1 /* $NetBSD: uvm_page.c,v 1.65 2001/06/27 23:57:16 thorpej 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 82 #define UVM_PAGE /* pull in uvm_page.h functions */ 83 #include <uvm/uvm.h> 84 85 /* 86 * global vars... XXXCDC: move to uvm. structure. 87 */ 88 89 /* 90 * physical memory config is stored in vm_physmem. 91 */ 92 93 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 94 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 95 96 /* 97 * Some supported CPUs in a given architecture don't support all 98 * of the things necessary to do idle page zero'ing efficiently. 99 * We therefore provide a way to disable it from machdep code here. 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 */ 105 boolean_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 */ 116 117 static vaddr_t virtual_space_start; 118 static 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 */ 125 126 static struct pglist uvm_bootbucket; 127 128 /* 129 * we allocate an initial number of page colors in uvm_page_init(), 130 * and remember them. We may re-color pages as cache sizes are 131 * discovered during the autoconfiguration phase. But we can never 132 * free the initial set of buckets, since they are allocated using 133 * uvm_pageboot_alloc(). 134 */ 135 136 static boolean_t have_recolored_pages /* = FALSE */; 137 138 /* 139 * local prototypes 140 */ 141 142 static void uvm_pageinsert __P((struct vm_page *)); 143 static void uvm_pageremove __P((struct vm_page *)); 144 145 /* 146 * inline functions 147 */ 148 149 /* 150 * uvm_pageinsert: insert a page in the object and the hash table 151 * 152 * => caller must lock object 153 * => caller must lock page queues 154 * => call should have already set pg's object and offset pointers 155 * and bumped the version counter 156 */ 157 158 __inline static void 159 uvm_pageinsert(pg) 160 struct vm_page *pg; 161 { 162 struct pglist *buck; 163 int s; 164 165 KASSERT((pg->flags & PG_TABLED) == 0); 166 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 167 s = splvm(); 168 simple_lock(&uvm.hashlock); 169 TAILQ_INSERT_TAIL(buck, pg, hashq); /* put in hash */ 170 simple_unlock(&uvm.hashlock); 171 splx(s); 172 173 TAILQ_INSERT_TAIL(&pg->uobject->memq, pg, listq); /* put in object */ 174 pg->flags |= PG_TABLED; 175 pg->uobject->uo_npages++; 176 } 177 178 /* 179 * uvm_page_remove: remove page from object and hash 180 * 181 * => caller must lock object 182 * => caller must lock page queues 183 */ 184 185 static __inline void 186 uvm_pageremove(pg) 187 struct vm_page *pg; 188 { 189 struct pglist *buck; 190 int s; 191 192 KASSERT(pg->flags & PG_TABLED); 193 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 194 s = splvm(); 195 simple_lock(&uvm.hashlock); 196 TAILQ_REMOVE(buck, pg, hashq); 197 simple_unlock(&uvm.hashlock); 198 splx(s); 199 200 if (UVM_OBJ_IS_VTEXT(pg->uobject)) { 201 uvmexp.vtextpages--; 202 } else if (UVM_OBJ_IS_VNODE(pg->uobject)) { 203 uvmexp.vnodepages--; 204 } 205 206 /* object should be locked */ 207 TAILQ_REMOVE(&pg->uobject->memq, pg, listq); 208 209 pg->flags &= ~PG_TABLED; 210 pg->uobject->uo_npages--; 211 pg->uobject = NULL; 212 pg->version++; 213 } 214 215 static void 216 uvm_page_init_buckets(struct pgfreelist *pgfl) 217 { 218 int color, i; 219 220 for (color = 0; color < uvmexp.ncolors; color++) { 221 for (i = 0; i < PGFL_NQUEUES; i++) { 222 TAILQ_INIT(&pgfl->pgfl_buckets[ 223 color].pgfl_queues[i]); 224 } 225 } 226 } 227 228 /* 229 * uvm_page_init: init the page system. called from uvm_init(). 230 * 231 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 232 */ 233 234 void 235 uvm_page_init(kvm_startp, kvm_endp) 236 vaddr_t *kvm_startp, *kvm_endp; 237 { 238 vsize_t freepages, pagecount, bucketcount, n; 239 struct pgflbucket *bucketarray; 240 struct vm_page *pagearray; 241 int lcv, i; 242 paddr_t paddr; 243 244 /* 245 * init the page queues and page queue locks, except the free 246 * list; we allocate that later (with the initial vm_page 247 * structures). 248 */ 249 250 TAILQ_INIT(&uvm.page_active); 251 TAILQ_INIT(&uvm.page_inactive); 252 simple_lock_init(&uvm.pageqlock); 253 simple_lock_init(&uvm.fpageqlock); 254 255 /* 256 * init the <obj,offset> => <page> hash table. for now 257 * we just have one bucket (the bootstrap bucket). later on we 258 * will allocate new buckets as we dynamically resize the hash table. 259 */ 260 261 uvm.page_nhash = 1; /* 1 bucket */ 262 uvm.page_hashmask = 0; /* mask for hash function */ 263 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 264 TAILQ_INIT(uvm.page_hash); /* init hash table */ 265 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 266 267 /* 268 * allocate vm_page structures. 269 */ 270 271 /* 272 * sanity check: 273 * before calling this function the MD code is expected to register 274 * some free RAM with the uvm_page_physload() function. our job 275 * now is to allocate vm_page structures for this memory. 