1 /* $NetBSD: uvm_page.c,v 1.83 2003/02/01 06:23:55 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 <sys/cdefs.h> 74 __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.83 2003/02/01 06:23:55 thorpej 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 MALLOC_DEFINE(M_VMPAGE, "VM page", "VM page"); 143 144 /* 145 * local prototypes 146 */ 147 148 static void uvm_pageinsert __P((struct vm_page *)); 149 static void uvm_pageremove __P((struct vm_page *)); 150 151 /* 152 * inline functions 153 */ 154 155 /* 156 * uvm_pageinsert: insert a page in the object and the hash table 157 * 158 * => caller must lock object 159 * => caller must lock page queues 160 * => call should have already set pg's object and offset pointers 161 * and bumped the version counter 162 */ 163 164 __inline static void 165 uvm_pageinsert(pg) 166 struct vm_page *pg; 167 { 168 struct pglist *buck; 169 struct uvm_object *uobj = pg->uobject; 170 171 KASSERT((pg->flags & PG_TABLED) == 0); 172 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 173 simple_lock(&uvm.hashlock); 174 TAILQ_INSERT_TAIL(buck, pg, hashq); 175 simple_unlock(&uvm.hashlock); 176 177 if (UVM_OBJ_IS_AOBJ(uobj)) { 178 uvmexp.anonpages++; 179 } 180 181 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 182 pg->flags |= PG_TABLED; 183 uobj->uo_npages++; 184 } 185 186 /* 187 * uvm_page_remove: remove page from object and hash 188 * 189 * => caller must lock object 190 * => caller must lock page queues 191 */ 192 193 static __inline void 194 uvm_pageremove(pg) 195 struct vm_page *pg; 196 { 197 struct pglist *buck; 198 struct uvm_object *uobj = pg->uobject; 199 200 KASSERT(pg->flags & PG_TABLED); 201 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 202 simple_lock(&uvm.hashlock); 203 TAILQ_REMOVE(buck, pg, hashq); 204 simple_unlock(&uvm.hashlock); 205 206 if (UVM_OBJ_IS_VTEXT(uobj)) { 207 uvmexp.execpages--; 208 } else if (UVM_OBJ_IS_VNODE(uobj)) { 209 uvmexp.filepages--; 210 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 211 uvmexp.anonpages--; 212 } 213 214 /* object should be locked */ 215 uobj->uo_npages--; 216 TAILQ_REMOVE(&uobj->memq, pg, listq); 217 pg->flags &= ~PG_TABLED; 218 pg->uobject = NULL; 219 } 220 221 static void 222 uvm_page_init_buckets(struct pgfreelist *pgfl) 223 { 224 int color, i; 225 226 for (color = 0; color < uvmexp.ncolors; color++) { 227 for (i = 0; i < PGFL_NQUEUES; i++) { 228 TAILQ_INIT(&pgfl->pgfl_buckets[ 229 color].pgfl_queues[i]); 230 } 231 } 232 } 233 234 /* 235 * uvm_page_init: init the page system. called from uvm_init(). 236 * 237 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 238 */ 239 240 void 241 uvm_page_init(kvm_startp, kvm_endp) 242 vaddr_t *kvm_startp, *kvm_endp; 243 { 244 vsize_t freepages, pagecount, bucketcount, n; 245 struct pgflbucket *bucketarray; 246 struct vm_page *pagearray; 247 int lcv; 248 u_int i; 249 paddr_t paddr; 250 251 /* 252 * init the page queues and page queue locks, except the free 253 * list; we allocate that later (with the initial vm_page 254 * structures). 255 */ 256 257 TAILQ_INIT(&uvm.page_active); 258 TAILQ_INIT(&uvm.page_inactive); 259 simple_lock_init(&uvm.pageqlock); 260 simple_lock_init(&uvm.fpageqlock); 261 262 /* 263 * init the <obj,offset> => <page> hash table. for now 264 * we just have one bucket (the bootstrap bucket). later on we 265 * will allocate new buckets as we dynamically resize the hash table. 266 */ 267 268 uvm.page_nhash = 1; /* 1 bucket */ 269 uvm.page_hashmask = 0; /* mask for hash function */ 270 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 271 TAILQ_INIT(uvm.page_hash); /* init hash table */ 272 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 273 274 /* 275 * allocate vm_page structures. 276 */ 277 278 /* 279 * sanity check: 280 * before calling this function the MD code is expected to register 281 * some free RAM with the uvm_page_physload() function. our job 282 * now is to allocate vm_page structures for this memory. 283 */ 284 285 if (vm_nphysseg == 0) 286 panic("uvm_page_bootstrap: no memory pre-allocated"); 287 288 /* 289 * first calculate the number of free pages... 290 * 291 * note that we use start/end rather than avail_start/avail_end. 292 * this allows us to allocate extra vm_page structures in case we 293 * want to return some memory to the pool after booting. 