1 /* $NetBSD: uvm_page.c,v 1.68 2001/09/28 11:59:55 chs Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 42 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 /* 70 * uvm_page.c: page ops. 71 */ 72 73 #include "opt_uvmhist.h" 74 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 #include <sys/proc.h> 82 83 #define UVM_PAGE /* pull in uvm_page.h functions */ 84 #include <uvm/uvm.h> 85 86 /* 87 * global vars... XXXCDC: move to uvm. structure. 88 */ 89 90 /* 91 * physical memory config is stored in vm_physmem. 92 */ 93 94 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 95 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 96 97 /* 98 * Some supported CPUs in a given architecture don't support all 99 * of the things necessary to do idle page zero'ing efficiently. 100 * We therefore provide a way to disable it from machdep code here. 101 */ 102 /* 103 * XXX disabled until we can find a way to do this without causing 104 * problems for either cpu caches or DMA latency. 105 */ 106 boolean_t vm_page_zero_enable = FALSE; 107 108 /* 109 * local variables 110 */ 111 112 /* 113 * these variables record the values returned by vm_page_bootstrap, 114 * for debugging purposes. The implementation of uvm_pageboot_alloc 115 * and pmap_startup here also uses them internally. 116 */ 117 118 static vaddr_t virtual_space_start; 119 static vaddr_t virtual_space_end; 120 121 /* 122 * we use a hash table with only one bucket during bootup. we will 123 * later rehash (resize) the hash table once the allocator is ready. 124 * we static allocate the one bootstrap bucket below... 125 */ 126 127 static struct pglist uvm_bootbucket; 128 129 /* 130 * we allocate an initial number of page colors in uvm_page_init(), 131 * and remember them. We may re-color pages as cache sizes are 132 * discovered during the autoconfiguration phase. But we can never 133 * free the initial set of buckets, since they are allocated using 134 * uvm_pageboot_alloc(). 135 */ 136 137 static boolean_t have_recolored_pages /* = FALSE */; 138 139 /* 140 * local prototypes 141 */ 142 143 static void uvm_pageinsert __P((struct vm_page *)); 144 static void uvm_pageremove __P((struct vm_page *)); 145 146 /* 147 * inline functions 148 */ 149 150 /* 151 * uvm_pageinsert: insert a page in the object and the hash table 152 * 153 * => caller must lock object 154 * => caller must lock page queues 155 * => call should have already set pg's object and offset pointers 156 * and bumped the version counter 157 */ 158 159 __inline static void 160 uvm_pageinsert(pg) 161 struct vm_page *pg; 162 { 163 struct pglist *buck; 164 struct uvm_object *uobj = pg->uobject; 165 166 KASSERT((pg->flags & PG_TABLED) == 0); 167 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 168 simple_lock(&uvm.hashlock); 169 TAILQ_INSERT_TAIL(buck, pg, hashq); 170 simple_unlock(&uvm.hashlock); 171 172 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 173 pg->flags |= PG_TABLED; 174 uobj->uo_npages++; 175 } 176 177 /* 178 * uvm_page_remove: remove page from object and hash 179 * 180 * => caller must lock object 181 * => caller must lock page queues 182 */ 183 184 static __inline void 185 uvm_pageremove(pg) 186 struct vm_page *pg; 187 { 188 struct pglist *buck; 189 struct uvm_object *uobj = pg->uobject; 190 191 KASSERT(pg->flags & PG_TABLED); 192 buck = &uvm.page_hash[uvm_pagehash(uobj ,pg->offset)]; 193 simple_lock(&uvm.hashlock); 194 TAILQ_REMOVE(buck, pg, hashq); 195 simple_unlock(&uvm.hashlock); 196 197 if (UVM_OBJ_IS_VTEXT(uobj)) { 198 uvmexp.vtextpages--; 199 } else if (UVM_OBJ_IS_VNODE(uobj)) { 200 uvmexp.vnodepages--; 201 } 202 203 /* object should be locked */ 204 uobj->uo_npages--; 205 TAILQ_REMOVE(&uobj->memq, pg, listq); 206 pg->flags &= ~PG_TABLED; 207 pg->uobject = NULL; 208 } 209 210 static void 211 uvm_page_init_buckets(struct pgfreelist *pgfl) 212 { 213 int color, i; 214 215 for (color = 0; color < uvmexp.ncolors; color++) { 216 for (i = 0; i < PGFL_NQUEUES; i++) { 217 TAILQ_INIT(&pgfl->pgfl_buckets[ 218 color].pgfl_queues[i]); 219 } 220 } 221 } 222 223 /* 224 * uvm_page_init: init the page system. called from uvm_init(). 225 * 226 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 227 */ 228 229 void 230 uvm_page_init(kvm_startp, kvm_endp) 231 vaddr_t *kvm_startp, *kvm_endp; 232 { 233 vsize_t freepages, pagecount, bucketcount, n; 234 struct pgflbucket *bucketarray; 235 struct vm_page *pagearray; 236 int lcv, i; 237 paddr_t paddr; 238 239 /* 240 * init the page queues and page queue locks, except the free 241 * list; we allocate that later (with the initial vm_page 242 * structures). 