1 /* $NetBSD: uvm_page.c,v 1.192 2017/02/05 07:25:49 maya 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. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 37 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp 38 * 39 * 40 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 41 * All rights reserved. 42 * 43 * Permission to use, copy, modify and distribute this software and 44 * its documentation is hereby granted, provided that both the copyright 45 * notice and this permission notice appear in all copies of the 46 * software, derivative works or modified versions, and any portions 47 * thereof, and that both notices appear in supporting documentation. 48 * 49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 52 * 53 * Carnegie Mellon requests users of this software to return to 54 * 55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 56 * School of Computer Science 57 * Carnegie Mellon University 58 * Pittsburgh PA 15213-3890 59 * 60 * any improvements or extensions that they make and grant Carnegie the 61 * rights to redistribute these changes. 62 */ 63 64 /* 65 * uvm_page.c: page ops. 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.192 2017/02/05 07:25:49 maya Exp $"); 70 71 #include "opt_ddb.h" 72 #include "opt_uvm.h" 73 #include "opt_uvmhist.h" 74 #include "opt_readahead.h" 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/sched.h> 79 #include <sys/kernel.h> 80 #include <sys/vnode.h> 81 #include <sys/proc.h> 82 #include <sys/atomic.h> 83 #include <sys/cpu.h> 84 #include <sys/extent.h> 85 86 #include <uvm/uvm.h> 87 #include <uvm/uvm_ddb.h> 88 #include <uvm/uvm_pdpolicy.h> 89 90 /* 91 * Some supported CPUs in a given architecture don't support all 92 * of the things necessary to do idle page zero'ing efficiently. 93 * We therefore provide a way to enable it from machdep code here. 94 */ 95 bool vm_page_zero_enable = false; 96 97 /* 98 * number of pages per-CPU to reserve for the kernel. 99 */ 100 #ifndef UVM_RESERVED_PAGES_PER_CPU 101 #define UVM_RESERVED_PAGES_PER_CPU 5 102 #endif 103 int vm_page_reserve_kernel = UVM_RESERVED_PAGES_PER_CPU; 104 105 /* 106 * physical memory size; 107 */ 108 psize_t physmem; 109 110 /* 111 * local variables 112 */ 113 114 /* 115 * these variables record the values returned by vm_page_bootstrap, 116 * for debugging purposes. The implementation of uvm_pageboot_alloc 117 * and pmap_startup here also uses them internally. 118 */ 119 120 static vaddr_t virtual_space_start; 121 static vaddr_t virtual_space_end; 122 123 /* 124 * we allocate an initial number of page colors in uvm_page_init(), 125 * and remember them. We may re-color pages as cache sizes are 126 * discovered during the autoconfiguration phase. But we can never 127 * free the initial set of buckets, since they are allocated using 128 * uvm_pageboot_alloc(). 129 */ 130 131 static size_t recolored_pages_memsize /* = 0 */; 132 133 #ifdef DEBUG 134 vaddr_t uvm_zerocheckkva; 135 #endif /* DEBUG */ 136 137 /* 138 * These functions are reserved for uvm(9) internal use and are not 139 * exported in the header file uvm_physseg.h 140 * 141 * Thus they are redefined here. 142 */ 143 void uvm_physseg_init_seg(uvm_physseg_t, struct vm_page *); 144 void uvm_physseg_seg_chomp_slab(uvm_physseg_t, struct vm_page *, size_t); 145 146 /* returns a pgs array */ 147 struct vm_page *uvm_physseg_seg_alloc_from_slab(uvm_physseg_t, size_t); 148 149 /* 150 * local prototypes 151 */ 152 153 static void uvm_pageinsert(struct uvm_object *, struct vm_page *); 154 static void uvm_pageremove(struct uvm_object *, struct vm_page *); 155 156 /* 157 * per-object tree of pages 158 */ 159 160 static signed int 161 uvm_page_compare_nodes(void *ctx, const void *n1, const void *n2) 162 { 163 const struct vm_page *pg1 = n1; 164 const struct vm_page *pg2 = n2; 165 const voff_t a = pg1->offset; 166 const voff_t b = pg2->offset; 167 168 if (a < b) 169 return -1; 170 if (a > b) 171 return 1; 172 return 0; 173 } 174 175 static signed int 176 uvm_page_compare_key(void *ctx, const void *n, const void *key) 177 { 178 const struct vm_page *pg = n; 179 const voff_t a = pg->offset; 180 const voff_t b = *(const voff_t *)key; 181 182 if (a < b) 183 return -1; 184 if (a > b) 185 return 1; 186 return 0; 187 } 188 189 const rb_tree_ops_t uvm_page_tree_ops = { 190 .rbto_compare_nodes = uvm_page_compare_nodes, 191 .rbto_compare_key = uvm_page_compare_key, 192 .rbto_node_offset = offsetof(struct vm_page, rb_node), 193 .rbto_context = NULL 194 }; 195 196 /* 197 * inline functions 198 */ 199 200 /* 201 * uvm_pageinsert: insert a page in the object. 202 * 203 * => caller must lock object 204 * => caller must lock page queues 205 * => call should have already set pg's object and offset pointers 206 * and bumped the version counter 207 */ 208 209 static inline void 210 uvm_pageinsert_list(struct uvm_object *uobj, struct vm_page *pg, 211 struct vm_page *where) 212 { 213 214 KASSERT(uobj == pg->uobject); 215 KASSERT(mutex_owned(uobj->vmobjlock)); 216 KASSERT((pg->flags & PG_TABLED) == 0); 217 KASSERT(where == NULL || (where->flags & PG_TABLED)); 218 KASSERT(where == NULL || (where->uobject == uobj)); 219 220 if (UVM_OBJ_IS_VNODE(uobj)) { 221 if (uobj->uo_npages == 0) { 222 struct vnode *vp = (struct vnode *)uobj; 223 224 vholdl(vp); 225 } 226 if (UVM_OBJ_IS_VTEXT(uobj)) { 227 atomic_inc_uint(&uvmexp.execpages); 228 } else { 229 atomic_inc_uint(&uvmexp.filepages); 230 } 231 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 232 atomic_inc_uint(&uvmexp.anonpages); 233 } 234 235 if (where) 236 TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq.queue); 237 else 238 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq.queue); 239 pg->flags |= PG_TABLED; 240 uobj->uo_npages++; 241 } 242 243 244 static inline void 245 uvm_pageinsert_tree(struct uvm_object *uobj, struct vm_page *pg) 246 { 247 struct vm_page *ret __diagused; 248 249 KASSERT(uobj == pg->uobject); 250 ret = rb_tree_insert_node(&uobj->rb_tree, pg); 251 KASSERT(ret == pg); 252 } 253 254 static inline void 255 uvm_pageinsert(struct uvm_object *uobj, struct vm_page *pg) 256 { 257 258 KDASSERT(uobj != NULL); 259 uvm_pageinsert_tree(uobj, pg); 260 uvm_pageinsert_list(uobj, pg, NULL); 261 } 262 263 /* 264 * uvm_page_remove: remove page from object. 