1 /* $NetBSD: uvm_page.c,v 1.126 2007/11/29 18:07:11 ad 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 1.126 2007/11/29 18:07:11 ad Exp $"); 75 76 #include "opt_uvmhist.h" 77 #include "opt_readahead.h" 78 79 #include <sys/param.h> 80 #include <sys/systm.h> 81 #include <sys/malloc.h> 82 #include <sys/sched.h> 83 #include <sys/kernel.h> 84 #include <sys/vnode.h> 85 #include <sys/proc.h> 86 #include <sys/atomic.h> 87 88 #include <uvm/uvm.h> 89 #include <uvm/uvm_pdpolicy.h> 90 91 /* 92 * global vars... XXXCDC: move to uvm. structure. 93 */ 94 95 /* 96 * physical memory config is stored in vm_physmem. 97 */ 98 99 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 100 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 101 102 /* 103 * Some supported CPUs in a given architecture don't support all 104 * of the things necessary to do idle page zero'ing efficiently. 105 * We therefore provide a way to disable it from machdep code here. 106 */ 107 /* 108 * XXX disabled until we can find a way to do this without causing 109 * problems for either CPU caches or DMA latency. 110 */ 111 bool vm_page_zero_enable = false; 112 113 /* 114 * local variables 115 */ 116 117 /* 118 * these variables record the values returned by vm_page_bootstrap, 119 * for debugging purposes. The implementation of uvm_pageboot_alloc 120 * and pmap_startup here also uses them internally. 121 */ 122 123 static vaddr_t virtual_space_start; 124 static vaddr_t virtual_space_end; 125 126 /* 127 * we use a hash table with only one bucket during bootup. we will 128 * later rehash (resize) the hash table once the allocator is ready. 129 * we static allocate the one bootstrap bucket below... 130 */ 131 132 static struct pglist uvm_bootbucket; 133 134 /* 135 * we allocate an initial number of page colors in uvm_page_init(), 136 * and remember them. We may re-color pages as cache sizes are 137 * discovered during the autoconfiguration phase. But we can never 138 * free the initial set of buckets, since they are allocated using 139 * uvm_pageboot_alloc(). 140 */ 141 142 static bool have_recolored_pages /* = false */; 143 144 MALLOC_DEFINE(M_VMPAGE, "VM page", "VM page"); 145 146 #ifdef DEBUG 147 vaddr_t uvm_zerocheckkva; 148 #endif /* DEBUG */ 149 150 /* 151 * locks on the hash table. allocated in 32 byte chunks to try 152 * and reduce cache traffic between CPUs. 153 */ 154 155 #define UVM_HASHLOCK_CNT 32 156 #define uvm_hashlock(hash) \ 157 (&uvm_hashlocks[(hash) & (UVM_HASHLOCK_CNT - 1)].lock) 158 159 static union { 160 kmutex_t lock; 161 uint8_t pad[32]; 162 } uvm_hashlocks[UVM_HASHLOCK_CNT] __aligned(32); 163 164 /* 165 * local prototypes 166 */ 167 168 static void uvm_pageinsert(struct vm_page *); 169 static void uvm_pageinsert_after(struct vm_page *, struct vm_page *); 170 static void uvm_pageremove(struct vm_page *); 171 172 /* 173 * inline functions 174 */ 175 176 /* 177 * uvm_pageinsert: insert a page in the object and the hash table 178 * uvm_pageinsert_after: insert a page into the specified place in listq 179 * 180 * => caller must lock object 181 * => caller must lock page queues 182 * => call should have already set pg's object and offset pointers 183 * and bumped the version counter 184 */ 185 186 inline static void 187 uvm_pageinsert_after(struct vm_page *pg, struct vm_page *where) 188 { 189 struct pglist *buck; 190 struct uvm_object *uobj = pg->uobject; 191 kmutex_t *lock; 192 u_int hash; 193 194 LOCK_ASSERT(simple_lock_held(&uobj->vmobjlock)); 195 KASSERT((pg->flags & PG_TABLED) == 0); 196 KASSERT(where == NULL || (where->flags & PG_TABLED)); 197 KASSERT(where == NULL || (where->uobject == uobj)); 198 199 hash = uvm_pagehash(uobj, pg->offset); 200 buck = &uvm.page_hash[hash]; 201 lock = uvm_hashlock(hash); 202 mutex_spin_enter(lock); 203 TAILQ_INSERT_TAIL(buck, pg, hashq); 204 mutex_spin_exit(lock); 205 206 if (UVM_OBJ_IS_VNODE(uobj)) { 207 if (uobj->uo_npages == 0) { 208 struct vnode *vp = (struct vnode *)uobj; 209 210 vholdl(vp); 211 } 212 if (UVM_OBJ_IS_VTEXT(uobj)) { 213 atomic_inc_uint(&uvmexp.execpages); 214 } else { 215 atomic_inc_uint(&uvmexp.filepages); 216 } 217 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 218 atomic_inc_uint(&uvmexp.anonpages); 219 } 220 221 if (where) 222 TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq); 223 else 224 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); 225 pg->flags |= PG_TABLED; 226 uobj->uo_npages++; 227 } 228 229 inline static void 230 uvm_pageinsert(struct vm_page *pg) 231 { 232 233 uvm_pageinsert_after(pg, NULL); 234 } 235 236 /* 237 * uvm_page_remove: remove page from object and hash 238 * 239 * => caller must lock object 240 * => caller must lock page queues 241 */ 242 243 static inline void 244 uvm_pageremove(struct vm_page *pg) 245 { 246 struct pglist *buck; 247 struct uvm_object *uobj = pg->uobject; 248 kmutex_t *lock; 249 u_int hash; 250 251 LOCK_ASSERT(simple_lock_held(&uobj->vmobjlock)); 