1 /* $NetBSD: uvm_page.c,v 1.107 2005/12/11 12:25:29 christos 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 1.107 2005/12/11 12:25:29 christos 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_C /* pull in uvm_page_i.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(struct vm_page *); 153 static void uvm_pageinsert_after(struct vm_page *, struct vm_page *); 154 static void uvm_pageremove(struct vm_page *); 155 156 /* 157 * inline functions 158 */ 159 160 /* 161 * uvm_pageinsert: insert a page in the object and the hash table 162 * uvm_pageinsert_after: insert a page into the specified place in listq 163 * 164 * => caller must lock object 165 * => caller must lock page queues 166 * => call should have already set pg's object and offset pointers 167 * and bumped the version counter 168 */ 169 170 __inline static void 171 uvm_pageinsert_after(struct vm_page *pg, struct vm_page *where) 172 { 173 struct pglist *buck; 174 struct uvm_object *uobj = pg->uobject; 175 176 KASSERT((pg->flags & PG_TABLED) == 0); 177 KASSERT(where == NULL || (where->flags & PG_TABLED)); 178 KASSERT(where == NULL || (where->uobject == uobj)); 179 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 180 simple_lock(&uvm.hashlock); 181 TAILQ_INSERT_TAIL(buck, pg, hashq); 182 simple_unlock(&uvm.hashlock); 183 184 if (UVM_OBJ_IS_VNODE(uobj)) { 185 if (uobj->uo_npages == 0) { 186 struct vnode *vp = (struct vnode *)uobj; 187 188 vholdl(vp); 189 } 190 if (UVM_OBJ_IS_VTEXT(uobj)) { 191 uvmexp.execpages++; 192 } else { 193 uvmexp.filepages++; 194 } 195 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 196 uvmexp.anonpages++; 197 } 198 199 if (where) 200 TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq); 201 else 202 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 203 pg->flags |= PG_TABLED; 204 uobj->uo_npages++; 205 } 206 207 __inline static void 208 uvm_pageinsert(struct vm_page *pg) 209 { 210 211 uvm_pageinsert_after(pg, NULL); 212 } 213 214 /* 215 * uvm_page_remove: remove page from object and hash 216 * 217 * => caller must lock object 218 * => caller must lock page queues 219 */ 220 221 static __inline void 222 uvm_pageremove(struct vm_page *pg) 223 { 224 struct pglist *buck; 225 struct uvm_object *uobj = pg->uobject; 226 227 KASSERT(pg->flags & PG_TABLED); 228 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 229 simple_lock(&uvm.hashlock); 230 TAILQ_REMOVE(buck, pg, hashq); 231 simple_unlock(&uvm.hashlock); 232 233 if (UVM_OBJ_IS_VNODE(uobj)) { 234 if (uobj->uo_npages == 1) { 235 struct vnode *vp = (struct vnode *)uobj; 236 237 holdrelel(vp); 238 } 239 if (UVM_OBJ_IS_VTEXT(uobj)) { 240 uvmexp.execpages--; 241 } else { 242 uvmexp.filepages--; 243 } 244 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 245 uvmexp.anonpages--; 246 } 247 248 /* object should be locked */ 249 uobj->uo_npages--; 250 TAILQ_REMOVE(&uobj->memq, pg, listq); 251 pg->flags &= ~PG_TABLED; 252 pg->uobject = NULL; 253 } 254 255 static void 256 uvm_page_init_buckets(struct pgfreelist *pgfl) 257 { 258 int color, i; 259 260 for (color = 0; color < uvmexp.ncolors; color++) { 261 for (i = 0; i < PGFL_NQUEUES; i++) { 262 TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); 263 } 264 } 265 } 266 267 /* 268 * uvm_page_init: init the page system. called from uvm_init(). 269 * 270 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 271 */ 272 273 void 274 uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp) 275 { 276 vsize_t freepages, pagecount, bucketcount, n; 277 struct pgflbucket *bucketarray; 278 struct vm_page *pagearray; 279 int lcv; 280 u_int i; 281 paddr_t paddr; 282 283 /* 284 * init the page queues and page queue locks, except the free 285 * list; we allocate that later (with the initial vm_page 286 * structures). 287 */ 288 289 TAILQ_INIT(&uvm.page_active); 290 TAILQ_INIT(&uvm.page_inactive); 291 simple_lock_init(&uvm.pageqlock); 292 simple_lock_init(&uvm.fpageqlock); 293 294 /* 295 * init the <obj,offset> => <page> hash table. for now 296 * we just have one bucket (the bootstrap bucket). later on we 297 * will allocate new buckets as we dynamically resize the hash table. 298 */ 299 300 uvm.page_nhash = 1; /* 1 bucket */ 301 uvm.page_hashmask = 0; /* mask for hash function */ 302 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 303 TAILQ_INIT(uvm.page_hash); /* init hash table */ 304 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 305 306 /* 307 * allocate vm_page structures. 308 */ 309 310 /* 311 * sanity check: 312 * before calling this function the MD code is expected to register 313 * some free RAM with the uvm_page_physload() function. our job 314 * now is to allocate vm_page structures for this memory. 315 */ 316 317 if (vm_nphysseg == 0) 318 panic("uvm_page_bootstrap: no memory pre-allocated"); 319 320 /* 321 * first calculate the number of free pages... 322 * 323 * note that we use start/end rather than avail_start/avail_end. 324 * this allows us to allocate extra vm_page structures in case we 325 * want to return some memory to the pool after booting. 