1 /* $NetBSD: uvm_page.c,v 1.95 2004/02/13 11:36:23 wiz 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 1.95 2004/02/13 11:36:23 wiz 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 #ifdef DEBUG 145 vaddr_t uvm_zerocheckkva; 146 #endif /* DEBUG */ 147 148 /* 149 * local prototypes 150 */ 151 152 static void uvm_pageinsert __P((struct vm_page *)); 153 static void uvm_pageremove __P((struct vm_page *)); 154 155 /* 156 * inline functions 157 */ 158 159 /* 160 * uvm_pageinsert: insert a page in the object and the hash table 161 * 162 * => caller must lock object 163 * => caller must lock page queues 164 * => call should have already set pg's object and offset pointers 165 * and bumped the version counter 166 */ 167 168 __inline static void 169 uvm_pageinsert(pg) 170 struct vm_page *pg; 171 { 172 struct pglist *buck; 173 struct uvm_object *uobj = pg->uobject; 174 175 KASSERT((pg->flags & PG_TABLED) == 0); 176 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 177 simple_lock(&uvm.hashlock); 178 TAILQ_INSERT_TAIL(buck, pg, hashq); 179 simple_unlock(&uvm.hashlock); 180 181 if (UVM_OBJ_IS_VNODE(uobj)) { 182 if (uobj->uo_npages == 0) { 183 struct vnode *vp = (struct vnode *)uobj; 184 185 vholdl(vp); 186 } 187 if (UVM_OBJ_IS_VTEXT(uobj)) { 188 uvmexp.execpages++; 189 } else { 190 uvmexp.filepages++; 191 } 192 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 193 uvmexp.anonpages++; 194 } 195 196 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 197 pg->flags |= PG_TABLED; 198 uobj->uo_npages++; 199 } 200 201 /* 202 * uvm_page_remove: remove page from object and hash 203 * 204 * => caller must lock object 205 * => caller must lock page queues 206 */ 207 208 static __inline void 209 uvm_pageremove(pg) 210 struct vm_page *pg; 211 { 212 struct pglist *buck; 213 struct uvm_object *uobj = pg->uobject; 214 215 KASSERT(pg->flags & PG_TABLED); 216 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 217 simple_lock(&uvm.hashlock); 218 TAILQ_REMOVE(buck, pg, hashq); 219 simple_unlock(&uvm.hashlock); 220 221 if (UVM_OBJ_IS_VNODE(uobj)) { 222 if (uobj->uo_npages == 1) { 223 struct vnode *vp = (struct vnode *)uobj; 224 225 holdrelel(vp); 226 } 227 if (UVM_OBJ_IS_VTEXT(uobj)) { 228 uvmexp.execpages--; 229 } else { 230 uvmexp.filepages--; 231 } 232 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 233 uvmexp.anonpages--; 234 } 235 236 /* object should be locked */ 237 uobj->uo_npages--; 238 TAILQ_REMOVE(&uobj->memq, pg, listq); 239 pg->flags &= ~PG_TABLED; 240 pg->uobject = NULL; 241 } 242 243 static void 244 uvm_page_init_buckets(struct pgfreelist *pgfl) 245 { 246 int color, i; 247 248 for (color = 0; color < uvmexp.ncolors; color++) { 249 for (i = 0; i < PGFL_NQUEUES; i++) { 250 TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); 251 } 252 } 253 } 254 255 /* 256 * uvm_page_init: init the page system. called from uvm_init(). 257 * 258 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 259 */ 260 261 void 262 uvm_page_init(kvm_startp, kvm_endp) 263 vaddr_t *kvm_startp, *kvm_endp; 264 { 265 vsize_t freepages, pagecount, bucketcount, n; 266 struct pgflbucket *bucketarray; 267 struct vm_page *pagearray; 268 int lcv; 269 u_int i; 270 paddr_t paddr; 271 272 /* 273 * init the page queues and page queue locks, except the free 274 * list; we allocate that later (with the initial vm_page 275 * structures). 276 */ 277 278 TAILQ_INIT(&uvm.page_active); 279 TAILQ_INIT(&uvm.page_inactive); 280 simple_lock_init(&uvm.pageqlock); 281 simple_lock_init(&uvm.fpageqlock); 282 283 /* 284 * init the <obj,offset> => <page> hash table. for now 285 * we just have one bucket (the bootstrap bucket). later on we 286 * will allocate new buckets as we dynamically resize the hash table. 287 */ 288 289 uvm.page_nhash = 1; /* 1 bucket */ 290 uvm.page_hashmask = 0; /* mask for hash function */ 291 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 292 TAILQ_INIT(uvm.page_hash); /* init hash table */ 293 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 294 295 /* 296 * allocate vm_page structures. 297 */ 298 299 /* 300 * sanity check: 301 * before calling this function the MD code is expected to register 302 * some free RAM with the uvm_page_physload() function. our job 303 * now is to allocate vm_page structures for this memory. 304 */ 305 306 if (vm_nphysseg == 0) 307 panic("uvm_page_bootstrap: no memory pre-allocated"); 308 309 /* 310 * first calculate the number of free pages... 311 * 312 * note that we use start/end rather than avail_start/avail_end. 313 * this allows us to allocate extra vm_page structures in case we 314 * want to return some memory to the pool after booting. 