243 */ 244 245 TAILQ_INIT(&uvm.page_active); 246 TAILQ_INIT(&uvm.page_inactive); 247 simple_lock_init(&uvm.pageqlock); 248 simple_lock_init(&uvm.fpageqlock); 249 250 /* 251 * init the <obj,offset> => <page> hash table. for now 252 * we just have one bucket (the bootstrap bucket). later on we 253 * will allocate new buckets as we dynamically resize the hash table. 254 */ 255 256 uvm.page_nhash = 1; /* 1 bucket */ 257 uvm.page_hashmask = 0; /* mask for hash function */ 258 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 259 TAILQ_INIT(uvm.page_hash); /* init hash table */ 260 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 261 262 /* 263 * allocate vm_page structures. 264 */ 265 266 /* 267 * sanity check: 268 * before calling this function the MD code is expected to register 269 * some free RAM with the uvm_page_physload() function. our job 270 * now is to allocate vm_page structures for this memory. 271 */ 272 273 if (vm_nphysseg == 0) 274 panic("uvm_page_bootstrap: no memory pre-allocated"); 275 276 /* 277 * first calculate the number of free pages... 278 * 279 * note that we use start/end rather than avail_start/avail_end. 280 * this allows us to allocate extra vm_page structures in case we 281 * want to return some memory to the pool after booting. 282 */ 283 284 freepages = 0; 285 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 286 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 287 288 /* 289 * Let MD code initialize the number of colors, or default 290 * to 1 color if MD code doesn't care. 291 */ 292 if (uvmexp.ncolors == 0) 293 uvmexp.ncolors = 1; 294 uvmexp.colormask = uvmexp.ncolors - 1; 295 296 /* 297 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 298 * use. for each page of memory we use we need a vm_page structure. 299 * thus, the total number of pages we can use is the total size of 300 * the memory divided by the PAGE_SIZE plus the size of the vm_page 301 * structure. we add one to freepages as a fudge factor to avoid 302 * truncation errors (since we can only allocate in terms of whole 303 * pages). 304 */ 305 306 bucketcount = uvmexp.ncolors * VM_NFREELIST; 307 pagecount = ((freepages + 1) << PAGE_SHIFT) / 308 (PAGE_SIZE + sizeof(struct vm_page)); 309 310 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 311 sizeof(struct pgflbucket)) + (pagecount * 312 sizeof(struct vm_page))); 313 pagearray = (struct vm_page *)(bucketarray + bucketcount); 314 315 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 316 uvm.page_free[lcv].pgfl_buckets = 317 (bucketarray + (lcv * uvmexp.ncolors)); 318 uvm_page_init_buckets(&uvm.page_free[lcv]); 319 } 320 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 321 322 /* 323 * init the vm_page structures and put them in the correct place. 324 */ 325 326 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 327 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 328 329 /* set up page array pointers */ 330 vm_physmem[lcv].pgs = pagearray; 331 pagearray += n; 332 pagecount -= n; 333 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 334 335 /* init and free vm_pages (we've already zeroed them) */ 336 paddr = ptoa(vm_physmem[lcv].start); 337 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 338 vm_physmem[lcv].pgs[i].phys_addr = paddr; 339 #ifdef __HAVE_VM_PAGE_MD 340 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 341 #endif 342 if (atop(paddr) >= vm_physmem[lcv].avail_start && 343 atop(paddr) <= vm_physmem[lcv].avail_end) { 344 uvmexp.npages++; 345 /* add page to free pool */ 346 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 347 } 348 } 349 } 350 351 /* 352 * pass up the values of virtual_space_start and 353 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 354 * layers of the VM. 355 */ 356 357 *kvm_startp = round_page(virtual_space_start); 358 *kvm_endp = trunc_page(virtual_space_end); 359 360 /* 361 * init locks for kernel threads 362 */ 363 364 simple_lock_init(&uvm.pagedaemon_lock); 365 simple_lock_init(&uvm.aiodoned_lock); 366 367 /* 368 * init various thresholds. 369 * XXXCDC - values may need adjusting 370 */ 371 372 uvmexp.reserve_pagedaemon = 1; 373 uvmexp.reserve_kernel = 5; 374 uvmexp.anonminpct = 10; 375 uvmexp.vnodeminpct = 10; 376 uvmexp.vtextminpct = 5; 377 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 378 uvmexp.vnodemin = uvmexp.vnodeminpct * 256 / 100; 379 uvmexp.vtextmin = uvmexp.vtextminpct * 256 / 100; 380 381 /* 382 * determine if we should zero pages in the idle loop. 383 */ 384 385 uvm.page_idle_zero = vm_page_zero_enable; 386 387 /* 388 * done! 389 */ 390 391 uvm.page_init_done = TRUE; 392 } 393 394 /* 395 * uvm_setpagesize: set the page size 396 * 397 * => sets page_shift and page_mask from uvmexp.pagesize. 