1 /* $NetBSD: uvm_page.c,v 1.109 2005/12/24 20:45:10 perry 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 1.109 2005/12/24 20:45:10 perry 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 uvm_pctparam_set(&uvmexp.inactivepct, 33); 437 438 /* 439 * determine if we should zero pages in the idle loop. 440 */ 441 442 uvm.page_idle_zero = vm_page_zero_enable; 443 444 /* 445 * done! 446 */ 447 448 uvm.page_init_done = TRUE; 449 } 450 451 /* 452 * uvm_setpagesize: set the page size 453 * 454 * => sets page_shift and page_mask from uvmexp.pagesize. 455 */ 456 457 void 458 uvm_setpagesize(void) 459 { 460 461 /* 462 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 463 * to be a constant (indicated by being a non-zero value). 464 */ 465 if (uvmexp.pagesize == 0) { 466 if (PAGE_SIZE == 0) 467 panic("uvm_setpagesize: uvmexp.pagesize not set"); 468 uvmexp.pagesize = PAGE_SIZE; 469 } 470 uvmexp.pagemask = uvmexp.pagesize - 1; 471 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 472 panic("uvm_setpagesize: page size not a power of two"); 473 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 474 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 475 break; 476 } 477 478 /* 479 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 480 */ 481 482 vaddr_t 483 uvm_pageboot_alloc(vsize_t size) 484 { 485 static boolean_t initialized = FALSE; 486 vaddr_t addr; 487 #if !defined(PMAP_STEAL_MEMORY) 488 vaddr_t vaddr; 489 paddr_t paddr; 490 #endif 491 492 /* 493 * on first call to this function, initialize ourselves. 494 */ 495 if (initialized == FALSE) { 496 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 497 498 /* round it the way we like it */ 499 virtual_space_start = round_page(virtual_space_start); 500 virtual_space_end = trunc_page(virtual_space_end); 501 502 initialized = TRUE; 503 } 504 505 /* round to page size */ 506 size = round_page(size); 507 508 #if defined(PMAP_STEAL_MEMORY) 509 510 /* 511 * defer bootstrap allocation to MD code (it may want to allocate 512 * from a direct-mapped segment). pmap_steal_memory should adjust 513 * virtual_space_start/virtual_space_end if necessary. 514 */ 515 516 addr = pmap_steal_memory(size, &virtual_space_start, 517 &virtual_space_end); 518 519 return(addr); 520 521 #else /* !PMAP_STEAL_MEMORY */ 522 523 /* 524 * allocate virtual memory for this request 525 */ 526 if (virtual_space_start == virtual_space_end || 527 (virtual_space_end - virtual_space_start) < size) 528 panic("uvm_pageboot_alloc: out of virtual space"); 529 530 addr = virtual_space_start; 531 532 #ifdef PMAP_GROWKERNEL 533 /* 534 * If the kernel pmap can't map the requested space, 535 * then allocate more resources for it. 536 */ 537 if (uvm_maxkaddr < (addr + size)) { 538 uvm_maxkaddr = pmap_growkernel(addr + size); 539 if (uvm_maxkaddr < (addr + size)) 540 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 541 } 542 #endif 543 544 virtual_space_start += size; 545 546 /* 547 * allocate and mapin physical pages to back new virtual pages 548 */ 549 550 for (vaddr = round_page(addr) ; vaddr < addr + size ; 551 vaddr += PAGE_SIZE) { 552 553 if (!uvm_page_physget(&paddr)) 554 panic("uvm_pageboot_alloc: out of memory"); 555 556 /* 557 * Note this memory is no longer managed, so using 558 * pmap_kenter is safe. 559 */ 560 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 561 } 562 pmap_update(pmap_kernel()); 563 return(addr); 564 #endif /* PMAP_STEAL_MEMORY */ 565 } 566 567 #if !defined(PMAP_STEAL_MEMORY) 568 /* 569 * uvm_page_physget: "steal" one page from the vm_physmem structure. 570 * 571 * => attempt to allocate it off the end of a segment in which the "avail" 572 * values match the start/end values. if we can't do that, then we 573 * will advance both values (making them equal, and removing some 574 * vm_page structures from the non-avail area). 575 * => return false if out of memory. 