276 */ 277 278 if (vm_nphysseg == 0) 279 panic("uvm_page_bootstrap: no memory pre-allocated"); 280 281 /* 282 * first calculate the number of free pages... 283 * 284 * note that we use start/end rather than avail_start/avail_end. 285 * this allows us to allocate extra vm_page structures in case we 286 * want to return some memory to the pool after booting. 287 */ 288 289 freepages = 0; 290 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 291 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 292 293 /* 294 * Let MD code initialize the number of colors, or default 295 * to 1 color if MD code doesn't care. 296 */ 297 if (uvmexp.ncolors == 0) 298 uvmexp.ncolors = 1; 299 uvmexp.colormask = uvmexp.ncolors - 1; 300 301 /* 302 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 303 * use. for each page of memory we use we need a vm_page structure. 304 * thus, the total number of pages we can use is the total size of 305 * the memory divided by the PAGE_SIZE plus the size of the vm_page 306 * structure. we add one to freepages as a fudge factor to avoid 307 * truncation errors (since we can only allocate in terms of whole 308 * pages). 309 */ 310 311 bucketcount = uvmexp.ncolors * VM_NFREELIST; 312 pagecount = ((freepages + 1) << PAGE_SHIFT) / 313 (PAGE_SIZE + sizeof(struct vm_page)); 314 315 bucketarray = (void *) uvm_pageboot_alloc((bucketcount * 316 sizeof(struct pgflbucket)) + (pagecount * 317 sizeof(struct vm_page))); 318 pagearray = (struct vm_page *)(bucketarray + bucketcount); 319 320 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 321 uvm.page_free[lcv].pgfl_buckets = 322 (bucketarray + (lcv * uvmexp.ncolors)); 323 uvm_page_init_buckets(&uvm.page_free[lcv]); 324 } 325 326 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 327 328 /* 329 * init the vm_page structures and put them in the correct place. 330 */ 331 332 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 333 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 334 if (n > pagecount) { 335 printf("uvm_page_init: lost %ld page(s) in init\n", 336 (long)(n - pagecount)); 337 panic("uvm_page_init"); /* XXXCDC: shouldn't happen? */ 338 /* n = pagecount; */ 339 } 340 341 /* set up page array pointers */ 342 vm_physmem[lcv].pgs = pagearray; 343 pagearray += n; 344 pagecount -= n; 345 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 346 347 /* init and free vm_pages (we've already zeroed them) */ 348 paddr = ptoa(vm_physmem[lcv].start); 349 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 350 vm_physmem[lcv].pgs[i].phys_addr = paddr; 351 #ifdef __HAVE_VM_PAGE_MD 352 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 353 #endif 354 if (atop(paddr) >= vm_physmem[lcv].avail_start && 355 atop(paddr) <= vm_physmem[lcv].avail_end) { 356 uvmexp.npages++; 357 /* add page to free pool */ 358 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 359 } 360 } 361 } 362 363 /* 364 * pass up the values of virtual_space_start and 365 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 366 * layers of the VM. 367 */ 368 369 *kvm_startp = round_page(virtual_space_start); 370 *kvm_endp = trunc_page(virtual_space_end); 371 372 /* 373 * init locks for kernel threads 374 */ 375 376 simple_lock_init(&uvm.pagedaemon_lock); 377 simple_lock_init(&uvm.aiodoned_lock); 378 379 /* 380 * init various thresholds. 381 * XXXCDC - values may need adjusting 382 */ 383 384 uvmexp.reserve_pagedaemon = 1; 385 uvmexp.reserve_kernel = 5; 386 uvmexp.anonminpct = 10; 387 uvmexp.vnodeminpct = 10; 388 uvmexp.vtextminpct = 5; 389 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 390 uvmexp.vnodemin = uvmexp.vnodeminpct * 256 / 100; 391 uvmexp.vtextmin = uvmexp.vtextminpct * 256 / 100; 392 393 /* 394 * determine if we should zero pages in the idle loop. 395 */ 396 397 uvm.page_idle_zero = vm_page_zero_enable; 398 399 /* 400 * done! 401 */ 402 403 uvm.page_init_done = TRUE; 404 } 405 406 /* 407 * uvm_setpagesize: set the page size 408 * 409 * => sets page_shift and page_mask from uvmexp.pagesize. 410 */ 411 412 void 413 uvm_setpagesize() 414 { 415 if (uvmexp.pagesize == 0) 416 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 417 uvmexp.pagemask = uvmexp.pagesize - 1; 418 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 419 panic("uvm_setpagesize: page size not a power of two"); 420 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 421 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 422 break; 423 } 424 425 /* 426 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 427 */ 428 429 vaddr_t 430 uvm_pageboot_alloc(size) 431 vsize_t size; 432 { 433 static boolean_t initialized = FALSE; 434 vaddr_t addr; 435 #if !defined(PMAP_STEAL_MEMORY) 436 vaddr_t vaddr; 437 paddr_t paddr; 438 #endif 439 440 /* 441 * on first call to this function, initialize ourselves. 