398 */ 399 400 void 401 uvm_setpagesize() 402 { 403 if (uvmexp.pagesize == 0) 404 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 405 uvmexp.pagemask = uvmexp.pagesize - 1; 406 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 407 panic("uvm_setpagesize: page size not a power of two"); 408 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 409 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 410 break; 411 } 412 413 /* 414 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 415 */ 416 417 vaddr_t 418 uvm_pageboot_alloc(size) 419 vsize_t size; 420 { 421 static boolean_t initialized = FALSE; 422 vaddr_t addr; 423 #if !defined(PMAP_STEAL_MEMORY) 424 vaddr_t vaddr; 425 paddr_t paddr; 426 #endif 427 428 /* 429 * on first call to this function, initialize ourselves. 430 */ 431 if (initialized == FALSE) { 432 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 433 434 /* round it the way we like it */ 435 virtual_space_start = round_page(virtual_space_start); 436 virtual_space_end = trunc_page(virtual_space_end); 437 438 initialized = TRUE; 439 } 440 441 /* round to page size */ 442 size = round_page(size); 443 444 #if defined(PMAP_STEAL_MEMORY) 445 446 /* 447 * defer bootstrap allocation to MD code (it may want to allocate 448 * from a direct-mapped segment). pmap_steal_memory should adjust 449 * virtual_space_start/virtual_space_end if necessary. 450 */ 451 452 addr = pmap_steal_memory(size, &virtual_space_start, 453 &virtual_space_end); 454 455 return(addr); 456 457 #else /* !PMAP_STEAL_MEMORY */ 458 459 /* 460 * allocate virtual memory for this request 461 */ 462 if (virtual_space_start == virtual_space_end || 463 (virtual_space_end - virtual_space_start) < size) 464 panic("uvm_pageboot_alloc: out of virtual space"); 465 466 addr = virtual_space_start; 467 468 #ifdef PMAP_GROWKERNEL 469 /* 470 * If the kernel pmap can't map the requested space, 471 * then allocate more resources for it. 472 */ 473 if (uvm_maxkaddr < (addr + size)) { 474 uvm_maxkaddr = pmap_growkernel(addr + size); 475 if (uvm_maxkaddr < (addr + size)) 476 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 477 } 478 #endif 479 480 virtual_space_start += size; 481 482 /* 483 * allocate and mapin physical pages to back new virtual pages 484 */ 485 486 for (vaddr = round_page(addr) ; vaddr < addr + size ; 487 vaddr += PAGE_SIZE) { 488 489 if (!uvm_page_physget(&paddr)) 490 panic("uvm_pageboot_alloc: out of memory"); 491 492 /* 493 * Note this memory is no longer managed, so using 494 * pmap_kenter is safe. 495 */ 496 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 497 } 498 pmap_update(pmap_kernel()); 499 return(addr); 500 #endif /* PMAP_STEAL_MEMORY */ 501 } 502 503 #if !defined(PMAP_STEAL_MEMORY) 504 /* 505 * uvm_page_physget: "steal" one page from the vm_physmem structure. 506 * 507 * => attempt to allocate it off the end of a segment in which the "avail" 508 * values match the start/end values. if we can't do that, then we 509 * will advance both values (making them equal, and removing some 510 * vm_page structures from the non-avail area). 511 * => return false if out of memory. 512 */ 513 514 /* subroutine: try to allocate from memory chunks on the specified freelist */ 515 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 516 517 static boolean_t 518 uvm_page_physget_freelist(paddrp, freelist) 519 paddr_t *paddrp; 520 int freelist; 521 { 522 int lcv, x; 523 524 /* pass 1: try allocating from a matching end */ 525 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 526 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 527 #else 528 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 529 #endif 530 { 531 532 if (uvm.page_init_done == TRUE) 533 panic("uvm_page_physget: called _after_ bootstrap"); 534 535 if (vm_physmem[lcv].free_list != freelist) 536 continue; 537 538 /* try from front */ 539 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 540 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 541 *paddrp = ptoa(vm_physmem[lcv].avail_start); 542 vm_physmem[lcv].avail_start++; 543 vm_physmem[lcv].start++; 544 /* nothing left? nuke it */ 545 if (vm_physmem[lcv].avail_start == 546 vm_physmem[lcv].end) { 547 if (vm_nphysseg == 1) 548 panic("vum_page_physget: out of memory!"); 549 vm_nphysseg--; 550 for (x = lcv ; x < vm_nphysseg ; x++) 551 /* structure copy */ 552 vm_physmem[x] = vm_physmem[x+1]; 553 } 554 return (TRUE); 555 } 556 557 /* try from rear */ 558 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 559 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 560 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 561 vm_physmem[lcv].avail_end--; 562 vm_physmem[lcv].end--; 563 /* nothing left? nuke it */ 564 if (vm_physmem[lcv].avail_end == 565 vm_physmem[lcv].start) { 566 if (vm_nphysseg == 1) 567 panic("uvm_page_physget: out of memory!"); 568 vm_nphysseg--; 569 for (x = lcv ; x < vm_nphysseg ; x++) 570 /* structure copy */ 571 vm_physmem[x] = vm_physmem[x+1]; 572 } 573 return (TRUE); 574 } 575 } 576 577 /* pass2: forget about matching ends, just allocate something */ 578 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 579 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 580 #else 581 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 582 #endif 583 { 584 585 /* any room in this bank? */ 586 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 587 continue; /* nope */ 588 589 *paddrp = ptoa(vm_physmem[lcv].avail_start); 590 vm_physmem[lcv].avail_start++; 591 /* truncate! */ 592 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 593 594 /* nothing left? nuke it */ 595 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 596 if (vm_nphysseg == 1) 597 panic("uvm_page_physget: out of memory!"); 598 vm_nphysseg--; 599 for (x = lcv ; x < vm_nphysseg ; x++) 600 /* structure copy */ 601 vm_physmem[x] = vm_physmem[x+1]; 602 } 603 return (TRUE); 604 } 605 606 return (FALSE); /* whoops! */ 607 } 608 609 boolean_t 610 uvm_page_physget(paddrp) 611 paddr_t *paddrp; 612 { 613 int i; 614 615 /* try in the order of freelist preference */ 616 for (i = 0; i < VM_NFREELIST; i++) 617 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 618 return (TRUE); 619 return (FALSE); 620 } 621 #endif /* PMAP_STEAL_MEMORY */ 622 623 /* 624 * uvm_page_physload: load physical memory into VM system 625 * 626 * => all args are PFs 627 * => all pages in start/end get vm_page structures 628 * => areas marked by avail_start/avail_end get added to the free page pool 629 * => we are limited to VM_PHYSSEG_MAX physical memory segments 630 */ 631 632 void 633 uvm_page_physload(start, end, avail_start, avail_end, free_list) 634 paddr_t start, end, avail_start, avail_end; 635 int free_list; 636 { 637 int preload, lcv; 638 psize_t npages; 639 struct vm_page *pgs; 640 struct vm_physseg *ps; 641 642 if (uvmexp.pagesize == 0) 643 panic("uvm_page_physload: page size not set!"); 644 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 645 panic("uvm_page_physload: bad free list %d\n", free_list); 646 if (start >= end) 647 panic("uvm_page_physload: start >= end"); 648 649 /* 650 * do we have room? 651 */ 652 653 if (vm_nphysseg == VM_PHYSSEG_MAX) { 654 printf("uvm_page_physload: unable to load physical memory " 655 "segment\n"); 656 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 657 VM_PHYSSEG_MAX, (long long)start, (long long)end); 658 printf("\tincrease VM_PHYSSEG_MAX\n"); 659 return; 660 } 661 662 /* 663 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 664 * called yet, so malloc is not available). 665 */ 666 667 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 668 if (vm_physmem[lcv].pgs) 669 break; 670 } 671 preload = (lcv == vm_nphysseg); 672 673 /* 674 * if VM is already running, attempt to malloc() vm_page structures 675 */ 676 677 if (!preload) { 678 #if defined(VM_PHYSSEG_NOADD) 679 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 680 #else 681 /* XXXCDC: need some sort of lockout for this case */ 682 paddr_t paddr; 683 npages = end - start; /* # of pages */ 684 pgs = malloc(sizeof(struct vm_page) * npages, 685 M_VMPAGE, M_NOWAIT); 686 if (pgs == NULL) { 687 printf("uvm_page_physload: can not malloc vm_page " 688 "structs for segment\n"); 689 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 690 return; 691 } 692 /* zero data, init phys_addr and free_list, and free pages */ 693 memset(pgs, 0, sizeof(struct vm_page) * npages); 694 for (lcv = 0, paddr = ptoa(start) ; 695 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 696 pgs[lcv].phys_addr = paddr; 697 pgs[lcv].free_list = free_list; 698 if (atop(paddr) >= avail_start && 699 atop(paddr) <= avail_end) 700 uvm_pagefree(&pgs[lcv]); 701 } 702 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 703 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 704 #endif 705 } else { 706 pgs = NULL; 707 npages = 0; 708 } 709 710 /* 711 * now insert us in the proper place in vm_physmem[] 712 */ 713 714 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 715 /* random: put it at the end (easy!) */ 716 ps = &vm_physmem[vm_nphysseg]; 717 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 718 { 719 int x; 720 /* sort by address for binary search */ 721 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 722 if (start < vm_physmem[lcv].start) 723 break; 724 ps = &vm_physmem[lcv]; 725 /* move back other entries, if necessary ... */ 726 for (x = vm_nphysseg ; x > lcv ; x--) 727 /* structure copy */ 728 vm_physmem[x] = vm_physmem[x - 1]; 729 } 730 