1 /* $NetBSD: uvm_page.c,v 1.73 2001/12/31 19:21:37 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 <sys/cdefs.h> 74 __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.73 2001/12/31 19:21:37 chs Exp $"); 75 76 #include "opt_uvmhist.h" 77 78 #include <sys/param.h> 79 #include <sys/systm.h> 80 #include <sys/malloc.h> 81 #include <sys/sched.h> 82 #include <sys/kernel.h> 83 #include <sys/vnode.h> 84 #include <sys/proc.h> 85 86 #define UVM_PAGE /* pull in uvm_page.h functions */ 87 #include <uvm/uvm.h> 88 89 /* 90 * global vars... XXXCDC: move to uvm. structure. 91 */ 92 93 /* 94 * physical memory config is stored in vm_physmem. 95 */ 96 97 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 98 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 99 100 /* 101 * Some supported CPUs in a given architecture don't support all 102 * of the things necessary to do idle page zero'ing efficiently. 103 * We therefore provide a way to disable it from machdep code here. 104 */ 105 /* 106 * XXX disabled until we can find a way to do this without causing 107 * problems for either cpu caches or DMA latency. 108 */ 109 boolean_t vm_page_zero_enable = FALSE; 110 111 /* 112 * local variables 113 */ 114 115 /* 116 * these variables record the values returned by vm_page_bootstrap, 117 * for debugging purposes. The implementation of uvm_pageboot_alloc 118 * and pmap_startup here also uses them internally. 119 */ 120 121 static vaddr_t virtual_space_start; 122 static vaddr_t virtual_space_end; 123 124 /* 125 * we use a hash table with only one bucket during bootup. we will 126 * later rehash (resize) the hash table once the allocator is ready. 127 * we static allocate the one bootstrap bucket below... 128 */ 129 130 static struct pglist uvm_bootbucket; 131 132 /* 133 * we allocate an initial number of page colors in uvm_page_init(), 134 * and remember them. We may re-color pages as cache sizes are 135 * discovered during the autoconfiguration phase. But we can never 136 * free the initial set of buckets, since they are allocated using 137 * uvm_pageboot_alloc(). 138 */ 139 140 static boolean_t have_recolored_pages /* = FALSE */; 141 142 /* 143 * local prototypes 144 */ 145 146 static void uvm_pageinsert __P((struct vm_page *)); 147 static void uvm_pageremove __P((struct vm_page *)); 148 149 /* 150 * inline functions 151 */ 152 153 /* 154 * uvm_pageinsert: insert a page in the object and the hash table 155 * 156 * => caller must lock object 157 * => caller must lock page queues 158 * => call should have already set pg's object and offset pointers 159 * and bumped the version counter 160 */ 161 162 __inline static void 163 uvm_pageinsert(pg) 164 struct vm_page *pg; 165 { 166 struct pglist *buck; 167 struct uvm_object *uobj = pg->uobject; 168 169 KASSERT((pg->flags & PG_TABLED) == 0); 170 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 171 simple_lock(&uvm.hashlock); 172 TAILQ_INSERT_TAIL(buck, pg, hashq); 173 simple_unlock(&uvm.hashlock); 174 175 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 176 pg->flags |= PG_TABLED; 177 uobj->uo_npages++; 178 } 179 180 /* 181 * uvm_page_remove: remove page from object and hash 182 * 183 * => caller must lock object 184 * => caller must lock page queues 185 */ 186 187 static __inline void 188 uvm_pageremove(pg) 189 struct vm_page *pg; 190 { 191 struct pglist *buck; 192 struct uvm_object *uobj = pg->uobject; 193 194 KASSERT(pg->flags & PG_TABLED); 195 buck = &uvm.page_hash[uvm_pagehash(uobj ,pg->offset)]; 196 simple_lock(&uvm.hashlock); 197 TAILQ_REMOVE(buck, pg, hashq); 198 simple_unlock(&uvm.hashlock); 199 200 if (UVM_OBJ_IS_VTEXT(uobj)) { 201 uvmexp.execpages--; 202 } else if (UVM_OBJ_IS_VNODE(uobj)) { 203 uvmexp.filepages--; 204 } 205 206 /* object should be locked */ 207 uobj->uo_npages--; 208 TAILQ_REMOVE(&uobj->memq, pg, listq); 209 pg->flags &= ~PG_TABLED; 210 pg->uobject = NULL; 211 } 212 213 static void 214 uvm_page_init_buckets(struct pgfreelist *pgfl) 215 { 216 int color, i; 217 218 for (color = 0; color < uvmexp.ncolors; color++) { 219 for (i = 0; i < PGFL_NQUEUES; i++) { 220 TAILQ_INIT(&pgfl->pgfl_buckets[ 221 color].pgfl_queues[i]); 222 } 223 } 224 } 225 226 /* 227 * uvm_page_init: init the page system. called from uvm_init(). 228 * 229 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 230 */ 231 232 void 233 uvm_page_init(kvm_startp, kvm_endp) 234 vaddr_t *kvm_startp, *kvm_endp; 235 { 236 vsize_t freepages, pagecount, bucketcount, n; 237 struct pgflbucket *bucketarray; 238 struct vm_page *pagearray; 239 int lcv, i; 240 paddr_t paddr; 241 242 /* 243 * init the page queues and page queue locks, except the free 244 * list; we allocate that later (with the initial vm_page 245 * structures). 