576 */ 577 578 /* subroutine: try to allocate from memory chunks on the specified freelist */ 579 static boolean_t uvm_page_physget_freelist(paddr_t *, int); 580 581 static boolean_t 582 uvm_page_physget_freelist(paddr_t *paddrp, int freelist) 583 { 584 int lcv, x; 585 586 /* pass 1: try allocating from a matching end */ 587 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 588 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 589 #else 590 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 591 #endif 592 { 593 594 if (uvm.page_init_done == TRUE) 595 panic("uvm_page_physget: called _after_ bootstrap"); 596 597 if (vm_physmem[lcv].free_list != freelist) 598 continue; 599 600 /* try from front */ 601 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 602 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 603 *paddrp = ptoa(vm_physmem[lcv].avail_start); 604 vm_physmem[lcv].avail_start++; 605 vm_physmem[lcv].start++; 606 /* nothing left? nuke it */ 607 if (vm_physmem[lcv].avail_start == 608 vm_physmem[lcv].end) { 609 if (vm_nphysseg == 1) 610 panic("uvm_page_physget: out of memory!"); 611 vm_nphysseg--; 612 for (x = lcv ; x < vm_nphysseg ; x++) 613 /* structure copy */ 614 vm_physmem[x] = vm_physmem[x+1]; 615 } 616 return (TRUE); 617 } 618 619 /* try from rear */ 620 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 621 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 622 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 623 vm_physmem[lcv].avail_end--; 624 vm_physmem[lcv].end--; 625 /* nothing left? nuke it */ 626 if (vm_physmem[lcv].avail_end == 627 vm_physmem[lcv].start) { 628 if (vm_nphysseg == 1) 629 panic("uvm_page_physget: out of memory!"); 630 vm_nphysseg--; 631 for (x = lcv ; x < vm_nphysseg ; x++) 632 /* structure copy */ 633 vm_physmem[x] = vm_physmem[x+1]; 634 } 635 return (TRUE); 636 } 637 } 638 639 /* pass2: forget about matching ends, just allocate something */ 640 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 641 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 642 #else 643 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 644 #endif 645 { 646 647 /* any room in this bank? */ 648 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 649 continue; /* nope */ 650 651 *paddrp = ptoa(vm_physmem[lcv].avail_start); 652 vm_physmem[lcv].avail_start++; 653 /* truncate! */ 654 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 655 656 /* nothing left? nuke it */ 657 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 658 if (vm_nphysseg == 1) 659 panic("uvm_page_physget: out of memory!"); 660 vm_nphysseg--; 661 for (x = lcv ; x < vm_nphysseg ; x++) 662 /* structure copy */ 663 vm_physmem[x] = vm_physmem[x+1]; 664 } 665 return (TRUE); 666 } 667 668 return (FALSE); /* whoops! */ 669 } 670 671 boolean_t 672 uvm_page_physget(paddr_t *paddrp) 673 { 674 int i; 675 676 /* try in the order of freelist preference */ 677 for (i = 0; i < VM_NFREELIST; i++) 678 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 679 return (TRUE); 680 return (FALSE); 681 } 682 #endif /* PMAP_STEAL_MEMORY */ 683 684 /* 685 * uvm_page_physload: load physical memory into VM system 686 * 687 * => all args are PFs 688 * => all pages in start/end get vm_page structures 689 * => areas marked by avail_start/avail_end get added to the free page pool 690 * => we are limited to VM_PHYSSEG_MAX physical memory segments 691 */ 692 693 void 694 uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start, 695 paddr_t avail_end, int free_list) 696 { 697 int preload, lcv; 698 psize_t npages; 699 struct vm_page *pgs; 700 struct vm_physseg *ps; 701 702 if (uvmexp.pagesize == 0) 703 panic("uvm_page_physload: page size not set!"); 704 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 705 panic("uvm_page_physload: bad free list %d", free_list); 706 if (start >= end) 707 panic("uvm_page_physload: start >= end"); 708 709 /* 710 * do we have room? 711 */ 712 713 if (vm_nphysseg == VM_PHYSSEG_MAX) { 714 printf("uvm_page_physload: unable to load physical memory " 715 "segment\n"); 716 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 717 VM_PHYSSEG_MAX, (long long)start, (long long)end); 718 printf("\tincrease VM_PHYSSEG_MAX\n"); 719 return; 720 } 721 722 /* 723 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 724 * called yet, so malloc is not available). 