294 */ 295 296 freepages = 0; 297 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 298 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 299 300 /* 301 * Let MD code initialize the number of colors, or default 302 * to 1 color if MD code doesn't care. 303 */ 304 if (uvmexp.ncolors == 0) 305 uvmexp.ncolors = 1; 306 uvmexp.colormask = uvmexp.ncolors - 1; 307 308 /* 309 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 310 * use. for each page of memory we use we need a vm_page structure. 311 * thus, the total number of pages we can use is the total size of 312 * the memory divided by the PAGE_SIZE plus the size of the vm_page 313 * structure. we add one to freepages as a fudge factor to avoid 314 * truncation errors (since we can only allocate in terms of whole 315 * pages). 316 */ 317 318 bucketcount = uvmexp.ncolors * VM_NFREELIST; 319 pagecount = ((freepages + 1) << PAGE_SHIFT) / 320 (PAGE_SIZE + sizeof(struct vm_page)); 321 322 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 323 sizeof(struct pgflbucket)) + (pagecount * 324 sizeof(struct vm_page))); 325 pagearray = (struct vm_page *)(bucketarray + bucketcount); 326 327 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 328 uvm.page_free[lcv].pgfl_buckets = 329 (bucketarray + (lcv * uvmexp.ncolors)); 330 uvm_page_init_buckets(&uvm.page_free[lcv]); 331 } 332 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 333 334 /* 335 * init the vm_page structures and put them in the correct place. 336 */ 337 338 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 339 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 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 */ 382 383 uvmexp.reserve_pagedaemon = 1; 384 uvmexp.reserve_kernel = 5; 385 uvmexp.anonminpct = 10; 386 uvmexp.fileminpct = 10; 387 uvmexp.execminpct = 5; 388 uvmexp.anonmaxpct = 80; 389 uvmexp.filemaxpct = 50; 390 uvmexp.execmaxpct = 30; 391 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 392 uvmexp.filemin = uvmexp.fileminpct * 256 / 100; 393 uvmexp.execmin = uvmexp.execminpct * 256 / 100; 394 uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; 395 uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; 396 uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; 397 398 /* 399 * determine if we should zero pages in the idle loop. 400 */ 401 402 uvm.page_idle_zero = vm_page_zero_enable; 403 404 /* 405 * done! 406 */ 407 408 uvm.page_init_done = TRUE; 409 } 410 411 /* 412 * uvm_setpagesize: set the page size 413 * 414 * => sets page_shift and page_mask from uvmexp.pagesize. 415 */ 416 417 void 418 uvm_setpagesize() 419 { 420 if (uvmexp.pagesize == 0) 421 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 422 uvmexp.pagemask = uvmexp.pagesize - 1; 423 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 424 panic("uvm_setpagesize: page size not a power of two"); 425 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 426 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 427 break; 428 } 429 430 /* 431 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 432 */ 433 434 vaddr_t 435 uvm_pageboot_alloc(size) 436 vsize_t size; 437 { 438 static boolean_t initialized = FALSE; 439 vaddr_t addr; 440 #if !defined(PMAP_STEAL_MEMORY) 441 vaddr_t vaddr; 442 paddr_t paddr; 443 #endif 444 445 /* 446 * on first call to this function, initialize ourselves. 447 */ 448 if (initialized == FALSE) { 449 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 450 451 /* round it the way we like it */ 452 virtual_space_start = round_page(virtual_space_start); 453 virtual_space_end = trunc_page(virtual_space_end); 454 455 initialized = TRUE; 456 } 457 458 /* round to page size */ 459 size = round_page(size); 460 461 #if defined(PMAP_STEAL_MEMORY) 462 463 /* 464 * defer bootstrap allocation to MD code (it may want to allocate 465 * from a direct-mapped segment). pmap_steal_memory should adjust 466 * virtual_space_start/virtual_space_end if necessary. 