265 * 266 * => caller must lock object 267 * => caller must lock page queues 268 */ 269 270 static inline void 271 uvm_pageremove_list(struct uvm_object *uobj, struct vm_page *pg) 272 { 273 274 KASSERT(uobj == pg->uobject); 275 KASSERT(mutex_owned(uobj->vmobjlock)); 276 KASSERT(pg->flags & PG_TABLED); 277 278 if (UVM_OBJ_IS_VNODE(uobj)) { 279 if (uobj->uo_npages == 1) { 280 struct vnode *vp = (struct vnode *)uobj; 281 282 holdrelel(vp); 283 } 284 if (UVM_OBJ_IS_VTEXT(uobj)) { 285 atomic_dec_uint(&uvmexp.execpages); 286 } else { 287 atomic_dec_uint(&uvmexp.filepages); 288 } 289 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 290 atomic_dec_uint(&uvmexp.anonpages); 291 } 292 293 /* object should be locked */ 294 uobj->uo_npages--; 295 TAILQ_REMOVE(&uobj->memq, pg, listq.queue); 296 pg->flags &= ~PG_TABLED; 297 pg->uobject = NULL; 298 } 299 300 static inline void 301 uvm_pageremove_tree(struct uvm_object *uobj, struct vm_page *pg) 302 { 303 304 KASSERT(uobj == pg->uobject); 305 rb_tree_remove_node(&uobj->rb_tree, pg); 306 } 307 308 static inline void 309 uvm_pageremove(struct uvm_object *uobj, struct vm_page *pg) 310 { 311 312 KDASSERT(uobj != NULL); 313 uvm_pageremove_tree(uobj, pg); 314 uvm_pageremove_list(uobj, pg); 315 } 316 317 static void 318 uvm_page_init_buckets(struct pgfreelist *pgfl) 319 { 320 int color, i; 321 322 for (color = 0; color < uvmexp.ncolors; color++) { 323 for (i = 0; i < PGFL_NQUEUES; i++) { 324 LIST_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); 325 } 326 } 327 } 328 329 /* 330 * uvm_page_init: init the page system. called from uvm_init(). 331 * 332 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 333 */ 334 335 void 336 uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp) 337 { 338 static struct uvm_cpu boot_cpu; 339 psize_t freepages, pagecount, bucketcount, n; 340 struct pgflbucket *bucketarray, *cpuarray; 341 struct vm_page *pagearray; 342 uvm_physseg_t bank; 343 int lcv; 344 345 KASSERT(ncpu <= 1); 346 CTASSERT(sizeof(pagearray->offset) >= sizeof(struct uvm_cpu *)); 347 348 /* 349 * init the page queues and page queue locks, except the free 350 * list; we allocate that later (with the initial vm_page 351 * structures). 352 */ 353 354 uvm.cpus[0] = &boot_cpu; 355 curcpu()->ci_data.cpu_uvm = &boot_cpu; 356 uvmpdpol_init(); 357 mutex_init(&uvm_pageqlock, MUTEX_DRIVER, IPL_NONE); 358 mutex_init(&uvm_fpageqlock, MUTEX_DRIVER, IPL_VM); 359 360 /* 361 * allocate vm_page structures. 362 */ 363 364 /* 365 * sanity check: 366 * before calling this function the MD code is expected to register 367 * some free RAM with the uvm_page_physload() function. our job 368 * now is to allocate vm_page structures for this memory. 369 */ 370 371 if (uvm_physseg_get_last() == UVM_PHYSSEG_TYPE_INVALID) 372 panic("uvm_page_bootstrap: no memory pre-allocated"); 373 374 /* 375 * first calculate the number of free pages... 376 * 377 * note that we use start/end rather than avail_start/avail_end. 378 * this allows us to allocate extra vm_page structures in case we 379 * want to return some memory to the pool after booting. 380 */ 381 382 freepages = 0; 383 384 for (bank = uvm_physseg_get_first(); 385 uvm_physseg_valid_p(bank) ; 386 bank = uvm_physseg_get_next(bank)) { 387 freepages += (uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank)); 388 } 389 390 /* 391 * Let MD code initialize the number of colors, or default 392 * to 1 color if MD code doesn't care. 393 */ 394 if (uvmexp.ncolors == 0) 395 uvmexp.ncolors = 1; 396 uvmexp.colormask = uvmexp.ncolors - 1; 397 KASSERT((uvmexp.colormask & uvmexp.ncolors) == 0); 398 399 /* 400 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 401 * use. for each page of memory we use we need a vm_page structure. 402 * thus, the total number of pages we can use is the total size of 403 * the memory divided by the PAGE_SIZE plus the size of the vm_page 404 * structure. we add one to freepages as a fudge factor to avoid 405 * truncation errors (since we can only allocate in terms of whole 406 * pages). 407 */ 408 409 bucketcount = uvmexp.ncolors * VM_NFREELIST; 410 pagecount = ((freepages + 1) << PAGE_SHIFT) / 411 (PAGE_SIZE + sizeof(struct vm_page)); 412 413 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 414 sizeof(struct pgflbucket) * 2) + (pagecount * 415 sizeof(struct vm_page))); 416 cpuarray = bucketarray + bucketcount; 417 pagearray = (struct vm_page *)(bucketarray + bucketcount * 2); 418 419 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 420 uvm.page_free[lcv].pgfl_buckets = 421 (bucketarray + (lcv * uvmexp.ncolors)); 422 uvm_page_init_buckets(&uvm.page_free[lcv]); 423 uvm.cpus[0]->page_free[lcv].pgfl_buckets = 424 (cpuarray + (lcv * uvmexp.ncolors)); 425 uvm_page_init_buckets(&uvm.cpus[0]->page_free[lcv]); 426 } 427 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 428 429 /* 430 * init the vm_page structures and put them in the correct place. 431 */ 432 /* First init the extent */ 433 434 for (bank = uvm_physseg_get_first(), 435 uvm_physseg_seg_chomp_slab(bank, pagearray, pagecount); 436 uvm_physseg_valid_p(bank); 437 bank = uvm_physseg_get_next(bank)) { 438 439 n = uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank); 440 uvm_physseg_seg_alloc_from_slab(bank, n); 441 uvm_physseg_init_seg(bank, pagearray); 442 443 /* set up page array pointers */ 444 pagearray += n; 445 pagecount -= n; 446 } 447 448 /* 449 * pass up the values of virtual_space_start and 450 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 451 * layers of the VM. 452 */ 453 454 *kvm_startp = round_page(virtual_space_start); 455 *kvm_endp = trunc_page(virtual_space_end); 456 #ifdef DEBUG 457 /* 458 * steal kva for uvm_pagezerocheck(). 459 */ 460 uvm_zerocheckkva = *kvm_startp; 461 *kvm_startp += PAGE_SIZE; 462 #endif /* DEBUG */ 463 464 /* 465 * init various thresholds. 466 */ 467 468 uvmexp.reserve_pagedaemon = 1; 469 uvmexp.reserve_kernel = vm_page_reserve_kernel; 470 471 /* 472 * determine if we should zero pages in the idle loop. 473 */ 474 475 uvm.cpus[0]->page_idle_zero = vm_page_zero_enable; 476 477 /* 478 * done! 479 */ 480 481 uvm.page_init_done = true; 482 } 483 484 /* 485 * uvm_setpagesize: set the page size 486 * 487 * => sets page_shift and page_mask from uvmexp.pagesize. 488 */ 489 490 void 491 uvm_setpagesize(void) 492 { 493 494 /* 495 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 496 * to be a constant (indicated by being a non-zero value). 