725 */ 726 727 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 728 if (vm_physmem[lcv].pgs) 729 break; 730 } 731 preload = (lcv == vm_nphysseg); 732 733 /* 734 * if VM is already running, attempt to malloc() vm_page structures 735 */ 736 737 if (!preload) { 738 #if defined(VM_PHYSSEG_NOADD) 739 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 740 #else 741 /* XXXCDC: need some sort of lockout for this case */ 742 paddr_t paddr; 743 npages = end - start; /* # of pages */ 744 pgs = malloc(sizeof(struct vm_page) * npages, 745 M_VMPAGE, M_NOWAIT); 746 if (pgs == NULL) { 747 printf("uvm_page_physload: can not malloc vm_page " 748 "structs for segment\n"); 749 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 750 return; 751 } 752 /* zero data, init phys_addr and free_list, and free pages */ 753 memset(pgs, 0, sizeof(struct vm_page) * npages); 754 for (lcv = 0, paddr = ptoa(start) ; 755 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 756 pgs[lcv].phys_addr = paddr; 757 pgs[lcv].free_list = free_list; 758 if (atop(paddr) >= avail_start && 759 atop(paddr) <= avail_end) 760 uvm_pagefree(&pgs[lcv]); 761 } 762 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 763 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 764 #endif 765 } else { 766 pgs = NULL; 767 npages = 0; 768 } 769 770 /* 771 * now insert us in the proper place in vm_physmem[] 772 */ 773 774 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 775 /* random: put it at the end (easy!) */ 776 ps = &vm_physmem[vm_nphysseg]; 777 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 778 { 779 int x; 780 /* sort by address for binary search */ 781 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 782 if (start < vm_physmem[lcv].start) 783 break; 784 ps = &vm_physmem[lcv]; 785 /* move back other entries, if necessary ... */ 786 for (x = vm_nphysseg ; x > lcv ; x--) 787 /* structure copy */ 788 vm_physmem[x] = vm_physmem[x - 1]; 789 } 790 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 791 { 792 int x; 793 /* sort by largest segment first */ 794 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 795 if ((end - start) > 796 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 797 break; 798 ps = &vm_physmem[lcv]; 799 /* move back other entries, if necessary ... */ 800 for (x = vm_nphysseg ; x > lcv ; x--) 801 /* structure copy */ 802 vm_physmem[x] = vm_physmem[x - 1]; 803 } 804 #else 805 panic("uvm_page_physload: unknown physseg strategy selected!"); 806 #endif 807 808 ps->start = start; 809 ps->end = end; 810 ps->avail_start = avail_start; 811 ps->avail_end = avail_end; 812 if (preload) { 813 ps->pgs = NULL; 814 } else { 815 ps->pgs = pgs; 816 ps->lastpg = pgs + npages - 1; 817 } 818 ps->free_list = free_list; 819 vm_nphysseg++; 820 821 if (!preload) 822 uvm_page_rehash(); 823 } 824 825 /* 826 * uvm_page_rehash: reallocate hash table based on number of free pages. 827 */ 828 829 void 830 uvm_page_rehash(void) 831 { 832 int freepages, lcv, bucketcount, oldcount; 833 struct pglist *newbuckets, *oldbuckets; 834 struct vm_page *pg; 835 size_t newsize, oldsize; 836 837 /* 838 * compute number of pages that can go in the free pool 839 */ 840 841 freepages = 0; 842 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 843 freepages += 844 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 845 846 /* 847 * compute number of buckets needed for this number of pages 848 */ 849 850 bucketcount = 1; 851 while (bucketcount < freepages) 852 bucketcount = bucketcount * 2; 853 854 /* 855 * compute the size of the current table and new table. 