246 */ 247 248 TAILQ_INIT(&uvm.page_active); 249 TAILQ_INIT(&uvm.page_inactive); 250 simple_lock_init(&uvm.pageqlock); 251 simple_lock_init(&uvm.fpageqlock); 252 253 /* 254 * init the <obj,offset> => <page> hash table. for now 255 * we just have one bucket (the bootstrap bucket). later on we 256 * will allocate new buckets as we dynamically resize the hash table. 257 */ 258 259 uvm.page_nhash = 1; /* 1 bucket */ 260 uvm.page_hashmask = 0; /* mask for hash function */ 261 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 262 TAILQ_INIT(uvm.page_hash); /* init hash table */ 263 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 264 265 /* 266 * allocate vm_page structures. 267 */ 268 269 /* 270 * sanity check: 271 * before calling this function the MD code is expected to register 272 * some free RAM with the uvm_page_physload() function. our job 273 * now is to allocate vm_page structures for this memory. 274 */ 275 276 if (vm_nphysseg == 0) 277 panic("uvm_page_bootstrap: no memory pre-allocated"); 278 279 /* 280 * first calculate the number of free pages... 281 * 282 * note that we use start/end rather than avail_start/avail_end. 283 * this allows us to allocate extra vm_page structures in case we 284 * want to return some memory to the pool after booting. 285 */ 286 287 freepages = 0; 288 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 289 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 290 291 /* 292 * Let MD code initialize the number of colors, or default 293 * to 1 color if MD code doesn't care. 294 */ 295 if (uvmexp.ncolors == 0) 296 uvmexp.ncolors = 1; 297 uvmexp.colormask = uvmexp.ncolors - 1; 298 299 /* 300 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 301 * use. for each page of memory we use we need a vm_page structure. 302 * thus, the total number of pages we can use is the total size of 303 * the memory divided by the PAGE_SIZE plus the size of the vm_page 304 * structure. we add one to freepages as a fudge factor to avoid 305 * truncation errors (since we can only allocate in terms of whole 306 * pages). 307 */ 308 309 bucketcount = uvmexp.ncolors * VM_NFREELIST; 310 pagecount = ((freepages + 1) << PAGE_SHIFT) / 311 (PAGE_SIZE + sizeof(struct vm_page)); 312 313 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 314 sizeof(struct pgflbucket)) + (pagecount * 315 sizeof(struct vm_page))); 316 pagearray = (struct vm_page *)(bucketarray + bucketcount); 317 318 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 319 uvm.page_free[lcv].pgfl_buckets = 320 (bucketarray + (lcv * uvmexp.ncolors)); 321 uvm_page_init_buckets(&uvm.page_free[lcv]); 322 } 323 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 324 325 /* 326 * init the vm_page structures and put them in the correct place. 327 */ 328 329 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 330 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 331 332 /* set up page array pointers */ 333 vm_physmem[lcv].pgs = pagearray; 334 pagearray += n; 335 pagecount -= n; 336 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 337 338 /* init and free vm_pages (we've already zeroed them) */ 339 paddr = ptoa(vm_physmem[lcv].start); 340 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 341 vm_physmem[lcv].pgs[i].phys_addr = paddr; 342 #ifdef __HAVE_VM_PAGE_MD 343 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 344 #endif 345 if (atop(paddr) >= vm_physmem[lcv].avail_start && 346 atop(paddr) <= vm_physmem[lcv].avail_end) { 347 uvmexp.npages++; 348 /* add page to free pool */ 349 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 350 } 351 } 352 } 353 354 /* 355 * pass up the values of virtual_space_start and 356 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 357 * layers of the VM. 358 */ 359 360 *kvm_startp = round_page(virtual_space_start); 361 *kvm_endp = trunc_page(virtual_space_end); 362 363 /* 364 * init locks for kernel threads 365 */ 366 367 simple_lock_init(&uvm.pagedaemon_lock); 368 simple_lock_init(&uvm.aiodoned_lock); 369 370 /* 371 * init various thresholds. 372 */ 373 374 uvmexp.reserve_pagedaemon = 1; 375 uvmexp.reserve_kernel = 5; 376 uvmexp.anonminpct = 10; 377 uvmexp.fileminpct = 10; 378 uvmexp.execminpct = 5; 379 uvmexp.anonmaxpct = 80; 380 uvmexp.filemaxpct = 50; 381 uvmexp.execmaxpct = 30; 382 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 383 uvmexp.filemin = uvmexp.fileminpct * 256 / 100; 384 uvmexp.execmin = uvmexp.execminpct * 256 / 100; 385 uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; 386 uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; 387 uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; 388 389 /* 390 * determine if we should zero pages in the idle loop. 391 */ 392 393 uvm.page_idle_zero = vm_page_zero_enable; 394 395 /* 396 * done! 397 */ 398 399 uvm.page_init_done = TRUE; 400 } 401 402 /* 403 * uvm_setpagesize: set the page size 404 * 405 * => sets page_shift and page_mask from uvmexp.pagesize. 