442 */ 443 if (initialized == FALSE) { 444 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 445 446 /* round it the way we like it */ 447 virtual_space_start = round_page(virtual_space_start); 448 virtual_space_end = trunc_page(virtual_space_end); 449 450 initialized = TRUE; 451 } 452 453 /* round to page size */ 454 size = round_page(size); 455 456 #if defined(PMAP_STEAL_MEMORY) 457 458 /* 459 * defer bootstrap allocation to MD code (it may want to allocate 460 * from a direct-mapped segment). pmap_steal_memory should adjust 461 * virtual_space_start/virtual_space_end if necessary. 462 */ 463 464 addr = pmap_steal_memory(size, &virtual_space_start, 465 &virtual_space_end); 466 467 return(addr); 468 469 #else /* !PMAP_STEAL_MEMORY */ 470 471 /* 472 * allocate virtual memory for this request 473 */ 474 if (virtual_space_start == virtual_space_end || 475 (virtual_space_end - virtual_space_start) < size) 476 panic("uvm_pageboot_alloc: out of virtual space"); 477 478 addr = virtual_space_start; 479 480 #ifdef PMAP_GROWKERNEL 481 /* 482 * If the kernel pmap can't map the requested space, 483 * then allocate more resources for it. 484 */ 485 if (uvm_maxkaddr < (addr + size)) { 486 uvm_maxkaddr = pmap_growkernel(addr + size); 487 if (uvm_maxkaddr < (addr + size)) 488 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 489 } 490 #endif 491 492 virtual_space_start += size; 493 494 /* 495 * allocate and mapin physical pages to back new virtual pages 496 */ 497 498 for (vaddr = round_page(addr) ; vaddr < addr + size ; 499 vaddr += PAGE_SIZE) { 500 501 if (!uvm_page_physget(&paddr)) 502 panic("uvm_pageboot_alloc: out of memory"); 503 504 /* 505 * Note this memory is no longer managed, so using 506 * pmap_kenter is safe. 507 */ 508 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 509 } 510 pmap_update(); 511 return(addr); 512 #endif /* PMAP_STEAL_MEMORY */ 513 } 514 515 #if !defined(PMAP_STEAL_MEMORY) 516 /* 517 * uvm_page_physget: "steal" one page from the vm_physmem structure. 518 * 519 * => attempt to allocate it off the end of a segment in which the "avail" 520 * values match the start/end values. if we can't do that, then we 521 * will advance both values (making them equal, and removing some 522 * vm_page structures from the non-avail area). 523 * => return false if out of memory. 524 */ 525 526 /* subroutine: try to allocate from memory chunks on the specified freelist */ 527 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 528 529 static boolean_t 530 uvm_page_physget_freelist(paddrp, freelist) 531 paddr_t *paddrp; 532 int freelist; 533 { 534 int lcv, x; 535 536 /* pass 1: try allocating from a matching end */ 537 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 538 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 539 #else 540 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 541 #endif 542 { 543 544 if (uvm.page_init_done == TRUE) 545 panic("uvm_page_physget: called _after_ bootstrap"); 546 547 if (vm_physmem[lcv].free_list != freelist) 548 continue; 549 550 /* try from front */ 551 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 552 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 553 *paddrp = ptoa(vm_physmem[lcv].avail_start); 554 vm_physmem[lcv].avail_start++; 555 vm_physmem[lcv].start++; 556 /* nothing left? nuke it */ 557 if (vm_physmem[lcv].avail_start == 558 vm_physmem[lcv].end) { 559 if (vm_nphysseg == 1) 560 panic("vum_page_physget: out of memory!"); 561 vm_nphysseg--; 562 for (x = lcv ; x < vm_nphysseg ; x++) 563 /* structure copy */ 564 vm_physmem[x] = vm_physmem[x+1]; 565 } 566 return (TRUE); 567 } 568 569 /* try from rear */ 570 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 571 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 572 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 573 vm_physmem[lcv].avail_end--; 574 vm_physmem[lcv].end--; 575 /* nothing left? nuke it */ 576 if (vm_physmem[lcv].avail_end == 577 vm_physmem[lcv].start) { 578 if (vm_nphysseg == 1) 579 panic("uvm_page_physget: out of memory!"); 580 vm_nphysseg--; 581 for (x = lcv ; x < vm_nphysseg ; x++) 582 /* structure copy */ 583 vm_physmem[x] = vm_physmem[x+1]; 584 } 585 return (TRUE); 586 } 587 } 588 589 /* pass2: forget about matching ends, just allocate something */ 590 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 591 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 592 #else 593 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 594 #endif 595 { 596 597 /* any room in this bank? */ 598 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 599 continue; /* nope */ 600 601 *paddrp = ptoa(vm_physmem[lcv].avail_start); 602 vm_physmem[lcv].avail_start++; 603 /* truncate! */ 604 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 605 606 /* nothing left? nuke it */ 607 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 608 if (vm_nphysseg == 1) 609 panic("uvm_page_physget: out of memory!"); 610 vm_nphysseg--; 611 for (x = lcv ; x < vm_nphysseg ; x++) 612 /* structure copy */ 613 vm_physmem[x] = vm_physmem[x+1]; 614 } 615 return (TRUE); 616 } 617 618 return (FALSE); /* whoops! */ 619 } 620 621 boolean_t 622 uvm_page_physget(paddrp) 623 paddr_t *paddrp; 624 { 625 int i; 626 627 /* try in the order of freelist preference */ 628 for (i = 0; i < VM_NFREELIST; i++) 629 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 630 return (TRUE); 631 return (FALSE); 632 } 633 #endif /* PMAP_STEAL_MEMORY */ 634 635 /* 636 * uvm_page_physload: load physical memory into VM system 637 * 638 * => all args are PFs 639 * => all pages in start/end get vm_page structures 640 * => areas marked by avail_start/avail_end get added to the free page pool 641 * => we are limited to VM_PHYSSEG_MAX physical memory segments 642 */ 643 644 void 645 uvm_page_physload(start, end, avail_start, avail_end, free_list) 646 paddr_t start, end, avail_start, avail_end; 647 int free_list; 648 { 649 int preload, lcv; 650 psize_t npages; 651 struct vm_page *pgs; 652 struct vm_physseg *ps; 653 654 if (uvmexp.pagesize == 0) 655 panic("uvm_page_physload: page size not set!"); 656 657 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 658 panic("uvm_page_physload: bad free list %d\n", free_list); 659 660 if (start >= end) 661 panic("uvm_page_physload: start >= end"); 662 663 /* 664 * do we have room? 665 */ 666 if (vm_nphysseg == VM_PHYSSEG_MAX) { 667 printf("uvm_page_physload: unable to load physical memory " 668 "segment\n"); 669 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 670 VM_PHYSSEG_MAX, (long long)start, (long long)end); 671 printf("\tincrease VM_PHYSSEG_MAX\n"); 672 return; 673 } 674 675 /* 676 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 677 * called yet, so malloc is not available). 678 */ 679 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 680 if (vm_physmem[lcv].pgs) 681 break; 682 } 683 preload = (lcv == vm_nphysseg); 684 685 /* 686 * if VM is already running, attempt to malloc() vm_page structures 687 */ 688 if (!preload) { 689 #if defined(VM_PHYSSEG_NOADD) 690 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 691 #else 692 /* XXXCDC: need some sort of lockout for this case */ 693 paddr_t paddr; 694 npages = end - start; /* # of pages */ 695 pgs = malloc(sizeof(struct vm_page) * npages, 696 M_VMPAGE, M_NOWAIT); 697 if (pgs == NULL) { 698 printf("uvm_page_physload: can not malloc vm_page " 699 "structs for segment\n"); 700 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 701 return; 702 } 703 /* zero data, init phys_addr and free_list, and free pages */ 704 memset(pgs, 0, sizeof(struct vm_page) * npages); 705 for (lcv = 0, paddr = ptoa(start) ; 706 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 707 pgs[lcv].phys_addr = paddr; 708 pgs[lcv].free_list = free_list; 709 if (atop(paddr) >= avail_start && 710 atop(paddr) <= avail_end) 711 uvm_pagefree(&pgs[lcv]); 712 } 713 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 714 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 715 #endif 716 } else { 717 718 /* gcc complains if these don't get init'd */ 719 pgs = NULL; 720 npages = 0; 721 722 } 723 724 /* 725 * now insert us in the proper place in vm_physmem[] 726 */ 727 728 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 729 730 /* random: put it at the end (easy!) */ 731 ps = &vm_physmem[vm_nphysseg]; 732 733 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 734 735 { 736 int x; 737 /* sort by address for binary search */ 738 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 739 if (start < vm_physmem[lcv].start) 740 break; 741 ps = &vm_physmem[lcv]; 742 /* move back other entries, if necessary ... */ 743 for (x = vm_nphysseg ; x > lcv ; x--) 744 /* structure copy */ 745 vm_physmem[x] = vm_physmem[x - 1]; 746 } 747 748 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 749 750 { 751 int x; 752 /* sort by largest segment first */ 753 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 754 if ((end - start) > 755 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 756 break; 757 ps = &vm_physmem[lcv]; 758 /* move back other entries, if necessary ... */ 759 for (x = vm_nphysseg ; x > lcv ; x--) 760 /* structure copy */ 761 vm_physmem[x] = vm_physmem[x - 1]; 762 } 763 764 #else 765 766 panic("uvm_page_physload: unknown physseg strategy selected!"); 767 768 #endif 769 770 ps->start = start; 771 ps->end = end; 772 ps->avail_start = avail_start; 773 ps->avail_end = avail_end; 774 if (preload) { 775 ps->pgs = NULL; 776 } else { 777 ps->pgs = pgs; 778 ps->lastpg = pgs + npages - 1; 779 } 780 ps->free_list = free_list; 781 vm_nphysseg++; 782 783 /* 784 * done! 785 */ 786 787 if (!preload) 788 uvm_page_rehash(); 789 790 return; 791 } 792 793 /* 794 * uvm_page_rehash: reallocate hash table based on number of free pages. 