252 KASSERT(pg->flags & PG_TABLED); 253 254 hash = uvm_pagehash(uobj, pg->offset); 255 buck = &uvm.page_hash[hash]; 256 lock = uvm_hashlock(hash); 257 mutex_spin_enter(lock); 258 TAILQ_REMOVE(buck, pg, hashq); 259 mutex_spin_exit(lock); 260 261 if (UVM_OBJ_IS_VNODE(uobj)) { 262 if (uobj->uo_npages == 1) { 263 struct vnode *vp = (struct vnode *)uobj; 264 265 holdrelel(vp); 266 } 267 if (UVM_OBJ_IS_VTEXT(uobj)) { 268 atomic_dec_uint(&uvmexp.execpages); 269 } else { 270 atomic_dec_uint(&uvmexp.filepages); 271 } 272 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 273 atomic_dec_uint(&uvmexp.anonpages); 274 } 275 276 /* object should be locked */ 277 uobj->uo_npages--; 278 TAILQ_REMOVE(&uobj->memq, pg, listq); 279 pg->flags &= ~PG_TABLED; 280 pg->uobject = NULL; 281 } 282 283 static void 284 uvm_page_init_buckets(struct pgfreelist *pgfl) 285 { 286 int color, i; 287 288 for (color = 0; color < uvmexp.ncolors; color++) { 289 for (i = 0; i < PGFL_NQUEUES; i++) { 290 TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); 291 } 292 } 293 } 294 295 /* 296 * uvm_page_init: init the page system. called from uvm_init(). 297 * 298 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 299 */ 300 301 void 302 uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp) 303 { 304 vsize_t freepages, pagecount, bucketcount, n; 305 struct pgflbucket *bucketarray; 306 struct vm_page *pagearray; 307 int lcv; 308 u_int i; 309 paddr_t paddr; 310 311 /* 312 * init the page queues and page queue locks, except the free 313 * list; we allocate that later (with the initial vm_page 314 * structures). 315 */ 316 317 uvmpdpol_init(); 318 simple_lock_init(&uvm.pageqlock); 319 mutex_init(&uvm_fpageqlock, MUTEX_DRIVER, IPL_VM); 320 321 /* 322 * init the <obj,offset> => <page> hash table. for now 323 * we just have one bucket (the bootstrap bucket). later on we 324 * will allocate new buckets as we dynamically resize the hash table. 325 */ 326 327 uvm.page_nhash = 1; /* 1 bucket */ 328 uvm.page_hashmask = 0; /* mask for hash function */ 329 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 330 TAILQ_INIT(uvm.page_hash); /* init hash table */ 331 332 /* 333 * init hashtable locks. these must be spinlocks, as they are 334 * called from sites in the pmap modules where we cannot block. 335 * if taking multiple locks, the order is: low numbered first, 336 * high numbered second. 337 */ 338 339 for (i = 0; i < UVM_HASHLOCK_CNT; i++) 340 mutex_init(&uvm_hashlocks[i].lock, MUTEX_SPIN, IPL_VM); 341 342 /* 343 * allocate vm_page structures. 344 */ 345 346 /* 347 * sanity check: 348 * before calling this function the MD code is expected to register 349 * some free RAM with the uvm_page_physload() function. our job 350 * now is to allocate vm_page structures for this memory. 351 */ 352 353 if (vm_nphysseg == 0) 354 panic("uvm_page_bootstrap: no memory pre-allocated"); 355 356 /* 357 * first calculate the number of free pages... 358 * 359 * note that we use start/end rather than avail_start/avail_end. 360 * this allows us to allocate extra vm_page structures in case we 361 * want to return some memory to the pool after booting. 362 */ 363 364 freepages = 0; 365 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 366 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 367 368 /* 369 * Let MD code initialize the number of colors, or default 370 * to 1 color if MD code doesn't care. 371 */ 372 if (uvmexp.ncolors == 0) 373 uvmexp.ncolors = 1; 374 uvmexp.colormask = uvmexp.ncolors - 1; 375 376 /* 377 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 378 * use. for each page of memory we use we need a vm_page structure. 379 * thus, the total number of pages we can use is the total size of 380 * the memory divided by the PAGE_SIZE plus the size of the vm_page 381 * structure. we add one to freepages as a fudge factor to avoid 382 * truncation errors (since we can only allocate in terms of whole 383 * pages). 384 */ 385 386 bucketcount = uvmexp.ncolors * VM_NFREELIST; 387 pagecount = ((freepages + 1) << PAGE_SHIFT) / 388 (PAGE_SIZE + sizeof(struct vm_page)); 389 390 bucketarray = (void *)uvm_pageboot_alloc((bucketcount * 391 sizeof(struct pgflbucket)) + (pagecount * 392 sizeof(struct vm_page))); 393 pagearray = (struct vm_page *)(bucketarray + bucketcount); 394 395 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 396 uvm.page_free[lcv].pgfl_buckets = 397 (bucketarray + (lcv * uvmexp.ncolors)); 398 uvm_page_init_buckets(&uvm.page_free[lcv]); 399 } 400 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 401 402 /* 403 * init the vm_page structures and put them in the correct place. 