856 */ 857 858 oldbuckets = uvm.page_hash; 859 oldcount = uvm.page_nhash; 860 oldsize = round_page(sizeof(struct pglist) * oldcount); 861 newsize = round_page(sizeof(struct pglist) * bucketcount); 862 863 /* 864 * allocate the new buckets 865 */ 866 867 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize, 868 0, UVM_KMF_WIRED); 869 if (newbuckets == NULL) { 870 printf("uvm_page_physrehash: WARNING: could not grow page " 871 "hash table\n"); 872 return; 873 } 874 for (lcv = 0 ; lcv < bucketcount ; lcv++) 875 TAILQ_INIT(&newbuckets[lcv]); 876 877 /* 878 * now replace the old buckets with the new ones and rehash everything 879 */ 880 881 simple_lock(&uvm.hashlock); 882 uvm.page_hash = newbuckets; 883 uvm.page_nhash = bucketcount; 884 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 885 886 /* ... and rehash */ 887 for (lcv = 0 ; lcv < oldcount ; lcv++) { 888 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 889 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 890 TAILQ_INSERT_TAIL( 891 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 892 pg, hashq); 893 } 894 } 895 simple_unlock(&uvm.hashlock); 896 897 /* 898 * free old bucket array if is not the boot-time table 899 */ 900 901 if (oldbuckets != &uvm_bootbucket) 902 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize, 903 UVM_KMF_WIRED); 904 } 905 906 /* 907 * uvm_page_recolor: Recolor the pages if the new bucket count is 908 * larger than the old one. 909 */ 910 911 void 912 uvm_page_recolor(int newncolors) 913 { 914 struct pgflbucket *bucketarray, *oldbucketarray; 915 struct pgfreelist pgfl; 916 struct vm_page *pg; 917 vsize_t bucketcount; 918 int s, lcv, color, i, ocolors; 919 920 if (newncolors <= uvmexp.ncolors) 921 return; 922 923 if (uvm.page_init_done == FALSE) { 924 uvmexp.ncolors = newncolors; 925 return; 926 } 927 928 bucketcount = newncolors * VM_NFREELIST; 929 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 930 M_VMPAGE, M_NOWAIT); 931 if (bucketarray == NULL) { 932 printf("WARNING: unable to allocate %ld page color buckets\n", 933 (long) bucketcount); 934 return; 935 } 936 937 s = uvm_lock_fpageq(); 938 939 /* Make sure we should still do this. */ 940 if (newncolors <= uvmexp.ncolors) { 941 uvm_unlock_fpageq(s); 942 free(bucketarray, M_VMPAGE); 943 return; 944 } 945 946 oldbucketarray = uvm.page_free[0].pgfl_buckets; 947 ocolors = uvmexp.ncolors; 948 949 uvmexp.ncolors = newncolors; 950 uvmexp.colormask = uvmexp.ncolors - 1; 951 952 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 953 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 954 uvm_page_init_buckets(&pgfl); 955 for (color = 0; color < ocolors; color++) { 956 for (i = 0; i < PGFL_NQUEUES; i++) { 957 while ((pg = TAILQ_FIRST(&uvm.page_free[ 958 lcv].pgfl_buckets[color].pgfl_queues[i])) 959 != NULL) { 960 TAILQ_REMOVE(&uvm.page_free[ 961 lcv].pgfl_buckets[ 962 color].pgfl_queues[i], pg, pageq); 963 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 964 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 965 i], pg, pageq); 966 } 967 } 968 } 969 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 970 } 971 972 if (have_recolored_pages) { 973 uvm_unlock_fpageq(s); 974 free(oldbucketarray, M_VMPAGE); 975 return; 976 } 977 978 have_recolored_pages = TRUE; 979 uvm_unlock_fpageq(s); 980 } 981 982 /* 983 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 984 */ 985 986 static inline struct vm_page * 987 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 988 int *trycolorp) 989 { 990 struct pglist *freeq; 991 struct vm_page *pg; 992 int color, trycolor = *trycolorp; 993 994 color = trycolor; 995 do { 996 if ((pg = TAILQ_FIRST((freeq = 997 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 998 goto gotit; 999 if ((pg = TAILQ_FIRST((freeq = 1000 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 1001 goto gotit; 1002 color = (color + 1) & uvmexp.colormask; 1003 } while (color != trycolor); 1004 1005 return (NULL); 1006 1007 gotit: 1008 TAILQ_REMOVE(freeq, pg, pageq); 1009 uvmexp.free--; 1010 1011 /* update zero'd page