795 */ 796 797 void 798 uvm_page_rehash() 799 { 800 int freepages, lcv, bucketcount, s, oldcount; 801 struct pglist *newbuckets, *oldbuckets; 802 struct vm_page *pg; 803 size_t newsize, oldsize; 804 805 /* 806 * compute number of pages that can go in the free pool 807 */ 808 809 freepages = 0; 810 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 811 freepages += 812 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 813 814 /* 815 * compute number of buckets needed for this number of pages 816 */ 817 818 bucketcount = 1; 819 while (bucketcount < freepages) 820 bucketcount = bucketcount * 2; 821 822 /* 823 * compute the size of the current table and new table. 824 */ 825 826 oldbuckets = uvm.page_hash; 827 oldcount = uvm.page_nhash; 828 oldsize = round_page(sizeof(struct pglist) * oldcount); 829 newsize = round_page(sizeof(struct pglist) * bucketcount); 830 831 /* 832 * allocate the new buckets 833 */ 834 835 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 836 if (newbuckets == NULL) { 837 printf("uvm_page_physrehash: WARNING: could not grow page " 838 "hash table\n"); 839 return; 840 } 841 for (lcv = 0 ; lcv < bucketcount ; lcv++) 842 TAILQ_INIT(&newbuckets[lcv]); 843 844 /* 845 * now replace the old buckets with the new ones and rehash everything 846 */ 847 848 s = splvm(); 849 simple_lock(&uvm.hashlock); 850 uvm.page_hash = newbuckets; 851 uvm.page_nhash = bucketcount; 852 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 853 854 /* ... and rehash */ 855 for (lcv = 0 ; lcv < oldcount ; lcv++) { 856 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 857 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 858 TAILQ_INSERT_TAIL( 859 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 860 pg, hashq); 861 } 862 } 863 simple_unlock(&uvm.hashlock); 864 splx(s); 865 866 /* 867 * free old bucket array if is not the boot-time table 868 */ 869 870 if (oldbuckets != &uvm_bootbucket) 871 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 872 873 /* 874 * done 875 */ 876 return; 877 } 878 879 /* 880 * uvm_page_recolor: Recolor the pages if the new bucket count is 881 * larger than the old one. 882 */ 883 884 void 885 uvm_page_recolor(int newncolors) 886 { 887 struct pgflbucket *bucketarray, *oldbucketarray; 888 struct pgfreelist pgfl; 889 struct vm_page *pg; 890 vsize_t bucketcount; 891 int s, lcv, color, i, ocolors; 892 893 if (newncolors <= uvmexp.ncolors) 894 return; 895 896 bucketcount = newncolors * VM_NFREELIST; 897 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 898 M_VMPAGE, M_NOWAIT); 899 if (bucketarray == NULL) { 900 printf("WARNING: unable to allocate %ld page color buckets\n", 901 (long) bucketcount); 902 return; 903 } 904 905 s = uvm_lock_fpageq(); 906 907 /* Make sure we should still do this. */ 908 if (newncolors <= uvmexp.ncolors) { 909 uvm_unlock_fpageq(s); 910 free(bucketarray, M_VMPAGE); 911 return; 912 } 913 914 oldbucketarray = uvm.page_free[0].pgfl_buckets; 915 ocolors = uvmexp.ncolors; 916 917 uvmexp.ncolors = newncolors; 918 uvmexp.colormask = uvmexp.ncolors - 1; 919 920 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 921 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 922 uvm_page_init_buckets(&pgfl); 923 for (color = 0; color < ocolors; color++) { 924 for (i = 0; i < PGFL_NQUEUES; i++) { 925 while ((pg = TAILQ_FIRST(&uvm.page_free[ 926 lcv].pgfl_buckets[color].pgfl_queues[i])) 927 != NULL) { 928 TAILQ_REMOVE(&uvm.page_free[ 929 lcv].pgfl_buckets[ 930 color].pgfl_queues[i], pg, pageq); 931 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 932 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 933 i], pg, pageq); 934 } 935 } 936 } 937 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 938 } 939 940 if (have_recolored_pages) { 941 uvm_unlock_fpageq(s); 942 free(oldbucketarray, M_VMPAGE); 943 return; 944 } 945 946 have_recolored_pages = TRUE; 947 uvm_unlock_fpageq(s); 948 } 949 950 #if 1 /* XXXCDC: TMP TMP TMP DEBUG DEBUG DEBUG */ 951 952 void uvm_page_physdump __P((void)); /* SHUT UP GCC */ 953 954 /* call from DDB */ 955 void 956 uvm_page_physdump() 957 { 958 int lcv; 959 960 printf("rehash: physical memory config [segs=%d of %d]:\n", 961 vm_nphysseg, VM_PHYSSEG_MAX); 962 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 963 printf("0x%llx->0x%llx [0x%llx->0x%llx]\n", 964 (long long)vm_physmem[lcv].start, 965 (long long)vm_physmem[lcv].end, 966 (long long)vm_physmem[lcv].avail_start, 967 (long long)vm_physmem[lcv].avail_end); 968 printf("STRATEGY = "); 969 switch (VM_PHYSSEG_STRAT) { 970 case VM_PSTRAT_RANDOM: printf("RANDOM\n"); break; 971 case VM_PSTRAT_BSEARCH: printf("BSEARCH\n"); break; 972 case VM_PSTRAT_BIGFIRST: printf("BIGFIRST\n"); break; 973 default: printf("<<UNKNOWN>>!!!!