406 */ 407 408 void 409 uvm_setpagesize() 410 { 411 if (uvmexp.pagesize == 0) 412 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 413 uvmexp.pagemask = uvmexp.pagesize - 1; 414 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 415 panic("uvm_setpagesize: page size not a power of two"); 416 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 417 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 418 break; 419 } 420 421 /* 422 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 423 */ 424 425 vaddr_t 426 uvm_pageboot_alloc(size) 427 vsize_t size; 428 { 429 static boolean_t initialized = FALSE; 430 vaddr_t addr; 431 #if !defined(PMAP_STEAL_MEMORY) 432 vaddr_t vaddr; 433 paddr_t paddr; 434 #endif 435 436 /* 437 * on first call to this function, initialize ourselves. 438 */ 439 if (initialized == FALSE) { 440 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 441 442 /* round it the way we like it */ 443 virtual_space_start = round_page(virtual_space_start); 444 virtual_space_end = trunc_page(virtual_space_end); 445 446 initialized = TRUE; 447 } 448 449 /* round to page size */ 450 size = round_page(size); 451 452 #if defined(PMAP_STEAL_MEMORY) 453 454 /* 455 * defer bootstrap allocation to MD code (it may want to allocate 456 * from a direct-mapped segment). pmap_steal_memory should adjust 457 * virtual_space_start/virtual_space_end if necessary. 458 */ 459 460 addr = pmap_steal_memory(size, &virtual_space_start, 461 &virtual_space_end); 462 463 return(addr); 464 465 #else /* !PMAP_STEAL_MEMORY */ 466 467 /* 468 * allocate virtual memory for this request 469 */ 470 if (virtual_space_start == virtual_space_end || 471 (virtual_space_end - virtual_space_start) < size) 472 panic("uvm_pageboot_alloc: out of virtual space"); 473 474 addr = virtual_space_start; 475 476 #ifdef PMAP_GROWKERNEL 477 /* 478 * If the kernel pmap can't map the requested space, 479 * then allocate more resources for it. 480 */ 481 if (uvm_maxkaddr < (addr + size)) { 482 uvm_maxkaddr = pmap_growkernel(addr + size); 483 if (uvm_maxkaddr < (addr + size)) 484 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 485 } 486 #endif 487 488 virtual_space_start += size; 489 490 /* 491 * allocate and mapin physical pages to back new virtual pages 492 */ 493 494 for (vaddr = round_page(addr) ; vaddr < addr + size ; 495 vaddr += PAGE_SIZE) { 496 497 if (!uvm_page_physget(&paddr)) 498 panic("uvm_pageboot_alloc: out of memory"); 499 500 /* 501 * Note this memory is no longer managed, so using 502 * pmap_kenter is safe. 503 */ 504 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 505 } 506 pmap_update(pmap_kernel()); 507 return(addr); 508 #endif /* PMAP_STEAL_MEMORY */ 509 } 510 511 #if !defined(PMAP_STEAL_MEMORY) 512 /* 513 * uvm_page_physget: "steal" one page from the vm_physmem structure. 514 * 515 * => attempt to allocate it off the end of a segment in which the "avail" 516 * values match the start/end values. if we can't do that, then we 517 * will advance both values (making them equal, and removing some 518 * vm_page structures from the non-avail area). 519 * => return false if out of memory. 520 */ 521 522 /* subroutine: try to allocate from memory chunks on the specified freelist */ 523 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 524 525 static boolean_t 526 uvm_page_physget_freelist(paddrp, freelist) 527 paddr_t *paddrp; 528 int freelist; 529 { 530 int lcv, x; 531 532 /* pass 1: try allocating from a matching end */ 533 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 534 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 535 #else 536 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 537 #endif 538 { 539 540 if (uvm.page_init_done == TRUE) 541 panic("uvm_page_physget: called _after_ bootstrap"); 542 543 if (vm_physmem[lcv].free_list != freelist) 544 continue; 545 546 /* try from front */ 547 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 548 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 549 *paddrp = ptoa(vm_physmem[lcv].avail_start); 550 vm_physmem[lcv].avail_start++; 551 vm_physmem[lcv].start++; 552 /* nothing left? nuke it */ 553 if (vm_physmem[lcv].avail_start == 554 vm_physmem[lcv].end) { 555 if (vm_nphysseg == 1) 556 panic("vum_page_physget: out of memory!"); 557 vm_nphysseg--; 558 for (x = lcv ; x < vm_nphysseg ; x++) 559 /* structure copy */ 560 vm_physmem[x] = vm_physmem[x+1]; 561 } 562 return (TRUE); 563 } 564 565 /* try from rear */ 566 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 567 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 568 