467 */ 468 469 addr = pmap_steal_memory(size, &virtual_space_start, 470 &virtual_space_end); 471 472 return(addr); 473 474 #else /* !PMAP_STEAL_MEMORY */ 475 476 /* 477 * allocate virtual memory for this request 478 */ 479 if (virtual_space_start == virtual_space_end || 480 (virtual_space_end - virtual_space_start) < size) 481 panic("uvm_pageboot_alloc: out of virtual space"); 482 483 addr = virtual_space_start; 484 485 #ifdef PMAP_GROWKERNEL 486 /* 487 * If the kernel pmap can't map the requested space, 488 * then allocate more resources for it. 489 */ 490 if (uvm_maxkaddr < (addr + size)) { 491 uvm_maxkaddr = pmap_growkernel(addr + size); 492 if (uvm_maxkaddr < (addr + size)) 493 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 494 } 495 #endif 496 497 virtual_space_start += size; 498 499 /* 500 * allocate and mapin physical pages to back new virtual pages 501 */ 502 503 for (vaddr = round_page(addr) ; vaddr < addr + size ; 504 vaddr += PAGE_SIZE) { 505 506 if (!uvm_page_physget(&paddr)) 507 panic("uvm_pageboot_alloc: out of memory"); 508 509 /* 510 * Note this memory is no longer managed, so using 511 * pmap_kenter is safe. 512 */ 513 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 514 } 515 pmap_update(pmap_kernel()); 516 return(addr); 517 #endif /* PMAP_STEAL_MEMORY */ 518 } 519 520 #if !defined(PMAP_STEAL_MEMORY) 521 /* 522 * uvm_page_physget: "steal" one page from the vm_physmem structure. 523 * 524 * => attempt to allocate it off the end of a segment in which the "avail" 525 * values match the start/end values. if we can't do that, then we 526 * will advance both values (making them equal, and removing some 527 * vm_page structures from the non-avail area). 528 * => return false if out of memory. 529 */ 530 531 /* subroutine: try to allocate from memory chunks on the specified freelist */ 532 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 533 534 static boolean_t 535 uvm_page_physget_freelist(paddrp, freelist) 536 paddr_t *paddrp; 537 int freelist; 538 { 539 int lcv, x; 540 541 /* pass 1: try allocating from a matching end */ 542 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 543 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 544 #else 545 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 546 #endif 547 { 548 549 if (uvm.page_init_done == TRUE) 550 panic("uvm_page_physget: called _after_ bootstrap"); 551 552 if (vm_physmem[lcv].free_list != freelist) 553 continue; 554 555 /* try from front */ 556 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 557 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 558 *paddrp = ptoa(vm_physmem[lcv].avail_start); 559 vm_physmem[lcv].avail_start++; 560 vm_physmem[lcv].start++; 561 /* nothing left? nuke it */ 562 if (vm_physmem[lcv].avail_start == 563 vm_physmem[lcv].end) { 564 if (vm_nphysseg == 1) 565 panic("vum_page_physget: out of memory!"); 566 vm_nphysseg--; 567 for (x = lcv ; x < vm_nphysseg ; x++) 568 /* structure copy */ 569 vm_physmem[x] = vm_physmem[x+1]; 570 } 571 return (TRUE); 572 } 573 574 /* try from rear */ 575 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 576 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 577 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 578 vm_physmem[lcv].avail_end--; 579 vm_physmem[lcv].end--; 580 /* nothing left? nuke it */ 581 if (vm_physmem[lcv].avail_end == 582 vm_physmem[lcv].start) { 583 if (vm_nphysseg == 1) 584 panic("uvm_page_physget: out of memory!"); 585 vm_nphysseg--; 586 for (x = lcv ; x < vm_nphysseg ; x++) 587 /* structure copy */ 588 vm_physmem[x] = vm_physmem[x+1]; 589 } 590 return (TRUE); 591 } 592 } 593 594 /* pass2: forget about matching ends, just allocate something */ 595 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 596 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 597 #else 598 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 599 #endif 600 { 601 602 /* any room in this bank? */ 603 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 604 continue; /* nope */ 605 606 *paddrp = ptoa(vm_physmem[lcv].avail_start); 607 vm_physmem[lcv].avail_start++; 608 /* truncate! */ 609 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 610 611 /* nothing left? nuke it */ 612 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 613 if (vm_nphysseg == 1) 614 panic("uvm_page_physget: out of memory!"); 615 vm_nphysseg--; 616 for (x = lcv ; x < vm_nphysseg ; x++) 617 /* structure copy */ 618 vm_physmem[x] = vm_physmem[x+1]; 619 } 620 return (TRUE); 621 } 622 623 return (FALSE); /* whoops! */ 624 } 625 626 boolean_t 627 uvm_page_physget(paddrp) 628 paddr_t *paddrp; 629 { 630 int i; 631 632 /* try in the order of freelist preference */ 633 for (i = 0; i < VM_NFREELIST; i++) 634 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 635 return (TRUE); 636 return (FALSE); 637 } 638 #endif /* PMAP_STEAL_MEMORY */ 639 640 /* 641 * uvm_page_physload: load physical memory into VM system 642 * 643 * => all args are PFs 