\n"); 974 } 975 printf("number of buckets = %d\n", uvm.page_nhash); 976 } 977 #endif 978 979 /* 980 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 981 */ 982 983 static __inline struct vm_page * 984 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 985 unsigned int *trycolorp) 986 { 987 struct pglist *freeq; 988 struct vm_page *pg; 989 int color, trycolor = *trycolorp; 990 991 color = trycolor; 992 do { 993 if ((pg = TAILQ_FIRST((freeq = 994 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 995 goto gotit; 996 if ((pg = TAILQ_FIRST((freeq = 997 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 998 goto gotit; 999 color = (color + 1) & uvmexp.colormask; 1000 } while (color != trycolor); 1001 1002 return (NULL); 1003 1004 gotit: 1005 TAILQ_REMOVE(freeq, pg, pageq); 1006 uvmexp.free--; 1007 1008 /* update zero'd page count */ 1009 if (pg->flags & PG_ZERO) 1010 uvmexp.zeropages--; 1011 1012 if (color == trycolor) 1013 uvmexp.colorhit++; 1014 else { 1015 uvmexp.colormiss++; 1016 *trycolorp = color; 1017 } 1018 1019 return (pg); 1020 } 1021 1022 /* 1023 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1024 * 1025 * => return null if no pages free 1026 * => wake up pagedaemon if number of free pages drops below low water mark 1027 * => if obj != NULL, obj must be locked (to put in hash) 1028 * => if anon != NULL, anon must be locked (to put in anon) 1029 * => only one of obj or anon can be non-null 1030 * => caller must activate/deactivate page if it is not wired. 1031 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1032 * => policy decision: it is more important to pull a page off of the 1033 * appropriate priority free list than it is to get a zero'd or 1034 * unknown contents page. This is because we live with the 1035 * consequences of a bad free list decision for the entire 1036 * lifetime of the page, e.g. if the page comes from memory that 1037 * is slower to access. 1038 */ 1039 1040 struct vm_page * 1041 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 1042 struct uvm_object *obj; 1043 voff_t off; 1044 int flags; 1045 struct vm_anon *anon; 1046 int strat, free_list; 1047 { 1048 int lcv, try1, try2, s, zeroit = 0, color; 1049 struct vm_page *pg; 1050 boolean_t use_reserve; 1051 1052 KASSERT(obj == NULL || anon == NULL); 1053 KASSERT(off == trunc_page(off)); 1054 1055 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1056 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1057 1058 s = uvm_lock_fpageq(); 1059 1060 /* 1061 * This implements a global round-robin page coloring 1062 * algorithm. 1063 * 1064 * XXXJRT: Should we make the `nextcolor' per-cpu? 1065 * XXXJRT: What about virtually-indexed caches? 1066 */ 1067 color = uvm.page_free_nextcolor; 1068 1069 /* 1070 * check to see if we need to generate some free pages waking 1071 * the pagedaemon. 1072 */ 1073 1074 UVM_KICK_PDAEMON(); 1075 1076 /* 1077 * fail if any of these conditions is true: 1078 * [1] there really are no free pages, or 1079 * [2] only kernel "reserved" pages remain and 1080 * the page isn't being allocated to a kernel object. 1081 * [3] only pagedaemon "reserved" pages remain and 1082 * the requestor isn't the pagedaemon. 1083 */ 1084 1085 use_reserve = (flags & UVM_PGA_USERESERVE) || 1086 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1087 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1088 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1089 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1090 goto fail; 1091 1092 #if PGFL_NQUEUES != 2 1093 #error uvm_pagealloc_strat needs to be updated 1094 #endif 1095 1096 /* 1097 * If we want a zero'd page, try the ZEROS queue first, otherwise 1098 * we try the UNKNOWN queue first. 1099 */ 1100 if (flags & UVM_PGA_ZERO) { 1101 try1 = PGFL_ZEROS; 1102 try2 = PGFL_UNKNOWN; 1103 } else { 1104 try1 = PGFL_UNKNOWN; 1105 try2 = PGFL_ZEROS; 1106 } 1107 1108 again: 1109 switch (strat) { 1110 case UVM_PGA_STRAT_NORMAL: 1111 /* Check all freelists in descending priority order. */ 1112 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1113 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1114 try1, try2, &color); 1115 if (pg != NULL) 1116 goto gotit; 1117 } 1118 1119 /* No pages free! */ 1120 goto fail; 1121 1122 case UVM_PGA_STRAT_ONLY: 1123 case UVM_PGA_STRAT_FALLBACK: 1124 /* Attempt to allocate from the specified free list. */ 1125 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1126 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1127 try1, try2, &color); 1128 if (pg != NULL) 1129 goto gotit; 1130 1131 /* Fall back, if possible. */ 1132 if (strat == UVM_PGA_STRAT_FALLBACK) { 1133 strat = UVM_PGA_STRAT_NORMAL; 1134 goto again; 1135 } 1136 1137 /* No pages free! */ 1138 goto fail; 1139 1140 default: 1141 panic("uvm_pagealloc_strat: bad strat %d", strat); 1142 /* NOTREACHED */ 1143 } 1144 1145 gotit: 1146 /* 1147 * We now know which color we actually allocated from; set 1148 * the next color accordingly. 