1 /* $NetBSD: uvm_page.c,v 1.101 2004/10/23 21:29:27 yamt 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 1.101 2004/10/23 21:29:27 yamt 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(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(pg, where) 172 struct vm_page *pg; 173 struct vm_page *where; 174 { 175 struct pglist *buck; 176 struct uvm_object *uobj = pg->uobject; 177 178 KASSERT((pg->flags & PG_TABLED) == 0); 179 KASSERT(where == NULL || (where->flags & PG_TABLED)); 180 KASSERT(where == NULL || (where->uobject == uobj)); 181 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 182 simple_lock(&uvm.hashlock); 183 TAILQ_INSERT_TAIL(buck, pg, hashq); 184 simple_unlock(&uvm.hashlock); 185 186 if (UVM_OBJ_IS_VNODE(uobj)) { 187 if (uobj->uo_npages == 0) { 188 struct vnode *vp = (struct vnode *)uobj; 189 190 vholdl(vp); 191 } 192 if (UVM_OBJ_IS_VTEXT(uobj)) { 193 uvmexp.execpages++; 194 } else { 195 uvmexp.filepages++; 196 } 197 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 198 uvmexp.anonpages++; 199 } 200 201 if (where) 202 TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq); 203 else 204 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 205 pg->flags |= PG_TABLED; 206 uobj->uo_npages++; 207 } 208 209 __inline static void 210 uvm_pageinsert(pg) 211 struct vm_page *pg; 212 { 213 214 uvm_pageinsert_after(pg, NULL); 215 } 216 217 /* 218 * uvm_page_remove: remove page from object and hash 219 * 220 * => caller must lock object 221 * => caller must lock page queues 222 */ 223 224 static __inline void 225 uvm_pageremove(pg) 226 struct vm_page *pg; 227 { 228 struct pglist *buck; 229 struct uvm_object *uobj = pg->uobject; 230 231 KASSERT(pg->flags & PG_TABLED); 232 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; 233 simple_lock(&uvm.hashlock); 234 TAILQ_REMOVE(buck, pg, hashq); 235 simple_unlock(&uvm.hashlock); 236 237 if (UVM_OBJ_IS_VNODE(uobj)) { 238 if (uobj->uo_npages == 1) { 239 struct vnode *vp = (struct vnode *)uobj; 240 241 holdrelel(vp); 242 } 243 if (UVM_OBJ_IS_VTEXT(uobj)) { 244 uvmexp.execpages--; 245 } else { 246 uvmexp.filepages--; 247 } 248 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 249 uvmexp.anonpages--; 250 } 251 252 /* object should be locked */ 253 uobj->uo_npages--; 254 TAILQ_REMOVE(&uobj->memq, pg, listq); 255 pg->flags &= ~PG_TABLED; 256 pg->uobject = NULL; 257 } 258 259 static void 260 uvm_page_init_buckets(struct pgfreelist *pgfl) 261 { 262 int color, i; 263 264 for (color = 0; color < uvmexp.ncolors; color++) { 265 for (i = 0; i < PGFL_NQUEUES; i++) { 266 TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); 267 } 268 } 269 } 270 271 /* 272 * uvm_page_init: init the page system. called from uvm_init(). 273 * 274 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 275 */ 276 277 void 278 uvm_page_init(kvm_startp, kvm_endp) 279 vaddr_t *kvm_startp, *kvm_endp; 280 { 281 vsize_t freepages, pagecount, bucketcount, n; 282 struct pgflbucket *bucketarray; 283 struct vm_page *pagearray; 284 int lcv; 285 u_int i; 286 paddr_t paddr; 287 288 /* 289 * init the page queues and page queue locks, except the free 290 * list; we allocate that later (with the initial vm_page 291 * structures). 292 */ 293 294 TAILQ_INIT(&uvm.page_active); 295 TAILQ_INIT(&uvm.page_inactive); 296 simple_lock_init(&uvm.pageqlock); 297 simple_lock_init(&uvm.fpageqlock); 298 299 /* 300 * init the <obj,offset> => <page> hash table. for now 301 * we just have one bucket (the bootstrap bucket). later on we 302 * will allocate new buckets as we dynamically resize the hash table. 303 */ 304 305 uvm.page_nhash = 1; /* 1 bucket */ 306 uvm.page_hashmask = 0; /* mask for hash function */ 307 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 308 TAILQ_INIT(uvm.page_hash); /* init hash table */ 309 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 310 311 /* 312 * allocate vm_page structures. 313 */ 314 315 /* 316 * sanity check: 317 * before calling this function the MD code is expected to register 318 * some free RAM with the uvm_page_physload() function. our job 319 * now is to allocate vm_page structures for this memory. 320 */ 321 322 if (vm_nphysseg == 0) 323 panic("uvm_page_bootstrap: no memory pre-allocated"); 324 325 /* 326 * first calculate the number of free pages... 327 * 328 * note that we use start/end rather than avail_start/avail_end. 329 * this allows us to allocate extra vm_page structures in case we 330 * want to return some memory to the pool after booting. 331 */ 332 333 freepages = 0; 334 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 335 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 336 337 /* 338 * Let MD code initialize the number of colors, or default 339 * to 1 color if MD code doesn't care. 340 */ 341 if (uvmexp.ncolors == 0) 342 uvmexp.ncolors = 1; 343 uvmexp.colormask = uvmexp.ncolors - 1; 344 345 /* 346 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 347 * use. for each page of memory we use we need a vm_page structure. 