326 */ 327 328 freepages = 0; 329 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 330 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 331 332 /* 333 * Let MD code initialize the number of colors, or default 334 * to 1 color if MD code doesn't care. 335 */ 336 if (uvmexp.ncolors == 0) 337 uvmexp.ncolors = 1; 338 uvmexp.colormask = uvmexp.ncolors - 1; 339 340 /* 341 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 342 * use. for each page of memory we use we need a vm_page structure. 343 * thus, the total number of pages we can use is the total size of 344 * the memory divided by the PAGE_SIZE plus the size of the vm_page 345 * structure. we add one to freepages as a fudge factor to avoid 346 * truncation errors (since we can only allocate in terms of whole 347 * pages). 348 */ 349 350 bucketcount = uvmexp.ncolors * VM_NFREELIST; 351 pagecount = ((freepages + 1) << PAGE_SHIFT) / 352 (PAGE_SIZE + sizeof(struct vm_page)); 353 354 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 355 sizeof(struct pgflbucket)) + (pagecount * 356 sizeof(struct vm_page))); 357 pagearray = (struct vm_page *)(bucketarray + bucketcount); 358 359 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 360 uvm.page_free[lcv].pgfl_buckets = 361 (bucketarray + (lcv * uvmexp.ncolors)); 362 uvm_page_init_buckets(&uvm.page_free[lcv]); 363 } 364 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 365 366 /* 367 * init the vm_page structures and put them in the correct place. 368 */ 369 370 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 371 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 372 373 /* set up page array pointers */ 374 vm_physmem[lcv].pgs = pagearray; 375 pagearray += n; 376 pagecount -= n; 377 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 378 379 /* init and free vm_pages (we've already zeroed them) */ 380 paddr = ptoa(vm_physmem[lcv].start); 381 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 382 vm_physmem[lcv].pgs[i].phys_addr = paddr; 383 #ifdef __HAVE_VM_PAGE_MD 384 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 385 #endif 386 if (atop(paddr) >= vm_physmem[lcv].avail_start && 387 atop(paddr) <= vm_physmem[lcv].avail_end) { 388 uvmexp.npages++; 389 /* add page to free pool */ 390 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 391 } 392 } 393 } 394 395 /* 396 * pass up the values of virtual_space_start and 397 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 398 * layers of the VM. 399 */ 400 401 *kvm_startp = round_page(virtual_space_start); 402 *kvm_endp = trunc_page(virtual_space_end); 403 #ifdef DEBUG 404 /* 405 * steal kva for uvm_pagezerocheck(). 406 */ 407 uvm_zerocheckkva = *kvm_startp; 408 *kvm_startp += PAGE_SIZE; 409 #endif /* DEBUG */ 410 411 /* 412 * init locks for kernel threads 413 */ 414 415 simple_lock_init(&uvm.pagedaemon_lock); 416 simple_lock_init(&uvm.aiodoned_lock); 417 418 /* 419 * init various thresholds. 420 */ 421 422 uvmexp.reserve_pagedaemon = 1; 423 uvmexp.reserve_kernel = 5; 424 uvmexp.anonminpct = 10; 425 uvmexp.fileminpct = 10; 426 uvmexp.execminpct = 5; 427 uvmexp.anonmaxpct = 80; 428 uvmexp.filemaxpct = 50; 429 uvmexp.execmaxpct = 30; 430 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 431 uvmexp.filemin = uvmexp.fileminpct * 256 / 100; 432 uvmexp.execmin = uvmexp.execminpct * 256 / 100; 433 uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; 434 uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; 435 uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; 436 437 /* 438 * determine if we should zero pages in the idle loop. 439 */ 440 441 uvm.page_idle_zero = vm_page_zero_enable; 442 443 /* 444 * done! 445 */ 446 447 uvm.page_init_done = TRUE; 448 } 449 450 /* 451 * uvm_setpagesize: set the page size 452 * 453 * => sets page_shift and page_mask from uvmexp.pagesize. 454 */ 455 456 void 457 uvm_setpagesize(void) 458 { 459 460 /* 461 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 462 * to be a constant (indicated by being a non-zero value). 463 */ 464 if (uvmexp.pagesize == 0) { 465 if (PAGE_SIZE == 0) 466 panic("uvm_setpagesize: uvmexp.pagesize not set"); 467 uvmexp.pagesize = PAGE_SIZE; 468 } 469 uvmexp.pagemask = uvmexp.pagesize - 1; 470 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 471 panic("uvm_setpagesize: page size not a power of two"); 472 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 473 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 474 break; 475 } 476 477 /* 478 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 479 */ 480 481 vaddr_t 482 uvm_pageboot_alloc(vsize_t size) 483 { 484 static boolean_t initialized = FALSE; 485 vaddr_t addr; 486 #if !defined(PMAP_STEAL_MEMORY) 487 vaddr_t vaddr; 488 paddr_t paddr; 489 #endif 490 491 /* 492 * on first call to this function, initialize ourselves. 