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 569 vm_physmem[lcv].avail_end--; 570 vm_physmem[lcv].end--; 571 /* nothing left? nuke it */ 572 if (vm_physmem[lcv].avail_end == 573 vm_physmem[lcv].start) { 574 if (vm_nphysseg == 1) 575 panic("uvm_page_physget: out of memory!"); 576 vm_nphysseg--; 577 for (x = lcv ; x < vm_nphysseg ; x++) 578 /* structure copy */ 579 vm_physmem[x] = vm_physmem[x+1]; 580 } 581 return (TRUE); 582 } 583 } 584 585 /* pass2: forget about matching ends, just allocate something */ 586 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 587 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 588 #else 589 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 590 #endif 591 { 592 593 /* any room in this bank? */ 594 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 595 continue; /* nope */ 596 597 *paddrp = ptoa(vm_physmem[lcv].avail_start); 598 vm_physmem[lcv].avail_start++; 599 /* truncate! */ 600 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 601 602 /* nothing left? nuke it */ 603 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 604 if (vm_nphysseg == 1) 605 panic("uvm_page_physget: out of memory!"); 606 vm_nphysseg--; 607 for (x = lcv ; x < vm_nphysseg ; x++) 608 /* structure copy */ 609 vm_physmem[x] = vm_physmem[x+1]; 610 } 611 return (TRUE); 612 } 613 614 return (FALSE); /* whoops! */ 615 } 616 617 boolean_t 618 uvm_page_physget(paddrp) 619 paddr_t *paddrp; 620 { 621 int i; 622 623 /* try in the order of freelist preference */ 624 for (i = 0; i < VM_NFREELIST; i++) 625 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 626 return (TRUE); 627 return (FALSE); 628 } 629 #endif /* PMAP_STEAL_MEMORY */ 630 631 /* 632 * uvm_page_physload: load physical memory into VM system 633 * 634 * => all args are PFs 635 * => all pages in start/end get vm_page structures 636 * => areas marked by avail_start/avail_end get added to the free page pool 637 * => we are limited to VM_PHYSSEG_MAX physical memory segments 638 */ 639 640 void 641 uvm_page_physload(start, end, avail_start, avail_end, free_list) 642 paddr_t start, end, avail_start, avail_end; 643 int free_list; 644 { 645 int preload, lcv; 646 psize_t npages; 647 struct vm_page *pgs; 648 struct vm_physseg *ps; 649 650 if (uvmexp.pagesize == 0) 651 panic("uvm_page_physload: page size not set!"); 652 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 653 panic("uvm_page_physload: bad free list %d\n", free_list); 654 if (start >= end) 655 panic("uvm_page_physload: start >= end"); 656 657 /* 658 * do we have room? 659 */ 660 661 if (vm_nphysseg == VM_PHYSSEG_MAX) { 662 printf("uvm_page_physload: unable to load physical memory " 663 "segment\n"); 664 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 665 VM_PHYSSEG_MAX, (long long)start, (long long)end); 666 printf("\tincrease VM_PHYSSEG_MAX\n"); 667 return; 668 } 669 670 /* 671 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 672 * called yet, so malloc is not available). 673 */ 674 675 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 676 if (vm_physmem[lcv].pgs) 677 break; 678 } 679 preload = (lcv == vm_nphysseg); 680 681 /* 682 * if VM is already running, attempt to malloc() vm_page structures 683 */ 684 685 if (!preload) { 686 #if defined(VM_PHYSSEG_NOADD) 687 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 688 #else 689 /* XXXCDC: need some sort of lockout for this case */ 690 paddr_t paddr; 691 npages = end - start; /* # of pages */ 692 pgs = malloc(sizeof(struct vm_page) * npages, 693 M_VMPAGE, M_NOWAIT); 694 if (pgs == NULL) { 695 printf("uvm_page_physload: can not malloc vm_page " 696 "structs for segment\n"); 697 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 698 return; 699 } 700 /* zero data, init phys_addr and free_list, and free pages */ 701 memset(pgs, 0, sizeof(struct vm_page) * npages); 702 for (lcv = 0, paddr = ptoa(start) ; 703 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 704 pgs[lcv].phys_addr = paddr; 705 pgs[lcv].free_list = free_list; 706 if (atop(paddr) >= avail_start && 707 atop(paddr) <= avail_end) 708 uvm_pagefree(&pgs[lcv]); 709 } 710 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 711 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 712 #endif 713 } else { 714 pgs = NULL; 715 npages = 0; 716 } 717 718 /* 719 * now insert us in the proper place in vm_physmem[] 720 */ 721 722 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 723 /* random: put it at the end (easy!) */ 724 ps = &vm_physmem[vm_nphysseg]; 725 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 726 { 727 int x; 728 /* sort by address for binary search */ 729 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 730 if (start < 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 