348 * thus, the total number of pages we can use is the total size of 349 * the memory divided by the PAGE_SIZE plus the size of the vm_page 350 * structure. we add one to freepages as a fudge factor to avoid 351 * truncation errors (since we can only allocate in terms of whole 352 * pages). 353 */ 354 355 bucketcount = uvmexp.ncolors * VM_NFREELIST; 356 pagecount = ((freepages + 1) << PAGE_SHIFT) / 357 (PAGE_SIZE + sizeof(struct vm_page)); 358 359 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 360 sizeof(struct pgflbucket)) + (pagecount * 361 sizeof(struct vm_page))); 362 pagearray = (struct vm_page *)(bucketarray + bucketcount); 363 364 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 365 uvm.page_free[lcv].pgfl_buckets = 366 (bucketarray + (lcv * uvmexp.ncolors)); 367 uvm_page_init_buckets(&uvm.page_free[lcv]); 368 } 369 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 370 371 /* 372 * init the vm_page structures and put them in the correct place. 373 */ 374 375 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 376 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 377 378 /* set up page array pointers */ 379 vm_physmem[lcv].pgs = pagearray; 380 pagearray += n; 381 pagecount -= n; 382 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 383 384 /* init and free vm_pages (we've already zeroed them) */ 385 paddr = ptoa(vm_physmem[lcv].start); 386 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 387 vm_physmem[lcv].pgs[i].phys_addr = paddr; 388 #ifdef __HAVE_VM_PAGE_MD 389 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 390 #endif 391 if (atop(paddr) >= vm_physmem[lcv].avail_start && 392 atop(paddr) <= vm_physmem[lcv].avail_end) { 393 uvmexp.npages++; 394 /* add page to free pool */ 395 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 396 } 397 } 398 } 399 400 /* 401 * pass up the values of virtual_space_start and 402 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 403 * layers of the VM. 404 */ 405 406 *kvm_startp = round_page(virtual_space_start); 407 *kvm_endp = trunc_page(virtual_space_end); 408 #ifdef DEBUG 409 /* 410 * steal kva for uvm_pagezerocheck(). 411 */ 412 uvm_zerocheckkva = *kvm_startp; 413 *kvm_startp += PAGE_SIZE; 414 #endif /* DEBUG */ 415 416 /* 417 * init locks for kernel threads 418 */ 419 420 simple_lock_init(&uvm.pagedaemon_lock); 421 simple_lock_init(&uvm.aiodoned_lock); 422 423 /* 424 * init various thresholds. 425 */ 426 427 uvmexp.reserve_pagedaemon = 1; 428 uvmexp.reserve_kernel = 5; 429 uvmexp.anonminpct = 10; 430 uvmexp.fileminpct = 10; 431 uvmexp.execminpct = 5; 432 uvmexp.anonmaxpct = 80; 433 uvmexp.filemaxpct = 50; 434 uvmexp.execmaxpct = 30; 435 uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; 436 uvmexp.filemin = uvmexp.fileminpct * 256 / 100; 437 uvmexp.execmin = uvmexp.execminpct * 256 / 100; 438 uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; 439 uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; 440 uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; 441 442 /* 443 * determine if we should zero pages in the idle loop. 444 */ 445 446 uvm.page_idle_zero = vm_page_zero_enable; 447 448 /* 449 * done! 450 */ 451 452 uvm.page_init_done = TRUE; 453 } 454 455 /* 456 * uvm_setpagesize: set the page size 457 * 458 * => sets page_shift and page_mask from uvmexp.pagesize. 459 */ 460 461 void 462 uvm_setpagesize() 463 { 464 465 /* 466 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 467 * to be a constant (indicated by being a non-zero value). 468 */ 469 if (uvmexp.pagesize == 0) { 470 if (PAGE_SIZE == 0) 471 panic("uvm_setpagesize: uvmexp.pagesize not set"); 472 uvmexp.pagesize = PAGE_SIZE; 473 } 474 uvmexp.pagemask = uvmexp.pagesize - 1; 475 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 476 panic("uvm_setpagesize: page size not a power of two"); 477 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 478 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 479 break; 480 } 481 482 /* 483 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 484 */ 485 486 vaddr_t 487 uvm_pageboot_alloc(size) 488 vsize_t size; 489 { 490 static boolean_t initialized = FALSE; 491 vaddr_t addr; 492 #if !defined(PMAP_STEAL_MEMORY) 493 vaddr_t vaddr; 494 paddr_t paddr; 495 #endif 496 497 /* 498 * on first call to this function, initialize ourselves. 499 */ 500 if (initialized == FALSE) { 501 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 502 503 /* round it the way we like it */ 504 virtual_space_start = round_page(virtual_space_start); 505 virtual_space_end = trunc_page(virtual_space_end); 506 507 initialized = TRUE; 508 } 509 510 /* round to page size */ 511 size = round_page(size); 512 513 #if defined(PMAP_STEAL_MEMORY) 514 515 /* 516 * defer bootstrap allocation to MD code (it may want to allocate 517 * from a direct-mapped segment). pmap_steal_memory should adjust 518 * virtual_space_start/virtual_space_end if necessary. 