (in fact, if it was loaned to an anon, the anon may have 1166 * already taken over ownership of the page by now and thus 1167 * changed the loan_count [e.g. in uvmfault_anonget()]) we just 1168 * return (when the last loan is dropped, then the page can be 1169 * freed by whatever was holding the last loan). 1170 */ 1171 1172 if (saved_loan_count) 1173 return; 1174 } else if (saved_loan_count && (pg->pqflags & PQ_ANON)) { 1175 1176 /* 1177 * if our page is owned by an anon and is loaned out to the 1178 * kernel then we just want to drop ownership and return. 1179 * the kernel must free the page when all its loans clear ... 1180 * note that the kernel can't change the loan status of our 1181 * page as long as we are holding PQ lock. 1182 */ 1183 1184 pg->pqflags &= ~PQ_ANON; 1185 pg->uanon = NULL; 1186 return; 1187 } 1188 KASSERT(saved_loan_count == 0); 1189 1190 /* 1191 * now remove the page from the queues 1192 */ 1193 1194 if (pg->pqflags & PQ_ACTIVE) { 1195 TAILQ_REMOVE(&uvm.page_active, pg, pageq); 1196 pg->pqflags &= ~PQ_ACTIVE; 1197 uvmexp.active--; 1198 } 1199 if (pg->pqflags & PQ_INACTIVE) { 1200 if (pg->pqflags & PQ_SWAPBACKED) 1201 TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq); 1202 else 1203 TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq); 1204 pg->pqflags &= ~PQ_INACTIVE; 1205 uvmexp.inactive--; 1206 } 1207 1208 /* 1209 * if the page was wired, unwire it now. 1210 */ 1211 1212 if (pg->wire_count) { 1213 pg->wire_count = 0; 1214 uvmexp.wired--; 1215 } 1216#ifdef UBC 1217 if (pg->uanon) { 1218 uvm_pgcnt_anon--; 1219 } 1220#endif 1221 1222 /* 1223 * and put on free queue 1224 */ 1225 1226 pg->flags &= ~PG_ZERO; 1227 1228 s = uvm_lock_fpageq(); 1229 TAILQ_INSERT_TAIL(&uvm.page_free[ 1230 uvm_page_lookup_freelist(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1231 pg->pqflags = PQ_FREE; 1232#ifdef DEBUG 1233 pg->uobject = (void *)0xdeadbeef; 1234 pg->offset = 0xdeadbeef; 1235 pg->uanon = (void *)0xdeadbeef; 1236#endif 1237 uvmexp.free++; 1238 1239 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1240 uvm.page_idle_zero = vm_page_zero_enable; 1241 1242 uvm_unlock_fpageq(s); 1243} 1244 1245/* 1246 * uvm_page_unbusy: unbusy an array of pages. 1247 * 1248 * => pages must either all belong to the same object, or all belong to anons. 1249 * => if pages are object-owned, object must be locked. 1250 * => if pages are anon-owned, anons must be unlockd and have 0 refcount. 1251 */ 1252 1253void 1254uvm_page_unbusy(pgs, npgs) 1255 struct vm_page **pgs; 1256 int npgs; 1257{ 1258 struct vm_page *pg; 1259 struct uvm_object *uobj; 1260 int i; 1261 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(pdhist); 1262 1263 for (i = 0; i < npgs; i++) { 1264 pg = pgs[i]; 1265 1266 if (pg == NULL || pg == PGO_DONTCARE) { 1267 continue; 1268 } 1269 if (pg->flags & PG_WANTED) { 1270 wakeup(pg); 1271 } 1272 if (pg->flags & PG_RELEASED) { 1273 UVMHIST_LOG(pdhist, "releasing pg %p", pg,0,0,0); 1274 uobj = pg->uobject; 1275 if (uobj != NULL) { 1276 uobj->pgops->pgo_releasepg(pg, NULL); 1277 } else { 1278 pg->flags &= ~(PG_BUSY); 1279 UVM_PAGE_OWN(pg, NULL); 1280 uvm_anfree(pg->uanon); 1281 } 1282 } else { 1283 UVMHIST_LOG(pdhist, "unbusying pg %p", pg,0,0,0); 1284 