497 */ 498 if (uvmexp.pagesize == 0) { 499 if (PAGE_SIZE == 0) 500 panic("uvm_setpagesize: uvmexp.pagesize not set"); 501 uvmexp.pagesize = PAGE_SIZE; 502 } 503 uvmexp.pagemask = uvmexp.pagesize - 1; 504 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 505 panic("uvm_setpagesize: page size %u (%#x) not a power of two", 506 uvmexp.pagesize, uvmexp.pagesize); 507 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 508 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 509 break; 510 } 511 512 /* 513 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 514 */ 515 516 vaddr_t 517 uvm_pageboot_alloc(vsize_t size) 518 { 519 static bool initialized = false; 520 vaddr_t addr; 521 #if !defined(PMAP_STEAL_MEMORY) 522 vaddr_t vaddr; 523 paddr_t paddr; 524 #endif 525 526 /* 527 * on first call to this function, initialize ourselves. 528 */ 529 if (initialized == false) { 530 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 531 532 /* round it the way we like it */ 533 virtual_space_start = round_page(virtual_space_start); 534 virtual_space_end = trunc_page(virtual_space_end); 535 536 initialized = true; 537 } 538 539 /* round to page size */ 540 size = round_page(size); 541 542 #if defined(PMAP_STEAL_MEMORY) 543 544 /* 545 * defer bootstrap allocation to MD code (it may want to allocate 546 * from a direct-mapped segment). pmap_steal_memory should adjust 547 * virtual_space_start/virtual_space_end if necessary. 548 */ 549 550 addr = pmap_steal_memory(size, &virtual_space_start, 551 &virtual_space_end); 552 553 return(addr); 554 555 #else /* !PMAP_STEAL_MEMORY */ 556 557 /* 558 * allocate virtual memory for this request 559 */ 560 if (virtual_space_start == virtual_space_end || 561 (virtual_space_end - virtual_space_start) < size) 562 panic("uvm_pageboot_alloc: out of virtual space"); 563 564 addr = virtual_space_start; 565 566 #ifdef PMAP_GROWKERNEL 567 /* 568 * If the kernel pmap can't map the requested space, 569 * then allocate more resources for it. 570 */ 571 if (uvm_maxkaddr < (addr + size)) { 572 uvm_maxkaddr = pmap_growkernel(addr + size); 573 if (uvm_maxkaddr < (addr + size)) 574 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 575 } 576 #endif 577 578 virtual_space_start += size; 579 580 /* 581 * allocate and mapin physical pages to back new virtual pages 582 */ 583 584 for (vaddr = round_page(addr) ; vaddr < addr + size ; 585 vaddr += PAGE_SIZE) { 586 587 if (!uvm_page_physget(&paddr)) 588 panic("uvm_pageboot_alloc: out of memory"); 589 590 /* 591 * Note this memory is no longer managed, so using 592 * pmap_kenter is safe. 593 */ 594 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE, 0); 595 } 596 pmap_update(pmap_kernel()); 597 return(addr); 598 #endif /* PMAP_STEAL_MEMORY */ 599 } 600 601 #if !defined(PMAP_STEAL_MEMORY) 602 /* 603 * uvm_page_physget: "steal" one page from the vm_physmem structure. 604 * 605 * => attempt to allocate it off the end of a segment in which the "avail" 606 * values match the start/end values. if we can't do that, then we 607 * will advance both values (making them equal, and removing some 608 * vm_page structures from the non-avail area). 609 * => return false if out of memory. 610 */ 611 612 /* subroutine: try to allocate from memory chunks on the specified freelist */ 613 static bool uvm_page_physget_freelist(paddr_t *, int); 614 615 static bool 616 uvm_page_physget_freelist(paddr_t *paddrp, int freelist) 617 { 618 uvm_physseg_t lcv; 619 620 /* pass 1: try allocating from a matching end */ 621 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 622 for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv)) 623 #else 624 for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv)) 625 #endif 626 { 627 if (uvm.page_init_done == true) 628 panic("uvm_page_physget: called _after_ bootstrap"); 629 630 /* Try to match at front or back on unused segment */ 631 if (uvm_page_physunload(lcv, freelist, paddrp) == false) { 632 if (paddrp == NULL) /* freelist fail, try next */ 633 continue; 634 } else 635 return true; 636 } 637 638 /* pass2: forget about matching ends, just allocate something */ 639 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 640 for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv)) 641 #else 642 for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv)) 643 #endif 644 { 645 /* Try the front regardless. */ 646 if (uvm_page_physunload_force(lcv, freelist, paddrp) == false) { 647 if (paddrp == NULL) /* freelist fail, try next */ 648 continue; 649 } else 650 return true; 651 } 652 return false; 653 } 654 655 bool 656 uvm_page_physget(paddr_t *paddrp) 657 { 658 int i; 659 660 /* try in the order of freelist preference */ 661 for (i = 0; i < VM_NFREELIST; i++) 662 if (uvm_page_physget_freelist(paddrp, i) == true) 663 return (true); 664 return (false); 665 } 666 #endif /* PMAP_STEAL_MEMORY */ 667 668 /* 669 * PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages 670 * back from an I/O mapping (ugh!). used in some MD code as well. 671 */ 672 struct vm_page * 673 uvm_phys_to_vm_page(paddr_t pa) 674 { 675 paddr_t pf = atop(pa); 676 paddr_t off; 677 uvm_physseg_t upm; 678 679 upm = uvm_physseg_find(pf, &off); 680 if (upm != UVM_PHYSSEG_TYPE_INVALID) 681 return uvm_physseg_get_pg(upm, off); 682 return(NULL); 683 } 684 685 paddr_t 686 uvm_vm_page_to_phys(const struct vm_page *pg) 687 { 688 689 return pg->phys_addr; 690 } 691 692 /* 693 * uvm_page_recolor: Recolor the pages if the new bucket count is 694 * larger than the old one. 695 */ 696 697 void 698 uvm_page_recolor(int newncolors) 699 { 700 struct pgflbucket *bucketarray, *cpuarray, *oldbucketarray; 701 struct pgfreelist gpgfl, pgfl; 702 struct vm_page *pg; 703 vsize_t bucketcount; 704 size_t bucketmemsize, oldbucketmemsize; 705 int color, i, ocolors; 706 int lcv; 707 struct uvm_cpu *ucpu; 708 709 KASSERT(((newncolors - 1) & newncolors) == 0); 710 711 if (newncolors <= uvmexp.ncolors) 712 return; 713 714 if (uvm.page_init_done == false) { 715 uvmexp.ncolors = newncolors; 716 return; 717 } 718 719 bucketcount = newncolors * VM_NFREELIST; 720 bucketmemsize = bucketcount * sizeof(struct pgflbucket) * 2; 721 bucketarray = kmem_alloc(bucketmemsize, KM_SLEEP); 722 cpuarray = bucketarray + bucketcount; 723 if (bucketarray == NULL) { 724 