519 */ 520 521 addr = pmap_steal_memory(size, &virtual_space_start, 522 &virtual_space_end); 523 524 return(addr); 525 526 #else /* !PMAP_STEAL_MEMORY */ 527 528 /* 529 * allocate virtual memory for this request 530 */ 531 if (virtual_space_start == virtual_space_end || 532 (virtual_space_end - virtual_space_start) < size) 533 panic("uvm_pageboot_alloc: out of virtual space"); 534 535 addr = virtual_space_start; 536 537 #ifdef PMAP_GROWKERNEL 538 /* 539 * If the kernel pmap can't map the requested space, 540 * then allocate more resources for it. 541 */ 542 if (uvm_maxkaddr < (addr + size)) { 543 uvm_maxkaddr = pmap_growkernel(addr + size); 544 if (uvm_maxkaddr < (addr + size)) 545 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 546 } 547 #endif 548 549 virtual_space_start += size; 550 551 /* 552 * allocate and mapin physical pages to back new virtual pages 553 */ 554 555 for (vaddr = round_page(addr) ; vaddr < addr + size ; 556 vaddr += PAGE_SIZE) { 557 558 if (!uvm_page_physget(&paddr)) 559 panic("uvm_pageboot_alloc: out of memory"); 560 561 /* 562 * Note this memory is no longer managed, so using 563 * pmap_kenter is safe. 564 */ 565 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 566 } 567 pmap_update(pmap_kernel()); 568 return(addr); 569 #endif /* PMAP_STEAL_MEMORY */ 570 } 571 572 #if !defined(PMAP_STEAL_MEMORY) 573 /* 574 * uvm_page_physget: "steal" one page from the vm_physmem structure. 575 * 576 * => attempt to allocate it off the end of a segment in which the "avail" 577 * values match the start/end values. if we can't do that, then we 578 * will advance both values (making them equal, and removing some 579 * vm_page structures from the non-avail area). 580 * => return false if out of memory. 581 */ 582 583 /* subroutine: try to allocate from memory chunks on the specified freelist */ 584 static boolean_t uvm_page_physget_freelist(paddr_t *, int); 585 586 static boolean_t 587 uvm_page_physget_freelist(paddrp, freelist) 588 paddr_t *paddrp; 589 int freelist; 590 { 591 int lcv, x; 592 593 /* pass 1: try allocating from a matching end */ 594 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 595 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 596 #else 597 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 598 #endif 599 { 600 601 if (uvm.page_init_done == TRUE) 602 panic("uvm_page_physget: called _after_ bootstrap"); 603 604 if (vm_physmem[lcv].free_list != freelist) 605 continue; 606 607 /* try from front */ 608 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 609 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 610 *paddrp = ptoa(vm_physmem[lcv].avail_start); 611 vm_physmem[lcv].avail_start++; 612 vm_physmem[lcv].start++; 613 /* nothing left? nuke it */ 614 if (vm_physmem[lcv].avail_start == 615 vm_physmem[lcv].end) { 616 if (vm_nphysseg == 1) 617 panic("uvm_page_physget: out of memory!"); 618 vm_nphysseg--; 619 for (x = lcv ; x < vm_nphysseg ; x++) 620 /* structure copy */ 621 vm_physmem[x] = vm_physmem[x+1]; 622 } 623 return (TRUE); 624 } 625 626 /* try from rear */ 627 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 628 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 629 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 630 vm_physmem[lcv].avail_end--; 631 vm_physmem[lcv].end--; 632 /* nothing left? nuke it */ 633 if (vm_physmem[lcv].avail_end == 634 vm_physmem[lcv].start) { 635 if (vm_nphysseg == 1) 636 panic("uvm_page_physget: out of memory!"); 637 vm_nphysseg--; 638 for (x = lcv ; x < vm_nphysseg ; x++) 639 /* structure copy */ 640 vm_physmem[x] = vm_physmem[x+1]; 641 } 642 return (TRUE); 643 } 644 } 645 646 /* pass2: forget about matching ends, just allocate something */ 647 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 648 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 649 #else 650 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 651 #endif 652 { 653 654 /* any room in this bank? */ 655 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 656 continue; /* nope */ 657 658 *paddrp = ptoa(vm_physmem[lcv].avail_start); 659 vm_physmem[lcv].avail_start++; 660 /* truncate! */ 661 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 662 663 /* nothing left? nuke it */ 664 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 665 if (vm_nphysseg == 1) 666 panic("uvm_page_physget: out of memory!"); 667 vm_nphysseg--; 668 for (x = lcv ; x < vm_nphysseg ; x++) 669 /* structure copy */ 670 vm_physmem[x] = vm_physmem[x+1]; 671 } 672 return (TRUE); 673 } 674 675 return (FALSE); /* whoops! */ 676 } 677 678 boolean_t 679 uvm_page_physget(paddrp) 680 paddr_t *paddrp; 681 { 682 int i; 683 684 /* try in the order of freelist preference */ 685 for (i = 0; i < VM_NFREELIST; i++) 686 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 687 return (TRUE); 688 return (FALSE); 689 } 690 #endif /* PMAP_STEAL_MEMORY */ 691 692 /* 693 * uvm_page_physload: load physical memory into VM system 694 * 695 * => all args are PFs 696 * => all pages