404 */ 405 406 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 407 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 408 409 /* set up page array pointers */ 410 vm_physmem[lcv].pgs = pagearray; 411 pagearray += n; 412 pagecount -= n; 413 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 414 415 /* init and free vm_pages (we've already zeroed them) */ 416 paddr = ptoa(vm_physmem[lcv].start); 417 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 418 vm_physmem[lcv].pgs[i].phys_addr = paddr; 419 #ifdef __HAVE_VM_PAGE_MD 420 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); 421 #endif 422 if (atop(paddr) >= vm_physmem[lcv].avail_start && 423 atop(paddr) <= vm_physmem[lcv].avail_end) { 424 uvmexp.npages++; 425 /* add page to free pool */ 426 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 427 } 428 } 429 } 430 431 /* 432 * pass up the values of virtual_space_start and 433 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 434 * layers of the VM. 435 */ 436 437 *kvm_startp = round_page(virtual_space_start); 438 *kvm_endp = trunc_page(virtual_space_end); 439 #ifdef DEBUG 440 /* 441 * steal kva for uvm_pagezerocheck(). 442 */ 443 uvm_zerocheckkva = *kvm_startp; 444 *kvm_startp += PAGE_SIZE; 445 #endif /* DEBUG */ 446 447 /* 448 * init locks for kernel threads 449 */ 450 451 mutex_init(&uvm_pagedaemon_lock, MUTEX_DEFAULT, IPL_NONE); 452 453 /* 454 * init various thresholds. 455 */ 456 457 uvmexp.reserve_pagedaemon = 1; 458 uvmexp.reserve_kernel = 5; 459 460 /* 461 * determine if we should zero pages in the idle loop. 462 */ 463 464 uvm.page_idle_zero = vm_page_zero_enable; 465 466 /* 467 * done! 468 */ 469 470 uvm.page_init_done = true; 471 } 472 473 /* 474 * uvm_setpagesize: set the page size 475 * 476 * => sets page_shift and page_mask from uvmexp.pagesize. 477 */ 478 479 void 480 uvm_setpagesize(void) 481 { 482 483 /* 484 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE 485 * to be a constant (indicated by being a non-zero value). 486 */ 487 if (uvmexp.pagesize == 0) { 488 if (PAGE_SIZE == 0) 489 panic("uvm_setpagesize: uvmexp.pagesize not set"); 490 uvmexp.pagesize = PAGE_SIZE; 491 } 492 uvmexp.pagemask = uvmexp.pagesize - 1; 493 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 494 panic("uvm_setpagesize: page size not a power of two"); 495 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 496 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 497 break; 498 } 499 500 /* 501 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 502 */ 503 504 vaddr_t 505 uvm_pageboot_alloc(vsize_t size) 506 { 507 static bool initialized = false; 508 vaddr_t addr; 509 #if !defined(PMAP_STEAL_MEMORY) 510 vaddr_t vaddr; 511 paddr_t paddr; 512 #endif 513 514 /* 515 * on first call to this function, initialize ourselves. 516 */ 517 if (initialized == false) { 518 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 519 520 /* round it the way we like it */ 521 virtual_space_start = round_page(virtual_space_start); 522 virtual_space_end = trunc_page(virtual_space_end); 523 524 initialized = true; 525 } 526 527 /* round to page size */ 528 size = round_page(size); 529 530 #if defined(PMAP_STEAL_MEMORY) 531 532 /* 533 * defer bootstrap allocation to MD code (it may want to allocate 534 * from a direct-mapped segment). pmap_steal_memory should adjust 535 * virtual_space_start/virtual_space_end if necessary. 536 */ 537 538 addr = pmap_steal_memory(size, &virtual_space_start, 539 &virtual_space_end); 540 541 return(addr); 542 543 #else /* !PMAP_STEAL_MEMORY */ 544 545 /* 546 * allocate virtual memory for this request 547 */ 548 if (virtual_space_start == virtual_space_end || 549 (virtual_space_end - virtual_space_start) < size) 550 panic("uvm_pageboot_alloc: out of virtual space"); 551 552 addr = virtual_space_start; 553 554 #ifdef PMAP_GROWKERNEL 555 /* 556 * If the kernel pmap can't map the requested space, 557 * then allocate more resources for it. 558 */ 559 if (uvm_maxkaddr < (addr + size)) { 560 uvm_maxkaddr = pmap_growkernel(addr + size); 561 if (uvm_maxkaddr < (addr + size)) 562 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 563 } 564 #endif 565 566 virtual_space_start += size; 567 568 /* 569 * allocate and mapin physical pages to back new virtual pages 570 */ 571 572 for (vaddr = round_page(addr) ; vaddr < addr + size ; 573 vaddr += PAGE_SIZE) { 574 575 if (!uvm_page_physget(&paddr)) 576 panic("uvm_pageboot_alloc: out of memory"); 577 578 /* 579 * Note this memory is no longer managed, so using 580 * pmap_kenter is safe. 581 */ 582 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 583 } 584 pmap_update(pmap_kernel()); 585 return(addr); 586 #endif /* PMAP_STEAL_MEMORY */ 587 } 588 589 #if !defined(PMAP_STEAL_MEMORY) 590 /* 591 * uvm_page_physget: "steal" one page from the vm_physmem structure. 592 * 593 * => attempt to allocate it off the end of a segment in which the "avail" 594 * values match the start/end values. if we can't do that, then we 595 * will advance both values (making them equal, and removing some 596 * vm_page structures from the non-avail area). 597 * => return false if out of memory. 