493 */ 494 if (initialized == FALSE) { 495 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 496 497 /* round it the way we like it */ 498 virtual_space_start = round_page(virtual_space_start); 499 virtual_space_end = trunc_page(virtual_space_end); 500 501 initialized = TRUE; 502 } 503 504 /* round to page size */ 505 size = round_page(size); 506 507 #if defined(PMAP_STEAL_MEMORY) 508 509 /* 510 * defer bootstrap allocation to MD code (it may want to allocate 511 * from a direct-mapped segment). pmap_steal_memory should adjust 512 * virtual_space_start/virtual_space_end if necessary. 513 */ 514 515 addr = pmap_steal_memory(size, &virtual_space_start, 516 &virtual_space_end); 517 518 return(addr); 519 520 #else /* !PMAP_STEAL_MEMORY */ 521 522 /* 523 * allocate virtual memory for this request 524 */ 525 if (virtual_space_start == virtual_space_end || 526 (virtual_space_end - virtual_space_start) < size) 527 panic("uvm_pageboot_alloc: out of virtual space"); 528 529 addr = virtual_space_start; 530 531 #ifdef PMAP_GROWKERNEL 532 /* 533 * If the kernel pmap can't map the requested space, 534 * then allocate more resources for it. 535 */ 536 if (uvm_maxkaddr < (addr + size)) { 537 uvm_maxkaddr = pmap_growkernel(addr + size); 538 if (uvm_maxkaddr < (addr + size)) 539 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 540 } 541 #endif 542 543 virtual_space_start += size; 544 545 /* 546 * allocate and mapin physical pages to back new virtual pages 547 */ 548 549 for (vaddr = round_page(addr) ; vaddr < addr + size ; 550 vaddr += PAGE_SIZE) { 551 552 if (!uvm_page_physget(&paddr)) 553 panic("uvm_pageboot_alloc: out of memory"); 554 555 /* 556 * Note this memory is no longer managed, so using 557 * pmap_kenter is safe. 558 */ 559 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 560 } 561 pmap_update(pmap_kernel()); 562 return(addr); 563 #endif /* PMAP_STEAL_MEMORY */ 564 } 565 566 #if !defined(PMAP_STEAL_MEMORY) 567 /* 568 * uvm_page_physget: "steal" one page from the vm_physmem structure. 569 * 570 * => attempt to allocate it off the end of a segment in which the "avail" 571 * values match the start/end values. if we can't do that, then we 572 * will advance both values (making them equal, and removing some 573 * vm_page structures from the non-avail area). 574 * => return false if out of memory. 575 */ 576 577 /* subroutine: try to allocate from memory chunks on the specified freelist */ 578 static boolean_t uvm_page_physget_freelist(paddr_t *, int); 579 580 static boolean_t 581 uvm_page_physget_freelist(paddr_t *paddrp, int freelist) 582 { 583 int lcv, x; 584 585 /* pass 1: try allocating from a matching end */ 586 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 587 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 588 #else 589 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 590 #endif 591 { 592 593 if (uvm.page_init_done == TRUE) 594 panic("uvm_page_physget: called _after_ bootstrap"); 595 596 if (vm_physmem[lcv].free_list != freelist) 597 continue; 598 599 /* try from front */ 600 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 601 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 602 *paddrp = ptoa(vm_physmem[lcv].avail_start); 603 vm_physmem[lcv].avail_start++; 604 vm_physmem[lcv].start++; 605 /* nothing left? nuke it */ 606 if (vm_physmem[lcv].avail_start == 607 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 /* try from rear */ 619 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 620 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 621 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 622 vm_physmem[lcv].avail_end--; 623 vm_physmem[lcv].end--; 624 /* nothing left? nuke it */ 625 if (vm_physmem[lcv].avail_end == 626 vm_physmem[lcv].start) { 627 if (vm_nphysseg == 1) 628 panic("uvm_page_physget: out of memory!"); 629 vm_nphysseg--; 630 for (x = lcv ; x < vm_nphysseg ; x++) 631 /* structure copy */ 632 vm_physmem[x] = vm_physmem[x+1]; 633 } 634 return (TRUE); 635 } 636 } 637 638 /* pass2: forget about matching ends, just allocate something */ 639 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 640 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 641 #else 642 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 643 #endif 644 { 645 646 /* any room in this bank? */ 647 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 648 continue; /* nope */ 649 650 *paddrp = ptoa(vm_physmem[lcv].avail_start); 651 vm_physmem[lcv].avail_start++; 652 /* truncate! */ 653 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 654 655 /* nothing left? nuke it */ 656 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 657 if (vm_nphysseg == 1) 658 panic("uvm_page_physget: out of memory!"); 659 vm_nphysseg--; 660 for (x = lcv ; x < vm_nphysseg ; x++) 661 /* structure copy */ 662 vm_physmem[x] = vm_physmem[x+1]; 663 } 664 return (TRUE); 665 } 666 667 return (FALSE); /* whoops! */ 668 } 669 670 boolean_t 671 uvm_page_physget(paddr_t *paddrp) 672 { 673 int i; 674 675 /* try in the order of