count */ 1012 if (pg->flags & PG_ZERO) 1013 uvmexp.zeropages--; 1014 1015 if (color == trycolor) 1016 uvmexp.colorhit++; 1017 else { 1018 uvmexp.colormiss++; 1019 *trycolorp = color; 1020 } 1021 1022 return (pg); 1023 } 1024 1025 /* 1026 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1027 * 1028 * => return null if no pages free 1029 * => wake up pagedaemon if number of free pages drops below low water mark 1030 * => if obj != NULL, obj must be locked (to put in hash) 1031 * => if anon != NULL, anon must be locked (to put in anon) 1032 * => only one of obj or anon can be non-null 1033 * => caller must activate/deactivate page if it is not wired. 1034 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1035 * => policy decision: it is more important to pull a page off of the 1036 * appropriate priority free list than it is to get a zero'd or 1037 * unknown contents page. This is because we live with the 1038 * consequences of a bad free list decision for the entire 1039 * lifetime of the page, e.g. if the page comes from memory that 1040 * is slower to access. 1041 */ 1042 1043 struct vm_page * 1044 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon, 1045 int flags, int strat, int free_list) 1046 { 1047 int lcv, try1, try2, s, zeroit = 0, color; 1048 struct vm_page *pg; 1049 boolean_t use_reserve; 1050 1051 KASSERT(obj == NULL || anon == NULL); 1052 KASSERT(off == trunc_page(off)); 1053 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1054 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1055 1056 s = uvm_lock_fpageq(); 1057 1058 /* 1059 * This implements a global round-robin page coloring 1060 * algorithm. 1061 * 1062 * XXXJRT: Should we make the `nextcolor' per-CPU? 1063 * XXXJRT: What about virtually-indexed caches? 1064 */ 1065 1066 color = uvm.page_free_nextcolor; 1067 1068 /* 1069 * check to see if we need to generate some free pages waking 1070 * the pagedaemon. 1071 */ 1072 1073 UVM_KICK_PDAEMON(); 1074 1075 /* 1076 * fail if any of these conditions is true: 1077 * [1] there really are no free pages, or 1078 * [2] only kernel "reserved" pages remain and 1079 * the page isn't being allocated to a kernel object. 1080 * [3] only pagedaemon "reserved" pages remain and 1081 * the requestor isn't the pagedaemon. 1082 */ 1083 1084 use_reserve = (flags & UVM_PGA_USERESERVE) || 1085 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1086 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1087 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1088 !(use_reserve && curproc == uvm.pagedaemon_proc))) 1089 goto fail; 1090 1091 #if PGFL_NQUEUES != 2 1092 #error uvm_pagealloc_strat needs to be updated 1093 #endif 1094 1095 /* 1096 * If we want a zero'd page, try the ZEROS queue first, otherwise 1097 * we try the UNKNOWN queue first. 1098 */ 1099 if (flags & UVM_PGA_ZERO) { 1100 try1 = PGFL_ZEROS; 1101 try2 = PGFL_UNKNOWN; 1102 } else { 1103 try1 = PGFL_UNKNOWN; 1104 try2 = PGFL_ZEROS; 1105 } 1106 1107 again: 1108 switch (strat) { 1109 case UVM_PGA_STRAT_NORMAL: 1110 /* Check all freelists in descending priority order. */ 1111 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1112 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1113 try1, try2, &color); 1114 if (pg != NULL) 1115 goto gotit; 1116 } 1117 1118 /* No pages free! */ 1119 goto fail; 1120 1121 case UVM_PGA_STRAT_ONLY: 1122 case UVM_PGA_STRAT_FALLBACK: 1123 /* Attempt to allocate from the specified free list. */ 1124 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1125 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1126 try1, try2, &color); 1127 if (pg != NULL) 1128 goto gotit; 1129 1130 /* Fall back, if possible. */ 1131 if (strat == UVM_PGA_STRAT_FALLBACK) { 1132 strat = UVM_PGA_STRAT_NORMAL; 1133 goto again; 1134 } 1135 1136 /* No pages free! */ 1137 goto fail; 1138 1139 default: 1140 panic("uvm_pagealloc_strat: bad strat %d", strat); 1141 /* NOTREACHED */ 1142 } 1143 1144 gotit: 1145 /* 1146 * We now know which color we actually allocated from; set 1147 * the next color accordingly. 