598 */ 599 600 /* subroutine: try to allocate from memory chunks on the specified freelist */ 601 static bool uvm_page_physget_freelist(paddr_t *, int); 602 603 static bool 604 uvm_page_physget_freelist(paddr_t *paddrp, int freelist) 605 { 606 int lcv, x; 607 608 /* pass 1: try allocating from a matching end */ 609 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 610 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 611 #else 612 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 613 #endif 614 { 615 616 if (uvm.page_init_done == true) 617 panic("uvm_page_physget: called _after_ bootstrap"); 618 619 if (vm_physmem[lcv].free_list != freelist) 620 continue; 621 622 /* try from front */ 623 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 624 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 625 *paddrp = ptoa(vm_physmem[lcv].avail_start); 626 vm_physmem[lcv].avail_start++; 627 vm_physmem[lcv].start++; 628 /* nothing left? nuke it */ 629 if (vm_physmem[lcv].avail_start == 630 vm_physmem[lcv].end) { 631 if (vm_nphysseg == 1) 632 panic("uvm_page_physget: out of memory!"); 633 vm_nphysseg--; 634 for (x = lcv ; x < vm_nphysseg ; x++) 635 /* structure copy */ 636 vm_physmem[x] = vm_physmem[x+1]; 637 } 638 return (true); 639 } 640 641 /* try from rear */ 642 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 643 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 644 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 645 vm_physmem[lcv].avail_end--; 646 vm_physmem[lcv].end--; 647 /* nothing left? nuke it */ 648 if (vm_physmem[lcv].avail_end == 649 vm_physmem[lcv].start) { 650 if (vm_nphysseg == 1) 651 panic("uvm_page_physget: out of memory!"); 652 vm_nphysseg--; 653 for (x = lcv ; x < vm_nphysseg ; x++) 654 /* structure copy */ 655 vm_physmem[x] = vm_physmem[x+1]; 656 } 657 return (true); 658 } 659 } 660 661 /* pass2: forget about matching ends, just allocate something */ 662 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 663 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 664 #else 665 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 666 #endif 667 { 668 669 /* any room in this bank? */ 670 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 671 continue; /* nope */ 672 673 *paddrp = ptoa(vm_physmem[lcv].avail_start); 674 vm_physmem[lcv].avail_start++; 675 /* truncate! */ 676 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 677 678 /* nothing left? nuke it */ 679 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 680 if (vm_nphysseg == 1) 681 panic("uvm_page_physget: out of memory!"); 682 vm_nphysseg--; 683 for (x = lcv ; x < vm_nphysseg ; x++) 684 /* structure copy */ 685 vm_physmem[x] = vm_physmem[x+1]; 686 } 687 return (true); 688 } 689 690 return (false); /* whoops! */ 691 } 692 693 bool 694 uvm_page_physget(paddr_t *paddrp) 695 { 696 int i; 697 698 /* try in the order of freelist preference */ 699 for (i = 0; i < VM_NFREELIST; i++) 700 if (uvm_page_physget_freelist(paddrp, i) == true) 701 return (true); 702 return (false); 703 } 704 #endif /* PMAP_STEAL_MEMORY */ 705 706 /* 707 * uvm_page_physload: load physical memory into VM system 708 * 709 * => all args are PFs 710 * => all pages in start/end get vm_page structures 711 * => areas marked by avail_start/avail_end get added to the free page pool 712 * => we are limited to VM_PHYSSEG_MAX physical memory segments 713 */ 714 715 void 716 uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start, 717 paddr_t avail_end, int free_list) 718 { 719 int preload, lcv; 720 psize_t npages; 721 struct vm_page *pgs; 722 struct vm_physseg *ps; 723 724 if (uvmexp.pagesize == 0) 725 panic("uvm_page_physload: page size not set!"); 726 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 727 panic("uvm_page_physload: bad free list %d", free_list); 728 if (start >= end) 729 panic("uvm_page_physload: start >= end"); 730 731 /* 732 * do we have room? 733 */ 734 735 if (vm_nphysseg == VM_PHYSSEG_MAX) { 736 printf("uvm_page_physload: unable to load physical memory " 737 "segment\n"); 738 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 739 VM_PHYSSEG_MAX, (long long)start, (long long)end); 740 printf("\tincrease VM_PHYSSEG_MAX\n"); 741 return; 742 } 743 744 /* 745 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 746 * called yet, so malloc is not available). 