315 */ 316 317 freepages = 0; 318 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 319 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 320 321 /* 322 * Let MD code initialize the number of colors, or default 323 * to 1 color if MD code doesn't care. 324 */ 325 if (uvmexp.ncolors == 0) 326 uvmexp.ncolors = 1; 327 uvmexp.colormask = uvmexp.ncolors - 1; 328 329 /* 330 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 331 * use. for each page of memory we use we need a vm_page structure. 332 * thus, the total number of pages we can use is the total size of 333 * the memory divided by the PAGE_SIZE plus the size of the vm_page 334 * structure. we add one to freepages as a fudge factor to avoid 335 * truncation errors (since we can only allocate in terms of whole 336 * pages). 337 */ 338 339 bucketcount = uvmexp.ncolors * VM_NFREELIST; 340 pagecount = ((freepages + 1) << PAGE_SHIFT) / 341 (PAGE_SIZE + sizeof(struct vm_page)); 342 343 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 344 sizeof(struct pgflbucket)) + (pagecount * 345 sizeof(struct vm_page))); 346 pagearray = (struct vm_page *)(bucketarray + bucketcount); 347 348 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 349 uvm.page_free[lcv].pgfl_buckets = 350 (bucketarray + (lcv * uvmexp.ncolors)); 351 uvm_page_init_buckets(&uvm.page_free[lcv]); 352 } 353 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 354 355 /* 356 * init the vm_page structures and put them in the correct place. 357 */ 358 359 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 360 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 361 362 /* set up page array pointers */ 363 vm_physmem[lcv].pgs = pagearray; 364 pagearray += n; 365 pagecount -= n; 366 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 367 368 /* init and free vm_pages (we've already zeroed them) */ 369 paddr = ptoa(vm_physmem[lcv].start); 370 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 371 vm_physmem[lcv].pgs[i].phys_addr = paddr; 372 #ifdef __HAVE_VM_PAGE_MD 373 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 374 #endif 375 if (atop(paddr) >= vm_physmem[lcv].avail_start && 376 atop(paddr) <= vm_physmem[lcv].avail_end) { 377 uvmexp.npages++; 378 /* add page to free pool */ 379 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 380 } 381 } 382 } 383 384 /* 385 * pass up the values of virtual_space_start and 386 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 387 * layers of the VM. 388 */ 389 390 *kvm_startp = round_page(virtual_space_start); 391 *kvm_endp = trunc_page(virtual_space_end); 392 #ifdef DEBUG 393 /* 394 * steal kva for uvm_pagezerocheck(). 395 */ 396 uvm_zerocheckkva = *kvm_startp; 397 *kvm_startp += PAGE_SIZE; 398 #endif /* DEBUG */ 399 400 /* 401 * init locks for kernel threads 402 */ 403 404 simple_lock_init(&uvm.pagedaemon_lock); 405 simple_lock_init(&uvm.aiodoned_lock); 406 407 /* 408 * init various thresholds. 409 */ 410 411 uvmexp.reserve_pagedaemon = 1; 412 uvmexp.reserve_kernel = 5; 413 uvmexp.anonminpct = 10; 414 uvmexp.fileminpct = 10; 415 uvmexp.execminpct = 5; 416 uvmexp.anonmaxpct = 80; 417 uvmexp.filemaxpct = 50; 418 uvmexp.execmaxpct = 30; 419 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 420 uvmexp.filemin = uvmexp.fileminpct * 256 / 100; 421 uvmexp.execmin = uvmexp.execminpct * 256 / 100; 422 uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; 423 uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; 424 uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; 425 426 /* 427 * determine if we should zero pages in the idle loop. 428 */ 429 430 uvm.page_idle_zero = vm_page_zero_enable; 431 432 /* 433 * done! 434 */ 435 436 uvm.page_init_done = TRUE; 437 } 438 439 /* 440 * uvm_setpagesize: set the page size 441 * 442 * => sets page_shift and page_mask from uvmexp.pagesize. 443 */ 444 445 void 446 uvm_setpagesize() 447 { 448 449 /* 450 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 451 * to be a constant (indicated by being a non-zero value). 452 */ 453 if (uvmexp.pagesize == 0) { 454 if (PAGE_SIZE == 0) 455 panic("uvm_setpagesize: uvmexp.pagesize not set"); 456 uvmexp.pagesize = PAGE_SIZE; 457 } 458 uvmexp.pagemask = uvmexp.pagesize - 1; 459 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 460 panic("uvm_setpagesize: page size not a power of two"); 461 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 462 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 463 break; 464 } 465 466 /* 467 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 468 */ 469 470 vaddr_t 471 uvm_pageboot_alloc(size) 472 vsize_t size; 473 { 474 static boolean_t initialized = FALSE; 475 vaddr_t addr; 476 #if !defined(PMAP_STEAL_MEMORY) 477 vaddr_t vaddr; 478 paddr_t paddr; 479 #endif 480 481 /* 482 * on first call to this function, initialize ourselves. 