freelist preference */ 676 for (i = 0; i < VM_NFREELIST; i++) 677 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 678 return (TRUE); 679 return (FALSE); 680 } 681 #endif /* PMAP_STEAL_MEMORY */ 682 683 /* 684 * uvm_page_physload: load physical memory into VM system 685 * 686 * => all args are PFs 687 * => all pages in start/end get vm_page structures 688 * => areas marked by avail_start/avail_end get added to the free page pool 689 * => we are limited to VM_PHYSSEG_MAX physical memory segments 690 */ 691 692 void 693 uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start, 694 paddr_t avail_end, int free_list) 695 { 696 int preload, lcv; 697 psize_t npages; 698 struct vm_page *pgs; 699 struct vm_physseg *ps; 700 701 if (uvmexp.pagesize == 0) 702 panic("uvm_page_physload: page size not set!"); 703 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 704 panic("uvm_page_physload: bad free list %d", free_list); 705 if (start >= end) 706 panic("uvm_page_physload: start >= end"); 707 708 /* 709 * do we have room? 710 */ 711 712 if (vm_nphysseg == VM_PHYSSEG_MAX) { 713 printf("uvm_page_physload: unable to load physical memory " 714 "segment\n"); 715 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 716 VM_PHYSSEG_MAX, (long long)start, (long long)end); 717 printf("\tincrease VM_PHYSSEG_MAX\n"); 718 return; 719 } 720 721 /* 722 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 723 * called yet, so malloc is not available). 724 */ 725 726 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 727 if (vm_physmem[lcv].pgs) 728 break; 729 } 730 preload = (lcv == vm_nphysseg); 731 732 /* 733 * if VM is already running, attempt to malloc() vm_page structures 734 */ 735 736 if (!preload) { 737 #if defined(VM_PHYSSEG_NOADD) 738 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 739 #else 740 /* XXXCDC: need some sort of lockout for this case */ 741 paddr_t paddr; 742 npages = end - start; /* # of pages */ 743 pgs = malloc(sizeof(struct vm_page) * npages, 744 M_VMPAGE, M_NOWAIT); 745 if (pgs == NULL) { 746 printf("uvm_page_physload: can not malloc vm_page " 747 "structs for segment\n"); 748 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 749 return; 750 } 751 /* zero data, init phys_addr and free_list, and free pages */ 752 memset(pgs, 0, sizeof(struct vm_page) * npages); 753 for (lcv = 0, paddr = ptoa(start) ; 754 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 755 pgs[lcv].phys_addr = paddr; 756 pgs[lcv].free_list = free_list; 757 if (atop(paddr) >= avail_start && 758 atop(paddr) <= avail_end) 759 uvm_pagefree(&pgs[lcv]); 760 } 761 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 762 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 763 #endif 764 } else { 765 pgs = NULL; 766 npages = 0; 767 } 768 769 /* 770 * now insert us in the proper place in vm_physmem[] 771 */ 772 773 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 774 /* random: put it at the end (easy!) */ 775 ps = &vm_physmem[vm_nphysseg]; 776 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 777 { 778 int x; 779 /* sort by address for binary search */ 780 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 781 if (start < vm_physmem[lcv].start) 782 break; 783 ps = &vm_physmem[lcv]; 784 /* move back other entries, if necessary ... */ 785 for (x = vm_nphysseg ; x > lcv ; x--) 786 /* structure copy */ 787 vm_physmem[x] = vm_physmem[x - 1]; 788 } 789 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 790 { 791 int x; 792 /* sort by largest segment first */ 793 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 794 if ((end - start) > 795 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 796 break; 797 ps = &vm_physmem[lcv]; 798 /* move back other entries, if necessary ... */ 799 for (x = vm_nphysseg ; x > lcv ; x--) 800 /* structure copy */ 801 vm_physmem[x] = vm_physmem[x - 1]; 802 } 803 #else 804 panic("uvm_page_physload: unknown physseg strategy selected!"); 805 #endif 806 807 ps->start = start; 808 ps->end = end; 809 ps->avail_start = avail_start; 810 ps->avail_end = avail_end; 811 if (preload) { 812 ps->pgs = NULL; 813 } else { 814 ps->pgs = pgs; 815 ps->lastpg = pgs + npages - 1; 816 } 817 ps->free_list = free_list; 818 vm_nphysseg++; 819 820 if (!preload) 821 uvm_page_rehash(); 822 } 823 824 /* 825 * uvm_page_rehash: reallocate hash table based on number of free pages. 826 */ 827 828 void 829 uvm_page_rehash(void) 830 { 831 int freepages, lcv, bucketcount, oldcount; 832 struct pglist *newbuckets, *oldbuckets; 833 struct vm_page *pg; 834 size_t newsize, oldsize; 835 836 /* 837 * compute number of pages that can go in the free pool 838 */ 839 840 freepages = 0; 841 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 842 freepages += 843 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 844 845 /* 846 * compute number of buckets needed for this number of pages 847 */ 848 849 bucketcount = 1; 850 while (bucketcount < freepages) 851 bucketcount = bucketcount * 2; 852 853 /* 854 * compute the size of the current table and new table. 