747 */ 748 749 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 750 if (vm_physmem[lcv].pgs) 751 break; 752 } 753 preload = (lcv == vm_nphysseg); 754 755 /* 756 * if VM is already running, attempt to malloc() vm_page structures 757 */ 758 759 if (!preload) { 760 #if defined(VM_PHYSSEG_NOADD) 761 panic("uvm_page_physload: tried to add RAM after vm_mem_init"); 762 #else 763 /* XXXCDC: need some sort of lockout for this case */ 764 paddr_t paddr; 765 npages = end - start; /* # of pages */ 766 pgs = malloc(sizeof(struct vm_page) * npages, 767 M_VMPAGE, M_NOWAIT); 768 if (pgs == NULL) { 769 printf("uvm_page_physload: can not malloc vm_page " 770 "structs for segment\n"); 771 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 772 return; 773 } 774 /* zero data, init phys_addr and free_list, and free pages */ 775 memset(pgs, 0, sizeof(struct vm_page) * npages); 776 for (lcv = 0, paddr = ptoa(start) ; 777 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 778 pgs[lcv].phys_addr = paddr; 779 pgs[lcv].free_list = free_list; 780 if (atop(paddr) >= avail_start && 781 atop(paddr) <= avail_end) 782 uvm_pagefree(&pgs[lcv]); 783 } 784 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 785 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 786 #endif 787 } else { 788 pgs = NULL; 789 npages = 0; 790 } 791 792 /* 793 * now insert us in the proper place in vm_physmem[] 794 */ 795 796 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 797 /* random: put it at the end (easy!) */ 798 ps = &vm_physmem[vm_nphysseg]; 799 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 800 { 801 int x; 802 /* sort by address for binary search */ 803 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 804 if (start < vm_physmem[lcv].start) 805 break; 806 ps = &vm_physmem[lcv]; 807 /* move back other entries, if necessary ... */ 808 for (x = vm_nphysseg ; x > lcv ; x--) 809 /* structure copy */ 810 vm_physmem[x] = vm_physmem[x - 1]; 811 } 812 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 813 { 814 int x; 815 /* sort by largest segment first */ 816 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 817 if ((end - start) > 818 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 819 break; 820 ps = &vm_physmem[lcv]; 821 /* move back other entries, if necessary ... */ 822 for (x = vm_nphysseg ; x > lcv ; x--) 823 /* structure copy */ 824 vm_physmem[x] = vm_physmem[x - 1]; 825 } 826 #else 827 panic("uvm_page_physload: unknown physseg strategy selected!"); 828 #endif 829 830 ps->start = start; 831 ps->end = end; 832 ps->avail_start = avail_start; 833 ps->avail_end = avail_end; 834 if (preload) { 835 ps->pgs = NULL; 836 } else { 837 ps->pgs = pgs; 838 ps->lastpg = pgs + npages - 1; 839 } 840 ps->free_list = free_list; 841 vm_nphysseg++; 842 843 if (!preload) { 844 uvm_page_rehash(); 845 uvmpdpol_reinit(); 846 } 847 } 848 849 /* 850 * uvm_page_rehash: reallocate hash table based on number of free pages. 851 */ 852 853 void 854 uvm_page_rehash(void) 855 { 856 int freepages, lcv, bucketcount, oldcount, i; 857 struct pglist *newbuckets, *oldbuckets; 858 struct vm_page *pg; 859 size_t newsize, oldsize; 860 861 /* 862 * compute number of pages that can go in the free pool 863 */ 864 865 freepages = 0; 866 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 867 freepages += 868 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 869 870 /* 871 * compute number of buckets needed for this number of pages 872 */ 873 874 bucketcount = 1; 875 while (bucketcount < freepages) 876 bucketcount = bucketcount * 2; 877 878 /* 879 * compute the size of the current table and new table. 880 */ 881 882 oldbuckets = uvm.page_hash; 883 oldcount = uvm.page_nhash; 884 oldsize = round_page(sizeof(struct pglist) * oldcount); 885 newsize = round_page(sizeof(struct pglist) * bucketcount); 886 887 /* 888 * allocate the new buckets 889 */ 890 891 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize, 892 0, UVM_KMF_WIRED); 893 if (newbuckets == NULL) { 894 printf("uvm_page_physrehash: WARNING: could not grow page " 895 "hash table\n"); 896 return; 897 } 898 for (lcv = 0 ; lcv < bucketcount ; lcv++) 899 TAILQ_INIT(&newbuckets[lcv]); 900 901 /* 902 * now replace the old buckets with the new ones and rehash everything 903 */ 904 905 for (i = 0; i < UVM_HASHLOCK_CNT; i++) 906 mutex_spin_enter(&uvm_hashlocks[i].lock); 907 908 uvm.page_hash = newbuckets; 909 uvm.page_nhash = bucketcount; 910 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 911 912 /* ... and rehash */ 913 for (lcv = 0 ; lcv < oldcount ; lcv++) { 914 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 915 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 916 TAILQ_INSERT_TAIL( 917 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 918 pg, hashq); 919 } 920 } 921 922 for (i = 0; i < UVM_HASHLOCK_CNT; i++) 923 mutex_spin_exit(&uvm_hashlocks[i].lock); 924 925 /* 926 * free old bucket array if is not the boot-time table 927 */ 928 929 if (oldbuckets != &uvm_bootbucket) 930 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize, 931 UVM_KMF_WIRED); 932 } 933 934 /* 935 * uvm_page_recolor: Recolor the pages if the new bucket count is 936 * larger than the old one. 937 */ 938 939 void 940 uvm_page_recolor(int newncolors) 941 { 942 struct pgflbucket *bucketarray, *oldbucketarray; 943 struct pgfreelist pgfl; 944 struct vm_page *pg; 945 vsize_t bucketcount; 946 int lcv, color, i, ocolors; 947 948 if (newncolors <= uvmexp.ncolors) 949 return; 950 951 if (uvm.page_init_done == false) { 952 uvmexp.ncolors = newncolors; 953 return; 954 } 955 956 bucketcount = newncolors * VM_NFREELIST; 957 