483 */ 484 if (initialized == FALSE) { 485 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 486 487 /* round it the way we like it */ 488 virtual_space_start = round_page(virtual_space_start); 489 virtual_space_end = trunc_page(virtual_space_end); 490 491 initialized = TRUE; 492 } 493 494 /* round to page size */ 495 size = round_page(size); 496 497 #if defined(PMAP_STEAL_MEMORY) 498 499 /* 500 * defer bootstrap allocation to MD code (it may want to allocate 501 * from a direct-mapped segment). pmap_steal_memory should adjust 502 * virtual_space_start/virtual_space_end if necessary. 503 */ 504 505 addr = pmap_steal_memory(size, &virtual_space_start, 506 &virtual_space_end); 507 508 return(addr); 509 510 #else /* !PMAP_STEAL_MEMORY */ 511 512 /* 513 * allocate virtual memory for this request 514 */ 515 if (virtual_space_start == virtual_space_end || 516 (virtual_space_end - virtual_space_start) < size) 517 panic("uvm_pageboot_alloc: out of virtual space"); 518 519 addr = virtual_space_start; 520 521 #ifdef PMAP_GROWKERNEL 522 /* 523 * If the kernel pmap can't map the requested space, 524 * then allocate more resources for it. 525 */ 526 if (uvm_maxkaddr < (addr + size)) { 527 uvm_maxkaddr = pmap_growkernel(addr + size); 528 if (uvm_maxkaddr < (addr + size)) 529 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 530 } 531 #endif 532 533 virtual_space_start += size; 534 535 /* 536 * allocate and mapin physical pages to back new virtual pages 537 */ 538 539 for (vaddr = round_page(addr) ; vaddr < addr + size ; 540 vaddr += PAGE_SIZE) { 541 542 if (!uvm_page_physget(&paddr)) 543 panic("uvm_pageboot_alloc: out of memory"); 544 545 /* 546 * Note this memory is no longer managed, so using 547 * pmap_kenter is safe. 548 */ 549 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 550 } 551 pmap_update(pmap_kernel()); 552 return(addr); 553 #endif /* PMAP_STEAL_MEMORY */ 554 } 555 556 #if !defined(PMAP_STEAL_MEMORY) 557 /* 558 * uvm_page_physget: "steal" one page from the vm_physmem structure. 559 * 560 * => attempt to allocate it off the end of a segment in which the "avail" 561 * values match the start/end values. if we can't do that, then we 562 * will advance both values (making them equal, and removing some 563 * vm_page structures from the non-avail area). 564 * => return false if out of memory. 565 */ 566 567 /* subroutine: try to allocate from memory chunks on the specified freelist */ 568 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 569 570 static boolean_t 571 uvm_page_physget_freelist(paddrp, freelist) 572 paddr_t *paddrp; 573 int freelist; 574 { 575 int lcv, x; 576 577 /* pass 1: try allocating from a matching end */ 578 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 579 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 580 #else 581 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 582 #endif 583 { 584 585 if (uvm.page_init_done == TRUE) 586 panic("uvm_page_physget: called _after_ bootstrap"); 587 588 if (vm_physmem[lcv].free_list != freelist) 589 continue; 590 591 /* try from front */ 592 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 593 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 594 *paddrp = ptoa(vm_physmem[lcv].avail_start); 595 vm_physmem[lcv].avail_start++; 596 vm_physmem[lcv].start++; 597 /* nothing left? nuke it */ 598 if (vm_physmem[lcv].avail_start == 599 vm_physmem[lcv].end) { 600 if (vm_nphysseg == 1) 601 panic("uvm_page_physget: out of memory!"); 602 vm_nphysseg--; 603 for (x = lcv ; x < vm_nphysseg ; x++) 604 /* structure copy */ 605 vm_physmem[x] = vm_physmem[x+1]; 606 } 607 return (TRUE); 608 } 609 610 /* try from rear */ 611 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 612 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 613 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 614 vm_physmem[lcv].avail_end--; 615 vm_physmem[lcv].end--; 616 /* nothing left? nuke it */ 617 if (vm_physmem[lcv].avail_end == 618 vm_physmem[lcv].start) { 619 if (vm_nphysseg == 1) 620 panic("uvm_page_physget: out of memory!"); 621 vm_nphysseg--; 622 for (x = lcv ; x < vm_nphysseg ; x++) 623 /* structure copy */ 624 vm_physmem[x] = vm_physmem[x+1]; 625 } 626 return (TRUE); 627 } 628 } 629 630 /* pass2: forget about matching ends, just allocate something */ 631 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 632 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 633 #else 634 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 635 #endif 636 { 637 638 /* any room in this bank? */ 639 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 640 continue; /* nope */ 641 642 *paddrp = ptoa(vm_physmem[lcv].avail_start); 643 vm_physmem[lcv].avail_start++; 644 /* truncate! */ 645 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 646 647 /* nothing left? nuke it */ 648 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 649 if (vm_nphysseg == 1) 650 panic("uvm_page_physget: out of memory!"); 651 vm_nphysseg--; 652 for (x = lcv ; x < vm_nphysseg ; x++) 