printf("WARNING: unable to allocate %ld page color buckets\n", 725 (long) bucketcount); 726 return; 727 } 728 729 mutex_spin_enter(&uvm_fpageqlock); 730 731 /* Make sure we should still do this. */ 732 if (newncolors <= uvmexp.ncolors) { 733 mutex_spin_exit(&uvm_fpageqlock); 734 kmem_free(bucketarray, bucketmemsize); 735 return; 736 } 737 738 oldbucketarray = uvm.page_free[0].pgfl_buckets; 739 ocolors = uvmexp.ncolors; 740 741 uvmexp.ncolors = newncolors; 742 uvmexp.colormask = uvmexp.ncolors - 1; 743 744 ucpu = curcpu()->ci_data.cpu_uvm; 745 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 746 gpgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 747 pgfl.pgfl_buckets = (cpuarray + (lcv * uvmexp.ncolors)); 748 uvm_page_init_buckets(&gpgfl); 749 uvm_page_init_buckets(&pgfl); 750 for (color = 0; color < ocolors; color++) { 751 for (i = 0; i < PGFL_NQUEUES; i++) { 752 while ((pg = LIST_FIRST(&uvm.page_free[ 753 lcv].pgfl_buckets[color].pgfl_queues[i])) 754 != NULL) { 755 LIST_REMOVE(pg, pageq.list); /* global */ 756 LIST_REMOVE(pg, listq.list); /* cpu */ 757 LIST_INSERT_HEAD(&gpgfl.pgfl_buckets[ 758 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 759 i], pg, pageq.list); 760 LIST_INSERT_HEAD(&pgfl.pgfl_buckets[ 761 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 762 i], pg, listq.list); 763 } 764 } 765 } 766 uvm.page_free[lcv].pgfl_buckets = gpgfl.pgfl_buckets; 767 ucpu->page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 768 } 769 770 oldbucketmemsize = recolored_pages_memsize; 771 772 recolored_pages_memsize = bucketmemsize; 773 mutex_spin_exit(&uvm_fpageqlock); 774 775 if (oldbucketmemsize) { 776 kmem_free(oldbucketarray, recolored_pages_memsize); 777 } 778 779 /* 780 * this calls uvm_km_alloc() which may want to hold 781 * uvm_fpageqlock. 782 */ 783 uvm_pager_realloc_emerg(); 784 } 785 786 /* 787 * uvm_cpu_attach: initialize per-CPU data structures. 788 */ 789 790 void 791 uvm_cpu_attach(struct cpu_info *ci) 792 { 793 struct pgflbucket *bucketarray; 794 struct pgfreelist pgfl; 795 struct uvm_cpu *ucpu; 796 vsize_t bucketcount; 797 int lcv; 798 799 if (CPU_IS_PRIMARY(ci)) { 800 /* Already done in uvm_page_init(). */ 801 goto attachrnd; 802 } 803 804 /* Add more reserve pages for this CPU. */ 805 uvmexp.reserve_kernel += vm_page_reserve_kernel; 806 807 /* Configure this CPU's free lists. */ 808 bucketcount = uvmexp.ncolors * VM_NFREELIST; 809 bucketarray = kmem_alloc(bucketcount * sizeof(struct pgflbucket), 810 KM_SLEEP); 811 ucpu = kmem_zalloc(sizeof(*ucpu), KM_SLEEP); 812 uvm.cpus[cpu_index(ci)] = ucpu; 813 ci->ci_data.cpu_uvm = ucpu; 814 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 815 pgfl.pgfl_buckets = (bucketarray + (lcv * uvmexp.ncolors)); 816 uvm_page_init_buckets(&pgfl); 817 ucpu->page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 818 } 819 820 attachrnd: 821 /* 822 * Attach RNG source for this CPU's VM events 823 */ 824 rnd_attach_source(&uvm.cpus[cpu_index(ci)]->rs, 825 ci->ci_data.cpu_name, RND_TYPE_VM, 826 RND_FLAG_COLLECT_TIME|RND_FLAG_COLLECT_VALUE| 827 RND_FLAG_ESTIMATE_VALUE); 828 829 } 830 831 /* 832 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 833 */ 834 835 static struct vm_page * 836 uvm_pagealloc_pgfl(struct uvm_cpu *ucpu, int flist, int try1, int try2, 837 int *trycolorp) 838 { 839 struct pgflist *freeq; 840 struct vm_page *pg; 841 int color, trycolor = *trycolorp; 842 struct pgfreelist *gpgfl, *pgfl; 843 844 KASSERT(mutex_owned(&uvm_fpageqlock)); 845 846 color = trycolor; 847 pgfl = &ucpu->page_free[flist]; 848 gpgfl = &uvm.page_free[flist]; 849 do { 850 /* cpu, try1 */ 851 if ((pg = LIST_FIRST((freeq = 852 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) { 853 KASSERT(pg->pqflags & PQ_FREE); 854 KASSERT(try1 == PGFL_ZEROS || !(pg->flags & PG_ZERO)); 855 KASSERT(try1 == PGFL_UNKNOWN || (pg->flags & PG_ZERO)); 856 KASSERT(ucpu == VM_FREE_PAGE_TO_CPU(pg)); 857 VM_FREE_PAGE_TO_CPU(pg)->pages[try1]--; 858 uvmexp.cpuhit++; 859 goto gotit; 860 } 861 /* global, try1 */ 862 if ((pg = LIST_FIRST((freeq = 863 &gpgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) { 864 KASSERT(pg->pqflags & PQ_FREE); 865 KASSERT(try1 == PGFL_ZEROS || !(pg->flags & PG_ZERO)); 866 KASSERT(try1 == PGFL_UNKNOWN || (pg->flags & PG_ZERO)); 867 KASSERT(ucpu != VM_FREE_PAGE_TO_CPU(pg)); 868 VM_FREE_PAGE_TO_CPU(pg)->pages[try1]--; 869 uvmexp.cpumiss++; 870 goto gotit; 871 } 872 /* cpu, try2 */ 873 if ((pg = LIST_FIRST((freeq = 874 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) { 875 KASSERT(pg->pqflags & PQ_FREE); 876 KASSERT(try2 == PGFL_ZEROS || !(pg->flags & PG_ZERO)); 877 KASSERT(try2 == PGFL_UNKNOWN || (pg->flags & PG_ZERO)); 878 KASSERT(ucpu == VM_FREE_PAGE_TO_CPU(pg)); 879 VM_FREE_PAGE_TO_CPU(pg)->pages[try2]--; 880 uvmexp.cpuhit++; 881 goto gotit; 882 } 883 /* global, try2 */ 884 if ((pg = LIST_FIRST((freeq = 885 &gpgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) { 886 KASSERT(pg->pqflags & PQ_FREE); 887 KASSERT(try2 == PGFL_ZEROS || !(pg->flags & PG_ZERO)); 888 KASSERT(try2 == PGFL_UNKNOWN || (pg->flags & PG_ZERO)); 889 KASSERT(ucpu != VM_FREE_PAGE_TO_CPU(pg)); 890 VM_FREE_PAGE_TO_CPU(pg)->pages[try2]--; 891 uvmexp.cpumiss++; 892 goto gotit; 893 } 894 color = (color + 1) & uvmexp.colormask; 895 } while (color != trycolor); 896 897 return (NULL); 898 899 gotit: 900 LIST_REMOVE(pg, pageq.list); /* global list */ 901 LIST_REMOVE(pg, listq.list); /* per-cpu list */ 902 uvmexp.free--; 903 904 /* update zero'd page count */ 905 if (pg->flags & PG_ZERO) 906 uvmexp.zeropages--; 907 908 if (color == trycolor) 909 uvmexp.colorhit++; 910 else { 911 uvmexp.colormiss++; 912 *trycolorp = color; 913 } 914 915 return (pg); 916 } 917 918 /* 919 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 920 * 921 * => return null if no pages free 922 * => wake up pagedaemon if number of free pages drops below low water mark 923 * => if obj != NULL, obj must be locked (to put in obj's tree) 924 * => if anon != NULL, anon must be locked (to put in anon) 925 * => only one of obj or anon can be non-null 926 * => caller must activate/deactivate page if it is not wired. 927 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 928 * => policy decision: it is more important to pull a page off of the 929 * appropriate priority free list than it is to get a zero'd or 930 * unknown contents page. This is because we live with the 931 * consequences of a bad free list decision for the entire 932 * lifetime of the page, e.g. if the page comes from memory that 933 * is slower to access. 