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), 958 M_VMPAGE, M_NOWAIT); 959 if (bucketarray == NULL) { 960 printf("WARNING: unable to allocate %ld page color buckets\n", 961 (long) bucketcount); 962 return; 963 } 964 965 mutex_spin_enter(&uvm_fpageqlock); 966 967 /* Make sure we should still do this. */ 968 if (newncolors <= uvmexp.ncolors) { 969 mutex_spin_exit(&uvm_fpageqlock); 970 free(bucketarray, M_VMPAGE); 971 return; 972 } 973 974 oldbucketarray = uvm.page_free[0].pgfl_buckets; 975 ocolors = uvmexp.ncolors; 976 977 uvmexp.ncolors = newncolors; 978 uvmexp.colormask = uvmexp.ncolors - 1; 979 980 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 981 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); 982 uvm_page_init_buckets(&pgfl); 983 for (color = 0; color < ocolors; color++) { 984 for (i = 0; i < PGFL_NQUEUES; i++) { 985 while ((pg = TAILQ_FIRST(&uvm.page_free[ 986 lcv].pgfl_buckets[color].pgfl_queues[i])) 987 != NULL) { 988 TAILQ_REMOVE(&uvm.page_free[ 989 lcv].pgfl_buckets[ 990 color].pgfl_queues[i], pg, pageq); 991 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ 992 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ 993 i], pg, pageq); 994 } 995 } 996 } 997 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; 998 } 999 1000 if (have_recolored_pages) { 1001 mutex_spin_exit(&uvm_fpageqlock); 1002 free(oldbucketarray, M_VMPAGE); 1003 return; 1004 } 1005 1006 have_recolored_pages = true; 1007 mutex_spin_exit(&uvm_fpageqlock); 1008 } 1009 1010 /* 1011 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat 1012 */ 1013 1014 static struct vm_page * 1015 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, 1016 int *trycolorp) 1017 { 1018 struct pglist *freeq; 1019 struct vm_page *pg; 1020 int color, trycolor = *trycolorp; 1021 1022 color = trycolor; 1023 do { 1024 if ((pg = TAILQ_FIRST((freeq = 1025 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) 1026 goto gotit; 1027 if ((pg = TAILQ_FIRST((freeq = 1028 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) 1029 goto gotit; 1030 color = (color + 1) & uvmexp.colormask; 1031 } while (color != trycolor); 1032 1033 return (NULL); 1034 1035 gotit: 1036 TAILQ_REMOVE(freeq, pg, pageq); 1037 uvmexp.free--; 1038 1039 /* update zero'd page count */ 1040 if (pg->flags & PG_ZERO) 1041 uvmexp.zeropages--; 1042 1043 if (color == trycolor) 1044 uvmexp.colorhit++; 1045 else { 1046 uvmexp.colormiss++; 1047 *trycolorp = color; 1048 } 1049 1050 return (pg); 1051 } 1052 1053 /* 1054 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 1055 * 1056 * => return null if no pages free 1057 * => wake up pagedaemon if number of free pages drops below low water mark 1058 * => if obj != NULL, obj must be locked (to put in hash) 1059 * => if anon != NULL, anon must be locked (to put in anon) 1060 * => only one of obj or anon can be non-null 1061 * => caller must activate/deactivate page if it is not wired. 1062 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 1063 * => policy decision: it is more important to pull a page off of the 1064 * appropriate priority free list than it is to get a zero'd or 1065 * unknown contents page. This is because we live with the 1066 * consequences of a bad free list decision for the entire 1067 * lifetime of the page, e.g. if the page comes from memory that 1068 * is slower to access. 1069 */ 1070 1071 struct vm_page * 1072 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon, 1073 int flags, int strat, int free_list) 1074 { 1075 int lcv, try1, try2, zeroit = 0, color; 1076 struct vm_page *pg; 1077 bool use_reserve; 1078 1079 KASSERT(obj == NULL || anon == NULL); 1080 KASSERT(anon == NULL || off == 0); 1081 KASSERT(off == trunc_page(off)); 1082 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); 1083 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); 1084 1085 mutex_spin_enter(&uvm_fpageqlock); 1086 1087 /* 1088 * This implements a global round-robin page coloring 1089 * algorithm. 1090 * 1091 * XXXJRT: Should we make the `nextcolor' per-CPU? 1092 * XXXJRT: What about virtually-indexed caches? 1093 */ 1094 1095 color = uvm.page_free_nextcolor; 1096 1097 /* 1098 * check to see if we need to generate some free pages waking 1099 * the pagedaemon. 1100 */ 1101 1102 uvm_kick_pdaemon(); 1103 1104 /* 1105 * fail if any of these conditions is true: 1106 * [1] there really are no free pages, or 1107 * [2] only kernel "reserved" pages remain and 1108 * the page isn't being allocated to a kernel object. 1109 * [3] only pagedaemon "reserved" pages remain and 1110 * the requestor isn't the pagedaemon. 1111 */ 1112 1113 use_reserve = (flags & UVM_PGA_USERESERVE) || 1114 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 1115 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 1116 (uvmexp.free <= uvmexp.reserve_pagedaemon && 1117 !