1149 */ 1150 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1151 1152 /* 1153 * update allocation statistics and remember if we have to 1154 * zero the page 1155 */ 1156 if (flags & UVM_PGA_ZERO) { 1157 if (pg->flags & PG_ZERO) { 1158 uvmexp.pga_zerohit++; 1159 zeroit = 0; 1160 } else { 1161 uvmexp.pga_zeromiss++; 1162 zeroit = 1; 1163 } 1164 } 1165 1166 uvm_unlock_fpageq(s); /* unlock free page queue */ 1167 1168 pg->offset = off; 1169 pg->uobject = obj; 1170 pg->uanon = anon; 1171 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1172 pg->version++; 1173 if (anon) { 1174 anon->u.an_page = pg; 1175 pg->pqflags = PQ_ANON; 1176 uvmexp.anonpages++; 1177 } else { 1178 if (obj) 1179 uvm_pageinsert(pg); 1180 pg->pqflags = 0; 1181 } 1182 #if defined(UVM_PAGE_TRKOWN) 1183 pg->owner_tag = NULL; 1184 #endif 1185 UVM_PAGE_OWN(pg, "new alloc"); 1186 1187 if (flags & UVM_PGA_ZERO) { 1188 /* 1189 * A zero'd page is not clean. If we got a page not already 1190 * zero'd, then we have to zero it ourselves. 1191 */ 1192 pg->flags &= ~PG_CLEAN; 1193 if (zeroit) 1194 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1195 } 1196 1197 return(pg); 1198 1199 fail: 1200 uvm_unlock_fpageq(s); 1201 return (NULL); 1202 } 1203 1204 /* 1205 * uvm_pagerealloc: reallocate a page from one object to another 1206 * 1207 * => both objects must be locked 1208 */ 1209 1210 void 1211 uvm_pagerealloc(pg, newobj, newoff) 1212 struct vm_page *pg; 1213 struct uvm_object *newobj; 1214 voff_t newoff; 1215 { 1216 /* 1217 * remove it from the old object 1218 */ 1219 1220 if (pg->uobject) { 1221 uvm_pageremove(pg); 1222 } 1223 1224 /* 1225 * put it in the new object 1226 */ 1227 1228 if (newobj) { 1229 pg->uobject = newobj; 1230 pg->offset = newoff; 1231 pg->version++; 1232 uvm_pageinsert(pg); 1233 } 1234 } 1235 1236 1237 /* 1238 * uvm_pagefree: free page 1239 * 1240 * => erase page's identity (i.e. remove from hash/object) 1241 * => put page on free list 1242 * => caller must lock owning object (either anon or uvm_object) 1243 * => caller must lock page queues 1244 * => assumes all valid mappings of pg are gone 1245 */ 1246 1247 void 1248 uvm_pagefree(pg) 1249 struct vm_page *pg; 1250 { 1251 int s; 1252 int saved_loan_count = pg->loan_count; 1253 1254 #ifdef DEBUG 1255 if (pg->uobject == (void *)0xdeadbeef && 1256 pg->uanon == (void *)0xdeadbeef) { 1257 panic("uvm_pagefree: freeing free page %p\n", pg); 1258 } 1259 #endif 1260 1261 /* 1262 * if the page was an object page (and thus "TABLED"), remove it 1263 * from the object. 1264 */ 1265 1266 if (pg->flags & PG_TABLED) { 1267 1268 /* 1269 * if the object page is on loan we are going to drop ownership. 1270 * it is possible that an anon will take over as owner for this 1271 * page later on. the anon will want a !PG_CLEAN page so that 1272 * it knows it needs to allocate swap if it wants to page the 1273 * page out. 1274 */ 1275 1276 if (saved_loan_count) 1277 pg->flags &= ~PG_CLEAN; /* in case an anon takes over */ 1278 uvm_pageremove(pg); 1279 1280 /* 1281 * if our page was on loan, then we just lost control over it 1282 * (in fact, if it was loaned to an anon, the anon may have 1283 * already taken over ownership of the page by now and thus 1284 * changed the loan_count [e.g. in uvmfault_anonget()]) we just 1285 * return (when the last loan is dropped, then the page can be 1286 * freed by whatever was holding the last loan). 1287 */ 1288 1289 if (saved_loan_count) 1290 return; 1291 } else if (saved_loan_count && (pg->pqflags & PQ_ANON)) { 1292 1293 /* 1294 * if our page is owned by an anon and is loaned out to the 1295 * kernel then we just want to drop ownership and return. 1296 * the kernel must free the page when all its loans clear ... 1297 * note that the kernel can't change the loan status of our 1298 * page as long as we are holding PQ lock. 1299 */ 1300 1301 pg->pqflags &= ~PQ_ANON; 1302 pg->uanon = NULL; 1303 return; 1304 } 1305 KASSERT(saved_loan_count == 0); 1306 1307 /* 1308 * now remove the page from the queues 1309 */ 1310 1311 if (pg->pqflags & PQ_ACTIVE) { 1312 TAILQ_REMOVE(&uvm.page_active, pg, pageq); 1313 pg->pqflags &= ~PQ_ACTIVE; 1314 uvmexp.active--; 1315 } else if (pg->pqflags & PQ_INACTIVE) { 1316 TAILQ_REMOVE(&uvm.page_inactive, pg, pageq); 1317 pg->pqflags &= ~PQ_INACTIVE; 1318 uvmexp.inactive--; 1319 } 1320 1321 /* 1322 * if the page was wired, unwire it now. 1323 */ 1324 1325 if (pg->wire_count) { 1326 pg->wire_count = 0; 1327 uvmexp.wired--; 1328 } 1329 if (pg->uanon) { 1330 uvmexp.anonpages--; 1331 } 1332 1333 /* 1334 * and put on free queue 1335 */ 1336 1337 pg->flags &= ~PG_ZERO; 1338 1339 s = uvm_lock_fpageq(); 1340 TAILQ_INSERT_TAIL(&uvm.page_free[ 1341 uvm_page_lookup_freelist(pg)].pgfl_buckets[ 1342 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1343 pg->pqflags = PQ_FREE; 1344 #ifdef DEBUG 1345 pg->uobject = (void *)0xdeadbeef; 1346 pg->offset = 0xdeadbeef; 1347 pg->uanon = (void *)0xdeadbeef; 1348 #endif 1349 uvmexp.free++; 1350 1351 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1352 uvm.page_idle_zero = vm_page_zero_enable; 1353 1354 uvm_unlock_fpageq(s); 1355 } 1356 1357 /* 1358 * uvm_page_unbusy: unbusy an array of pages. 