1148 */ 1149 1150 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1151 1152 /* 1153 * update allocation statistics and remember if we have to 1154 * zero the page 1155 */ 1156 1157 if (flags & UVM_PGA_ZERO) { 1158 if (pg->flags & PG_ZERO) { 1159 uvmexp.pga_zerohit++; 1160 zeroit = 0; 1161 } else { 1162 uvmexp.pga_zeromiss++; 1163 zeroit = 1; 1164 } 1165 } 1166 uvm_unlock_fpageq(s); 1167 1168 pg->offset = off; 1169 pg->uobject = obj; 1170 pg->uanon = anon; 1171 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1172 if (anon) { 1173 anon->an_page = pg; 1174 pg->pqflags = PQ_ANON; 1175 uvmexp.anonpages++; 1176 } else { 1177 if (obj) { 1178 uvm_pageinsert(pg); 1179 } 1180 pg->pqflags = 0; 1181 } 1182 #if defined(UVM_PAGE_TRKOWN) 1183 pg->owner_tag = NULL; 1184 #endif 1185 UVM_PAGE_OWN(pg, "new alloc"); 1186 1187 if (flags & UVM_PGA_ZERO) { 1188 /* 1189 * A zero'd page is not clean. If we got a page not already 1190 * zero'd, then we have to zero it ourselves. 1191 */ 1192 pg->flags &= ~PG_CLEAN; 1193 if (zeroit) 1194 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1195 } 1196 1197 return(pg); 1198 1199 fail: 1200 uvm_unlock_fpageq(s); 1201 return (NULL); 1202 } 1203 1204 /* 1205 * uvm_pagereplace: replace a page with another 1206 * 1207 * => object must be locked 1208 */ 1209 1210 void 1211 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg) 1212 { 1213 1214 KASSERT((oldpg->flags & PG_TABLED) != 0); 1215 KASSERT(oldpg->uobject != NULL); 1216 KASSERT((newpg->flags & PG_TABLED) == 0); 1217 KASSERT(newpg->uobject == NULL); 1218 LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock)); 1219 1220 newpg->uobject = oldpg->uobject; 1221 newpg->offset = oldpg->offset; 1222 1223 uvm_pageinsert_after(newpg, oldpg); 1224 uvm_pageremove(oldpg); 1225 } 1226 1227 /* 1228 * uvm_pagerealloc: reallocate a page from one object to another 1229 * 1230 * => both objects must be locked 1231 */ 1232 1233 void 1234 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) 1235 { 1236 /* 1237 * remove it from the old object 1238 */ 1239 1240 if (pg->uobject) { 1241 uvm_pageremove(pg); 1242 } 1243 1244 /* 1245 * put it in the new object 1246 */ 1247 1248 if (newobj) { 1249 pg->uobject = newobj; 1250 pg->offset = newoff; 1251 uvm_pageinsert(pg); 1252 } 1253 } 1254 1255 #ifdef DEBUG 1256 /* 1257 * check if page is zero-filled 1258 * 1259 * - called with free page queue lock held. 1260 */ 1261 void 1262 uvm_pagezerocheck(struct vm_page *pg) 1263 { 1264 int *p, *ep; 1265 1266 KASSERT(uvm_zerocheckkva != 0); 1267 LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock)); 1268 1269 /* 1270 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1271 * uvm page allocator. 1272 * 1273 * it might be better to have "CPU-local temporary map" pmap interface. 1274 */ 1275 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); 1276 p = (int *)uvm_zerocheckkva; 1277 ep = (int *)((char *)p + PAGE_SIZE); 1278 pmap_update(pmap_kernel()); 1279 while (p < ep) { 1280 if (*p != 0) 1281 panic("PG_ZERO page isn't zero-filled"); 1282 p++; 1283 } 1284 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1285 } 1286 #endif /* DEBUG */ 1287 1288 /* 1289 * uvm_pagefree: free page 1290 * 1291 * => erase page's identity (i.e. remove from hash/object) 1292 * => put page on free list 1293 * => caller must lock owning object (either anon or uvm_object) 1294 * => caller must lock page queues 1295 * => assumes all valid mappings of pg are gone 1296 */ 1297 1298 void 1299 uvm_pagefree(struct vm_page *pg) 1300 { 1301 int s; 1302 struct pglist *pgfl; 1303 boolean_t iszero; 1304 1305 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1306 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1307 (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 1308 LOCK_ASSERT(pg->uobject == NULL || 1309 simple_lock_held(&pg->uobject->vmobjlock)); 1310 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1311 simple_lock_held(&pg->uanon->an_lock)); 1312 1313 #ifdef DEBUG 1314 if (pg->uobject == (void *)0xdeadbeef && 1315 pg->uanon == (void *)0xdeadbeef) { 1316 panic("uvm_pagefree: freeing free page %p", pg); 1317 } 1318 #endif /* DEBUG */ 1319 1320 /* 1321 * if the page is loaned, resolve the loan instead of freeing. 