934 */ 935 936 struct vm_page * 937 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon, 938 int flags, int strat, int free_list) 939 { 940 int try1, try2, zeroit = 0, color; 941 int lcv; 942 struct uvm_cpu *ucpu; 943 struct vm_page *pg; 944 lwp_t *l; 945 946 KASSERT(obj == NULL || anon == NULL); 947 KASSERT(anon == NULL || (flags & UVM_FLAG_COLORMATCH) || off == 0); 948 KASSERT(off == trunc_page(off)); 949 KASSERT(obj == NULL || mutex_owned(obj->vmobjlock)); 950 KASSERT(anon == NULL || anon->an_lock == NULL || 951 mutex_owned(anon->an_lock)); 952 953 mutex_spin_enter(&uvm_fpageqlock); 954 955 /* 956 * This implements a global round-robin page coloring 957 * algorithm. 958 */ 959 960 ucpu = curcpu()->ci_data.cpu_uvm; 961 if (flags & UVM_FLAG_COLORMATCH) { 962 color = atop(off) & uvmexp.colormask; 963 } else { 964 color = ucpu->page_free_nextcolor; 965 } 966 967 /* 968 * check to see if we need to generate some free pages waking 969 * the pagedaemon. 970 */ 971 972 uvm_kick_pdaemon(); 973 974 /* 975 * fail if any of these conditions is true: 976 * [1] there really are no free pages, or 977 * [2] only kernel "reserved" pages remain and 978 * reserved pages have not been requested. 979 * [3] only pagedaemon "reserved" pages remain and 980 * the requestor isn't the pagedaemon. 981 * we make kernel reserve pages available if called by a 982 * kernel thread or a realtime thread. 983 */ 984 l = curlwp; 985 if (__predict_true(l != NULL) && lwp_eprio(l) >= PRI_KTHREAD) { 986 flags |= UVM_PGA_USERESERVE; 987 } 988 if ((uvmexp.free <= uvmexp.reserve_kernel && 989 (flags & UVM_PGA_USERESERVE) == 0) || 990 (uvmexp.free <= uvmexp.reserve_pagedaemon && 991 curlwp != uvm.pagedaemon_lwp)) 992 goto fail; 993 994 #if PGFL_NQUEUES != 2 995 #error uvm_pagealloc_strat needs to be updated 996 #endif 997 998 /* 999 * If we want a zero'd page, try the ZEROS queue first, otherwise 1000 * we try the UNKNOWN queue first. 1001 */ 1002 if (flags & UVM_PGA_ZERO) { 1003 try1 = PGFL_ZEROS; 1004 try2 = PGFL_UNKNOWN; 1005 } else { 1006 try1 = PGFL_UNKNOWN; 1007 try2 = PGFL_ZEROS; 1008 } 1009 1010 again: 1011 switch (strat) { 1012 case UVM_PGA_STRAT_NORMAL: 1013 /* Check freelists: descending priority (ascending id) order */ 1014 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1015 pg = uvm_pagealloc_pgfl(ucpu, lcv, 1016 try1, try2, &color); 1017 if (pg != NULL) 1018 goto gotit; 1019 } 1020 1021 /* No pages free! */ 1022 goto fail; 1023 1024 case UVM_PGA_STRAT_ONLY: 1025 case UVM_PGA_STRAT_FALLBACK: 1026 /* Attempt to allocate from the specified free list. */ 1027 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1028 pg = uvm_pagealloc_pgfl(ucpu, free_list, 1029 try1, try2, &color); 1030 if (pg != NULL) 1031 goto gotit; 1032 1033 /* Fall back, if possible. */ 1034 if (strat == UVM_PGA_STRAT_FALLBACK) { 1035 strat = UVM_PGA_STRAT_NORMAL; 1036 goto again; 1037 } 1038 1039 /* No pages free! */ 1040 goto fail; 1041 1042 default: 1043 panic("uvm_pagealloc_strat: bad strat %d", strat); 1044 /* NOTREACHED */ 1045 } 1046 1047 gotit: 1048 /* 1049 * We now know which color we actually allocated from; set 1050 * the next color accordingly. 1051 */ 1052 1053 ucpu->page_free_nextcolor = (color + 1) & uvmexp.colormask; 1054 1055 /* 1056 * update allocation statistics and remember if we have to 1057 * zero the page 1058 */ 1059 1060 if (flags & UVM_PGA_ZERO) { 1061 if (pg->flags & PG_ZERO) { 1062 uvmexp.pga_zerohit++; 1063 zeroit = 0; 1064 } else { 1065 uvmexp.pga_zeromiss++; 1066 zeroit = 1; 1067 } 1068 if (ucpu->pages[PGFL_ZEROS] < ucpu->pages[PGFL_UNKNOWN]) { 1069 ucpu->page_idle_zero = vm_page_zero_enable; 1070 } 1071 } 1072 KASSERT(pg->pqflags == PQ_FREE); 1073 1074 pg->offset = off; 1075 pg->uobject = obj; 1076 pg->uanon = anon; 1077 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1078 if (anon) { 1079 anon->an_page = pg; 1080 pg->pqflags = PQ_ANON; 1081 atomic_inc_uint(&uvmexp.anonpages); 1082 } else { 1083 if (obj) { 1084 uvm_pageinsert(obj, pg); 1085 } 1086 pg->pqflags = 0; 1087 } 1088 mutex_spin_exit(&uvm_fpageqlock); 1089 1090 #if defined(UVM_PAGE_TRKOWN) 1091 pg->owner_tag = NULL; 1092 #endif 1093 UVM_PAGE_OWN(pg, "new alloc"); 1094 1095 if (flags & UVM_PGA_ZERO) { 1096 /* 1097 * A zero'd page is not clean. If we got a page not already 1098 * zero'd, then we have to zero it ourselves. 1099 */ 1100 pg->flags &= ~PG_CLEAN; 1101 if (zeroit) 1102 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1103 } 1104 1105 return(pg); 1106 1107 fail: 1108 mutex_spin_exit(&uvm_fpageqlock); 1109 return (NULL); 1110 } 1111 1112 /* 1113 * uvm_pagereplace: replace a page with another 1114 * 1115 * => object must be locked 1116 */ 1117 1118 void 1119 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg) 1120 { 1121 struct uvm_object *uobj = oldpg->uobject; 1122 1123 KASSERT((oldpg->flags & PG_TABLED) != 0); 1124 KASSERT(uobj != NULL); 1125 KASSERT((newpg->flags & PG_TABLED) == 0); 1126 KASSERT(newpg->uobject == NULL); 1127 KASSERT(mutex_owned(uobj->vmobjlock)); 1128 1129 newpg->uobject = uobj; 1130 newpg->offset = oldpg->offset; 1131 1132 uvm_pageremove_tree(uobj, oldpg); 1133 uvm_pageinsert_tree(uobj, newpg); 1134 uvm_pageinsert_list(uobj, newpg, oldpg); 1135 uvm_pageremove_list(uobj, oldpg); 1136 } 1137 1138 /* 1139 * uvm_pagerealloc: reallocate a page from one object to another 1140 * 1141 * => both objects must be locked 1142 */ 1143 1144 void 1145 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) 1146 { 1147 /* 1148 * remove it from the old object 1149 */ 1150 1151 if (pg->uobject) { 1152 uvm_pageremove(pg->uobject, pg); 1153 } 1154 1155 /* 1156 * put it in the new object 1157 */ 1158 1159 if (newobj) { 1160 pg->uobject = newobj; 1161 pg->offset = newoff; 1162 uvm_pageinsert(newobj, pg); 1163 } 1164 } 1165 1166 #ifdef DEBUG 1167 /* 1168 * check if page is zero-filled 1169 * 1170 * - called with free page queue lock held. 1171 */ 1172 void 1173 uvm_pagezerocheck(struct vm_page *pg) 1174 { 1175 int *p, *ep; 1176 1177 KASSERT(uvm_zerocheckkva != 0); 1178 KASSERT(mutex_owned(&uvm_fpageqlock)); 1179 1180 /* 1181 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1182 * uvm page allocator. 