in start/end get vm_page structures 697 * => areas marked by avail_start/avail_end get added to the free page pool 698 * => we are limited to VM_PHYSSEG_MAX physical memory segments 699 */ 700 701 void 702 uvm_page_physload(start, end, avail_start, avail_end, free_list) 703 paddr_t start, end, avail_start, avail_end; 704 int free_list; 705 { 706 int preload, lcv; 707 psize_t npages; 708 struct vm_page *pgs; 709 struct vm_physseg *ps; 710 711 if (uvmexp.pagesize == 0) 712 panic("uvm_page_physload: page size not set!"); 713 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 714 panic("uvm_page_physload: bad free list %d", free_list); 715 if (start >= end) 716 panic("uvm_page_physload: start >= end"); 717 718 /* 719 * do we have room? 720 */ 721 722 if (vm_nphysseg == VM_PHYSSEG_MAX) { 723 printf("uvm_page_physload: unable to load physical memory " 724 "segment\n"); 725 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 726 VM_PHYSSEG_MAX, (long long)start, (long long)end); 727 printf("\tincrease VM_PHYSSEG_MAX\n"); 728 return; 729 } 730 731 /* 732 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 733 * called yet, so malloc is not available). 734 */ 735 736 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 737 if (vm_physmem[lcv].pgs) 738 break; 739 } 740 preload = (lcv == vm_nphysseg); 741 742 /* 743 * if VM is already running, attempt to malloc() vm_page structures 744 */ 745 746 if (!preload) { 747 #if defined(VM_PHYSSEG_NOADD) 748 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 749 #else 750 /* XXXCDC: need some sort of lockout for this case */ 751 paddr_t paddr; 752 npages = end - start; /* # of pages */ 753 pgs = malloc(sizeof(struct vm_page) * npages, 754 M_VMPAGE, M_NOWAIT); 755 if (pgs == NULL) { 756 printf("uvm_page_physload: can not malloc vm_page " 757 "structs for segment\n"); 758 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 759 return; 760 } 761 /* zero data, init phys_addr and free_list, and free pages */ 762 memset(pgs, 0, sizeof(struct vm_page) * npages); 763 for (lcv = 0, paddr = ptoa(start) ; 764 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 765 pgs[lcv].phys_addr = paddr; 766 pgs[lcv].free_list = free_list; 767 if (atop(paddr) >= avail_start && 768 atop(paddr) <= avail_end) 769 uvm_pagefree(&pgs[lcv]); 770 } 771 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 772 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 773 #endif 774 } else { 775 pgs = NULL; 776 npages = 0; 777 } 778 779 /* 780 * now insert us in the proper place in vm_physmem[] 781 */ 782 783 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 784 /* random: put it at the end (easy!) */ 785 ps = &vm_physmem[vm_nphysseg]; 786 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 787 { 788 int x; 789 /* sort by address for binary search */ 790 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 791 if (start < vm_physmem[lcv].start) 792 break; 793 ps = &vm_physmem[lcv]; 794 /* move back other entries, if necessary ... */ 795 for (x = vm_nphysseg ; x > lcv ; x--) 796 /* structure copy */ 797 vm_physmem[x] = vm_physmem[x - 1]; 798 } 799 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 800 { 801 int x; 802 /* sort by largest segment first */ 803 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 804 if ((end - start) > 805 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 806 break; 807 ps = &vm_physmem[lcv]; 808 /* move back other entries, if necessary ... */ 809 for (x = vm_nphysseg ; x > lcv ; x--) 810 /* structure copy */ 811 vm_physmem[x] = vm_physmem[x - 1]; 812 } 813 #else 814 panic("uvm_page_physload: unknown physseg strategy selected!"); 815 #endif 816 817 ps->start = start; 818 ps->end = end; 819 ps->avail_start = avail_start; 820 ps->avail_end = avail_end; 821 if (preload) { 822 ps->pgs = NULL; 823 } else { 824 ps->pgs = pgs; 825 ps->lastpg = pgs + npages - 1; 826 } 827 ps->free_list = free_list; 828 vm_nphysseg++; 829 830 if (!preload) 831 uvm_page_rehash(); 832 } 833 834 /* 835 * uvm_page_rehash: reallocate hash table based on number of free pages. 836 */ 837 838 void 839 uvm_page_rehash() 840 { 841 int freepages, lcv, bucketcount, oldcount; 842 struct pglist *newbuckets, *oldbuckets; 843 struct vm_page *pg; 844 size_t newsize, oldsize; 845 846 /* 847 * compute number of pages that can go in the free pool 848 */ 849 850 freepages = 0; 851 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 852 freepages += 853 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 854 855 /* 856 * compute number of buckets needed for this number of pages 857 */ 858 859 bucketcount = 1; 860 while (bucketcount < freepages) 861 bucketcount = bucketcount * 2; 862 863 /* 864 * compute the size of the current table and new table. 