1322 */ 1323 1324 if (pg->loan_count) { 1325 KASSERT(pg->wire_count == 0); 1326 1327 /* 1328 * if the page is owned by an anon then we just want to 1329 * drop anon ownership. the kernel will free the page when 1330 * it is done with it. if the page is owned by an object, 1331 * remove it from the object and mark it dirty for the benefit 1332 * of possible anon owners. 1333 * 1334 * regardless of previous ownership, wakeup any waiters, 1335 * unbusy the page, and we're done. 1336 */ 1337 1338 if (pg->uobject != NULL) { 1339 uvm_pageremove(pg); 1340 pg->flags &= ~PG_CLEAN; 1341 } else if (pg->uanon != NULL) { 1342 if ((pg->pqflags & PQ_ANON) == 0) { 1343 pg->loan_count--; 1344 } else { 1345 pg->pqflags &= ~PQ_ANON; 1346 uvmexp.anonpages--; 1347 } 1348 pg->uanon->an_page = NULL; 1349 pg->uanon = NULL; 1350 } 1351 if (pg->flags & PG_WANTED) { 1352 wakeup(pg); 1353 } 1354 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1355 #ifdef UVM_PAGE_TRKOWN 1356 pg->owner_tag = NULL; 1357 #endif 1358 if (pg->loan_count) { 1359 uvm_pagedequeue(pg); 1360 return; 1361 } 1362 } 1363 1364 /* 1365 * remove page from its object or anon. 1366 */ 1367 1368 if (pg->uobject != NULL) { 1369 uvm_pageremove(pg); 1370 } else if (pg->uanon != NULL) { 1371 pg->uanon->an_page = NULL; 1372 uvmexp.anonpages--; 1373 } 1374 1375 /* 1376 * now remove the page from the queues. 1377 */ 1378 1379 uvm_pagedequeue(pg); 1380 1381 /* 1382 * if the page was wired, unwire it now. 1383 */ 1384 1385 if (pg->wire_count) { 1386 pg->wire_count = 0; 1387 uvmexp.wired--; 1388 } 1389 1390 /* 1391 * and put on free queue 1392 */ 1393 1394 iszero = (pg->flags & PG_ZERO); 1395 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. 1396 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 1397 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; 1398 1399 pg->pqflags = PQ_FREE; 1400 #ifdef DEBUG 1401 pg->uobject = (void *)0xdeadbeef; 1402 pg->offset = 0xdeadbeef; 1403 pg->uanon = (void *)0xdeadbeef; 1404 #endif 1405 1406 s = uvm_lock_fpageq(); 1407 1408 #ifdef DEBUG 1409 if (iszero) 1410 uvm_pagezerocheck(pg); 1411 #endif /* DEBUG */ 1412 1413 TAILQ_INSERT_HEAD(pgfl, pg, pageq); 1414 uvmexp.free++; 1415 if (iszero) 1416 uvmexp.zeropages++; 1417 1418 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1419 uvm.page_idle_zero = vm_page_zero_enable; 1420 1421 uvm_unlock_fpageq(s); 1422 } 1423 1424 /* 1425 * uvm_page_unbusy: unbusy an array of pages. 1426 * 1427 * => pages must either all belong to the same object, or all belong to anons. 1428 * => if pages are object-owned, object must be locked. 1429 * => if pages are anon-owned, anons must be locked. 1430 * => caller must lock page queues if pages may be released. 1431 * => caller must make sure that anon-owned pages are not PG_RELEASED. 1432 */ 1433 1434 void 1435 uvm_page_unbusy(struct vm_page **pgs, int npgs) 1436 { 1437 struct vm_page *pg; 1438 int i; 1439 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1440 1441 for (i = 0; i < npgs; i++) { 1442 pg = pgs[i]; 1443 if (pg == NULL || pg == PGO_DONTCARE) { 1444 continue; 1445 } 1446 1447 LOCK_ASSERT(pg->uobject == NULL || 1448 simple_lock_held(&pg->uobject->vmobjlock)); 1449 LOCK_ASSERT(pg->uobject != NULL || 1450 (pg->uanon != NULL && 1451 simple_lock_held(&pg->uanon->an_lock))); 1452 1453 KASSERT(pg->flags & PG_BUSY); 1454 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1455 if (pg->flags & PG_WANTED) { 1456 wakeup(pg); 1457 } 1458 if (pg->flags & PG_RELEASED) { 1459 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1460 KASSERT(pg->uobject != NULL || 1461 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 