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 739 { 740 int x; 741 /* sort by largest segment first */ 742 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 743 if ((end - start) > 744 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 745 break; 746 ps = &vm_physmem[lcv]; 747 /* move back other entries, if necessary ... */ 748 for (x = vm_nphysseg ; x > lcv ; x--) 749 /* structure copy */ 750 vm_physmem[x] = vm_physmem[x - 1]; 751 } 752 #else 753 panic("uvm_page_physload: unknown physseg strategy selected!"); 754 #endif 755 756 ps->start = start; 757 ps->end = end; 758 ps->avail_start = avail_start; 759 ps->avail_end = avail_end; 760 if (preload) { 761 ps->pgs = NULL; 762 } else { 763 ps->pgs = pgs; 764 ps->lastpg = pgs + npages - 1; 765 } 766 ps->free_list = free_list; 767 vm_nphysseg++; 768 769 if (!preload) 770 uvm_page_rehash(); 771 } 772 773 /* 774 * uvm_page_rehash: reallocate hash table based on number of free pages. 775 */ 776 777 void 778 uvm_page_rehash() 779 { 780 int freepages, lcv, bucketcount, oldcount; 781 struct pglist *newbuckets, *oldbuckets; 782 struct vm_page *pg; 783 size_t newsize, oldsize; 784 785 /* 786 * compute number of pages that can go in the free pool 787 */ 788 789 freepages = 0; 790 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 791 freepages += 792 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 793 794 /* 795 * compute number of buckets needed for this number of pages 796 */ 797 798 bucketcount = 1; 799 while (bucketcount < freepages) 800 bucketcount = bucketcount * 2; 801 802 /* 803 * compute the size of the current table and new table. 804 */ 805 806 oldbuckets = uvm.page_hash; 807 oldcount = uvm.page_nhash; 808 oldsize = round_page(sizeof(struct pglist) * oldcount); 809 newsize = round_page(sizeof(struct pglist) * bucketcount); 810 811 /* 812 * allocate the new buckets 813 */ 814 815 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 816 if (newbuckets == NULL) { 817 printf("uvm_page_physrehash: WARNING: could not grow page " 818 "hash table\n"); 819 return; 820 } 821 for (lcv = 0 ; lcv < bucketcount ; lcv++) 822 TAILQ_INIT(&newbuckets[lcv]); 823 824 /* 825 * now replace the old buckets with the new ones and rehash everything 826 */ 827 828 simple_lock(&uvm.hashlock); 829 uvm.page_hash = newbuckets; 830 uvm.page_nhash = bucketcount; 831 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 832 833 /* ... and rehash */ 834 for (lcv = 0 ; lcv < oldcount ; lcv++) { 835 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 836 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 837 TAILQ_INSERT_TAIL( 838 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 839 pg, hashq); 840 } 841 } 842 simple_unlock(&uvm.hashlock); 843 844 /* 845 * free old bucket array if is not the boot-time table 846 */ 847 848 if (oldbuckets != &uvm_bootbucket) 849 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 850 } 851 852 /* 853 * uvm_page_recolor: Recolor the pages if the new bucket count is 854 * larger than the old one. 855 */ 856 857 void 858 uvm_page_recolor(int newncolors) 859 { 860 struct pgflbucket *bucketarray, *oldbucketarray; 861 struct pgfreelist pgfl; 862 struct vm_page *pg; 863 vsize_t bucketcount; 864 int s, lcv, color, i, ocolors; 865 866 if (newncolors <= uvmexp.ncolors) 867 return; 868 869 bucketcount = newncolors * VM_NFREELIST; 870 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 871 M_VMPAGE, M_NOWAIT); 872 if (bucketarray == NULL) { 873 printf("WARNING: unable to allocate %ld page color buckets\n", 874 (long) bucketcount); 875 return; 876 } 877 878 s = uvm_lock_fpageq(); 879 880 /* Make sure we should still do this. */ 881 if (newncolors <= uvmexp.ncolors) { 882 uvm_unlock_fpageq(s); 883 free(bucketarray, M_VMPAGE); 884 return; 885 } 886 887 oldbucketarray = uvm.page_free[0].pgfl_buckets; 888 ocolors = uvmexp.ncolors; 889 890 uvmexp.ncolors = newncolors; 891 uvmexp.colormask = uvmexp.ncolors - 1; 892 893 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 894 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 895 uvm_page_init_buckets(&pgfl); 896 for (color = 0; color < ocolors; color++) { 897 for (i = 0; i < PGFL_NQUEUES; i++) { 898 while ((pg = TAILQ_FIRST(&uvm.page_free[ 899 lcv].pgfl_buckets[color].pgfl_queues[i])) 900 != NULL) { 901 TAILQ_REMOVE(&uvm.page_free[ 902 lcv].pgfl_buckets[ 903 color].pgfl_queues[i], pg, pageq); 904 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 905 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 906 i], pg, pageq); 907 } 908 } 909 } 910 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 911 } 912 913 if (have_recolored_pages) { 914 uvm_unlock_fpageq(s); 915 free(oldbucketarray, M_VMPAGE); 916 return; 917 } 918 919 have_recolored_pages = TRUE; 920 uvm_unlock_fpageq(s); 