pg->flags &= ~(PG_WANTED|PG_BUSY); 1285 UVM_PAGE_OWN(pg, NULL); 1286 } 1287 } 1288} 1289 1290#if defined(UVM_PAGE_TRKOWN) 1291/* 1292 * uvm_page_own: set or release page ownership 1293 * 1294 * => this is a debugging function that keeps track of who sets PG_BUSY 1295 * and where they do it. it can be used to track down problems 1296 * such a process setting "PG_BUSY" and never releasing it. 1297 * => page's object [if any] must be locked 1298 * => if "tag" is NULL then we are releasing page ownership 1299 */ 1300void 1301uvm_page_own(pg, tag) 1302 struct vm_page *pg; 1303 char *tag; 1304{ 1305 /* gain ownership? */ 1306 if (tag) { 1307 if (pg->owner_tag) { 1308 printf("uvm_page_own: page %p already owned " 1309 "by proc %d [%s]\n", pg, 1310 pg->owner, pg->owner_tag); 1311 panic("uvm_page_own"); 1312 } 1313 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1314 pg->owner_tag = tag; 1315 return; 1316 } 1317 1318 /* drop ownership */ 1319 if (pg->owner_tag == NULL) { 1320 printf("uvm_page_own: dropping ownership of an non-owned " 1321 "page (%p)\n", pg); 1322 panic("uvm_page_own"); 1323 } 1324 pg->owner_tag = NULL; 1325 return; 1326} 1327#endif 1328 1329/* 1330 * uvm_pageidlezero: zero free pages while the system is idle. 1331 * 1332 * => we do at least one iteration per call, if we are below the target. 1333 * => we loop until we either reach the target or whichqs indicates that 1334 * there is a process ready to run. 1335 */ 1336void 1337uvm_pageidlezero() 1338{ 1339 struct vm_page *pg; 1340 struct pgfreelist *pgfl; 1341 int free_list, s; 1342 UVMHIST_FUNC("uvm_pageidlezero"); UVMHIST_CALLED(pghist); 1343 1344 do { 1345 s = uvm_lock_fpageq(); 1346 1347 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1348 uvm.page_idle_zero = FALSE; 1349 uvm_unlock_fpageq(s); 1350 return; 1351 } 1352 1353 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1354 pgfl = &uvm.page_free[free_list]; 1355 if ((pg = TAILQ_FIRST(&pgfl->pgfl_queues[ 1356 PGFL_UNKNOWN])) != NULL) 1357 break; 1358 } 1359 1360 if (pg == NULL) { 1361 /* 1362 * No non-zero'd pages; don't bother trying again 1363 * until we know we have non-zero'd pages free. 1364 */ 1365 uvm.page_idle_zero = FALSE; 1366 uvm_unlock_fpageq(s); 1367 return; 1368 } 1369 1370 TAILQ_REMOVE(&pgfl->pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1371 uvmexp.free--; 1372 uvm_unlock_fpageq(s); 1373 1374#ifdef PMAP_PAGEIDLEZERO 1375 if (PMAP_PAGEIDLEZERO(pg) == FALSE) { 1376 /* 1377 * The machine-dependent code detected some 1378 * reason for us to abort zeroing pages, 1379 * probably because there is a process now 1380 * ready to run. 1381 */ 1382 s = uvm_lock_fpageq(); 1383 TAILQ_INSERT_HEAD(&pgfl->pgfl_queues[PGFL_UNKNOWN], 1384 pg, pageq); 1385 uvmexp.free++; 1386 uvmexp.zeroaborts++; 1387 uvm_unlock_fpageq(s); 1388 return; 1389 } 1390#else 1391 /* 1392 * XXX This will toast the cache unless the pmap_zero_page() 1393 * XXX implementation does uncached access. 1394 */ 1395 pmap_zero_page(pg); 1396#endif 1397 pg->flags |= PG_ZERO; 1398 1399 s = uvm_lock_fpageq(); 1400 TAILQ_INSERT_HEAD(&pgfl->pgfl_queues[PGFL_ZEROS], pg, pageq); 1401 uvmexp.free++; 1402 uvmexp.zeropages++; 1403 uvm_unlock_fpageq(s); 1404 } while (whichqs == 0); 1405} 1406