1183 * 1184 * it might be better to have "CPU-local temporary map" pmap interface. 1185 */ 1186 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ, 0); 1187 p = (int *)uvm_zerocheckkva; 1188 ep = (int *)((char *)p + PAGE_SIZE); 1189 pmap_update(pmap_kernel()); 1190 while (p < ep) { 1191 if (*p != 0) 1192 panic("PG_ZERO page isn't zero-filled"); 1193 p++; 1194 } 1195 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1196 /* 1197 * pmap_update() is not necessary here because no one except us 1198 * uses this VA. 1199 */ 1200 } 1201 #endif /* DEBUG */ 1202 1203 /* 1204 * uvm_pagefree: free page 1205 * 1206 * => erase page's identity (i.e. remove from object) 1207 * => put page on free list 1208 * => caller must lock owning object (either anon or uvm_object) 1209 * => caller must lock page queues 1210 * => assumes all valid mappings of pg are gone 1211 */ 1212 1213 void 1214 uvm_pagefree(struct vm_page *pg) 1215 { 1216 struct pgflist *pgfl; 1217 struct uvm_cpu *ucpu; 1218 int index, color, queue; 1219 bool iszero; 1220 1221 #ifdef DEBUG 1222 if (pg->uobject == (void *)0xdeadbeef && 1223 pg->uanon == (void *)0xdeadbeef) { 1224 panic("uvm_pagefree: freeing free page %p", pg); 1225 } 1226 #endif /* DEBUG */ 1227 1228 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1229 KASSERT(!(pg->pqflags & PQ_FREE)); 1230 //KASSERT(mutex_owned(&uvm_pageqlock) || !uvmpdpol_pageisqueued_p(pg)); 1231 KASSERT(pg->uobject == NULL || mutex_owned(pg->uobject->vmobjlock)); 1232 KASSERT(pg->uobject != NULL || pg->uanon == NULL || 1233 mutex_owned(pg->uanon->an_lock)); 1234 1235 /* 1236 * if the page is loaned, resolve the loan instead of freeing. 1237 */ 1238 1239 if (pg->loan_count) { 1240 KASSERT(pg->wire_count == 0); 1241 1242 /* 1243 * if the page is owned by an anon then we just want to 1244 * drop anon ownership. the kernel will free the page when 1245 * it is done with it. if the page is owned by an object, 1246 * remove it from the object and mark it dirty for the benefit 1247 * of possible anon owners. 1248 * 1249 * regardless of previous ownership, wakeup any waiters, 1250 * unbusy the page, and we're done. 1251 */ 1252 1253 if (pg->uobject != NULL) { 1254 uvm_pageremove(pg->uobject, pg); 1255 pg->flags &= ~PG_CLEAN; 1256 } else if (pg->uanon != NULL) { 1257 if ((pg->pqflags & PQ_ANON) == 0) { 1258 pg->loan_count--; 1259 } else { 1260 pg->pqflags &= ~PQ_ANON; 1261 atomic_dec_uint(&uvmexp.anonpages); 1262 } 1263 pg->uanon->an_page = NULL; 1264 pg->uanon = NULL; 1265 } 1266 if (pg->flags & PG_WANTED) { 1267 wakeup(pg); 1268 } 1269 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1270 #ifdef UVM_PAGE_TRKOWN 1271 pg->owner_tag = NULL; 1272 #endif 1273 if (pg->loan_count) { 1274 KASSERT(pg->uobject == NULL); 1275 if (pg->uanon == NULL) { 1276 KASSERT(mutex_owned(&uvm_pageqlock)); 1277 uvm_pagedequeue(pg); 1278 } 1279 return; 1280 } 1281 } 1282 1283 /* 1284 * remove page from its object or anon. 1285 */ 1286 1287 if (pg->uobject != NULL) { 1288 uvm_pageremove(pg->uobject, pg); 1289 } else if (pg->uanon != NULL) { 1290 pg->uanon->an_page = NULL; 1291 atomic_dec_uint(&uvmexp.anonpages); 1292 } 1293 1294 /* 1295 * now remove the page from the queues. 1296 */ 1297 if (uvmpdpol_pageisqueued_p(pg)) { 1298 KASSERT(mutex_owned(&uvm_pageqlock)); 1299 uvm_pagedequeue(pg); 1300 } 1301 1302 /* 1303 * if the page was wired, unwire it now. 1304 */ 1305 1306 if (pg->wire_count) { 1307 pg->wire_count = 0; 1308 uvmexp.wired--; 1309 } 1310 1311 /* 1312 * and put on free queue 1313 */ 1314 1315 iszero = (pg->flags & PG_ZERO); 1316 index = uvm_page_lookup_freelist(pg); 1317 color = VM_PGCOLOR_BUCKET(pg); 1318 queue = (iszero ? PGFL_ZEROS : PGFL_UNKNOWN); 1319 1320 #ifdef DEBUG 1321 pg->uobject = (void *)0xdeadbeef; 1322 pg->uanon = (void *)0xdeadbeef; 1323 #endif 1324 1325 mutex_spin_enter(&uvm_fpageqlock); 1326 pg->pqflags = PQ_FREE; 1327 1328 #ifdef DEBUG 1329 if (iszero) 1330 uvm_pagezerocheck(pg); 1331 #endif /* DEBUG */ 1332 1333 1334 /* global list */ 1335 pgfl = &uvm.page_free[index].pgfl_buckets[color].pgfl_queues[queue]; 1336 LIST_INSERT_HEAD(pgfl, pg, pageq.list); 1337 uvmexp.free++; 1338 if (iszero) { 1339 uvmexp.zeropages++; 1340 } 1341 1342 /* per-cpu list */ 1343 ucpu = curcpu()->ci_data.cpu_uvm; 1344 pg->offset = (uintptr_t)ucpu; 1345 pgfl = &ucpu->page_free[index].pgfl_buckets[color].pgfl_queues[queue]; 1346 LIST_INSERT_HEAD(pgfl, pg, listq.list); 1347 ucpu->pages[queue]++; 1348 if (ucpu->pages[PGFL_ZEROS] < ucpu->pages[PGFL_UNKNOWN]) { 1349 ucpu->page_idle_zero = vm_page_zero_enable; 1350 } 1351 1352 mutex_spin_exit(&uvm_fpageqlock); 1353 } 1354 1355 /* 1356 * uvm_page_unbusy: unbusy an array of pages. 1357 * 1358 * => pages must either all belong to the same object, or all belong to anons. 1359 * => if pages are object-owned, object must be locked. 1360 * => if pages are anon-owned, anons must be locked. 1361 * => caller must lock page queues if pages may be released. 1362 * => caller must make sure that anon-owned pages are not PG_RELEASED. 1363 */ 1364 1365 void 1366 uvm_page_unbusy(struct vm_page **pgs, int npgs) 1367 { 1368 struct vm_page *pg; 1369 int i; 1370 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1371 1372 for (i = 0; i < npgs; i++) { 1373 pg = pgs[i]; 1374 if (pg == NULL || pg == PGO_DONTCARE) { 1375 continue; 1376 } 1377 1378 KASSERT(uvm_page_locked_p(pg)); 1379 KASSERT(pg->flags & PG_BUSY); 1380 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1381 if (pg->flags & PG_WANTED) { 1382 wakeup(pg); 1383 } 1384 if (pg->flags & PG_RELEASED) { 1385 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1386 KASSERT(pg->uobject != NULL || 1387 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 1388 pg->flags &= ~PG_RELEASED; 1389 uvm_pagefree(pg); 1390 } else { 1391 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1392 KASSERT((pg->flags & PG_FAKE) == 0); 1393 pg->flags &= ~(PG_WANTED|PG_BUSY); 1394 UVM_PAGE_OWN(pg, NULL); 1395 } 1396 } 1397 } 1398 1399 #if defined(UVM_PAGE_TRKOWN) 1400 /* 1401 * uvm_page_own: set or release page ownership 1402 * 1403 * => this is a debugging function that keeps track of who sets PG_BUSY 1404 * and where they do it. it can be used to track down problems 1405 * such a process setting "PG_BUSY" and never releasing it. 1406 * => page's