921 } 922 923 /* 924 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 925 */ 926 927 static __inline struct vm_page * 928 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 929 int *trycolorp) 930 { 931 struct pglist *freeq; 932 struct vm_page *pg; 933 int color, trycolor = *trycolorp; 934 935 color = trycolor; 936 do { 937 if ((pg = TAILQ_FIRST((freeq = 938 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 939 goto gotit; 940 if ((pg = TAILQ_FIRST((freeq = 941 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 942 goto gotit; 943 color = (color + 1) & uvmexp.colormask; 944 } while (color != trycolor); 945 946 return (NULL); 947 948 gotit: 949 TAILQ_REMOVE(freeq, pg, pageq); 950 uvmexp.free--; 951 952 /* update zero'd page count */ 953 if (pg->flags & PG_ZERO) 954 uvmexp.zeropages--; 955 956 if (color == trycolor) 957 uvmexp.colorhit++; 958 else { 959 uvmexp.colormiss++; 960 *trycolorp = color; 961 } 962 963 return (pg); 964 } 965 966 /* 967 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 968 * 969 * => return null if no pages free 970 * => wake up pagedaemon if number of free pages drops below low water mark 971 * => if obj != NULL, obj must be locked (to put in hash) 972 * => if anon != NULL, anon must be locked (to put in anon) 973 * => only one of obj or anon can be non-null 974 * => caller must activate/deactivate page if it is not wired. 975 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 976 * => policy decision: it is more important to pull a page off of the 977 * appropriate priority free list than it is to get a zero'd or 978 * unknown contents page. This is because we live with the 979 * consequences of a bad free list decision for the entire 980 * lifetime of the page, e.g. if the page comes from memory that 981 * is slower to access. 982 */ 983 984 struct vm_page * 985 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 986 struct uvm_object *obj; 987 voff_t off; 988 int flags; 989 struct vm_anon *anon; 990 int strat, free_list; 991 { 992 int lcv, try1, try2, s, zeroit = 0, color; 993 struct vm_page *pg; 994 boolean_t use_reserve; 995 996 KASSERT(obj == NULL || anon == NULL); 997 KASSERT(off == trunc_page(off)); 998 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 999 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1000 1001 s = uvm_lock_fpageq(); 1002 1003 /* 1004 * This implements a global round-robin page coloring 1005 * algorithm. 1006 * 1007 * XXXJRT: Should we make the `nextcolor' per-cpu? 1008 * XXXJRT: What about virtually-indexed caches? 1009 */ 1010 1011 color = uvm.page_free_nextcolor; 1012 1013 /* 1014 * check to see if we need to generate some free pages waking 1015 * the pagedaemon. 1016 */ 1017 1018 UVM_KICK_PDAEMON(); 1019 1020 /* 1021 * fail if any of these conditions is true: 1022 * [1] there really are no free pages, or 1023 * [2] only kernel "reserved" pages remain and 1024 * the page isn't being allocated to a kernel object. 1025 * [3] only pagedaemon "reserved" pages remain and 1026 * the requestor isn't the pagedaemon. 1027 */ 1028 1029 use_reserve = (flags & UVM_PGA_USERESERVE) || 1030 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1031 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1032 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1033 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1034 goto fail; 1035 1036 #if PGFL_NQUEUES != 2 1037 #error uvm_pagealloc_strat needs to be updated 1038 #endif 1039 1040 /* 1041 * If we want a zero'd page, try the ZEROS queue first, otherwise 1042 * we try the UNKNOWN queue first. 1043 */ 1044 if (flags & UVM_PGA_ZERO) { 1045 try1 = PGFL_ZEROS; 1046 try2 = PGFL_UNKNOWN; 1047 } else { 1048 try1 = PGFL_UNKNOWN; 1049 try2 = PGFL_ZEROS; 1050 } 1051 1052 again: 1053 switch (strat) { 1054 case UVM_PGA_STRAT_NORMAL: 1055 /* Check all freelists in descending priority order. */ 1056 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1057 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1058 try1, try2, &color); 1059 if (pg != NULL) 1060 goto gotit; 1061 } 1062 1063 /* No pages free! */ 1064 goto fail; 1065 1066 case UVM_PGA_STRAT_ONLY: 1067 case UVM_PGA_STRAT_FALLBACK: 1068 /* Attempt to allocate from the specified free list. */ 1069 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1070 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1071 try1, try2, &color); 1072 if (pg != NULL) 1073 goto gotit; 1074 1075 /* Fall back, if possible. */ 1076 if (strat == UVM_PGA_STRAT_FALLBACK) { 1077 strat = UVM_PGA_STRAT_NORMAL; 1078 goto again; 1079 } 1080 1081 /* No pages free! */ 1082 goto fail; 1083 1084 default: 1085 panic("uvm_pagealloc_strat: bad strat %d", strat); 1086 /* NOTREACHED */ 1087 } 1088 1089 gotit: 1090 /* 1091 * We now know which color we actually allocated from; set 1092 * the next color accordingly. 