855 */ 856 857 oldbuckets = uvm.page_hash; 858 oldcount = uvm.page_nhash; 859 oldsize = round_page(sizeof(struct pglist) * oldcount); 860 newsize = round_page(sizeof(struct pglist) * bucketcount); 861 862 /* 863 * allocate the new buckets 864 */ 865 866 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize, 867 0, UVM_KMF_WIRED); 868 if (newbuckets == NULL) { 869 printf("uvm_page_physrehash: WARNING: could not grow page " 870 "hash table\n"); 871 return; 872 } 873 for (lcv = 0 ; lcv < bucketcount ; lcv++) 874 TAILQ_INIT(&newbuckets[lcv]); 875 876 /* 877 * now replace the old buckets with the new ones and rehash everything 878 */ 879 880 simple_lock(&uvm.hashlock); 881 uvm.page_hash = newbuckets; 882 uvm.page_nhash = bucketcount; 883 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 884 885 /* ... and rehash */ 886 for (lcv = 0 ; lcv < oldcount ; lcv++) { 887 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 888 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 889 TAILQ_INSERT_TAIL( 890 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 891 pg, hashq); 892 } 893 } 894 simple_unlock(&uvm.hashlock); 895 896 /* 897 * free old bucket array if is not the boot-time table 898 */ 899 900 if (oldbuckets != &uvm_bootbucket) 901 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize, 902 UVM_KMF_WIRED); 903 } 904 905 /* 906 * uvm_page_recolor: Recolor the pages if the new bucket count is 907 * larger than the old one. 908 */ 909 910 void 911 uvm_page_recolor(int newncolors) 912 { 913 struct pgflbucket *bucketarray, *oldbucketarray; 914 struct pgfreelist pgfl; 915 struct vm_page *pg; 916 vsize_t bucketcount; 917 int s, lcv, color, i, ocolors; 918 919 if (newncolors <= uvmexp.ncolors) 920 return; 921 922 if (uvm.page_init_done == FALSE) { 923 uvmexp.ncolors = newncolors; 924 return; 925 } 926 927 bucketcount = newncolors * VM_NFREELIST; 928 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 929 M_VMPAGE, M_NOWAIT); 930 if (bucketarray == NULL) { 931 printf("WARNING: unable to allocate %ld page color buckets\n", 932 (long) bucketcount); 933 return; 934 } 935 936 s = uvm_lock_fpageq(); 937 938 /* Make sure we should still do this. */ 939 if (newncolors <= uvmexp.ncolors) { 940 uvm_unlock_fpageq(s); 941 free(bucketarray, M_VMPAGE); 942 return; 943 } 944 945 oldbucketarray = uvm.page_free[0].pgfl_buckets; 946 ocolors = uvmexp.ncolors; 947 948 uvmexp.ncolors = newncolors; 949 uvmexp.colormask = uvmexp.ncolors - 1; 950 951 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 952 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 953 uvm_page_init_buckets(&pgfl); 954 for (color = 0; color < ocolors; color++) { 955 for (i = 0; i < PGFL_NQUEUES; i++) { 956 while ((pg = TAILQ_FIRST(&uvm.page_free[ 957 lcv].pgfl_buckets[color].pgfl_queues[i])) 958 != NULL) { 959 TAILQ_REMOVE(&uvm.page_free[ 960 lcv].pgfl_buckets[ 961 color].pgfl_queues[i], pg, pageq); 962 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 963 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 964 i], pg, pageq); 965 } 966 } 967 } 968 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 969 } 970 971 if (have_recolored_pages) { 972 uvm_unlock_fpageq(s); 973 free(oldbucketarray, M_VMPAGE); 974 return; 975 } 976 977 have_recolored_pages = TRUE; 978 uvm_unlock_fpageq(s); 979 } 980 981 /* 982 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 983 */ 984 985 static __inline struct vm_page * 986 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 987 int *trycolorp) 988 { 989 struct pglist *freeq; 990 struct vm_page *pg; 991 int color, trycolor = *trycolorp; 992 993 color = trycolor; 994 do { 995 if ((pg = TAILQ_FIRST((freeq = 996 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 997 goto gotit; 998 if ((pg = TAILQ_FIRST((freeq = 999 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 1000 goto gotit; 1001 color = (color + 1) & uvmexp.colormask; 1002 } while (color != trycolor); 1003 1004 return (NULL); 1005 1006 gotit: 1007 TAILQ_REMOVE(freeq, pg, pageq); 1008 uvmexp.free--; 1009 1010 /* update zero'd page count */ 1011 if (pg->flags & PG_ZERO) 1012 uvmexp.zeropages--; 1013 1014 if (color == trycolor) 1015 uvmexp.colorhit++; 1016 else { 1017 uvmexp.colormiss++; 1018 *trycolorp = color; 1019 } 1020 1021 return (pg); 1022 } 1023 1024 /* 1025 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1026 * 1027 * => return null if no pages free 1028 * => wake up pagedaemon if number of free pages drops below low water mark 1029 * => if obj != NULL, obj must be locked (to put in hash) 1030 * => if anon != NULL, anon must be locked (to put in anon) 1031 * => only one of obj or anon can be non-null 1032 * => caller must activate/deactivate page if it is not wired. 