865 */ 866 867 oldbuckets = uvm.page_hash; 868 oldcount = uvm.page_nhash; 869 oldsize = round_page(sizeof(struct pglist) * oldcount); 870 newsize = round_page(sizeof(struct pglist) * bucketcount); 871 872 /* 873 * allocate the new buckets 874 */ 875 876 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 877 if (newbuckets == NULL) { 878 printf("uvm_page_physrehash: WARNING: could not grow page " 879 "hash table\n"); 880 return; 881 } 882 for (lcv = 0 ; lcv < bucketcount ; lcv++) 883 TAILQ_INIT(&newbuckets[lcv]); 884 885 /* 886 * now replace the old buckets with the new ones and rehash everything 887 */ 888 889 simple_lock(&uvm.hashlock); 890 uvm.page_hash = newbuckets; 891 uvm.page_nhash = bucketcount; 892 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 893 894 /* ... and rehash */ 895 for (lcv = 0 ; lcv < oldcount ; lcv++) { 896 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 897 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 898 TAILQ_INSERT_TAIL( 899 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 900 pg, hashq); 901 } 902 } 903 simple_unlock(&uvm.hashlock); 904 905 /* 906 * free old bucket array if is not the boot-time table 907 */ 908 909 if (oldbuckets != &uvm_bootbucket) 910 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 911 } 912 913 /* 914 * uvm_page_recolor: Recolor the pages if the new bucket count is 915 * larger than the old one. 916 */ 917 918 void 919 uvm_page_recolor(int newncolors) 920 { 921 struct pgflbucket *bucketarray, *oldbucketarray; 922 struct pgfreelist pgfl; 923 struct vm_page *pg; 924 vsize_t bucketcount; 925 int s, lcv, color, i, ocolors; 926 927 if (newncolors <= uvmexp.ncolors) 928 return; 929 930 if (uvm.page_init_done == FALSE) { 931 uvmexp.ncolors = newncolors; 932 return; 933 } 934 935 bucketcount = newncolors * VM_NFREELIST; 936 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 937 M_VMPAGE, M_NOWAIT); 938 if (bucketarray == NULL) { 939 printf("WARNING: unable to allocate %ld page color buckets\n", 940 (long) bucketcount); 941 return; 942 } 943 944 s = uvm_lock_fpageq(); 945 946 /* Make sure we should still do this. */ 947 if (newncolors <= uvmexp.ncolors) { 948 uvm_unlock_fpageq(s); 949 free(bucketarray, M_VMPAGE); 950 return; 951 } 952 953 oldbucketarray = uvm.page_free[0].pgfl_buckets; 954 ocolors = uvmexp.ncolors; 955 956 uvmexp.ncolors = newncolors; 957 uvmexp.colormask = uvmexp.ncolors - 1; 958 959 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 960 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 961 uvm_page_init_buckets(&pgfl); 962 for (color = 0; color < ocolors; color++) { 963 for (i = 0; i < PGFL_NQUEUES; i++) { 964 while ((pg = TAILQ_FIRST(&uvm.page_free[ 965 lcv].pgfl_buckets[color].pgfl_queues[i])) 966 != NULL) { 967 TAILQ_REMOVE(&uvm.page_free[ 968 lcv].pgfl_buckets[ 969 color].pgfl_queues[i], pg, pageq); 970 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 971 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 972 i], pg, pageq); 973 } 974 } 975 } 976 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 977 } 978 979 if (have_recolored_pages) { 980 uvm_unlock_fpageq(s); 981 free(oldbucketarray, M_VMPAGE); 982 return; 983 } 984 985 have_recolored_pages = TRUE; 986 uvm_unlock_fpageq(s); 987 } 988 989 /* 990 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 991 */ 992 993 static __inline struct vm_page * 994 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 995 int *trycolorp) 996 { 997 struct pglist *freeq; 998 struct vm_page *pg; 999 int color, trycolor = *trycolorp; 1000 1001 color = trycolor; 1002 do { 1003 if ((pg = TAILQ_FIRST((freeq = 1004 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 1005 goto gotit; 1006 if ((pg = TAILQ_FIRST((freeq = 1007 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 1008 goto gotit; 1009 color = (color + 1) & uvmexp.colormask; 1010 } while (color != trycolor); 1011 1012 return (NULL); 1013 1014 gotit: 1015 TAILQ_REMOVE(freeq, pg, pageq); 1016 uvmexp.free--; 1017 1018 /* update zero'd page count */ 1019 if (pg->flags & PG_ZERO) 1020 uvmexp.zeropages--; 1021 1022 if (color == trycolor) 1023 uvmexp.colorhit++; 1024 else { 1025 uvmexp.colormiss++; 1026 *trycolorp = color; 1027 } 1028 1029 return (pg); 1030 } 1031 1032 /* 1033 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1034 * 1035 * => return null if no pages free 1036 * => wake up pagedaemon if number of free pages drops below low water mark 1037 * => if obj != NULL, obj must be locked (to put in hash) 1038 * => if anon != NULL, anon must be locked (to put in anon) 1039 * => only one of obj or anon can be non-null 1040 * => caller must activate/deactivate page if it is not wired. 1041 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1042 * => policy decision: it is more important to pull a page off of the 1043 * appropriate priority free list than it is to get a zero'd or 1044 * unknown contents page. This is because we live with the 1045 * consequences of a bad free list decision for the entire 1046 * lifetime of the page, e.g. if the page comes from memory that 1047 * is slower to access. 