(use_reserve && curlwp == uvm.pagedaemon_lwp))) 1118 goto fail; 1119 1120 #if PGFL_NQUEUES != 2 1121 #error uvm_pagealloc_strat needs to be updated 1122 #endif 1123 1124 /* 1125 * If we want a zero'd page, try the ZEROS queue first, otherwise 1126 * we try the UNKNOWN queue first. 1127 */ 1128 if (flags & UVM_PGA_ZERO) { 1129 try1 = PGFL_ZEROS; 1130 try2 = PGFL_UNKNOWN; 1131 } else { 1132 try1 = PGFL_UNKNOWN; 1133 try2 = PGFL_ZEROS; 1134 } 1135 1136 again: 1137 switch (strat) { 1138 case UVM_PGA_STRAT_NORMAL: 1139 /* Check all freelists in descending priority order. */ 1140 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 1141 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], 1142 try1, try2, &color); 1143 if (pg != NULL) 1144 goto gotit; 1145 } 1146 1147 /* No pages free! */ 1148 goto fail; 1149 1150 case UVM_PGA_STRAT_ONLY: 1151 case UVM_PGA_STRAT_FALLBACK: 1152 /* Attempt to allocate from the specified free list. */ 1153 KASSERT(free_list >= 0 && free_list < VM_NFREELIST); 1154 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], 1155 try1, try2, &color); 1156 if (pg != NULL) 1157 goto gotit; 1158 1159 /* Fall back, if possible. */ 1160 if (strat == UVM_PGA_STRAT_FALLBACK) { 1161 strat = UVM_PGA_STRAT_NORMAL; 1162 goto again; 1163 } 1164 1165 /* No pages free! */ 1166 goto fail; 1167 1168 default: 1169 panic("uvm_pagealloc_strat: bad strat %d", strat); 1170 /* NOTREACHED */ 1171 } 1172 1173 gotit: 1174 /* 1175 * We now know which color we actually allocated from; set 1176 * the next color accordingly. 1177 */ 1178 1179 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; 1180 1181 /* 1182 * update allocation statistics and remember if we have to 1183 * zero the page 1184 */ 1185 1186 if (flags & UVM_PGA_ZERO) { 1187 if (pg->flags & PG_ZERO) { 1188 uvmexp.pga_zerohit++; 1189 zeroit = 0; 1190 } else { 1191 uvmexp.pga_zeromiss++; 1192 zeroit = 1; 1193 } 1194 } 1195 mutex_spin_exit(&uvm_fpageqlock); 1196 1197 pg->offset = off; 1198 pg->uobject = obj; 1199 pg->uanon = anon; 1200 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1201 if (anon) { 1202 anon->an_page = pg; 1203 pg->pqflags = PQ_ANON; 1204 atomic_inc_uint(&uvmexp.anonpages); 1205 } else { 1206 if (obj) { 1207 uvm_pageinsert(pg); 1208 } 1209 pg->pqflags = 0; 1210 } 1211 #if defined(UVM_PAGE_TRKOWN) 1212 pg->owner_tag = NULL; 1213 #endif 1214 UVM_PAGE_OWN(pg, "new alloc"); 1215 1216 if (flags & UVM_PGA_ZERO) { 1217 /* 1218 * A zero'd page is not clean. If we got a page not already 1219 * zero'd, then we have to zero it ourselves. 1220 */ 1221 pg->flags &= ~PG_CLEAN; 1222 if (zeroit) 1223 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1224 } 1225 1226 return(pg); 1227 1228 fail: 1229 mutex_spin_exit(&uvm_fpageqlock); 1230 return (NULL); 1231 } 1232 1233 /* 1234 * uvm_pagereplace: replace a page with another 1235 * 1236 * => object must be locked 1237 */ 1238 1239 void 1240 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg) 1241 { 1242 1243 KASSERT((oldpg->flags & PG_TABLED) != 0); 1244 KASSERT(oldpg->uobject != NULL); 1245 KASSERT((newpg->flags & PG_TABLED) == 0); 1246 KASSERT(newpg->uobject == NULL); 1247 LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock)); 1248 1249 newpg->uobject = oldpg->uobject; 1250 newpg->offset = oldpg->offset; 1251 1252 uvm_pageinsert_after(newpg, oldpg); 1253 uvm_pageremove(oldpg); 1254 } 1255 1256 /* 1257 * uvm_pagerealloc: reallocate a page from one object to another 1258 * 1259 * => both objects must be locked 1260 */ 1261 1262 void 1263 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) 1264 { 1265 /* 1266 * remove it from the old object 1267 */ 1268 1269 if (pg->uobject) { 1270 uvm_pageremove(pg); 1271 } 1272 1273 /* 1274 * put it in the new object 1275 */ 1276 1277 if (newobj) { 1278 pg->uobject = newobj; 1279 pg->offset = newoff; 1280 uvm_pageinsert(pg); 1281 } 1282 } 1283 1284 #ifdef DEBUG 1285 /* 1286 * check if page is zero-filled 1287 * 1288 * - called with free page queue lock held. 1289 */ 1290 void 1291 uvm_pagezerocheck(struct vm_page *pg) 1292 { 1293 int *p, *ep; 1294 1295 KASSERT(uvm_zerocheckkva != 0); 1296 KASSERT(mutex_owned(&uvm_fpageqlock)); 1297 1298 /* 1299 * XXX assuming pmap_kenter_pa and pmap_kremove never call 1300 * uvm page allocator. 1301 * 1302 * it might be better to have "CPU-local temporary map" pmap interface. 