1093 */ 1094 1095 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1096 1097 /* 1098 * update allocation statistics and remember if we have to 1099 * zero the page 1100 */ 1101 1102 if (flags & UVM_PGA_ZERO) { 1103 if (pg->flags & PG_ZERO) { 1104 uvmexp.pga_zerohit++; 1105 zeroit = 0; 1106 } else { 1107 uvmexp.pga_zeromiss++; 1108 zeroit = 1; 1109 } 1110 } 1111 uvm_unlock_fpageq(s); 1112 1113 pg->offset = off; 1114 pg->uobject = obj; 1115 pg->uanon = anon; 1116 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1117 if (anon) { 1118 anon->u.an_page = pg; 1119 pg->pqflags = PQ_ANON; 1120 uvmexp.anonpages++; 1121 } else { 1122 if (obj) { 1123 uvm_pageinsert(pg); 1124 } 1125 pg->pqflags = 0; 1126 } 1127 #if defined(UVM_PAGE_TRKOWN) 1128 pg->owner_tag = NULL; 1129 #endif 1130 UVM_PAGE_OWN(pg, "new alloc"); 1131 1132 if (flags & UVM_PGA_ZERO) { 1133 /* 1134 * A zero'd page is not clean. If we got a page not already 1135 * zero'd, then we have to zero it ourselves. 1136 */ 1137 pg->flags &= ~PG_CLEAN; 1138 if (zeroit) 1139 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1140 } 1141 1142 return(pg); 1143 1144 fail: 1145 uvm_unlock_fpageq(s); 1146 return (NULL); 1147 } 1148 1149 /* 1150 * uvm_pagerealloc: reallocate a page from one object to another 1151 * 1152 * => both objects must be locked 1153 */ 1154 1155 void 1156 uvm_pagerealloc(pg, newobj, newoff) 1157 struct vm_page *pg; 1158 struct uvm_object *newobj; 1159 voff_t newoff; 1160 { 1161 /* 1162 * remove it from the old object 1163 */ 1164 1165 if (pg->uobject) { 1166 uvm_pageremove(pg); 1167 } 1168 1169 /* 1170 * put it in the new object 1171 */ 1172 1173 if (newobj) { 1174 pg->uobject = newobj; 1175 pg->offset = newoff; 1176 uvm_pageinsert(pg); 1177 } 1178 } 1179 1180 /* 1181 * uvm_pagefree: free page 1182 * 1183 * => erase page's identity (i.e. remove from hash/object) 1184 * => put page on free list 1185 * => caller must lock owning object (either anon or uvm_object) 1186 * => caller must lock page queues 1187 * => assumes all valid mappings of pg are gone 1188 */ 1189 1190 void 1191 uvm_pagefree(pg) 1192 struct vm_page *pg; 1193 { 1194 int s; 1195 1196 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1197 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1198 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1199 LOCK_ASSERT(pg->uobject == NULL || 1200 simple_lock_held(&pg->uobject->vmobjlock)); 1201 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1202 simple_lock_held(&pg->uanon->an_lock)); 1203 1204 #ifdef DEBUG 1205 if (pg->uobject == (void *)0xdeadbeef && 1206 pg->uanon == (void *)0xdeadbeef) { 1207 panic("uvm_pagefree: freeing free page %p\n", pg); 1208 } 1209 #endif 1210 1211 /* 1212 * if the page is loaned, resolve the loan instead of freeing. 1213 */ 1214 1215 if (pg->loan_count) { 1216 KASSERT(pg->wire_count == 0); 1217 1218 /* 1219 * if the page is owned by an anon then we just want to 1220 * drop anon ownership. the kernel will free the page when 1221 * it is done with it. if the page is owned by an object, 1222 * remove it from the object and mark it dirty for the benefit 1223 * of possible anon owners. 1224 * 1225 * regardless of previous ownership, wakeup any waiters, 1226 * unbusy the page, and we're done. 1227 */ 1228 1229 if (pg->uobject != NULL) { 1230 uvm_pageremove(pg); 1231 pg->flags &= ~PG_CLEAN; 1232 } else if (pg->uanon != NULL) { 1233 if ((pg->pqflags & PQ_ANON) == 0) { 1234 pg->loan_count--; 1235 } else { 1236 pg->pqflags &= ~PQ_ANON; 1237 } 1238 pg->uanon = NULL; 1239 } 1240 if (pg->flags & PG_WANTED) { 1241 wakeup(pg); 1242 } 1243 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED); 1244 #ifdef UVM_PAGE_TRKOWN 1245 pg->owner_tag = NULL; 1246 #endif 1247 if (pg->loan_count) { 1248 return; 1249 } 1250 } 1251 1252 /* 1253 * remove page from its object or anon. 1254 */ 1255 1256 if (pg->uobject != NULL) { 1257 uvm_pageremove(pg); 1258 } else if (pg->uanon != NULL) { 1259 pg->uanon->u.an_page = NULL; 1260 uvmexp.anonpages--; 1261 } 1262 1263 /* 1264 * now remove the page from the queues. 1265 */ 1266 1267 uvm_pagedequeue(pg); 1268 1269 /* 1270 * if the page was wired, unwire it now. 1271 */ 1272 1273 if (pg->wire_count) { 1274 pg->wire_count = 0; 1275 uvmexp.wired--; 1276 } 1277 1278 /* 1279 * and put on free queue 1280 */ 1281 1282 pg->flags &= ~PG_ZERO; 1283 1284 s = uvm_lock_fpageq(); 1285 TAILQ_INSERT_TAIL(&uvm.page_free[ 1286 uvm_page_lookup_freelist(pg)].pgfl_buckets[ 1287 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1288 pg->pqflags = PQ_FREE; 1289 #ifdef DEBUG 1290 pg->uobject = (void *)0xdeadbeef; 1291 pg->offset = 0xdeadbeef; 1292 pg->uanon = (void *)0xdeadbeef; 1293 #endif 1294 uvmexp.free++; 1295 1296 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1297 uvm.page_idle_zero = vm_page_zero_enable; 1298 1299 uvm_unlock_fpageq(s); 1300 } 1301 1302 /* 1303 * uvm_page_unbusy: unbusy an array of pages. 