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 731 { 732 int x; 733 /* sort by largest segment first */ 734 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 735 if ((end - start) > 736 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 737 break; 738 ps = &vm_physmem[lcv]; 739 /* move back other entries, if necessary ... */ 740 for (x = vm_nphysseg ; x > lcv ; x--) 741 /* structure copy */ 742 vm_physmem[x] = vm_physmem[x - 1]; 743 } 744 #else 745 panic("uvm_page_physload: unknown physseg strategy selected!"); 746 #endif 747 748 ps->start = start; 749 ps->end = end; 750 ps->avail_start = avail_start; 751 ps->avail_end = avail_end; 752 if (preload) { 753 ps->pgs = NULL; 754 } else { 755 ps->pgs = pgs; 756 ps->lastpg = pgs + npages - 1; 757 } 758 ps->free_list = free_list; 759 vm_nphysseg++; 760 761 if (!preload) 762 uvm_page_rehash(); 763 } 764 765 /* 766 * uvm_page_rehash: reallocate hash table based on number of free pages. 767 */ 768 769 void 770 uvm_page_rehash() 771 { 772 int freepages, lcv, bucketcount, oldcount; 773 struct pglist *newbuckets, *oldbuckets; 774 struct vm_page *pg; 775 size_t newsize, oldsize; 776 777 /* 778 * compute number of pages that can go in the free pool 779 */ 780 781 freepages = 0; 782 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 783 freepages += 784 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 785 786 /* 787 * compute number of buckets needed for this number of pages 788 */ 789 790 bucketcount = 1; 791 while (bucketcount < freepages) 792 bucketcount = bucketcount * 2; 793 794 /* 795 * compute the size of the current table and new table. 796 */ 797 798 oldbuckets = uvm.page_hash; 799 oldcount = uvm.page_nhash; 800 oldsize = round_page(sizeof(struct pglist) * oldcount); 801 newsize = round_page(sizeof(struct pglist) * bucketcount); 802 803 /* 804 * allocate the new buckets 805 */ 806 807 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 808 if (newbuckets == NULL) { 809 printf("uvm_page_physrehash: WARNING: could not grow page " 810 "hash table\n"); 811 return; 812 } 813 for (lcv = 0 ; lcv < bucketcount ; lcv++) 814 TAILQ_INIT(&newbuckets[lcv]); 815 816 /* 817 * now replace the old buckets with the new ones and rehash everything 818 */ 819 820 simple_lock(&uvm.hashlock); 821 uvm.page_hash = newbuckets; 822 uvm.page_nhash = bucketcount; 823 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 824 825 /* ... and rehash */ 826 for (lcv = 0 ; lcv < oldcount ; lcv++) { 827 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 828 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 829 TAILQ_INSERT_TAIL( 830 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 831 pg, hashq); 832 } 833 } 834 simple_unlock(&uvm.hashlock); 835 836 /* 837 * free old bucket array if is not the boot-time table 838 */ 839 840 if (oldbuckets != &uvm_bootbucket) 841 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 842 } 843 844 /* 845 * uvm_page_recolor: Recolor the pages if the new bucket count is 846 * larger than the old one. 847 */ 848 849 void 850 uvm_page_recolor(int newncolors) 851 { 852 struct pgflbucket *bucketarray, *oldbucketarray; 853 struct pgfreelist pgfl; 854 struct vm_page *pg; 855 vsize_t bucketcount; 856 int s, lcv, color, i, ocolors; 857 858 if (newncolors <= uvmexp.ncolors) 859 return; 860 861 bucketcount = newncolors * VM_NFREELIST; 862 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 863 M_VMPAGE, M_NOWAIT); 864 if (bucketarray == NULL) { 865 printf("WARNING: unable to allocate %ld page color buckets\n", 866 (long) bucketcount); 867 return; 868 } 869 870 s = uvm_lock_fpageq(); 871 872 /* Make sure we should still do this. */ 873 if (newncolors <= uvmexp.ncolors) { 874 uvm_unlock_fpageq(s); 875 free(bucketarray, M_VMPAGE); 876 return; 877 } 878 879 oldbucketarray = uvm.page_free[0].pgfl_buckets; 880 ocolors = uvmexp.ncolors; 881 882 uvmexp.ncolors = newncolors; 883 uvmexp.colormask = uvmexp.ncolors - 1; 884 885 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 886 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 887 uvm_page_init_buckets(&pgfl); 888 for (color = 0; color < ocolors; color++) { 889 for (i = 0; i < PGFL_NQUEUES; i++) { 890 while ((pg = TAILQ_FIRST(&uvm.page_free[ 891 lcv].pgfl_buckets[color].pgfl_queues[i])) 892 != NULL) { 893 TAILQ_REMOVE(&uvm.page_free[ 894 lcv].pgfl_buckets[ 895 color].pgfl_queues[i], pg, pageq); 896 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 897 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 898 i], pg, pageq); 899 } 900 } 901 } 902 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 903 } 904 905 if (have_recolored_pages) { 906 uvm_unlock_fpageq(s); 907 free(oldbucketarray, M_VMPAGE); 908 return; 909 } 910 