644 * => all pages in start/end get vm_page structures 645 * => areas marked by avail_start/avail_end get added to the free page pool 646 * => we are limited to VM_PHYSSEG_MAX physical memory segments 647 */ 648 649 void 650 uvm_page_physload(start, end, avail_start, avail_end, free_list) 651 paddr_t start, end, avail_start, avail_end; 652 int free_list; 653 { 654 int preload, lcv; 655 psize_t npages; 656 struct vm_page *pgs; 657 struct vm_physseg *ps; 658 659 if (uvmexp.pagesize == 0) 660 panic("uvm_page_physload: page size not set!"); 661 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 662 panic("uvm_page_physload: bad free list %d", free_list); 663 if (start >= end) 664 panic("uvm_page_physload: start >= end"); 665 666 /* 667 * do we have room? 668 */ 669 670 if (vm_nphysseg == VM_PHYSSEG_MAX) { 671 printf("uvm_page_physload: unable to load physical memory " 672 "segment\n"); 673 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 674 VM_PHYSSEG_MAX, (long long)start, (long long)end); 675 printf("\tincrease VM_PHYSSEG_MAX\n"); 676 return; 677 } 678 679 /* 680 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 681 * called yet, so malloc is not available). 682 */ 683 684 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 685 if (vm_physmem[lcv].pgs) 686 break; 687 } 688 preload = (lcv == vm_nphysseg); 689 690 /* 691 * if VM is already running, attempt to malloc() vm_page structures 692 */ 693 694 if (!preload) { 695 #if defined(VM_PHYSSEG_NOADD) 696 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 697 #else 698 /* XXXCDC: need some sort of lockout for this case */ 699 paddr_t paddr; 700 npages = end - start; /* # of pages */ 701 pgs = malloc(sizeof(struct vm_page) * npages, 702 M_VMPAGE, M_NOWAIT); 703 if (pgs == NULL) { 704 printf("uvm_page_physload: can not malloc vm_page " 705 "structs for segment\n"); 706 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 707 return; 708 } 709 /* zero data, init phys_addr and free_list, and free pages */ 710 memset(pgs, 0, sizeof(struct vm_page) * npages); 711 for (lcv = 0, paddr = ptoa(start) ; 712 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 713 pgs[lcv].phys_addr = paddr; 714 pgs[lcv].free_list = free_list; 715 if (atop(paddr) >= avail_start && 716 atop(paddr) <= avail_end) 717 uvm_pagefree(&pgs[lcv]); 718 } 719 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 720 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 721 #endif 722 } else { 723 pgs = NULL; 724 npages = 0; 725 } 726 727 /* 728 * now insert us in the proper place in vm_physmem[] 729 */ 730 731 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 732 /* random: put it at the end (easy!) */ 733 ps = &vm_physmem[vm_nphysseg]; 734 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 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 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 748 { 749 int x; 750 /* sort by largest segment first */ 751 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 752 if ((end - start) > 753 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 754 break; 755 ps = &vm_physmem[lcv]; 756 /* move back other entries, if necessary ... */ 757 for (x = vm_nphysseg ; x > lcv ; x--) 758 /* structure copy */ 759 vm_physmem[x] = vm_physmem[x - 1]; 760 } 761 #else 762 panic("uvm_page_physload: unknown physseg strategy selected!"); 763 #endif 764 765 ps->start = start; 766 ps->end = end; 767 ps->avail_start = avail_start; 768 ps->avail_end = avail_end; 769 if (preload) { 770 ps->pgs = NULL; 771 } else { 772 ps->pgs = pgs; 773 ps->lastpg = pgs + npages - 1; 774 } 775 ps->free_list = free_list; 776 vm_nphysseg++; 777 778 if (!preload) 779 uvm_page_rehash(); 780 } 781 782 /* 783 * uvm_page_rehash: reallocate hash table based on number of free pages. 784 */ 785 786 void 787 uvm_page_rehash() 788 { 789 int freepages, lcv, bucketcount, oldcount; 790 struct pglist *newbuckets, *oldbuckets; 791 struct vm_page *pg; 792 size_t newsize, oldsize; 793 794 /* 795 * compute number of pages that can go in the free pool 796 */ 797 798 freepages = 0; 799 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 800 freepages += 801 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 802 803 /* 804 * compute number of buckets needed for this number of pages 805 */ 806 807 bucketcount = 1; 808 while (bucketcount < freepages) 809 bucketcount = bucketcount * 2; 810 811 /* 812 * compute the size of the current table and new table. 