653 /* structure copy */ 654 vm_physmem[x] = vm_physmem[x+1]; 655 } 656 return (TRUE); 657 } 658 659 return (FALSE); /* whoops! */ 660 } 661 662 boolean_t 663 uvm_page_physget(paddrp) 664 paddr_t *paddrp; 665 { 666 int i; 667 668 /* try in the order of freelist preference */ 669 for (i = 0; i < VM_NFREELIST; i++) 670 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 671 return (TRUE); 672 return (FALSE); 673 } 674 #endif /* PMAP_STEAL_MEMORY */ 675 676 /* 677 * uvm_page_physload: load physical memory into VM system 678 * 679 * => all args are PFs 680 * => all pages in start/end get vm_page structures 681 * => areas marked by avail_start/avail_end get added to the free page pool 682 * => we are limited to VM_PHYSSEG_MAX physical memory segments 683 */ 684 685 void 686 uvm_page_physload(start, end, avail_start, avail_end, free_list) 687 paddr_t start, end, avail_start, avail_end; 688 int free_list; 689 { 690 int preload, lcv; 691 psize_t npages; 692 struct vm_page *pgs; 693 struct vm_physseg *ps; 694 695 if (uvmexp.pagesize == 0) 696 panic("uvm_page_physload: page size not set!"); 697 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 698 panic("uvm_page_physload: bad free list %d", free_list); 699 if (start >= end) 700 panic("uvm_page_physload: start >= end"); 701 702 /* 703 * do we have room? 704 */ 705 706 if (vm_nphysseg == VM_PHYSSEG_MAX) { 707 printf("uvm_page_physload: unable to load physical memory " 708 "segment\n"); 709 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 710 VM_PHYSSEG_MAX, (long long)start, (long long)end); 711 printf("\tincrease VM_PHYSSEG_MAX\n"); 712 return; 713 } 714 715 /* 716 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 717 * called yet, so malloc is not available). 718 */ 719 720 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 721 if (vm_physmem[lcv].pgs) 722 break; 723 } 724 preload = (lcv == vm_nphysseg); 725 726 /* 727 * if VM is already running, attempt to malloc() vm_page structures 728 */ 729 730 if (!preload) { 731 #if defined(VM_PHYSSEG_NOADD) 732 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 733 #else 734 /* XXXCDC: need some sort of lockout for this case */ 735 paddr_t paddr; 736 npages = end - start; /* # of pages */ 737 pgs = malloc(sizeof(struct vm_page) * npages, 738 M_VMPAGE, M_NOWAIT); 739 if (pgs == NULL) { 740 printf("uvm_page_physload: can not malloc vm_page " 741 "structs for segment\n"); 742 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 743 return; 744 } 745 /* zero data, init phys_addr and free_list, and free pages */ 746 memset(pgs, 0, sizeof(struct vm_page) * npages); 747 for (lcv = 0, paddr = ptoa(start) ; 748 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 749 pgs[lcv].phys_addr = paddr; 750 pgs[lcv].free_list = free_list; 751 if (atop(paddr) >= avail_start && 752 atop(paddr) <= avail_end) 753 uvm_pagefree(&pgs[lcv]); 754 } 755 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 756 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 757 #endif 758 } else { 759 pgs = NULL; 760 npages = 0; 761 } 762 763 /* 764 * now insert us in the proper place in vm_physmem[] 765 */ 766 767 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 768 /* random: put it at the end (easy!) */ 769 ps = &vm_physmem[vm_nphysseg]; 770 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 771 { 772 int x; 773 /* sort by address for binary search */ 774 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 775 if (start < vm_physmem[lcv].start) 776 break; 777 ps = &vm_physmem[lcv]; 778 /* move back other entries, if necessary ... */ 779 for (x = vm_nphysseg ; x > lcv ; x--) 780 /* structure copy */ 781 vm_physmem[x] = vm_physmem[x - 1]; 782 } 783 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 784 { 785 int x; 786 /* sort by largest segment first */ 787 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 788 if ((end - start) > 789 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 790 break; 791 ps = &vm_physmem[lcv]; 792 /* move back other entries, if necessary ... */ 793 for (x = vm_nphysseg ; x > lcv ; x--) 794 /* structure copy */ 795 vm_physmem[x] = vm_physmem[x - 1]; 796 } 797 #else 798 panic("uvm_page_physload: unknown physseg strategy selected!"); 799 #endif 800 801 ps->start = start; 802 ps->end = end; 803 ps->avail_start = avail_start; 804 ps->avail_end = avail_end; 805 if (preload) { 806 ps->pgs = NULL; 807 } else { 808 ps->pgs = pgs; 809 ps->lastpg = pgs + npages - 1; 810 } 811 ps->free_list = free_list; 812 vm_nphysseg++; 813 814 if (!preload) 815 uvm_page_rehash(); 816 } 817 818 /* 819 * uvm_page_rehash: reallocate hash table based on number of free pages. 