1048 */ 1049 1050 struct vm_page * 1051 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 1052 struct uvm_object *obj; 1053 voff_t off; 1054 int flags; 1055 struct vm_anon *anon; 1056 int strat, free_list; 1057 { 1058 int lcv, try1, try2, s, zeroit = 0, color; 1059 struct vm_page *pg; 1060 boolean_t use_reserve; 1061 1062 KASSERT(obj == NULL || anon == NULL); 1063 KASSERT(off == trunc_page(off)); 1064 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1065 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1066 1067 s = uvm_lock_fpageq(); 1068 1069 /* 1070 * This implements a global round-robin page coloring 1071 * algorithm. 1072 * 1073 * XXXJRT: Should we make the `nextcolor' per-CPU? 1074 * XXXJRT: What about virtually-indexed caches? 1075 */ 1076 1077 color = uvm.page_free_nextcolor; 1078 1079 /* 1080 * check to see if we need to generate some free pages waking 1081 * the pagedaemon. 1082 */ 1083 1084 UVM_KICK_PDAEMON(); 1085 1086 /* 1087 * fail if any of these conditions is true: 1088 * [1] there really are no free pages, or 1089 * [2] only kernel "reserved" pages remain and 1090 * the page isn't being allocated to a kernel object. 1091 * [3] only pagedaemon "reserved" pages remain and 1092 * the requestor isn't the pagedaemon. 1093 */ 1094 1095 use_reserve = (flags & UVM_PGA_USERESERVE) || 1096 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1097 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1098 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1099 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1100 goto fail; 1101 1102 #if PGFL_NQUEUES != 2 1103 #error uvm_pagealloc_strat needs to be updated 1104 #endif 1105 1106 /* 1107 * If we want a zero'd page, try the ZEROS queue first, otherwise 1108 * we try the UNKNOWN queue first. 1109 */ 1110 if (flags & UVM_PGA_ZERO) { 1111 try1 = PGFL_ZEROS; 1112 try2 = PGFL_UNKNOWN; 1113 } else { 1114 try1 = PGFL_UNKNOWN; 1115 try2 = PGFL_ZEROS; 1116 } 1117 1118 again: 1119 switch (strat) { 1120 case UVM_PGA_STRAT_NORMAL: 1121 /* Check all freelists in descending priority order. */ 1122 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1123 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1124 try1, try2, &color); 1125 if (pg != NULL) 1126 goto gotit; 1127 } 1128 1129 /* No pages free! */ 1130 goto fail; 1131 1132 case UVM_PGA_STRAT_ONLY: 1133 case UVM_PGA_STRAT_FALLBACK: 1134 /* Attempt to allocate from the specified free list. */ 1135 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1136 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1137 try1, try2, &color); 1138 if (pg != NULL) 1139 goto gotit; 1140 1141 /* Fall back, if possible. */ 1142 if (strat == UVM_PGA_STRAT_FALLBACK) { 1143 strat = UVM_PGA_STRAT_NORMAL; 1144 goto again; 1145 } 1146 1147 /* No pages free! */ 1148 goto fail; 1149 1150 default: 1151 panic("uvm_pagealloc_strat: bad strat %d", strat); 1152 /* NOTREACHED */ 1153 } 1154 1155 gotit: 1156 /* 1157 * We now know which color we actually allocated from; set 1158 * the next color accordingly. 1159 */ 1160 1161 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1162 1163 /* 1164 * update allocation statistics and remember if we have to 1165 * zero the page 1166 */ 1167 1168 if (flags & UVM_PGA_ZERO) { 1169 if (pg->flags & PG_ZERO) { 1170 uvmexp.pga_zerohit++; 1171 zeroit = 0; 1172 } else { 1173 uvmexp.pga_zeromiss++; 1174 zeroit = 1; 1175 } 1176 } 1177 uvm_unlock_fpageq(s); 1178 1179 pg->offset = off; 1180 pg->uobject = obj; 1181 pg->uanon = anon; 1182 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1183 if (anon) { 1184 anon->u.an_page = pg; 1185 pg->pqflags = PQ_ANON; 1186 uvmexp.anonpages++; 1187 } else { 1188 if (obj) { 1189 uvm_pageinsert(pg); 1190 } 1191 pg->pqflags = 0; 1192 } 1193 #if defined(UVM_PAGE_TRKOWN) 1194 pg->owner_tag = NULL; 1195 #endif 1196 UVM_PAGE_OWN(pg, "new alloc"); 1197 1198 if (flags & UVM_PGA_ZERO) { 1199 /* 1200 * A zero'd page is not clean. If we got a page not already 1201 * zero'd, then we have to zero it ourselves. 1202 */ 1203 pg->flags &= ~PG_CLEAN; 1204 if (zeroit) 1205 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1206 } 1207 1208 return(pg); 1209 1210 fail: 1211 uvm_unlock_fpageq(s); 1212 return (NULL); 1213 } 1214 1215 /* 1216 * uvm_pagereplace: replace a page with another 1217 * 1218 * => object must be locked 1219 */ 1220 1221 void 1222 uvm_pagereplace(oldpg, newpg) 1223 struct vm_page *oldpg; 1224 struct vm_page *newpg; 1225 { 1226 1227 KASSERT((oldpg->flags & PG_TABLED) != 0); 1228 KASSERT(oldpg->uobject != NULL); 1229 KASSERT((newpg->flags & PG_TABLED) == 0); 1230 KASSERT(newpg->uobject == NULL); 1231 LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock)); 1232 1233 newpg->uobject = oldpg->uobject; 1234 newpg->offset = oldpg->offset; 1235 1236 uvm_pageinsert_after(newpg, oldpg); 1237 uvm_pageremove(oldpg); 1238 } 1239 1240 /* 1241 * uvm_pagerealloc: reallocate a page from one object to another 1242 * 1243 * => both objects must be locked 1244 */ 1245 1246 void 1247 uvm_pagerealloc(pg, newobj, newoff) 1248 