813 */ 814 815 oldbuckets = uvm.page_hash; 816 oldcount = uvm.page_nhash; 817 oldsize = round_page(sizeof(struct pglist) * oldcount); 818 newsize = round_page(sizeof(struct pglist) * bucketcount); 819 820 /* 821 * allocate the new buckets 822 */ 823 824 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 825 if (newbuckets == NULL) { 826 printf("uvm_page_physrehash: WARNING: could not grow page " 827 "hash table\n"); 828 return; 829 } 830 for (lcv = 0 ; lcv < bucketcount ; lcv++) 831 TAILQ_INIT(&newbuckets[lcv]); 832 833 /* 834 * now replace the old buckets with the new ones and rehash everything 835 */ 836 837 simple_lock(&uvm.hashlock); 838 uvm.page_hash = newbuckets; 839 uvm.page_nhash = bucketcount; 840 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 841 842 /* ... and rehash */ 843 for (lcv = 0 ; lcv < oldcount ; lcv++) { 844 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 845 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 846 TAILQ_INSERT_TAIL( 847 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 848 pg, hashq); 849 } 850 } 851 simple_unlock(&uvm.hashlock); 852 853 /* 854 * free old bucket array if is not the boot-time table 855 */ 856 857 if (oldbuckets != &uvm_bootbucket) 858 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 859 } 860 861 /* 862 * uvm_page_recolor: Recolor the pages if the new bucket count is 863 * larger than the old one. 864 */ 865 866 void 867 uvm_page_recolor(int newncolors) 868 { 869 struct pgflbucket *bucketarray, *oldbucketarray; 870 struct pgfreelist pgfl; 871 struct vm_page *pg; 872 vsize_t bucketcount; 873 int s, lcv, color, i, ocolors; 874 875 if (newncolors <= uvmexp.ncolors) 876 return; 877 878 if (uvm.page_init_done == FALSE) { 879 uvmexp.ncolors = newncolors; 880 return; 881 } 882 883 bucketcount = newncolors * VM_NFREELIST; 884 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 885 M_VMPAGE, M_NOWAIT); 886 if (bucketarray == NULL) { 887 printf("WARNING: unable to allocate %ld page color buckets\n", 888 (long) bucketcount); 889 return; 890 } 891 892 s = uvm_lock_fpageq(); 893 894 /* Make sure we should still do this. */ 895 if (newncolors <= uvmexp.ncolors) { 896 uvm_unlock_fpageq(s); 897 free(bucketarray, M_VMPAGE); 898 return; 899 } 900 901 oldbucketarray = uvm.page_free[0].pgfl_buckets; 902 ocolors = uvmexp.ncolors; 903 904 uvmexp.ncolors = newncolors; 905 uvmexp.colormask = uvmexp.ncolors - 1; 906 907 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 908 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 909 uvm_page_init_buckets(&pgfl); 910 for (color = 0; color < ocolors; color++) { 911 for (i = 0; i < PGFL_NQUEUES; i++) { 912 while ((pg = TAILQ_FIRST(&uvm.page_free[ 913 lcv].pgfl_buckets[color].pgfl_queues[i])) 914 != NULL) { 915 TAILQ_REMOVE(&uvm.page_free[ 916 lcv].pgfl_buckets[ 917 color].pgfl_queues[i], pg, pageq); 918 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 919 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 920 i], pg, pageq); 921 } 922 } 923 } 924 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 925 } 926 927 if (have_recolored_pages) { 928 uvm_unlock_fpageq(s); 929 free(oldbucketarray, M_VMPAGE); 930 return; 931 } 932 933 have_recolored_pages = TRUE; 934 uvm_unlock_fpageq(s); 935 } 936 937 /* 938 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 939 */ 940 941 static __inline struct vm_page * 942 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 943 int *trycolorp) 944 { 945 struct pglist *freeq; 946 struct vm_page *pg; 947 int color, trycolor = *trycolorp; 948 949 color = trycolor; 950 do { 951 if ((pg = TAILQ_FIRST((freeq = 952 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 953 goto gotit; 954 if ((pg = TAILQ_FIRST((freeq = 955 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 956 goto gotit; 957 color = (color + 1) & uvmexp.colormask; 958 } while (color != trycolor); 959 960 return (NULL); 961 962 gotit: 963 TAILQ_REMOVE(freeq, pg, pageq); 964 uvmexp.free--; 965 966 /* update zero'd page count */ 967 if (pg->flags & PG_ZERO) 968 uvmexp.zeropages--; 969 970 if (color == trycolor) 971 uvmexp.colorhit++; 972 else { 973 uvmexp.colormiss++; 974 *trycolorp = color; 975 } 976 977 return (pg); 978 } 979 980 /* 981 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 982 * 983 * => return null if no pages free 984 * => wake up pagedaemon if number of free pages drops below low water mark 985 * => if obj != NULL, obj must be locked (to put in hash) 986 * => if anon != NULL, anon must be locked (to put in anon) 987 * => only one of obj or anon can be non-null 988 * => caller must activate/deactivate page if it is not wired. 