object [if any] must be locked 1407 * => if "tag" is NULL then we are releasing page ownership 1408 */ 1409 void 1410 uvm_page_own(struct vm_page *pg, const char *tag) 1411 { 1412 1413 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1414 KASSERT((pg->flags & PG_WANTED) == 0); 1415 KASSERT(uvm_page_locked_p(pg)); 1416 1417 /* gain ownership? */ 1418 if (tag) { 1419 KASSERT((pg->flags & PG_BUSY) != 0); 1420 if (pg->owner_tag) { 1421 printf("uvm_page_own: page %p already owned " 1422 "by proc %d [%s]\n", pg, 1423 pg->owner, pg->owner_tag); 1424 panic("uvm_page_own"); 1425 } 1426 pg->owner = curproc->p_pid; 1427 pg->lowner = curlwp->l_lid; 1428 pg->owner_tag = tag; 1429 return; 1430 } 1431 1432 /* drop ownership */ 1433 KASSERT((pg->flags & PG_BUSY) == 0); 1434 if (pg->owner_tag == NULL) { 1435 printf("uvm_page_own: dropping ownership of an non-owned " 1436 "page (%p)\n", pg); 1437 panic("uvm_page_own"); 1438 } 1439 if (!uvmpdpol_pageisqueued_p(pg)) { 1440 KASSERT((pg->uanon == NULL && pg->uobject == NULL) || 1441 pg->wire_count > 0); 1442 } else { 1443 KASSERT(pg->wire_count == 0); 1444 } 1445 pg->owner_tag = NULL; 1446 } 1447 #endif 1448 1449 /* 1450 * uvm_pageidlezero: zero free pages while the system is idle. 1451 * 1452 * => try to complete one color bucket at a time, to reduce our impact 1453 * on the CPU cache. 1454 * => we loop until we either reach the target or there is a lwp ready 1455 * to run, or MD code detects a reason to break early. 1456 */ 1457 void 1458 uvm_pageidlezero(void) 1459 { 1460 struct vm_page *pg; 1461 struct pgfreelist *pgfl, *gpgfl; 1462 struct uvm_cpu *ucpu; 1463 int free_list, firstbucket, nextbucket; 1464 bool lcont = false; 1465 1466 ucpu = curcpu()->ci_data.cpu_uvm; 1467 if (!ucpu->page_idle_zero || 1468 ucpu->pages[PGFL_UNKNOWN] < uvmexp.ncolors) { 1469 ucpu->page_idle_zero = false; 1470 return; 1471 } 1472 if (!mutex_tryenter(&uvm_fpageqlock)) { 1473 /* Contention: let other CPUs to use the lock. */ 1474 return; 1475 } 1476 firstbucket = ucpu->page_free_nextcolor; 1477 nextbucket = firstbucket; 1478 do { 1479 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1480 if (sched_curcpu_runnable_p()) { 1481 goto quit; 1482 } 1483 pgfl = &ucpu->page_free[free_list]; 1484 gpgfl = &uvm.page_free[free_list]; 1485 while ((pg = LIST_FIRST(&pgfl->pgfl_buckets[ 1486 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1487 if (lcont || sched_curcpu_runnable_p()) { 1488 goto quit; 1489 } 1490 LIST_REMOVE(pg, pageq.list); /* global list */ 1491 LIST_REMOVE(pg, listq.list); /* per-cpu list */ 1492 ucpu->pages[PGFL_UNKNOWN]--; 1493 uvmexp.free--; 1494 KASSERT(pg->pqflags == PQ_FREE); 1495 pg->pqflags = 0; 1496 mutex_spin_exit(&uvm_fpageqlock); 1497 #ifdef PMAP_PAGEIDLEZERO 1498 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1499 1500 /* 1501 * The machine-dependent code detected 1502 * some reason for us to abort zeroing 1503 * pages, probably because there is a 1504 * process now ready to run. 1505 */ 1506 1507 mutex_spin_enter(&uvm_fpageqlock); 1508 pg->pqflags = PQ_FREE; 1509 LIST_INSERT_HEAD(&gpgfl->pgfl_buckets[ 1510 nextbucket].pgfl_queues[ 1511 PGFL_UNKNOWN], pg, pageq.list); 1512 LIST_INSERT_HEAD(&pgfl->pgfl_buckets[ 1513 nextbucket].pgfl_queues[ 1514 PGFL_UNKNOWN], pg, listq.list); 1515 ucpu->pages[PGFL_UNKNOWN]++; 1516 uvmexp.free++; 1517 uvmexp.zeroaborts++; 1518 goto quit; 1519 } 1520 #else 1521 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1522 #endif /* PMAP_PAGEIDLEZERO */ 1523 pg->flags |= PG_ZERO; 1524 1525 if (!mutex_tryenter(&uvm_fpageqlock)) { 1526 lcont = true; 1527 mutex_spin_enter(&uvm_fpageqlock); 1528 } else { 1529 lcont = false; 1530 } 1531 pg->pqflags = PQ_FREE; 1532 LIST_INSERT_HEAD(&gpgfl->pgfl_buckets[ 1533 nextbucket].pgfl_queues[PGFL_ZEROS], 1534 pg, pageq.list); 1535 LIST_INSERT_HEAD(&pgfl->pgfl_buckets[ 1536 nextbucket].pgfl_queues[PGFL_ZEROS], 1537 pg, listq.list); 1538 ucpu->pages[PGFL_ZEROS]++; 1539 uvmexp.free++; 1540 uvmexp.zeropages++; 1541 } 1542 } 1543 if (ucpu->pages[PGFL_UNKNOWN] < uvmexp.ncolors) { 1544 break; 1545 } 1546 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1547 } while (nextbucket != firstbucket); 1548 ucpu->page_idle_zero = false; 1549 quit: 1550 mutex_spin_exit(&uvm_fpageqlock); 1551 } 1552 1553 /* 1554 * uvm_pagelookup: look up a page 1555 * 1556 * => caller should lock object to keep someone from pulling the page 1557 * out from under it 1558 */ 1559 1560 struct vm_page * 1561 uvm_pagelookup(struct uvm_object *obj, voff_t off) 1562 { 1563 struct vm_page *pg; 1564 1565 KASSERT(mutex_owned(obj->vmobjlock)); 1566 1567 pg = rb_tree_find_node(&obj->rb_tree, &off); 1568 1569 KASSERT(pg == NULL || obj->uo_npages != 0); 1570 KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 1571 (pg->flags & PG_BUSY) != 0); 1572 return pg; 1573 } 1574 1575 /* 1576 * uvm_pagewire: wire the page, thus removing it from the daemon's grasp 1577 * 1578 * => caller must lock page queues 1579 */ 1580 1581 void 1582 uvm_pagewire(struct vm_page *pg) 1583 { 1584 KASSERT(mutex_owned(&uvm_pageqlock)); 1585 #if defined(READAHEAD_STATS) 1586 if ((pg->pqflags & PQ_READAHEAD) != 0) { 1587 uvm_ra_hit.ev_count++; 1588 pg->pqflags &= ~PQ_READAHEAD; 1589 } 1590 #endif /* defined(READAHEAD_STATS) */ 1591 if (pg->wire_count == 0) { 1592 uvm_pagedequeue(pg); 1593 uvmexp.wired++; 1594 } 1595 pg->wire_count++; 1596 } 1597 1598 /* 1599 * uvm_pageunwire: unwire the page. 1600 * 1601 * => activate if wire count goes to zero. 1602 * => caller must lock page queues 1603 */ 1604 1605 void 1606 uvm_pageunwire(struct vm_page *pg) 1607 { 1608 KASSERT(mutex_owned(&uvm_pageqlock)); 1609 pg->wire_count--; 1610 if (pg->wire_count == 0) { 1611 uvm_pageactivate(pg); 1612 uvmexp.wired--; 1613 } 1614 } 1615 1616 /* 1617 * uvm_pagedeactivate: deactivate page 1618 * 1619 * => caller must lock page queues 1620 * => caller must check to make sure page is not wired 1621 * => object that page belongs to must be locked (so we can adjust pg->flags) 1622 * => caller must clear the reference on the page before calling 1623 */ 1624 1625 void 1626 uvm_pagedeactivate(struct vm_page *pg) 1627 { 1628 1629 KASSERT(mutex_owned(&uvm_pageqlock)); 1630 KASSERT(uvm_page_locked_p(pg)); 1631 KASSERT(pg->wire_count != 0 || uvmpdpol_pageisqueued_p(pg)); 1632 uvmpdpol_pagedeactivate(pg); 1633 } 1634 1635 /* 1636 * uvm_pageactivate: activate page 1637 * 1638 * => caller must lock page queues 1639 */ 1640 1641 void 1642 uvm_pageactivate(struct vm_page *pg) 1643 { 1644 1645 KASSERT(mutex_owned(&uvm_pageqlock)); 1646 KASSERT(uvm_page_locked_p(pg)); 1647 #if defined(READAHEAD_STATS) 1648 if ((pg->pqflags & PQ_READAHEAD) != 0) { 1649 uvm_ra_hit.ev_count++; 1650 pg->pqflags &= ~PQ_READAHEAD; 1651 } 1652 #endif /* defined(READAHEAD_STATS) */ 1653 if (pg->wire_count != 0) { 1654 return; 1655 } 1656 uvmpdpol_pageactivate(pg); 1657 } 1658 1659 /* 1660 * uvm_pagedequeue: remove a page from any paging queue 1661 */ 1662 1663 void 1664 uvm_pagedequeue(struct vm_page *pg) 1665 { 1666 1667 if (uvmpdpol_pageisqueued_p(pg)) { 1668 KASSERT(mutex_owned(&uvm_pageqlock)); 1669 } 1670 1671 uvmpdpol_pagedequeue(pg); 1672 } 1673 1674 /* 1675 * uvm_pageenqueue: add a page to a paging queue without activating. 