1462 pg->flags &= ~PG_RELEASED; 1463 uvm_pagefree(pg); 1464 } else { 1465 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1466 pg->flags &= ~(PG_WANTED|PG_BUSY); 1467 UVM_PAGE_OWN(pg, NULL); 1468 } 1469 } 1470 } 1471 1472 #if defined(UVM_PAGE_TRKOWN) 1473 /* 1474 * uvm_page_own: set or release page ownership 1475 * 1476 * => this is a debugging function that keeps track of who sets PG_BUSY 1477 * and where they do it. it can be used to track down problems 1478 * such a process setting "PG_BUSY" and never releasing it. 1479 * => page's object [if any] must be locked 1480 * => if "tag" is NULL then we are releasing page ownership 1481 */ 1482 void 1483 uvm_page_own(struct vm_page *pg, const char *tag) 1484 { 1485 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1486 1487 /* gain ownership? */ 1488 if (tag) { 1489 if (pg->owner_tag) { 1490 printf("uvm_page_own: page %p already owned " 1491 "by proc %d [%s]\n", pg, 1492 pg->owner, pg->owner_tag); 1493 panic("uvm_page_own"); 1494 } 1495 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1496 pg->owner_tag = tag; 1497 return; 1498 } 1499 1500 /* drop ownership */ 1501 if (pg->owner_tag == NULL) { 1502 printf("uvm_page_own: dropping ownership of an non-owned " 1503 "page (%p)\n", pg); 1504 panic("uvm_page_own"); 1505 } 1506 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || 1507 (pg->uanon == NULL && pg->uobject == NULL) || 1508 pg->uobject == uvm.kernel_object || 1509 pg->wire_count > 0 || 1510 (pg->loan_count == 1 && pg->uanon == NULL) || 1511 pg->loan_count > 1); 1512 pg->owner_tag = NULL; 1513 } 1514 #endif 1515 1516 /* 1517 * uvm_pageidlezero: zero free pages while the system is idle. 1518 * 1519 * => try to complete one color bucket at a time, to reduce our impact 1520 * on the CPU cache. 1521 * => we loop until we either reach the target or whichqs indicates that 1522 * there is a process ready to run. 1523 */ 1524 void 1525 uvm_pageidlezero(void) 1526 { 1527 struct vm_page *pg; 1528 struct pgfreelist *pgfl; 1529 int free_list, s, firstbucket; 1530 static int nextbucket; 1531 1532 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1533 s = uvm_lock_fpageq(); 1534 firstbucket = nextbucket; 1535 do { 1536 if (sched_whichqs != 0) 1537 goto quit; 1538 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1539 uvm.page_idle_zero = FALSE; 1540 goto quit; 1541 } 1542 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1543 pgfl = &uvm.page_free[free_list]; 1544 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1545 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1546 if (sched_whichqs != 0) 1547 goto quit; 1548 1549 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1550 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1551 pg, pageq); 1552 uvmexp.free--; 1553 uvm_unlock_fpageq(s); 1554 KERNEL_UNLOCK(); 1555 #ifdef PMAP_PAGEIDLEZERO 1556 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1557 1558 /* 1559 * The machine-dependent code detected 1560 * some reason for us to abort zeroing 1561 * pages, probably because there is a 1562 * process now ready to run. 1563 */ 1564 1565 KERNEL_LOCK( 1566 LK_EXCLUSIVE | LK_CANRECURSE); 1567 s = uvm_lock_fpageq(); 1568 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1569 nextbucket].pgfl_queues[ 1570 PGFL_UNKNOWN], pg, pageq); 1571 uvmexp.free++; 1572 uvmexp.zeroaborts++; 1573 goto quit; 1574 } 1575 #else 1576 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1577 #endif /* PMAP_PAGEIDLEZERO */ 1578 pg->flags |= PG_ZERO; 1579 1580 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); 1581 s = uvm_lock_fpageq(); 1582 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1583 nextbucket].pgfl_queues[PGFL_ZEROS], 1584 pg, pageq); 1585 uvmexp.free++; 1586 uvmexp.zeropages++; 1587 } 1588 } 1589 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1590 } while (nextbucket != firstbucket); 1591 quit: 1592 uvm_unlock_fpageq(s); 1593 KERNEL_UNLOCK(); 1594 } 1595