989 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 990 * => policy decision: it is more important to pull a page off of the 991 * appropriate priority free list than it is to get a zero'd or 992 * unknown contents page. This is because we live with the 993 * consequences of a bad free list decision for the entire 994 * lifetime of the page, e.g. if the page comes from memory that 995 * is slower to access. 996 */ 997 998 struct vm_page * 999 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 1000 struct uvm_object *obj; 1001 voff_t off; 1002 int flags; 1003 struct vm_anon *anon; 1004 int strat, free_list; 1005 { 1006 int lcv, try1, try2, s, zeroit = 0, color; 1007 struct vm_page *pg; 1008 boolean_t use_reserve; 1009 1010 KASSERT(obj == NULL || anon == NULL); 1011 KASSERT(off == trunc_page(off)); 1012 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1013 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1014 1015 s = uvm_lock_fpageq(); 1016 1017 /* 1018 * This implements a global round-robin page coloring 1019 * algorithm. 1020 * 1021 * XXXJRT: Should we make the `nextcolor' per-cpu? 1022 * XXXJRT: What about virtually-indexed caches? 1023 */ 1024 1025 color = uvm.page_free_nextcolor; 1026 1027 /* 1028 * check to see if we need to generate some free pages waking 1029 * the pagedaemon. 1030 */ 1031 1032 UVM_KICK_PDAEMON(); 1033 1034 /* 1035 * fail if any of these conditions is true: 1036 * [1] there really are no free pages, or 1037 * [2] only kernel "reserved" pages remain and 1038 * the page isn't being allocated to a kernel object. 1039 * [3] only pagedaemon "reserved" pages remain and 1040 * the requestor isn't the pagedaemon. 1041 */ 1042 1043 use_reserve = (flags & UVM_PGA_USERESERVE) || 1044 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1045 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1046 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1047 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1048 goto fail; 1049 1050 #if PGFL_NQUEUES != 2 1051 #error uvm_pagealloc_strat needs to be updated 1052 #endif 1053 1054 /* 1055 * If we want a zero'd page, try the ZEROS queue first, otherwise 1056 * we try the UNKNOWN queue first. 1057 */ 1058 if (flags & UVM_PGA_ZERO) { 1059 try1 = PGFL_ZEROS; 1060 try2 = PGFL_UNKNOWN; 1061 } else { 1062 try1 = PGFL_UNKNOWN; 1063 try2 = PGFL_ZEROS; 1064 } 1065 1066 again: 1067 switch (strat) { 1068 case UVM_PGA_STRAT_NORMAL: 1069 /* Check all freelists in descending priority order. */ 1070 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1071 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1072 try1, try2, &color); 1073 if (pg != NULL) 1074 goto gotit; 1075 } 1076 1077 /* No pages free! */ 1078 goto fail; 1079 1080 case UVM_PGA_STRAT_ONLY: 1081 case UVM_PGA_STRAT_FALLBACK: 1082 /* Attempt to allocate from the specified free list. */ 1083 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1084 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1085 try1, try2, &color); 1086 if (pg != NULL) 1087 goto gotit; 1088 1089 /* Fall back, if possible. */ 1090 if (strat == UVM_PGA_STRAT_FALLBACK) { 1091 strat = UVM_PGA_STRAT_NORMAL; 1092 goto again; 1093 } 1094 1095 /* No pages free! */ 1096 goto fail; 1097 1098 default: 1099 panic("uvm_pagealloc_strat: bad strat %d", strat); 1100 /* NOTREACHED */ 1101 } 1102 1103 gotit: 1104 /* 1105 * We now know which color we actually allocated from; set 1106 * the next color accordingly. 1107 */ 1108 1109 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1110 1111 /* 1112 * update allocation statistics and remember if we have to 1113 * zero the page 1114 */ 1115 1116 if (flags & UVM_PGA_ZERO) { 1117 if (pg->flags & PG_ZERO) { 1118 uvmexp.pga_zerohit++; 1119 zeroit = 0; 1120 } else { 1121 uvmexp.pga_zeromiss++; 1122 zeroit = 1; 1123 } 1124 } 1125 uvm_unlock_fpageq(s); 1126 1127 pg->offset = off; 1128 pg->uobject = obj; 1129 pg->uanon = anon; 1130 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1131 if (anon) { 1132 anon->u.an_page = pg; 1133 pg->pqflags = PQ_ANON; 1134 uvmexp.anonpages++; 1135 } else { 1136 if (obj) { 1137 uvm_pageinsert(pg); 1138 } 1139 pg->pqflags = 0; 1140 } 1141 #if defined(UVM_PAGE_TRKOWN) 1142 pg->owner_tag = NULL; 1143 #endif 1144 UVM_PAGE_OWN(pg, "new alloc"); 1145 1146 if (flags & UVM_PGA_ZERO) { 1147 /* 1148 * A zero'd page is not clean. If we got a page not already 1149 * zero'd, then we have to zero it ourselves. 