911 have_recolored_pages = TRUE; 912 uvm_unlock_fpageq(s); 913 } 914 915 /* 916 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 917 */ 918 919 static __inline struct vm_page * 920 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 921 unsigned int *trycolorp) 922 { 923 struct pglist *freeq; 924 struct vm_page *pg; 925 int color, trycolor = *trycolorp; 926 927 color = trycolor; 928 do { 929 if ((pg = TAILQ_FIRST((freeq = 930 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 931 goto gotit; 932 if ((pg = TAILQ_FIRST((freeq = 933 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 934 goto gotit; 935 color = (color + 1) & uvmexp.colormask; 936 } while (color != trycolor); 937 938 return (NULL); 939 940 gotit: 941 TAILQ_REMOVE(freeq, pg, pageq); 942 uvmexp.free--; 943 944 /* update zero'd page count */ 945 if (pg->flags & PG_ZERO) 946 uvmexp.zeropages--; 947 948 if (color == trycolor) 949 uvmexp.colorhit++; 950 else { 951 uvmexp.colormiss++; 952 *trycolorp = color; 953 } 954 955 return (pg); 956 } 957 958 /* 959 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 960 * 961 * => return null if no pages free 962 * => wake up pagedaemon if number of free pages drops below low water mark 963 * => if obj != NULL, obj must be locked (to put in hash) 964 * => if anon != NULL, anon must be locked (to put in anon) 965 * => only one of obj or anon can be non-null 966 * => caller must activate/deactivate page if it is not wired. 967 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 968 * => policy decision: it is more important to pull a page off of the 969 * appropriate priority free list than it is to get a zero'd or 970 * unknown contents page. This is because we live with the 971 * consequences of a bad free list decision for the entire 972 * lifetime of the page, e.g. if the page comes from memory that 973 * is slower to access. 974 */ 975 976 struct vm_page * 977 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 978 struct uvm_object *obj; 979 voff_t off; 980 int flags; 981 struct vm_anon *anon; 982 int strat, free_list; 983 { 984 int lcv, try1, try2, s, zeroit = 0, color; 985 struct vm_page *pg; 986 boolean_t use_reserve; 987 988 KASSERT(obj == NULL || anon == NULL); 989 KASSERT(off == trunc_page(off)); 990 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 991 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 992 993 s = uvm_lock_fpageq(); 994 995 /* 996 * This implements a global round-robin page coloring 997 * algorithm. 998 * 999 * XXXJRT: Should we make the `nextcolor' per-cpu? 1000 * XXXJRT: What about virtually-indexed caches? 1001 */ 1002 1003 color = uvm.page_free_nextcolor; 1004 1005 /* 1006 * check to see if we need to generate some free pages waking 1007 * the pagedaemon. 1008 */ 1009 1010 UVM_KICK_PDAEMON(); 1011 1012 /* 1013 * fail if any of these conditions is true: 1014 * [1] there really are no free pages, or 1015 * [2] only kernel "reserved" pages remain and 1016 * the page isn't being allocated to a kernel object. 1017 * [3] only pagedaemon "reserved" pages remain and 1018 * the requestor isn't the pagedaemon. 1019 */ 1020 1021 use_reserve = (flags & UVM_PGA_USERESERVE) || 1022 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1023 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1024 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1025 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1026 goto fail; 1027 1028 #if PGFL_NQUEUES != 2 1029 #error uvm_pagealloc_strat needs to be updated 1030 #endif 1031 1032 /* 1033 * If we want a zero'd page, try the ZEROS queue first, otherwise 1034 * we try the UNKNOWN queue first. 1035 */ 1036 if (flags & UVM_PGA_ZERO) { 1037 try1 = PGFL_ZEROS; 1038 try2 = PGFL_UNKNOWN; 1039 } else { 1040 try1 = PGFL_UNKNOWN; 1041 try2 = PGFL_ZEROS; 1042 } 1043 1044 again: 1045 switch (strat) { 1046 case UVM_PGA_STRAT_NORMAL: 1047 /* Check all freelists in descending priority order. */ 1048 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1049 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1050 try1, try2, &color); 1051 if (pg != NULL) 1052 goto gotit; 1053 } 1054 1055 /* No pages free! */ 1056 goto fail; 1057 1058 case UVM_PGA_STRAT_ONLY: 1059 case UVM_PGA_STRAT_FALLBACK: 1060 /* Attempt to allocate from the specified free list. */ 1061 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1062 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1063 try1, try2, &color); 1064 if (pg != NULL) 1065 goto gotit; 1066 1067 /* Fall back, if possible. */ 1068 if (strat == UVM_PGA_STRAT_FALLBACK) { 1069 strat = UVM_PGA_STRAT_NORMAL; 1070 goto again; 1071 } 1072 1073 /* No pages free! */ 1074 goto fail; 1075 1076 default: 1077 panic("uvm_pagealloc_strat: bad strat %d", strat); 1078 /* NOTREACHED */ 1079 } 1080 1081 gotit: 1082 /* 1083 * We now know which color we actually allocated from; set 1084 * the next color accordingly. 