820 */ 821 822 void 823 uvm_page_rehash() 824 { 825 int freepages, lcv, bucketcount, oldcount; 826 struct pglist *newbuckets, *oldbuckets; 827 struct vm_page *pg; 828 size_t newsize, oldsize; 829 830 /* 831 * compute number of pages that can go in the free pool 832 */ 833 834 freepages = 0; 835 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 836 freepages += 837 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 838 839 /* 840 * compute number of buckets needed for this number of pages 841 */ 842 843 bucketcount = 1; 844 while (bucketcount < freepages) 845 bucketcount = bucketcount * 2; 846 847 /* 848 * compute the size of the current table and new table. 849 */ 850 851 oldbuckets = uvm.page_hash; 852 oldcount = uvm.page_nhash; 853 oldsize = round_page(sizeof(struct pglist) * oldcount); 854 newsize = round_page(sizeof(struct pglist) * bucketcount); 855 856 /* 857 * allocate the new buckets 858 */ 859 860 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 861 if (newbuckets == NULL) { 862 printf("uvm_page_physrehash: WARNING: could not grow page " 863 "hash table\n"); 864 return; 865 } 866 for (lcv = 0 ; lcv < bucketcount ; lcv++) 867 TAILQ_INIT(&newbuckets[lcv]); 868 869 /* 870 * now replace the old buckets with the new ones and rehash everything 871 */ 872 873 simple_lock(&uvm.hashlock); 874 uvm.page_hash = newbuckets; 875 uvm.page_nhash = bucketcount; 876 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 877 878 /* ... and rehash */ 879 for (lcv = 0 ; lcv < oldcount ; lcv++) { 880 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 881 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 882 TAILQ_INSERT_TAIL( 883 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 884 pg, hashq); 885 } 886 } 887 simple_unlock(&uvm.hashlock); 888 889 /* 890 * free old bucket array if is not the boot-time table 891 */ 892 893 if (oldbuckets != &uvm_bootbucket) 894 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 895 } 896 897 /* 898 * uvm_page_recolor: Recolor the pages if the new bucket count is 899 * larger than the old one. 900 */ 901 902 void 903 uvm_page_recolor(int newncolors) 904 { 905 struct pgflbucket *bucketarray, *oldbucketarray; 906 struct pgfreelist pgfl; 907 struct vm_page *pg; 908 vsize_t bucketcount; 909 int s, lcv, color, i, ocolors; 910 911 if (newncolors <= uvmexp.ncolors) 912 return; 913 914 if (uvm.page_init_done == FALSE) { 915 uvmexp.ncolors = newncolors; 916 return; 917 } 918 919 bucketcount = newncolors * VM_NFREELIST; 920 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 921 M_VMPAGE, M_NOWAIT); 922 if (bucketarray == NULL) { 923 printf("WARNING: unable to allocate %ld page color buckets\n", 924 (long) bucketcount); 925 return; 926 } 927 928 s = uvm_lock_fpageq(); 929 930 /* Make sure we should still do this. */ 931 if (newncolors <= uvmexp.ncolors) { 932 uvm_unlock_fpageq(s); 933 free(bucketarray, M_VMPAGE); 934 return; 935 } 936 937 oldbucketarray = uvm.page_free[0].pgfl_buckets; 938 ocolors = uvmexp.ncolors; 939 940 uvmexp.ncolors = newncolors; 941 uvmexp.colormask = uvmexp.ncolors - 1; 942 943 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 944 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 945 uvm_page_init_buckets(&pgfl); 946 for (color = 0; color < ocolors; color++) { 947 for (i = 0; i < PGFL_NQUEUES; i++) { 948 while ((pg = TAILQ_FIRST(&uvm.page_free[ 949 lcv].pgfl_buckets[color].pgfl_queues[i])) 950 != NULL) { 951 TAILQ_REMOVE(&uvm.page_free[ 952 lcv].pgfl_buckets[ 953 color].pgfl_queues[i], pg, pageq); 954 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 955 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 956 i], pg, pageq); 957 } 958 } 959 } 960 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 961 } 962 963 if (have_recolored_pages) { 964 uvm_unlock_fpageq(s); 965 free(oldbucketarray, M_VMPAGE); 966 return; 967 } 968 969 have_recolored_pages = TRUE; 970 uvm_unlock_fpageq(s); 971 } 972 973 /* 974 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 975 */ 976 977 static __inline struct vm_page * 978 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 979 int *trycolorp) 980 { 981 struct pglist *freeq; 982 struct vm_page *pg; 983 int color, trycolor = *trycolorp; 984 985 color = trycolor; 986 do { 987 if ((pg = TAILQ_FIRST((freeq = 988 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 989 goto gotit; 990 if ((pg = TAILQ_FIRST((freeq = 991 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 992 goto gotit; 993 color = (color + 1) & uvmexp.colormask; 994 } while (color != trycolor); 995 996 return (NULL); 997 998 gotit: 999 TAILQ_REMOVE(freeq, pg, pageq); 1000 uvmexp.free--; 1001 1002 /* update zero'd page count */ 1003 if (pg->flags & PG_ZERO) 1004 uvmexp.zeropages--; 1005 1006 if (color == trycolor) 1007 uvmexp.colorhit++; 1008 else { 1009 uvmexp.colormiss++; 1010 *trycolorp = color; 1011 } 1012 1013 return (pg); 1014 } 1015 1016 /* 1017 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1018 * 1019 * => return null if no pages free 1020 * => wake up pagedaemon if number of free pages drops below low water mark 1021 * => if obj != NULL, obj must be locked (to put in hash) 1022 * => if anon != NULL, anon must be locked (to put in anon) 1023 * => only one of obj or anon can be non-null 1024 * => caller must activate/deactivate page if it is not wired. 