struct vm_page *pg; 1249 struct uvm_object *newobj; 1250 voff_t newoff; 1251 { 1252 /* 1253 * remove it from the old object 1254 */ 1255 1256 if (pg->uobject) { 1257 uvm_pageremove(pg); 1258 } 1259 1260 /* 1261 * put it in the new object 1262 */ 1263 1264 if (newobj) { 1265 pg->uobject = newobj; 1266 pg->offset = newoff; 1267 uvm_pageinsert(pg); 1268 } 1269 } 1270 1271 #ifdef DEBUG 1272 /* 1273 * check if page is zero-filled 1274 * 1275 * - called with free page queue lock held. 1276 */ 1277 void 1278 uvm_pagezerocheck(struct vm_page *pg) 1279 { 1280 int *p, *ep; 1281 1282 KASSERT(uvm_zerocheckkva != 0); 1283 LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock)); 1284 1285 /* 1286 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1287 * uvm page allocator. 1288 * 1289 * it might be better to have "CPU-local temporary map" pmap interface. 1290 */ 1291 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); 1292 p = (int *)uvm_zerocheckkva; 1293 ep = (int *)((char *)p + PAGE_SIZE); 1294 pmap_update(pmap_kernel()); 1295 while (p < ep) { 1296 if (*p != 0) 1297 panic("PG_ZERO page isn't zero-filled"); 1298 p++; 1299 } 1300 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1301 } 1302 #endif /* DEBUG */ 1303 1304 /* 1305 * uvm_pagefree: free page 1306 * 1307 * => erase page's identity (i.e. remove from hash/object) 1308 * => put page on free list 1309 * => caller must lock owning object (either anon or uvm_object) 1310 * => caller must lock page queues 1311 * => assumes all valid mappings of pg are gone 1312 */ 1313 1314 void 1315 uvm_pagefree(pg) 1316 struct vm_page *pg; 1317 { 1318 int s; 1319 struct pglist *pgfl; 1320 boolean_t iszero; 1321 1322 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1323 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1324 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1325 LOCK_ASSERT(pg->uobject == NULL || 1326 simple_lock_held(&pg->uobject->vmobjlock)); 1327 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1328 simple_lock_held(&pg->uanon->an_lock)); 1329 1330 #ifdef DEBUG 1331 if (pg->uobject == (void *)0xdeadbeef && 1332 pg->uanon == (void *)0xdeadbeef) { 1333 panic("uvm_pagefree: freeing free page %p", pg); 1334 } 1335 #endif /* DEBUG */ 1336 1337 /* 1338 * if the page is loaned, resolve the loan instead of freeing. 1339 */ 1340 1341 if (pg->loan_count) { 1342 KASSERT(pg->wire_count == 0); 1343 1344 /* 1345 * if the page is owned by an anon then we just want to 1346 * drop anon ownership. the kernel will free the page when 1347 * it is done with it. if the page is owned by an object, 1348 * remove it from the object and mark it dirty for the benefit 1349 * of possible anon owners. 1350 * 1351 * regardless of previous ownership, wakeup any waiters, 1352 * unbusy the page, and we're done. 1353 */ 1354 1355 if (pg->uobject != NULL) { 1356 uvm_pageremove(pg); 1357 pg->flags &= ~PG_CLEAN; 1358 } else if (pg->uanon != NULL) { 1359 if ((pg->pqflags & PQ_ANON) == 0) { 1360 pg->loan_count--; 1361 } else { 1362 pg->pqflags &= ~PQ_ANON; 1363 uvmexp.anonpages--; 1364 } 1365 pg->uanon->u.an_page = NULL; 1366 pg->uanon = NULL; 1367 } 1368 if (pg->flags & PG_WANTED) { 1369 wakeup(pg); 1370 } 1371 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1372 #ifdef UVM_PAGE_TRKOWN 1373 pg->owner_tag = NULL; 1374 #endif 1375 if (pg->loan_count) { 1376 uvm_pagedequeue(pg); 1377 return; 1378 } 1379 } 1380 1381 /* 1382 * remove page from its object or anon. 1383 */ 1384 1385 if (pg->uobject != NULL) { 1386 uvm_pageremove(pg); 1387 } else if (pg->uanon != NULL) { 1388 pg->uanon->u.an_page = NULL; 1389 uvmexp.anonpages--; 1390 } 1391 1392 /* 1393 * now remove the page from the queues. 1394 */ 1395 1396 uvm_pagedequeue(pg); 1397 1398 /* 1399 * if the page was wired, unwire it now. 1400 */ 1401 1402 if (pg->wire_count) { 1403 pg->wire_count = 0; 1404 uvmexp.wired--; 1405 } 1406 1407 /* 1408 * and put on free queue 1409 */ 1410 1411 iszero = (pg->flags & PG_ZERO); 1412 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. 1413 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 1414 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; 1415 1416 pg->pqflags = PQ_FREE; 1417 #ifdef DEBUG 1418 pg->uobject = (void *)0xdeadbeef; 1419 pg->offset = 0xdeadbeef; 1420 pg->uanon = (void *)0xdeadbeef; 1421 #endif 1422 1423 s = uvm_lock_fpageq(); 1424 1425 #ifdef DEBUG 1426 if (iszero) 1427 uvm_pagezerocheck(pg); 1428 #endif /* DEBUG */ 1429 1430 TAILQ_INSERT_HEAD(pgfl, pg, pageq); 1431 uvmexp.free++; 1432 if (iszero) 1433 uvmexp.zeropages++; 1434 1435 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1436 uvm.page_idle_zero = vm_page_zero_enable; 1437 1438 uvm_unlock_fpageq(s); 1439 } 1440 1441 /* 1442 * uvm_page_unbusy: unbusy an array of pages. 1443 * 1444 * => pages must either all belong to the same object, or all belong to anons. 1445 * => if pages are object-owned, object must be locked. 1446 * => if pages are anon-owned, anons must be locked. 