1085 */ 1086 1087 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1088 1089 /* 1090 * update allocation statistics and remember if we have to 1091 * zero the page 1092 */ 1093 1094 if (flags & UVM_PGA_ZERO) { 1095 if (pg->flags & PG_ZERO) { 1096 uvmexp.pga_zerohit++; 1097 zeroit = 0; 1098 } else { 1099 uvmexp.pga_zeromiss++; 1100 zeroit = 1; 1101 } 1102 } 1103 uvm_unlock_fpageq(s); 1104 1105 pg->offset = off; 1106 pg->uobject = obj; 1107 pg->uanon = anon; 1108 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1109 if (anon) { 1110 anon->u.an_page = pg; 1111 pg->pqflags = PQ_ANON; 1112 uvmexp.anonpages++; 1113 } else { 1114 if (obj) { 1115 uvm_pageinsert(pg); 1116 } 1117 pg->pqflags = 0; 1118 } 1119 #if defined(UVM_PAGE_TRKOWN) 1120 pg->owner_tag = NULL; 1121 #endif 1122 UVM_PAGE_OWN(pg, "new alloc"); 1123 1124 if (flags & UVM_PGA_ZERO) { 1125 /* 1126 * A zero'd page is not clean. If we got a page not already 1127 * zero'd, then we have to zero it ourselves. 1128 */ 1129 pg->flags &= ~PG_CLEAN; 1130 if (zeroit) 1131 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1132 } 1133 1134 return(pg); 1135 1136 fail: 1137 uvm_unlock_fpageq(s); 1138 return (NULL); 1139 } 1140 1141 /* 1142 * uvm_pagerealloc: reallocate a page from one object to another 1143 * 1144 * => both objects must be locked 1145 */ 1146 1147 void 1148 uvm_pagerealloc(pg, newobj, newoff) 1149 struct vm_page *pg; 1150 struct uvm_object *newobj; 1151 voff_t newoff; 1152 { 1153 /* 1154 * remove it from the old object 1155 */ 1156 1157 if (pg->uobject) { 1158 uvm_pageremove(pg); 1159 } 1160 1161 /* 1162 * put it in the new object 1163 */ 1164 1165 if (newobj) { 1166 pg->uobject = newobj; 1167 pg->offset = newoff; 1168 uvm_pageinsert(pg); 1169 } 1170 } 1171 1172 /* 1173 * uvm_pagefree: free page 1174 * 1175 * => erase page's identity (i.e. remove from hash/object) 1176 * => put page on free list 1177 * => caller must lock owning object (either anon or uvm_object) 1178 * => caller must lock page queues 1179 * => assumes all valid mappings of pg are gone 1180 */ 1181 1182 void 1183 uvm_pagefree(pg) 1184 struct vm_page *pg; 1185 { 1186 int s; 1187 1188 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1189 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1190 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1191 1192 #ifdef DEBUG 1193 if (pg->uobject == (void *)0xdeadbeef && 1194 pg->uanon == (void *)0xdeadbeef) { 1195 panic("uvm_pagefree: freeing free page %p\n", pg); 1196 } 1197 #endif 1198 1199 /* 1200 * if the page is loaned, resolve the loan instead of freeing. 1201 */ 1202 1203 if (pg->loan_count) { 1204 1205 /* 1206 * if the page is owned by an anon then we just want to 1207 * drop ownership and return. the kernel will free the page 1208 * when it is done with it. if the page is owned by an object, 1209 * mark it clean for the benefit of possible anon owners 1210 * and mark it as anon-owned if there current anon loanees. 1211 */ 1212 1213 if (pg->pqflags & PQ_ANON) { 1214 pg->pqflags &= ~PQ_ANON; 1215 pg->uanon = NULL; 1216 } else if (pg->flags & PG_TABLED) { 1217 pg->flags &= ~PG_CLEAN; 1218 if (pg->uanon) { 1219 pg->pqflags |= PQ_ANON; 1220 } 1221 } 1222 return; 1223 } 1224 1225 /* 1226 * remove page from its object or anon. 1227 * adjust swpgonly if the page is swap-backed. 1228 */ 1229 1230 if (pg->flags & PG_TABLED) { 1231 if (pg->pqflags & PQ_AOBJ && 1232 uao_find_swslot(pg->uobject, 1233 pg->offset >> PAGE_SHIFT) != 0) { 1234 simple_lock(&uvm.swap_data_lock); 1235 uvmexp.swpgonly++; 1236 simple_unlock(&uvm.swap_data_lock); 1237 } 1238 uvm_pageremove(pg); 1239 } else if (pg->pqflags & PQ_ANON) { 1240 if (pg->uanon->an_swslot) { 1241 simple_lock(&uvm.swap_data_lock); 1242 uvmexp.swpgonly++; 1243 simple_unlock(&uvm.swap_data_lock); 1244 } 1245 pg->uanon->u.an_page = NULL; 1246 } 1247 1248 /* 1249 * now remove the page from the queues 1250 */ 1251 1252 uvm_pagedequeue(pg); 1253 1254 /* 1255 * if the page was wired, unwire it now. 1256 */ 1257 1258 if (pg->wire_count) { 1259 pg->wire_count = 0; 1260 uvmexp.wired--; 1261 } 1262 if (pg->pqflags & PQ_ANON) { 1263 uvmexp.anonpages--; 1264 } 1265 1266 /* 1267 * and put on free queue 1268 */ 1269 1270 pg->flags &= ~PG_ZERO; 1271 1272 s = uvm_lock_fpageq(); 1273 TAILQ_INSERT_TAIL(&uvm.page_free[ 1274 uvm_page_lookup_freelist(pg)].pgfl_buckets[ 1275 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1276 pg->pqflags = PQ_FREE; 1277 #ifdef DEBUG 1278 pg->uobject = (void *)0xdeadbeef; 1279 pg->offset = 0xdeadbeef; 1280 pg->uanon = (void *)0xdeadbeef; 1281 #endif 1282 uvmexp.free++; 1283 1284 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1285 uvm.page_idle_zero = vm_page_zero_enable; 1286 1287 uvm_unlock_fpageq(s); 1288 } 1289 1290 /* 1291 * uvm_page_unbusy: unbusy an array of pages. 