1025 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1026 * => policy decision: it is more important to pull a page off of the 1027 * appropriate priority free list than it is to get a zero'd or 1028 * unknown contents page. This is because we live with the 1029 * consequences of a bad free list decision for the entire 1030 * lifetime of the page, e.g. if the page comes from memory that 1031 * is slower to access. 1032 */ 1033 1034 struct vm_page * 1035 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 1036 struct uvm_object *obj; 1037 voff_t off; 1038 int flags; 1039 struct vm_anon *anon; 1040 int strat, free_list; 1041 { 1042 int lcv, try1, try2, s, zeroit = 0, color; 1043 struct vm_page *pg; 1044 boolean_t use_reserve; 1045 1046 KASSERT(obj == NULL || anon == NULL); 1047 KASSERT(off == trunc_page(off)); 1048 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1049 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1050 1051 s = uvm_lock_fpageq(); 1052 1053 /* 1054 * This implements a global round-robin page coloring 1055 * algorithm. 1056 * 1057 * XXXJRT: Should we make the `nextcolor' per-CPU? 1058 * XXXJRT: What about virtually-indexed caches? 1059 */ 1060 1061 color = uvm.page_free_nextcolor; 1062 1063 /* 1064 * check to see if we need to generate some free pages waking 1065 * the pagedaemon. 1066 */ 1067 1068 UVM_KICK_PDAEMON(); 1069 1070 /* 1071 * fail if any of these conditions is true: 1072 * [1] there really are no free pages, or 1073 * [2] only kernel "reserved" pages remain and 1074 * the page isn't being allocated to a kernel object. 1075 * [3] only pagedaemon "reserved" pages remain and 1076 * the requestor isn't the pagedaemon. 1077 */ 1078 1079 use_reserve = (flags & UVM_PGA_USERESERVE) || 1080 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1081 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1082 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1083 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1084 goto fail; 1085 1086 #if PGFL_NQUEUES != 2 1087 #error uvm_pagealloc_strat needs to be updated 1088 #endif 1089 1090 /* 1091 * If we want a zero'd page, try the ZEROS queue first, otherwise 1092 * we try the UNKNOWN queue first. 1093 */ 1094 if (flags & UVM_PGA_ZERO) { 1095 try1 = PGFL_ZEROS; 1096 try2 = PGFL_UNKNOWN; 1097 } else { 1098 try1 = PGFL_UNKNOWN; 1099 try2 = PGFL_ZEROS; 1100 } 1101 1102 again: 1103 switch (strat) { 1104 case UVM_PGA_STRAT_NORMAL: 1105 /* Check all freelists in descending priority order. */ 1106 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1107 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1108 try1, try2, &color); 1109 if (pg != NULL) 1110 goto gotit; 1111 } 1112 1113 /* No pages free! */ 1114 goto fail; 1115 1116 case UVM_PGA_STRAT_ONLY: 1117 case UVM_PGA_STRAT_FALLBACK: 1118 /* Attempt to allocate from the specified free list. */ 1119 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1120 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1121 try1, try2, &color); 1122 if (pg != NULL) 1123 goto gotit; 1124 1125 /* Fall back, if possible. */ 1126 if (strat == UVM_PGA_STRAT_FALLBACK) { 1127 strat = UVM_PGA_STRAT_NORMAL; 1128 goto again; 1129 } 1130 1131 /* No pages free! */ 1132 goto fail; 1133 1134 default: 1135 panic("uvm_pagealloc_strat: bad strat %d", strat); 1136 /* NOTREACHED */ 1137 } 1138 1139 gotit: 1140 /* 1141 * We now know which color we actually allocated from; set 1142 * the next color accordingly. 1143 */ 1144 1145 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1146 1147 /* 1148 * update allocation statistics and remember if we have to 1149 * zero the page 1150 */ 1151 1152 if (flags & UVM_PGA_ZERO) { 1153 if (pg->flags & PG_ZERO) { 1154 uvmexp.pga_zerohit++; 1155 zeroit = 0; 1156 } else { 1157 uvmexp.pga_zeromiss++; 1158 zeroit = 1; 1159 } 1160 } 1161 uvm_unlock_fpageq(s); 1162 1163 pg->offset = off; 1164 pg->uobject = obj; 1165 pg->uanon = anon; 1166 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1167 if (anon) { 1168 anon->u.an_page = pg; 1169 pg->pqflags = PQ_ANON; 1170 uvmexp.anonpages++; 1171 } else { 1172 if (obj) { 1173 uvm_pageinsert(pg); 1174 } 1175 pg->pqflags = 0; 1176 } 1177 #if defined(UVM_PAGE_TRKOWN) 1178 pg->owner_tag = NULL; 1179 #endif 1180 UVM_PAGE_OWN(pg, "new alloc"); 1181 1182 if (flags & UVM_PGA_ZERO) { 1183 /* 1184 * A zero'd page is not clean. If we got a page not already 1185 * zero'd, then we have to zero it ourselves. 