1150 */ 1151 pg->flags &= ~PG_CLEAN; 1152 if (zeroit) 1153 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1154 } 1155 1156 return(pg); 1157 1158 fail: 1159 uvm_unlock_fpageq(s); 1160 return (NULL); 1161 } 1162 1163 /* 1164 * uvm_pagerealloc: reallocate a page from one object to another 1165 * 1166 * => both objects must be locked 1167 */ 1168 1169 void 1170 uvm_pagerealloc(pg, newobj, newoff) 1171 struct vm_page *pg; 1172 struct uvm_object *newobj; 1173 voff_t newoff; 1174 { 1175 /* 1176 * remove it from the old object 1177 */ 1178 1179 if (pg->uobject) { 1180 uvm_pageremove(pg); 1181 } 1182 1183 /* 1184 * put it in the new object 1185 */ 1186 1187 if (newobj) { 1188 pg->uobject = newobj; 1189 pg->offset = newoff; 1190 uvm_pageinsert(pg); 1191 } 1192 } 1193 1194 /* 1195 * uvm_pagefree: free page 1196 * 1197 * => erase page's identity (i.e. remove from hash/object) 1198 * => put page on free list 1199 * => caller must lock owning object (either anon or uvm_object) 1200 * => caller must lock page queues 1201 * => assumes all valid mappings of pg are gone 1202 */ 1203 1204 void 1205 uvm_pagefree(pg) 1206 struct vm_page *pg; 1207 { 1208 int s; 1209 1210 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1211 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1212 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1213 LOCK_ASSERT(pg->uobject == NULL || 1214 simple_lock_held(&pg->uobject->vmobjlock)); 1215 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1216 simple_lock_held(&pg->uanon->an_lock)); 1217 1218 #ifdef DEBUG 1219 if (pg->uobject == (void *)0xdeadbeef && 1220 pg->uanon == (void *)0xdeadbeef) { 1221 panic("uvm_pagefree: freeing free page %p", pg); 1222 } 1223 #endif 1224 1225 /* 1226 * if the page is loaned, resolve the loan instead of freeing. 1227 */ 1228 1229 if (pg->loan_count) { 1230 KASSERT(pg->wire_count == 0); 1231 1232 /* 1233 * if the page is owned by an anon then we just want to 1234 * drop anon ownership. the kernel will free the page when 1235 * it is done with it. if the page is owned by an object, 1236 * remove it from the object and mark it dirty for the benefit 1237 * of possible anon owners. 1238 * 1239 * regardless of previous ownership, wakeup any waiters, 1240 * unbusy the page, and we're done. 1241 */ 1242 1243 if (pg->uobject != NULL) { 1244 uvm_pageremove(pg); 1245 pg->flags &= ~PG_CLEAN; 1246 } else if (pg->uanon != NULL) { 1247 if ((pg->pqflags & PQ_ANON) == 0) { 1248 pg->loan_count--; 1249 } else { 1250 pg->pqflags &= ~PQ_ANON; 1251 } 1252 pg->uanon = NULL; 1253 } 1254 if (pg->flags & PG_WANTED) { 1255 wakeup(pg); 1256 } 1257 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED); 1258 #ifdef UVM_PAGE_TRKOWN 1259 pg->owner_tag = NULL; 1260 #endif 1261 if (pg->loan_count) { 1262 uvm_pagedequeue(pg); 1263 return; 1264 } 1265 } 1266 1267 /* 1268 * remove page from its object or anon. 1269 */ 1270 1271 if (pg->uobject != NULL) { 1272 uvm_pageremove(pg); 1273 } else if (pg->uanon != NULL) { 1274 pg->uanon->u.an_page = NULL; 1275 uvmexp.anonpages--; 1276 } 1277 1278 /* 1279 * now remove the page from the queues. 1280 */ 1281 1282 uvm_pagedequeue(pg); 1283 1284 /* 1285 * if the page was wired, unwire it now. 1286 */ 1287 1288 if (pg->wire_count) { 1289 pg->wire_count = 0; 1290 uvmexp.wired--; 1291 } 1292 1293 /* 1294 * and put on free queue 1295 */ 1296 1297 pg->flags &= ~PG_ZERO; 1298 1299 s = uvm_lock_fpageq(); 1300 TAILQ_INSERT_TAIL(&uvm.page_free[ 1301 uvm_page_lookup_freelist(pg)].pgfl_buckets[ 1302 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1303 pg->pqflags = PQ_FREE; 1304 #ifdef DEBUG 1305 pg->uobject = (void *)0xdeadbeef; 1306 pg->offset = 0xdeadbeef; 1307 pg->uanon = (void *)0xdeadbeef; 1308 #endif 1309 uvmexp.free++; 1310 1311 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1312 uvm.page_idle_zero = vm_page_zero_enable; 1313 1314 uvm_unlock_fpageq(s); 1315 } 1316 1317 /* 1318 * uvm_page_unbusy: unbusy an array of pages. 1319 * 1320 * => pages must either all belong to the same object, or all belong to anons. 1321 * => if pages are object-owned, object must be locked. 