1304 * 1305 * => pages must either all belong to the same object, or all belong to anons. 1306 * => if pages are object-owned, object must be locked. 1307 * => if pages are anon-owned, anons must be locked. 1308 */ 1309 1310 void 1311 uvm_page_unbusy(pgs, npgs) 1312 struct vm_page **pgs; 1313 int npgs; 1314 { 1315 struct vm_page *pg; 1316 int i; 1317 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1318 1319 for (i = 0; i < npgs; i++) { 1320 pg = pgs[i]; 1321 if (pg == NULL) { 1322 continue; 1323 } 1324 if (pg->flags & PG_WANTED) { 1325 wakeup(pg); 1326 } 1327 if (pg->flags & PG_RELEASED) { 1328 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1329 pg->flags &= ~PG_RELEASED; 1330 uvm_pagefree(pg); 1331 } else { 1332 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1333 pg->flags &= ~(PG_WANTED|PG_BUSY); 1334 UVM_PAGE_OWN(pg, NULL); 1335 } 1336 } 1337 } 1338 1339 #if defined(UVM_PAGE_TRKOWN) 1340 /* 1341 * uvm_page_own: set or release page ownership 1342 * 1343 * => this is a debugging function that keeps track of who sets PG_BUSY 1344 * and where they do it. it can be used to track down problems 1345 * such a process setting "PG_BUSY" and never releasing it. 1346 * => page's object [if any] must be locked 1347 * => if "tag" is NULL then we are releasing page ownership 1348 */ 1349 void 1350 uvm_page_own(pg, tag) 1351 struct vm_page *pg; 1352 char *tag; 1353 { 1354 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1355 1356 /* gain ownership? */ 1357 if (tag) { 1358 if (pg->owner_tag) { 1359 printf("uvm_page_own: page %p already owned " 1360 "by proc %d [%s]\n", pg, 1361 pg->owner, pg->owner_tag); 1362 panic("uvm_page_own"); 1363 } 1364 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1365 pg->owner_tag = tag; 1366 return; 1367 } 1368 1369 /* drop ownership */ 1370 if (pg->owner_tag == NULL) { 1371 printf("uvm_page_own: dropping ownership of an non-owned " 1372 "page (%p)\n", pg); 1373 panic("uvm_page_own"); 1374 } 1375 pg->owner_tag = NULL; 1376 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1377 (pg->uanon == NULL && pg->uobject == NULL) || 1378 pg->uobject == uvm.kernel_object || 1379 pg->wire_count > 0 || 1380 (pg->loan_count == 1 && pg->uanon == NULL) || 1381 pg->loan_count > 1); 1382 return; 1383 } 1384 #endif 1385 1386 /* 1387 * uvm_pageidlezero: zero free pages while the system is idle. 1388 * 1389 * => try to complete one color bucket at a time, to reduce our impact 1390 * on the CPU cache. 1391 * => we loop until we either reach the target or whichqs indicates that 1392 * there is a process ready to run. 1393 */ 1394 void 1395 uvm_pageidlezero() 1396 { 1397 struct vm_page *pg; 1398 struct pgfreelist *pgfl; 1399 int free_list, s, firstbucket; 1400 static int nextbucket; 1401 1402 s = uvm_lock_fpageq(); 1403 firstbucket = nextbucket; 1404 do { 1405 if (sched_whichqs != 0) { 1406 uvm_unlock_fpageq(s); 1407 return; 1408 } 1409 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1410 uvm.page_idle_zero = FALSE; 1411 uvm_unlock_fpageq(s); 1412 return; 1413 } 1414 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1415 pgfl = &uvm.page_free[free_list]; 1416 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1417 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1418 if (sched_whichqs != 0) { 1419 uvm_unlock_fpageq(s); 1420 return; 1421 } 1422 1423 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1424 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1425 pg, pageq); 1426 uvmexp.free--; 1427 uvm_unlock_fpageq(s); 1428 #ifdef PMAP_PAGEIDLEZERO 1429 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1430 1431 /* 1432 * The machine-dependent code detected 1433 * some reason for us to abort zeroing 1434 * pages, probably because there is a 1435 * process now ready to run. 1436 */ 1437 1438 s = uvm_lock_fpageq(); 1439 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1440 nextbucket].pgfl_queues[ 1441 PGFL_UNKNOWN], pg, pageq); 1442 uvmexp.free++; 1443 uvmexp.zeroaborts++; 1444 uvm_unlock_fpageq(s); 1445 return; 1446 } 1447 #else 1448 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1449 #endif /* PMAP_PAGEIDLEZERO */ 1450 pg->flags |= PG_ZERO; 1451 1452 s = uvm_lock_fpageq(); 1453 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1454 nextbucket].pgfl_queues[PGFL_ZEROS], 1455 pg, pageq); 1456 uvmexp.free++; 1457 uvmexp.zeropages++; 1458 } 1459 } 1460 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1461 } while (nextbucket != firstbucket); 1462 uvm_unlock_fpageq(s); 1463 } 1464