1186 */ 1187 pg->flags &= ~PG_CLEAN; 1188 if (zeroit) 1189 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1190 } 1191 1192 return(pg); 1193 1194 fail: 1195 uvm_unlock_fpageq(s); 1196 return (NULL); 1197 } 1198 1199 /* 1200 * uvm_pagerealloc: reallocate a page from one object to another 1201 * 1202 * => both objects must be locked 1203 */ 1204 1205 void 1206 uvm_pagerealloc(pg, newobj, newoff) 1207 struct vm_page *pg; 1208 struct uvm_object *newobj; 1209 voff_t newoff; 1210 { 1211 /* 1212 * remove it from the old object 1213 */ 1214 1215 if (pg->uobject) { 1216 uvm_pageremove(pg); 1217 } 1218 1219 /* 1220 * put it in the new object 1221 */ 1222 1223 if (newobj) { 1224 pg->uobject = newobj; 1225 pg->offset = newoff; 1226 uvm_pageinsert(pg); 1227 } 1228 } 1229 1230 #ifdef DEBUG 1231 /* 1232 * check if page is zero-filled 1233 * 1234 * - called with free page queue lock held. 1235 */ 1236 void 1237 uvm_pagezerocheck(struct vm_page *pg) 1238 { 1239 int *p, *ep; 1240 1241 KASSERT(uvm_zerocheckkva != 0); 1242 LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock)); 1243 1244 /* 1245 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1246 * uvm page allocator. 1247 * 1248 * it might be better to have "CPU-local temporary map" pmap interface. 1249 */ 1250 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); 1251 p = (int *)uvm_zerocheckkva; 1252 ep = (int *)((char *)p + PAGE_SIZE); 1253 pmap_update(pmap_kernel()); 1254 while (p < ep) { 1255 if (*p != 0) 1256 panic("PG_ZERO page isn't zero-filled"); 1257 p++; 1258 } 1259 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1260 } 1261 #endif /* DEBUG */ 1262 1263 /* 1264 * uvm_pagefree: free page 1265 * 1266 * => erase page's identity (i.e. remove from hash/object) 1267 * => put page on free list 1268 * => caller must lock owning object (either anon or uvm_object) 1269 * => caller must lock page queues 1270 * => assumes all valid mappings of pg are gone 1271 */ 1272 1273 void 1274 uvm_pagefree(pg) 1275 struct vm_page *pg; 1276 { 1277 int s; 1278 struct pglist *pgfl; 1279 boolean_t iszero; 1280 1281 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1282 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1283 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1284 LOCK_ASSERT(pg->uobject == NULL || 1285 simple_lock_held(&pg->uobject->vmobjlock)); 1286 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1287 simple_lock_held(&pg->uanon->an_lock)); 1288 1289 #ifdef DEBUG 1290 if (pg->uobject == (void *)0xdeadbeef && 1291 pg->uanon == (void *)0xdeadbeef) { 1292 panic("uvm_pagefree: freeing free page %p", pg); 1293 } 1294 #endif /* DEBUG */ 1295 1296 /* 1297 * if the page is loaned, resolve the loan instead of freeing. 1298 */ 1299 1300 if (pg->loan_count) { 1301 KASSERT(pg->wire_count == 0); 1302 1303 /* 1304 * if the page is owned by an anon then we just want to 1305 * drop anon ownership. the kernel will free the page when 1306 * it is done with it. if the page is owned by an object, 1307 * remove it from the object and mark it dirty for the benefit 1308 * of possible anon owners. 1309 * 1310 * regardless of previous ownership, wakeup any waiters, 1311 * unbusy the page, and we're done. 1312 */ 1313 1314 if (pg->uobject != NULL) { 1315 uvm_pageremove(pg); 1316 pg->flags &= ~PG_CLEAN; 1317 } else if (pg->uanon != NULL) { 1318 if ((pg->pqflags & PQ_ANON) == 0) { 1319 pg->loan_count--; 1320 } else { 1321 pg->pqflags &= ~PQ_ANON; 1322 } 1323 pg->uanon = NULL; 1324 } 1325 if (pg->flags & PG_WANTED) { 1326 wakeup(pg); 1327 } 1328 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1329 #ifdef UVM_PAGE_TRKOWN 1330 pg->owner_tag = NULL; 1331 #endif 1332 if (pg->loan_count) { 1333 uvm_pagedequeue(pg); 1334 return; 1335 } 1336 } 1337 1338 /* 1339 * remove page from its object or anon. 1340 */ 1341 1342 if (pg->uobject != NULL) { 1343 uvm_pageremove(pg); 1344 } else if (pg->uanon != NULL) { 1345 pg->uanon->u.an_page = NULL; 1346 uvmexp.anonpages--; 1347 } 1348 1349 /* 1350 * now remove the page from the queues. 1351 */ 1352 1353 uvm_pagedequeue(pg); 1354 1355 /* 1356 * if the page was wired, unwire it now. 1357 */ 1358 1359 if (pg->wire_count) { 1360 pg->wire_count = 0; 1361 uvmexp.wired--; 1362 } 1363 1364 /* 1365 * and put on free queue 1366 */ 1367 1368 iszero = (pg->flags & PG_ZERO); 1369 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. 1370 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 1371 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; 1372 1373 pg->pqflags = PQ_FREE; 1374 #ifdef DEBUG 1375 pg->uobject = (void *)0xdeadbeef; 1376 pg->offset = 0xdeadbeef; 1377 pg->uanon = (void *)0xdeadbeef; 1378 #endif 1379 1380 s = uvm_lock_fpageq(); 1381 1382 #ifdef DEBUG 1383 if (iszero) 1384 uvm_pagezerocheck(pg); 1385 #endif /* DEBUG */ 1386 1387 TAILQ_INSERT_TAIL(pgfl, pg, pageq); 1388 uvmexp.free++; 1389 if (iszero) 1390 uvmexp.zeropages++; 1391 1392 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1393 uvm.page_idle_zero = vm_page_zero_enable; 1394 1395 uvm_unlock_fpageq(s); 1396 } 1397 1398 /* 1399 * uvm_page_unbusy: unbusy an array of pages. 