1322 * => if pages are anon-owned, anons must be locked. 1323 * => caller must lock page queues if pages may be released. 1324 */ 1325 1326 void 1327 uvm_page_unbusy(pgs, npgs) 1328 struct vm_page **pgs; 1329 int npgs; 1330 { 1331 struct vm_page *pg; 1332 int i; 1333 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1334 1335 for (i = 0; i < npgs; i++) { 1336 pg = pgs[i]; 1337 if (pg == NULL || pg == PGO_DONTCARE) { 1338 continue; 1339 } 1340 if (pg->flags & PG_WANTED) { 1341 wakeup(pg); 1342 } 1343 if (pg->flags & PG_RELEASED) { 1344 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1345 pg->flags &= ~PG_RELEASED; 1346 uvm_pagefree(pg); 1347 } else { 1348 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1349 pg->flags &= ~(PG_WANTED|PG_BUSY); 1350 UVM_PAGE_OWN(pg, NULL); 1351 } 1352 } 1353 } 1354 1355 #if defined(UVM_PAGE_TRKOWN) 1356 /* 1357 * uvm_page_own: set or release page ownership 1358 * 1359 * => this is a debugging function that keeps track of who sets PG_BUSY 1360 * and where they do it. it can be used to track down problems 1361 * such a process setting "PG_BUSY" and never releasing it. 1362 * => page's object [if any] must be locked 1363 * => if "tag" is NULL then we are releasing page ownership 1364 */ 1365 void 1366 uvm_page_own(pg, tag) 1367 struct vm_page *pg; 1368 char *tag; 1369 { 1370 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1371 1372 /* gain ownership? */ 1373 if (tag) { 1374 if (pg->owner_tag) { 1375 printf("uvm_page_own: page %p already owned " 1376 "by proc %d [%s]\n", pg, 1377 pg->owner, pg->owner_tag); 1378 panic("uvm_page_own"); 1379 } 1380 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1381 pg->owner_tag = tag; 1382 return; 1383 } 1384 1385 /* drop ownership */ 1386 if (pg->owner_tag == NULL) { 1387 printf("uvm_page_own: dropping ownership of an non-owned " 1388 "page (%p)\n", pg); 1389 panic("uvm_page_own"); 1390 } 1391 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1392 (pg->uanon == NULL && pg->uobject == NULL) || 1393 pg->uobject == uvm.kernel_object || 1394 pg->wire_count > 0 || 1395 (pg->loan_count == 1 && pg->uanon == NULL) || 1396 pg->loan_count > 1); 1397 pg->owner_tag = NULL; 1398 } 1399 #endif 1400 1401 /* 1402 * uvm_pageidlezero: zero free pages while the system is idle. 1403 * 1404 * => try to complete one color bucket at a time, to reduce our impact 1405 * on the CPU cache. 1406 * => we loop until we either reach the target or whichqs indicates that 1407 * there is a process ready to run. 1408 */ 1409 void 1410 uvm_pageidlezero() 1411 { 1412 struct vm_page *pg; 1413 struct pgfreelist *pgfl; 1414 int free_list, s, firstbucket; 1415 static int nextbucket; 1416 1417 s = uvm_lock_fpageq(); 1418 firstbucket = nextbucket; 1419 do { 1420 if (sched_whichqs != 0) { 1421 uvm_unlock_fpageq(s); 1422 return; 1423 } 1424 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1425 uvm.page_idle_zero = FALSE; 1426 uvm_unlock_fpageq(s); 1427 return; 1428 } 1429 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1430 pgfl = &uvm.page_free[free_list]; 1431 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1432 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1433 if (sched_whichqs != 0) { 1434 uvm_unlock_fpageq(s); 1435 return; 1436 } 1437 1438 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1439 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1440 pg, pageq); 1441 uvmexp.free--; 1442 uvm_unlock_fpageq(s); 1443 #ifdef PMAP_PAGEIDLEZERO 1444 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1445 1446 /* 1447 * The machine-dependent code detected 1448 * some reason for us to abort zeroing 1449 * pages, probably because there is a 1450 * process now ready to run. 1451 */ 1452 1453 s = uvm_lock_fpageq(); 1454 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1455 nextbucket].pgfl_queues[ 1456 PGFL_UNKNOWN], pg, pageq); 1457 uvmexp.free++; 1458 uvmexp.zeroaborts++; 1459 uvm_unlock_fpageq(s); 1460 return; 1461 } 1462 #else 1463 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1464 #endif /* PMAP_PAGEIDLEZERO */ 1465 pg->flags |= PG_ZERO; 1466 1467 s = uvm_lock_fpageq(); 1468 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1469 nextbucket].pgfl_queues[PGFL_ZEROS], 1470 pg, pageq); 1471 uvmexp.free++; 1472 uvmexp.zeropages++; 1473 } 1474 } 1475 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1476 } while (nextbucket != firstbucket); 1477 uvm_unlock_fpageq(s); 1478 } 1479