1359 * 1360 * => pages must either all belong to the same object, or all belong to anons. 1361 * => if pages are object-owned, object must be locked. 1362 * => if pages are anon-owned, anons must be unlockd and have 0 refcount. 1363 */ 1364 1365 void 1366 uvm_page_unbusy(pgs, npgs) 1367 struct vm_page **pgs; 1368 int npgs; 1369 { 1370 struct vm_page *pg; 1371 struct uvm_object *uobj; 1372 int i; 1373 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1374 1375 for (i = 0; i < npgs; i++) { 1376 pg = pgs[i]; 1377 1378 if (pg == NULL) { 1379 continue; 1380 } 1381 if (pg->flags & PG_WANTED) { 1382 wakeup(pg); 1383 } 1384 if (pg->flags & PG_RELEASED) { 1385 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1386 uobj = pg->uobject; 1387 if (uobj != NULL) { 1388 uobj->pgops->pgo_releasepg(pg, NULL); 1389 } else { 1390 pg->flags &= ~(PG_BUSY); 1391 UVM_PAGE_OWN(pg, NULL); 1392 uvm_anfree(pg->uanon); 1393 } 1394 } else { 1395 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1396 KASSERT(pg->wire_count || 1397 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE))); 1398 pg->flags &= ~(PG_WANTED|PG_BUSY); 1399 UVM_PAGE_OWN(pg, NULL); 1400 } 1401 } 1402 } 1403 1404 #if defined(UVM_PAGE_TRKOWN) 1405 /* 1406 * uvm_page_own: set or release page ownership 1407 * 1408 * => this is a debugging function that keeps track of who sets PG_BUSY 1409 * and where they do it. it can be used to track down problems 1410 * such a process setting "PG_BUSY" and never releasing it. 1411 * => page's object [if any] must be locked 1412 * => if "tag" is NULL then we are releasing page ownership 1413 */ 1414 void 1415 uvm_page_own(pg, tag) 1416 struct vm_page *pg; 1417 char *tag; 1418 { 1419 /* gain ownership? */ 1420 if (tag) { 1421 if (pg->owner_tag) { 1422 printf("uvm_page_own: page %p already owned " 1423 "by proc %d [%s]\n", pg, 1424 pg->owner, pg->owner_tag); 1425 panic("uvm_page_own"); 1426 } 1427 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1428 pg->owner_tag = tag; 1429 return; 1430 } 1431 1432 /* drop ownership */ 1433 if (pg->owner_tag == NULL) { 1434 printf("uvm_page_own: dropping ownership of an non-owned " 1435 "page (%p)\n", pg); 1436 panic("uvm_page_own"); 1437 } 1438 pg->owner_tag = NULL; 1439 return; 1440 } 1441 #endif 1442 1443 /* 1444 * uvm_pageidlezero: zero free pages while the system is idle. 1445 * 1446 * => try to complete one color bucket at a time, to reduce our impact 1447 * on the CPU cache. 1448 * => we loop until we either reach the target or whichqs indicates that 1449 * there is a process ready to run. 1450 */ 1451 void 1452 uvm_pageidlezero() 1453 { 1454 struct vm_page *pg; 1455 struct pgfreelist *pgfl; 1456 int free_list, s, firstbucket; 1457 static int nextbucket; 1458 1459 s = uvm_lock_fpageq(); 1460 1461 firstbucket = nextbucket; 1462 do { 1463 if (sched_whichqs != 0) { 1464 uvm_unlock_fpageq(s); 1465 return; 1466 } 1467 1468 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1469 uvm.page_idle_zero = FALSE; 1470 uvm_unlock_fpageq(s); 1471 return; 1472 } 1473 1474 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1475 pgfl = &uvm.page_free[free_list]; 1476 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1477 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1478 if (sched_whichqs != 0) { 1479 uvm_unlock_fpageq(s); 1480 return; 1481 } 1482 1483 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1484 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1485 pg, pageq); 1486 uvmexp.free--; 1487 uvm_unlock_fpageq(s); 1488 #ifdef PMAP_PAGEIDLEZERO 1489 if (PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg)) == 1490 FALSE) { 1491 /* 1492 * The machine-dependent code detected 1493 * some reason for us to abort zeroing 1494 * pages, probably because there is a 1495 * process now ready to run. 1496 */ 1497 s = uvm_lock_fpageq(); 1498 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1499 nextbucket].pgfl_queues[ 1500 PGFL_UNKNOWN], pg, pageq); 1501 uvmexp.free++; 1502 uvmexp.zeroaborts++; 1503 uvm_unlock_fpageq(s); 1504 return; 1505 } 1506 #else 1507 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1508 #endif /* PMAP_PAGEIDLEZERO */ 1509 pg->flags |= PG_ZERO; 1510 1511 s = uvm_lock_fpageq(); 1512 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1513 nextbucket].pgfl_queues[PGFL_ZEROS], 1514 pg, pageq); 1515 uvmexp.free++; 1516 uvmexp.zeropages++; 1517 } 1518 } 1519 1520 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1521 } while (nextbucket != firstbucket); 1522 1523 uvm_unlock_fpageq(s); 1524 } 1525