1447 * => caller must lock page queues if pages may be released. 1448 * => caller must make sure that anon-owned pages are not PG_RELEASED. 1449 */ 1450 1451 void 1452 uvm_page_unbusy(pgs, npgs) 1453 struct vm_page **pgs; 1454 int npgs; 1455 { 1456 struct vm_page *pg; 1457 int i; 1458 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1459 1460 for (i = 0; i < npgs; i++) { 1461 pg = pgs[i]; 1462 if (pg == NULL || pg == PGO_DONTCARE) { 1463 continue; 1464 } 1465 1466 LOCK_ASSERT(pg->uobject == NULL || 1467 simple_lock_held(&pg->uobject->vmobjlock)); 1468 LOCK_ASSERT(pg->uobject != NULL || 1469 (pg->uanon != NULL && 1470 simple_lock_held(&pg->uanon->an_lock))); 1471 1472 KASSERT(pg->flags & PG_BUSY); 1473 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1474 if (pg->flags & PG_WANTED) { 1475 wakeup(pg); 1476 } 1477 if (pg->flags & PG_RELEASED) { 1478 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1479 KASSERT(pg->uobject != NULL || 1480 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 1481 pg->flags &= ~PG_RELEASED; 1482 uvm_pagefree(pg); 1483 } else { 1484 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1485 pg->flags &= ~(PG_WANTED|PG_BUSY); 1486 UVM_PAGE_OWN(pg, NULL); 1487 } 1488 } 1489 } 1490 1491 #if defined(UVM_PAGE_TRKOWN) 1492 /* 1493 * uvm_page_own: set or release page ownership 1494 * 1495 * => this is a debugging function that keeps track of who sets PG_BUSY 1496 * and where they do it. it can be used to track down problems 1497 * such a process setting "PG_BUSY" and never releasing it. 1498 * => page's object [if any] must be locked 1499 * => if "tag" is NULL then we are releasing page ownership 1500 */ 1501 void 1502 uvm_page_own(pg, tag) 1503 struct vm_page *pg; 1504 char *tag; 1505 { 1506 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1507 1508 /* gain ownership? */ 1509 if (tag) { 1510 if (pg->owner_tag) { 1511 printf("uvm_page_own: page %p already owned " 1512 "by proc %d [%s]\n", pg, 1513 pg->owner, pg->owner_tag); 1514 panic("uvm_page_own"); 1515 } 1516 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1517 pg->owner_tag = tag; 1518 return; 1519 } 1520 1521 /* drop ownership */ 1522 if (pg->owner_tag == NULL) { 1523 printf("uvm_page_own: dropping ownership of an non-owned " 1524 "page (%p)\n", pg); 1525 panic("uvm_page_own"); 1526 } 1527 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1528 (pg->uanon == NULL && pg->uobject == NULL) || 1529 pg->uobject == uvm.kernel_object || 1530 pg->wire_count > 0 || 1531 (pg->loan_count == 1 && pg->uanon == NULL) || 1532 pg->loan_count > 1); 1533 pg->owner_tag = NULL; 1534 } 1535 #endif 1536 1537 /* 1538 * uvm_pageidlezero: zero free pages while the system is idle. 1539 * 1540 * => try to complete one color bucket at a time, to reduce our impact 1541 * on the CPU cache. 1542 * => we loop until we either reach the target or whichqs indicates that 1543 * there is a process ready to run. 1544 */ 1545 void 1546 uvm_pageidlezero() 1547 { 1548 struct vm_page *pg; 1549 struct pgfreelist *pgfl; 1550 int free_list, s, firstbucket; 1551 static int nextbucket; 1552 1553 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1554 s = uvm_lock_fpageq(); 1555 firstbucket = nextbucket; 1556 do { 1557 if (sched_whichqs != 0) 1558 goto quit; 1559 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1560 uvm.page_idle_zero = FALSE; 1561 goto quit; 1562 } 1563 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1564 pgfl = &uvm.page_free[free_list]; 1565 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1566 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1567 if (sched_whichqs != 0) 1568 goto quit; 1569 1570 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1571 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1572 pg, pageq); 1573 uvmexp.free--; 1574 uvm_unlock_fpageq(s); 1575 KERNEL_UNLOCK(); 1576 #ifdef PMAP_PAGEIDLEZERO 1577 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1578 1579 /* 1580 * The machine-dependent code detected 1581 * some reason for us to abort zeroing 1582 * pages, probably because there is a 1583 * process now ready to run. 1584 */ 1585 1586 KERNEL_LOCK( 1587 LK_EXCLUSIVE | LK_CANRECURSE); 1588 s = uvm_lock_fpageq(); 1589 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1590 nextbucket].pgfl_queues[ 1591 PGFL_UNKNOWN], pg, pageq); 1592 uvmexp.free++; 1593 uvmexp.zeroaborts++; 1594 goto quit; 1595 } 1596 #else 1597 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1598 #endif /* PMAP_PAGEIDLEZERO */ 1599 pg->flags |= PG_ZERO; 1600 1601 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1602 s = uvm_lock_fpageq(); 1603 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1604 nextbucket].pgfl_queues[PGFL_ZEROS], 1605 pg, pageq); 1606 uvmexp.free++; 1607 uvmexp.zeropages++; 1608 } 1609 } 1610 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1611 } while (nextbucket != firstbucket); 1612 quit: 1613 uvm_unlock_fpageq(s); 1614 KERNEL_UNLOCK(); 1615 } 1616