1033 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1034 * => policy decision: it is more important to pull a page off of the 1035 * appropriate priority free list than it is to get a zero'd or 1036 * unknown contents page. This is because we live with the 1037 * consequences of a bad free list decision for the entire 1038 * lifetime of the page, e.g. if the page comes from memory that 1039 * is slower to access. 1040 */ 1041 1042 struct vm_page * 1043 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon, 1044 int flags, int strat, int free_list) 1045 { 1046 int lcv, try1, try2, s, zeroit = 0, color; 1047 struct vm_page *pg; 1048 boolean_t use_reserve; 1049 1050 KASSERT(obj == NULL || anon == NULL); 1051 KASSERT(off == trunc_page(off)); 1052 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1053 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1054 1055 s = uvm_lock_fpageq(); 1056 1057 /* 1058 * This implements a global round-robin page coloring 1059 * algorithm. 1060 * 1061 * XXXJRT: Should we make the `nextcolor' per-CPU? 1062 * XXXJRT: What about virtually-indexed caches? 1063 */ 1064 1065 color = uvm.page_free_nextcolor; 1066 1067 /* 1068 * check to see if we need to generate some free pages waking 1069 * the pagedaemon. 1070 */ 1071 1072 UVM_KICK_PDAEMON(); 1073 1074 /* 1075 * fail if any of these conditions is true: 1076 * [1] there really are no free pages, or 1077 * [2] only kernel "reserved" pages remain and 1078 * the page isn't being allocated to a kernel object. 1079 * [3] only pagedaemon "reserved" pages remain and 1080 * the requestor isn't the pagedaemon. 1081 */ 1082 1083 use_reserve = (flags & UVM_PGA_USERESERVE) || 1084 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1085 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1086 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1087 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1088 goto fail; 1089 1090 #if PGFL_NQUEUES != 2 1091 #error uvm_pagealloc_strat needs to be updated 1092 #endif 1093 1094 /* 1095 * If we want a zero'd page, try the ZEROS queue first, otherwise 1096 * we try the UNKNOWN queue first. 1097 */ 1098 if (flags & UVM_PGA_ZERO) { 1099 try1 = PGFL_ZEROS; 1100 try2 = PGFL_UNKNOWN; 1101 } else { 1102 try1 = PGFL_UNKNOWN; 1103 try2 = PGFL_ZEROS; 1104 } 1105 1106 again: 1107 switch (strat) { 1108 case UVM_PGA_STRAT_NORMAL: 1109 /* Check all freelists in descending priority order. */ 1110 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1111 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1112 try1, try2, &color); 1113 if (pg != NULL) 1114 goto gotit; 1115 } 1116 1117 /* No pages free! */ 1118 goto fail; 1119 1120 case UVM_PGA_STRAT_ONLY: 1121 case UVM_PGA_STRAT_FALLBACK: 1122 /* Attempt to allocate from the specified free list. */ 1123 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1124 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1125 try1, try2, &color); 1126 if (pg != NULL) 1127 goto gotit; 1128 1129 /* Fall back, if possible. */ 1130 if (strat == UVM_PGA_STRAT_FALLBACK) { 1131 strat = UVM_PGA_STRAT_NORMAL; 1132 goto again; 1133 } 1134 1135 /* No pages free! */ 1136 goto fail; 1137 1138 default: 1139 panic("uvm_pagealloc_strat: bad strat %d", strat); 1140 /* NOTREACHED */ 1141 } 1142 1143 gotit: 1144 /* 1145 * We now know which color we actually allocated from; set 1146 * the next color accordingly. 1147 */ 1148 1149 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1150 1151 /* 1152 * update allocation statistics and remember if we have to 1153 * zero the page 1154 */ 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 uvm_unlock_fpageq(s); 1166 1167 pg->offset = off; 1168 pg->uobject = obj; 1169 pg->uanon = anon; 1170 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1171 if (anon) { 1172 anon->an_page = pg; 1173 pg->pqflags = PQ_ANON; 1174 uvmexp.anonpages++; 1175 } else { 1176 if (obj) { 1177 uvm_pageinsert(pg); 1178 } 1179 pg->pqflags = 0; 1180 } 1181 #if defined(UVM_PAGE_TRKOWN) 1182 pg->owner_tag = NULL; 1183 #endif 1184 UVM_PAGE_OWN(pg, "new alloc"); 1185 1186 if (flags & UVM_PGA_ZERO) { 1187 /* 1188 * A zero'd page is not clean. If we got a page not already 1189 * zero'd, then we have to zero it ourselves. 1190 */ 1191 pg->flags &= ~PG_CLEAN; 1192 if (zeroit) 1193 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1194 } 1195 1196 return(pg); 1197 1198 fail: 1199 uvm_unlock_fpageq(s); 1200 return (NULL); 1201 } 1202 1203 /* 1204 * uvm_pagereplace: replace a page with another 1205 * 1206 * => object must be locked 1207 */ 1208 1209 void 1210 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg) 1211 { 1212 1213 KASSERT((oldpg->flags & PG_TABLED) != 0); 1214 KASSERT(oldpg->uobject != NULL); 1215 KASSERT((newpg->flags & PG_TABLED) == 0); 1216 KASSERT(newpg->uobject == NULL); 1217 LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock)); 1218 1219 newpg->uobject = oldpg->uobject; 1220 newpg->offset = oldpg->offset; 1221 1222 uvm_pageinsert_after(newpg, oldpg); 1223 uvm_pageremove(oldpg); 1224 } 1225 1226 /* 1227 * uvm_pagerealloc: reallocate a page from one object to another 1228 * 1229 * => both objects must be locked 1230 */ 1231 1232 void 1233 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) 1234 { 1235 /* 1236 * remove it from the old object 1237 */ 1238 1239 if (pg->uobject) { 1240 uvm_pageremove(pg); 1241 } 1242 1243 /* 1244 * put it in the new object 1245 */ 1246 1247 if (newobj) { 1248 pg->uobject = newobj; 1249 pg->offset = newoff; 1250 uvm_pageinsert(pg); 1251 } 1252 } 1253 1254 #ifdef DEBUG 1255 /* 1256 * check if page is zero-filled 1257 * 1258 * - called with free page queue lock held. 1259 */ 1260 void 1261 uvm_pagezerocheck(struct vm_page *pg) 1262 { 1263 int *p, *ep; 1264 1265 KASSERT(uvm_zerocheckkva != 0); 1266 LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock)); 1267 1268 /* 1269 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1270 * uvm page allocator. 1271 * 1272 * it might be better to have "CPU-local temporary map" pmap interface. 1273 */ 1274 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); 1275 p = (int *)uvm_zerocheckkva; 1276 ep = (int *)((char *)p + PAGE_SIZE); 1277 pmap_update(pmap_kernel()); 1278 while (p < ep) { 1279 if (*p != 0) 1280 panic("PG_ZERO page isn't zero-filled"); 1281 p++; 1282 } 1283 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1284 } 1285 #endif /* DEBUG */ 1286 1287 /* 1288 * uvm_pagefree: free page 1289 * 1290 * => erase page's identity (i.e. remove from hash/object) 1291 * => put page on free list 1292 * => caller must lock owning object (either anon or uvm_object) 1293 * => caller must lock page queues 1294 * => assumes all valid mappings of pg are gone 1295 */ 1296 1297 void 1298 uvm_pagefree(struct vm_page *pg) 1299 { 1300 int s; 1301 struct pglist *pgfl; 1302 boolean_t iszero; 1303 1304 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1305 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1306 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1307 LOCK_ASSERT(pg->uobject == NULL || 1308 simple_lock_held(&pg->uobject->vmobjlock)); 1309 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1310 simple_lock_held(&pg->uanon->an_lock)); 1311 1312 #ifdef DEBUG 1313 if (pg->uobject == (void *)0xdeadbeef && 1314 pg->uanon == (void *)0xdeadbeef) { 1315 panic("uvm_pagefree: freeing free page %p", pg); 1316 } 1317 #endif /* DEBUG */ 1318 1319 /* 1320 * if the page is loaned, resolve the loan instead of freeing. 1321 */ 1322 1323 if (pg->loan_count) { 1324 KASSERT(pg->wire_count == 0); 1325 1326 /* 1327 * if the page is owned by an anon then we just want to 1328 * drop anon ownership. the kernel will free the page when 1329 * it is done with it. if the page is owned by an object, 1330 * remove it from the object and mark it dirty for the benefit 1331 * of possible anon owners. 1332 * 1333 * regardless of previous ownership, wakeup any waiters, 1334 * unbusy the page, and we're done. 1335 */ 1336 1337 if (pg->uobject != NULL) { 1338 uvm_pageremove(pg); 1339 pg->flags &= ~PG_CLEAN; 1340 } else if (pg->uanon != NULL) { 1341 if ((pg->pqflags & PQ_ANON) == 0) { 1342 pg->loan_count--; 1343 } else { 1344 pg->pqflags &= ~PQ_ANON; 1345 uvmexp.anonpages--; 1346 } 1347 pg->uanon->an_page = NULL; 1348 pg->uanon = NULL; 1349 } 1350 if (pg->flags & PG_WANTED) { 1351 wakeup(pg); 1352 } 1353 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1354 #ifdef UVM_PAGE_TRKOWN 1355 pg->owner_tag = NULL; 1356 #endif 1357 if (pg->loan_count) { 1358 uvm_pagedequeue(pg); 1359 return; 1360 } 1361 } 1362 1363 /* 1364 * remove page from its object or anon. 1365 */ 1366 1367 if (pg->uobject != NULL) { 1368 uvm_pageremove(pg); 1369 } else if (pg->uanon != NULL) { 1370 pg->uanon->an_page = NULL; 1371 uvmexp.anonpages--; 1372 } 1373 1374 /* 1375 * now remove the page from the queues. 1376 */ 1377 1378 uvm_pagedequeue(pg); 1379 1380 /* 1381 * if the page was wired, unwire it now. 1382 */ 1383 1384 if (pg->wire_count) { 1385 pg->wire_count = 0; 1386 uvmexp.wired--; 1387 } 1388 1389 /* 1390 * and put on free queue 1391 */ 1392 1393 iszero = (pg->flags & PG_ZERO); 1394 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. 1395 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 1396 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; 1397 1398 pg->pqflags = PQ_FREE; 1399 #ifdef DEBUG 1400 pg->uobject = (void *)0xdeadbeef; 1401 pg->offset = 0xdeadbeef; 1402 pg->uanon = (void *)0xdeadbeef; 1403 #endif 1404 1405 s = uvm_lock_fpageq(); 1406 1407 #ifdef DEBUG 1408 if (iszero) 1409 uvm_pagezerocheck(pg); 1410 #endif /* DEBUG */ 1411 1412 TAILQ_INSERT_HEAD(pgfl, pg, pageq); 1413 uvmexp.free++; 1414 if (iszero) 1415 uvmexp.zeropages++; 1416 1417 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1418 uvm.page_idle_zero = vm_page_zero_enable; 1419 1420 uvm_unlock_fpageq(s); 1421 } 1422 1423 /* 1424 * uvm_page_unbusy: unbusy an array of pages. 1425 * 1426 * => pages must either all belong to the same object, or all belong to anons. 1427 * => if pages are object-owned, object must be locked. 