1400 * 1401 * => pages must either all belong to the same object, or all belong to anons. 1402 * => if pages are object-owned, object must be locked. 1403 * => if pages are anon-owned, anons must be locked. 1404 * => caller must lock page queues if pages may be released. 1405 */ 1406 1407 void 1408 uvm_page_unbusy(pgs, npgs) 1409 struct vm_page **pgs; 1410 int npgs; 1411 { 1412 struct vm_page *pg; 1413 int i; 1414 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1415 1416 for (i = 0; i < npgs; i++) { 1417 pg = pgs[i]; 1418 if (pg == NULL || pg == PGO_DONTCARE) { 1419 continue; 1420 } 1421 if (pg->flags & PG_WANTED) { 1422 wakeup(pg); 1423 } 1424 if (pg->flags & PG_RELEASED) { 1425 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1426 pg->flags &= ~PG_RELEASED; 1427 uvm_pagefree(pg); 1428 } else { 1429 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1430 pg->flags &= ~(PG_WANTED|PG_BUSY); 1431 UVM_PAGE_OWN(pg, NULL); 1432 } 1433 } 1434 } 1435 1436 #if defined(UVM_PAGE_TRKOWN) 1437 /* 1438 * uvm_page_own: set or release page ownership 1439 * 1440 * => this is a debugging function that keeps track of who sets PG_BUSY 1441 * and where they do it. it can be used to track down problems 1442 * such a process setting "PG_BUSY" and never releasing it. 1443 * => page's object [if any] must be locked 1444 * => if "tag" is NULL then we are releasing page ownership 1445 */ 1446 void 1447 uvm_page_own(pg, tag) 1448 struct vm_page *pg; 1449 char *tag; 1450 { 1451 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1452 1453 /* gain ownership? */ 1454 if (tag) { 1455 if (pg->owner_tag) { 1456 printf("uvm_page_own: page %p already owned " 1457 "by proc %d [%s]\n", pg, 1458 pg->owner, pg->owner_tag); 1459 panic("uvm_page_own"); 1460 } 1461 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1462 pg->owner_tag = tag; 1463 return; 1464 } 1465 1466 /* drop ownership */ 1467 if (pg->owner_tag == NULL) { 1468 printf("uvm_page_own: dropping ownership of an non-owned " 1469 "page (%p)\n", pg); 1470 panic("uvm_page_own"); 1471 } 1472 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1473 (pg->uanon == NULL && pg->uobject == NULL) || 1474 pg->uobject == uvm.kernel_object || 1475 pg->wire_count > 0 || 1476 (pg->loan_count == 1 && pg->uanon == NULL) || 1477 pg->loan_count > 1); 1478 pg->owner_tag = NULL; 1479 } 1480 #endif 1481 1482 /* 1483 * uvm_pageidlezero: zero free pages while the system is idle. 1484 * 1485 * => try to complete one color bucket at a time, to reduce our impact 1486 * on the CPU cache. 1487 * => we loop until we either reach the target or whichqs indicates that 1488 * there is a process ready to run. 1489 */ 1490 void 1491 uvm_pageidlezero() 1492 { 1493 struct vm_page *pg; 1494 struct pgfreelist *pgfl; 1495 int free_list, s, firstbucket; 1496 static int nextbucket; 1497 1498 s = uvm_lock_fpageq(); 1499 firstbucket = nextbucket; 1500 do { 1501 if (sched_whichqs != 0) { 1502 uvm_unlock_fpageq(s); 1503 return; 1504 } 1505 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1506 uvm.page_idle_zero = FALSE; 1507 uvm_unlock_fpageq(s); 1508 return; 1509 } 1510 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1511 pgfl = &uvm.page_free[free_list]; 1512 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1513 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1514 if (sched_whichqs != 0) { 1515 uvm_unlock_fpageq(s); 1516 return; 1517 } 1518 1519 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1520 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1521 pg, pageq); 1522 uvmexp.free--; 1523 uvm_unlock_fpageq(s); 1524 #ifdef PMAP_PAGEIDLEZERO 1525 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1526 1527 /* 1528 * The machine-dependent code detected 1529 * some reason for us to abort zeroing 1530 * pages, probably because there is a 1531 * process now ready to run. 1532 */ 1533 1534 s = uvm_lock_fpageq(); 1535 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1536 nextbucket].pgfl_queues[ 1537 PGFL_UNKNOWN], pg, pageq); 1538 uvmexp.free++; 1539 uvmexp.zeroaborts++; 1540 uvm_unlock_fpageq(s); 1541 return; 1542 } 1543 #else 1544 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1545 #endif /* PMAP_PAGEIDLEZERO */ 1546 pg->flags |= PG_ZERO; 1547 1548 s = uvm_lock_fpageq(); 1549 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1550 nextbucket].pgfl_queues[PGFL_ZEROS], 1551 pg, pageq); 1552 uvmexp.free++; 1553 uvmexp.zeropages++; 1554 } 1555 } 1556 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1557 } while (nextbucket != firstbucket); 1558 uvm_unlock_fpageq(s); 1559 } 1560