1292 * 1293 * => pages must either all belong to the same object, or all belong to anons. 1294 * => if pages are object-owned, object must be locked. 1295 * => if pages are anon-owned, anons must be locked. 1296 */ 1297 1298 void 1299 uvm_page_unbusy(pgs, npgs) 1300 struct vm_page **pgs; 1301 int npgs; 1302 { 1303 struct vm_page *pg; 1304 int i; 1305 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1306 1307 for (i = 0; i < npgs; i++) { 1308 pg = pgs[i]; 1309 if (pg == NULL) { 1310 continue; 1311 } 1312 if (pg->flags & PG_WANTED) { 1313 wakeup(pg); 1314 } 1315 if (pg->flags & PG_RELEASED) { 1316 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1317 pg->flags &= ~PG_RELEASED; 1318 uvm_pagefree(pg); 1319 } else { 1320 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1321 pg->flags &= ~(PG_WANTED|PG_BUSY); 1322 UVM_PAGE_OWN(pg, NULL); 1323 } 1324 } 1325 } 1326 1327 #if defined(UVM_PAGE_TRKOWN) 1328 /* 1329 * uvm_page_own: set or release page ownership 1330 * 1331 * => this is a debugging function that keeps track of who sets PG_BUSY 1332 * and where they do it. it can be used to track down problems 1333 * such a process setting "PG_BUSY" and never releasing it. 1334 * => page's object [if any] must be locked 1335 * => if "tag" is NULL then we are releasing page ownership 1336 */ 1337 void 1338 uvm_page_own(pg, tag) 1339 struct vm_page *pg; 1340 char *tag; 1341 { 1342 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1343 1344 /* gain ownership? */ 1345 if (tag) { 1346 if (pg->owner_tag) { 1347 printf("uvm_page_own: page %p already owned " 1348 "by proc %d [%s]\n", pg, 1349 pg->owner, pg->owner_tag); 1350 panic("uvm_page_own"); 1351 } 1352 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1353 pg->owner_tag = tag; 1354 return; 1355 } 1356 1357 /* drop ownership */ 1358 if (pg->owner_tag == NULL) { 1359 printf("uvm_page_own: dropping ownership of an non-owned " 1360 "page (%p)\n", pg); 1361 panic("uvm_page_own"); 1362 } 1363 pg->owner_tag = NULL; 1364 KASSERT((pg->uanon == NULL && pg->uobject == NULL) || 1365 pg->uobject == uvm.kernel_object || 1366 pg->wire_count || (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE))); 1367 return; 1368 } 1369 #endif 1370 1371 /* 1372 * uvm_pageidlezero: zero free pages while the system is idle. 1373 * 1374 * => try to complete one color bucket at a time, to reduce our impact 1375 * on the CPU cache. 1376 * => we loop until we either reach the target or whichqs indicates that 1377 * there is a process ready to run. 1378 */ 1379 void 1380 uvm_pageidlezero() 1381 { 1382 struct vm_page *pg; 1383 struct pgfreelist *pgfl; 1384 int free_list, s, firstbucket; 1385 static int nextbucket; 1386 1387 s = uvm_lock_fpageq(); 1388 firstbucket = nextbucket; 1389 do { 1390 if (sched_whichqs != 0) { 1391 uvm_unlock_fpageq(s); 1392 return; 1393 } 1394 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1395 uvm.page_idle_zero = FALSE; 1396 uvm_unlock_fpageq(s); 1397 return; 1398 } 1399 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1400 pgfl = &uvm.page_free[free_list]; 1401 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1402 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1403 if (sched_whichqs != 0) { 1404 uvm_unlock_fpageq(s); 1405 return; 1406 } 1407 1408 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1409 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1410 pg, pageq); 1411 uvmexp.free--; 1412 uvm_unlock_fpageq(s); 1413 #ifdef PMAP_PAGEIDLEZERO 1414 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1415 1416 /* 1417 * The machine-dependent code detected 1418 * some reason for us to abort zeroing 1419 * pages, probably because there is a 1420 * process now ready to run. 1421 */ 1422 1423 s = uvm_lock_fpageq(); 1424 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1425 nextbucket].pgfl_queues[ 1426 PGFL_UNKNOWN], pg, pageq); 1427 uvmexp.free++; 1428 uvmexp.zeroaborts++; 1429 uvm_unlock_fpageq(s); 1430 return; 1431 } 1432 #else 1433 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1434 #endif /* PMAP_PAGEIDLEZERO */ 1435 pg->flags |= PG_ZERO; 1436 1437 s = uvm_lock_fpageq(); 1438 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1439 nextbucket].pgfl_queues[PGFL_ZEROS], 1440 pg, pageq); 1441 uvmexp.free++; 1442 uvmexp.zeropages++; 1443 } 1444 } 1445 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1446 } while (nextbucket != firstbucket); 1447 uvm_unlock_fpageq(s); 1448 } 1449