1676 * used where a page is not really demanded (yet). eg. read-ahead 1677 */ 1678 1679 void 1680 uvm_pageenqueue(struct vm_page *pg) 1681 { 1682 1683 KASSERT(mutex_owned(&uvm_pageqlock)); 1684 if (pg->wire_count != 0) { 1685 return; 1686 } 1687 uvmpdpol_pageenqueue(pg); 1688 } 1689 1690 /* 1691 * uvm_pagezero: zero fill a page 1692 * 1693 * => if page is part of an object then the object should be locked 1694 * to protect pg->flags. 1695 */ 1696 1697 void 1698 uvm_pagezero(struct vm_page *pg) 1699 { 1700 pg->flags &= ~PG_CLEAN; 1701 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1702 } 1703 1704 /* 1705 * uvm_pagecopy: copy a page 1706 * 1707 * => if page is part of an object then the object should be locked 1708 * to protect pg->flags. 1709 */ 1710 1711 void 1712 uvm_pagecopy(struct vm_page *src, struct vm_page *dst) 1713 { 1714 1715 dst->flags &= ~PG_CLEAN; 1716 pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst)); 1717 } 1718 1719 /* 1720 * uvm_pageismanaged: test it see that a page (specified by PA) is managed. 1721 */ 1722 1723 bool 1724 uvm_pageismanaged(paddr_t pa) 1725 { 1726 1727 return (uvm_physseg_find(atop(pa), NULL) != UVM_PHYSSEG_TYPE_INVALID); 1728 } 1729 1730 /* 1731 * uvm_page_lookup_freelist: look up the free list for the specified page 1732 */ 1733 1734 int 1735 uvm_page_lookup_freelist(struct vm_page *pg) 1736 { 1737 uvm_physseg_t upm; 1738 1739 upm = uvm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL); 1740 KASSERT(upm != UVM_PHYSSEG_TYPE_INVALID); 1741 return uvm_physseg_get_free_list(upm); 1742 } 1743 1744 /* 1745 * uvm_page_locked_p: return true if object associated with page is 1746 * locked. this is a weak check for runtime assertions only. 1747 */ 1748 1749 bool 1750 uvm_page_locked_p(struct vm_page *pg) 1751 { 1752 1753 if (pg->uobject != NULL) { 1754 return mutex_owned(pg->uobject->vmobjlock); 1755 } 1756 if (pg->uanon != NULL) { 1757 return mutex_owned(pg->uanon->an_lock); 1758 } 1759 return true; 1760 } 1761 1762 #if defined(DDB) || defined(DEBUGPRINT) 1763 1764 /* 1765 * uvm_page_printit: actually print the page 1766 */ 1767 1768 static const char page_flagbits[] = UVM_PGFLAGBITS; 1769 static const char page_pqflagbits[] = UVM_PQFLAGBITS; 1770 1771 void 1772 uvm_page_printit(struct vm_page *pg, bool full, 1773 void (*pr)(const char *, ...)) 1774 { 1775 struct vm_page *tpg; 1776 struct uvm_object *uobj; 1777 struct pgflist *pgl; 1778 char pgbuf[128]; 1779 char pqbuf[128]; 1780 1781 (*pr)("PAGE %p:\n", pg); 1782 snprintb(pgbuf, sizeof(pgbuf), page_flagbits, pg->flags); 1783 snprintb(pqbuf, sizeof(pqbuf), page_pqflagbits, pg->pqflags); 1784 (*pr)(" flags=%s, pqflags=%s, wire_count=%d, pa=0x%lx\n", 1785 pgbuf, pqbuf, pg->wire_count, (long)VM_PAGE_TO_PHYS(pg)); 1786 (*pr)(" uobject=%p, uanon=%p, offset=0x%llx loan_count=%d\n", 1787 pg->uobject, pg->uanon, (long long)pg->offset, pg->loan_count); 1788 #if defined(UVM_PAGE_TRKOWN) 1789 if (pg->flags & PG_BUSY) 1790 (*pr)(" owning process = %d, tag=%s\n", 1791 pg->owner, pg->owner_tag); 1792 else 1793 (*pr)(" page not busy, no owner\n"); 1794 #else 1795 (*pr)(" [page ownership tracking disabled]\n"); 1796 #endif 1797 1798 if (!full) 1799 return; 1800 1801 /* cross-verify object/anon */ 1802 if ((pg->pqflags & PQ_FREE) == 0) { 1803 if (pg->pqflags & PQ_ANON) { 1804 if (pg->uanon == NULL || pg->uanon->an_page != pg) 1805 (*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n", 1806 (pg->uanon) ? pg->uanon->an_page : NULL); 1807 else 1808 (*pr)(" anon backpointer is OK\n"); 1809 } else { 1810 uobj = pg->uobject; 1811 if (uobj) { 1812 (*pr)(" checking object list\n"); 1813 TAILQ_FOREACH(tpg, &uobj->memq, listq.queue) { 1814 if (tpg == pg) { 1815 break; 1816 } 1817 } 1818 if (tpg) 1819 (*pr)(" page found on object list\n"); 1820 else 1821 (*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n"); 1822 } 1823 } 1824 } 1825 1826 /* cross-verify page queue */ 1827 if (pg->pqflags & PQ_FREE) { 1828 int fl = uvm_page_lookup_freelist(pg); 1829 int color = VM_PGCOLOR_BUCKET(pg); 1830 pgl = &uvm.page_free[fl].pgfl_buckets[color].pgfl_queues[ 1831 ((pg)->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN]; 1832 } else { 1833 pgl = NULL; 1834 } 1835 1836 if (pgl) { 1837 (*pr)(" checking pageq list\n"); 1838 LIST_FOREACH(tpg, pgl, pageq.list) { 1839 if (tpg == pg) { 1840 break; 1841 } 1842 } 1843 if (tpg) 1844 (*pr)(" page found on pageq list\n"); 1845 else 1846 (*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n"); 1847 } 1848 } 1849 1850 /* 1851 * uvm_pages_printthem - print a summary of all managed pages 1852 */ 1853 1854 void 1855 uvm_page_printall(void (*pr)(const char *, ...)) 1856 { 1857 uvm_physseg_t i; 1858 paddr_t pfn; 1859 struct vm_page *pg; 1860 1861 (*pr)("%18s %4s %4s %18s %18s" 1862 #ifdef UVM_PAGE_TRKOWN 1863 " OWNER" 1864 #endif 1865 "\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON"); 1866 for (i = uvm_physseg_get_first(); 1867 uvm_physseg_valid_p(i); 1868 i = uvm_physseg_get_next(i)) { 1869 for (pfn = uvm_physseg_get_start(i); 1870 pfn < uvm_physseg_get_end(i); 1871 pfn++) { 1872 pg = PHYS_TO_VM_PAGE(ptoa(pfn)); 1873 1874 (*pr)("%18p %04x %04x %18p %18p", 1875 pg, pg->flags, pg->pqflags, pg->uobject, 1876 pg->uanon); 1877 #ifdef UVM_PAGE_TRKOWN 1878 if (pg->flags & PG_BUSY) 1879 (*pr)(" %d [%s]", pg->owner, pg->owner_tag); 1880 #endif 1881 (*pr)("\n"); 1882 } 1883 } 1884 } 1885 1886 #endif /* DDB || DEBUGPRINT */ 1887