1428 * => if pages are anon-owned, anons must be locked. 1429 * => caller must lock page queues if pages may be released. 1430 * => caller must make sure that anon-owned pages are not PG_RELEASED. 1431 */ 1432 1433 void 1434 uvm_page_unbusy(struct vm_page **pgs, int npgs) 1435 { 1436 struct vm_page *pg; 1437 int i; 1438 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1439 1440 for (i = 0; i < npgs; i++) { 1441 pg = pgs[i]; 1442 if (pg == NULL || pg == PGO_DONTCARE) { 1443 continue; 1444 } 1445 1446 LOCK_ASSERT(pg->uobject == NULL || 1447 simple_lock_held(&pg->uobject->vmobjlock)); 1448 LOCK_ASSERT(pg->uobject != NULL || 1449 (pg->uanon != NULL && 1450 simple_lock_held(&pg->uanon->an_lock))); 1451 1452 KASSERT(pg->flags & PG_BUSY); 1453 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1454 if (pg->flags & PG_WANTED) { 1455 wakeup(pg); 1456 } 1457 if (pg->flags & PG_RELEASED) { 1458 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1459 KASSERT(pg->uobject != NULL || 1460 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 1461 pg->flags &= ~PG_RELEASED; 1462 uvm_pagefree(pg); 1463 } else { 1464 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1465 pg->flags &= ~(PG_WANTED|PG_BUSY); 1466 UVM_PAGE_OWN(pg, NULL); 1467 } 1468 } 1469 } 1470 1471 #if defined(UVM_PAGE_TRKOWN) 1472 /* 1473 * uvm_page_own: set or release page ownership 1474 * 1475 * => this is a debugging function that keeps track of who sets PG_BUSY 1476 * and where they do it. it can be used to track down problems 1477 * such a process setting "PG_BUSY" and never releasing it. 1478 * => page's object [if any] must be locked 1479 * => if "tag" is NULL then we are releasing page ownership 1480 */ 1481 void 1482 uvm_page_own(struct vm_page *pg, const char *tag) 1483 { 1484 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1485 1486 /* gain ownership? */ 1487 if (tag) { 1488 if (pg->owner_tag) { 1489 printf("uvm_page_own: page %p already owned " 1490 "by proc %d [%s]\n", pg, 1491 pg->owner, pg->owner_tag); 1492 panic("uvm_page_own"); 1493 } 1494 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1495 pg->owner_tag = tag; 1496 return; 1497 } 1498 1499 /* drop ownership */ 1500 if (pg->owner_tag == NULL) { 1501 printf("uvm_page_own: dropping ownership of an non-owned " 1502 "page (%p)\n", pg); 1503 panic("uvm_page_own"); 1504 } 1505 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1506 (pg->uanon == NULL && pg->uobject == NULL) || 1507 pg->uobject == uvm.kernel_object || 1508 pg->wire_count > 0 || 1509 (pg->loan_count == 1 && pg->uanon == NULL) || 1510 pg->loan_count > 1); 1511 pg->owner_tag = NULL; 1512 } 1513 #endif 1514 1515 /* 1516 * uvm_pageidlezero: zero free pages while the system is idle. 1517 * 1518 * => try to complete one color bucket at a time, to reduce our impact 1519 * on the CPU cache. 1520 * => we loop until we either reach the target or whichqs indicates that 1521 * there is a process ready to run. 1522 */ 1523 void 1524 uvm_pageidlezero(void) 1525 { 1526 struct vm_page *pg; 1527 struct pgfreelist *pgfl; 1528 int free_list, s, firstbucket; 1529 static int nextbucket; 1530 1531 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1532 s = uvm_lock_fpageq(); 1533 firstbucket = nextbucket; 1534 do { 1535 if (sched_whichqs != 0) 1536 goto quit; 1537 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1538 uvm.page_idle_zero = FALSE; 1539 goto quit; 1540 } 1541 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1542 pgfl = &uvm.page_free[free_list]; 1543 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1544 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1545 if (sched_whichqs != 0) 1546 goto quit; 1547 1548 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1549 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1550 pg, pageq); 1551 uvmexp.free--; 1552 uvm_unlock_fpageq(s); 1553 KERNEL_UNLOCK(); 1554 #ifdef PMAP_PAGEIDLEZERO 1555 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1556 1557 /* 1558 * The machine-dependent code detected 1559 * some reason for us to abort zeroing 1560 * pages, probably because there is a 1561 * process now ready to run. 1562 */ 1563 1564 KERNEL_LOCK( 1565 LK_EXCLUSIVE | LK_CANRECURSE); 1566 s = uvm_lock_fpageq(); 1567 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1568 nextbucket].pgfl_queues[ 1569 PGFL_UNKNOWN], pg, pageq); 1570 uvmexp.free++; 1571 uvmexp.zeroaborts++; 1572 goto quit; 1573 } 1574 #else 1575 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1576 #endif /* PMAP_PAGEIDLEZERO */ 1577 pg->flags |= PG_ZERO; 1578 1579 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1580 s = uvm_lock_fpageq(); 1581 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1582 nextbucket].pgfl_queues[PGFL_ZEROS], 1583 pg, pageq); 1584 uvmexp.free++; 1585 uvmexp.zeropages++; 1586 } 1587 } 1588 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1589 } while (nextbucket != firstbucket); 1590 quit: 1591 uvm_unlock_fpageq(s); 1592 KERNEL_UNLOCK(); 1593 } 1594