1303 */ 1304 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); 1305 p = (int *)uvm_zerocheckkva; 1306 ep = (int *)((char *)p + PAGE_SIZE); 1307 pmap_update(pmap_kernel()); 1308 while (p < ep) { 1309 if (*p != 0) 1310 panic("PG_ZERO page isn't zero-filled"); 1311 p++; 1312 } 1313 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); 1314 } 1315 #endif /* DEBUG */ 1316 1317 /* 1318 * uvm_pagefree: free page 1319 * 1320 * => erase page's identity (i.e. remove from hash/object) 1321 * => put page on free list 1322 * => caller must lock owning object (either anon or uvm_object) 1323 * => caller must lock page queues 1324 * => assumes all valid mappings of pg are gone 1325 */ 1326 1327 void 1328 uvm_pagefree(struct vm_page *pg) 1329 { 1330 struct pglist *pgfl; 1331 bool iszero; 1332 1333 #ifdef DEBUG 1334 if (pg->uobject == (void *)0xdeadbeef && 1335 pg->uanon == (void *)0xdeadbeef) { 1336 panic("uvm_pagefree: freeing free page %p", pg); 1337 } 1338 #endif /* DEBUG */ 1339 1340 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1341 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || 1342 !uvmpdpol_pageisqueued_p(pg)); 1343 LOCK_ASSERT(pg->uobject == NULL || 1344 simple_lock_held(&pg->uobject->vmobjlock)); 1345 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || 1346 simple_lock_held(&pg->uanon->an_lock)); 1347 1348 /* 1349 * if the page is loaned, resolve the loan instead of freeing. 1350 */ 1351 1352 if (pg->loan_count) { 1353 KASSERT(pg->wire_count == 0); 1354 1355 /* 1356 * if the page is owned by an anon then we just want to 1357 * drop anon ownership. the kernel will free the page when 1358 * it is done with it. if the page is owned by an object, 1359 * remove it from the object and mark it dirty for the benefit 1360 * of possible anon owners. 1361 * 1362 * regardless of previous ownership, wakeup any waiters, 1363 * unbusy the page, and we're done. 1364 */ 1365 1366 if (pg->uobject != NULL) { 1367 uvm_pageremove(pg); 1368 pg->flags &= ~PG_CLEAN; 1369 } else if (pg->uanon != NULL) { 1370 if ((pg->pqflags & PQ_ANON) == 0) { 1371 pg->loan_count--; 1372 } else { 1373 pg->pqflags &= ~PQ_ANON; 1374 atomic_dec_uint(&uvmexp.anonpages); 1375 } 1376 pg->uanon->an_page = NULL; 1377 pg->uanon = NULL; 1378 } 1379 if (pg->flags & PG_WANTED) { 1380 wakeup(pg); 1381 } 1382 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); 1383 #ifdef UVM_PAGE_TRKOWN 1384 pg->owner_tag = NULL; 1385 #endif 1386 if (pg->loan_count) { 1387 KASSERT(pg->uobject == NULL); 1388 if (pg->uanon == NULL) { 1389 uvm_pagedequeue(pg); 1390 } 1391 return; 1392 } 1393 } 1394 1395 /* 1396 * remove page from its object or anon. 1397 */ 1398 1399 if (pg->uobject != NULL) { 1400 uvm_pageremove(pg); 1401 } else if (pg->uanon != NULL) { 1402 pg->uanon->an_page = NULL; 1403 atomic_dec_uint(&uvmexp.anonpages); 1404 } 1405 1406 /* 1407 * now remove the page from the queues. 1408 */ 1409 1410 uvm_pagedequeue(pg); 1411 1412 /* 1413 * if the page was wired, unwire it now. 1414 */ 1415 1416 if (pg->wire_count) { 1417 pg->wire_count = 0; 1418 uvmexp.wired--; 1419 } 1420 1421 /* 1422 * and put on free queue 1423 */ 1424 1425 iszero = (pg->flags & PG_ZERO); 1426 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. 1427 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 1428 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; 1429 1430 pg->pqflags = PQ_FREE; 1431 #ifdef DEBUG 1432 pg->uobject = (void *)0xdeadbeef; 1433 pg->offset = 0xdeadbeef; 1434 pg->uanon = (void *)0xdeadbeef; 1435 #endif 1436 1437 mutex_spin_enter(&uvm_fpageqlock); 1438 1439 #ifdef DEBUG 1440 if (iszero) 1441 uvm_pagezerocheck(pg); 1442 #endif /* DEBUG */ 1443 1444 TAILQ_INSERT_HEAD(pgfl, pg, pageq); 1445 uvmexp.free++; 1446 if (iszero) 1447 uvmexp.zeropages++; 1448 1449 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1450 uvm.page_idle_zero = vm_page_zero_enable; 1451 1452 mutex_spin_exit(&uvm_fpageqlock); 1453 } 1454 1455 /* 1456 * uvm_page_unbusy: unbusy an array of pages. 1457 * 1458 * => pages must either all belong to the same object, or all belong to anons. 1459 * => if pages are object-owned, object must be locked. 1460 * => if pages are anon-owned, anons must be locked. 1461 * => caller must lock page queues if pages may be released. 1462 * => caller must make sure that anon-owned pages are not PG_RELEASED. 1463 */ 1464 1465 void 1466 uvm_page_unbusy(struct vm_page **pgs, int npgs) 1467 { 1468 struct vm_page *pg; 1469 int i; 1470 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); 1471 1472 for (i = 0; i < npgs; i++) { 1473 pg = pgs[i]; 1474 if (pg == NULL || pg == PGO_DONTCARE) { 1475 continue; 1476 } 1477 1478 LOCK_ASSERT(pg->uobject == NULL || 1479 simple_lock_held(&pg->uobject->vmobjlock)); 1480 LOCK_ASSERT(pg->uobject != NULL || 1481 (pg->uanon != NULL && 1482 simple_lock_held(&pg->uanon->an_lock))); 1483 1484 KASSERT(pg->flags & PG_BUSY); 1485 KASSERT((pg->flags & PG_PAGEOUT) == 0); 1486 if (pg->flags & PG_WANTED) { 1487 wakeup(pg); 1488 } 1489 if (pg->flags & PG_RELEASED) { 1490 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); 1491 KASSERT(pg->uobject != NULL || 1492 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 1493 pg->flags &= ~PG_RELEASED; 1494 uvm_pagefree(pg); 1495 } else { 1496 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); 1497 pg->flags &= ~(PG_WANTED|PG_BUSY); 1498 UVM_PAGE_OWN(pg, NULL); 1499 } 1500 } 1501 } 1502 1503 #if defined(UVM_PAGE_TRKOWN) 1504 /* 1505 * uvm_page_own: set or release page ownership 1506 * 1507 * => this is a debugging function that keeps track of who sets PG_BUSY 1508 * and where they do it. it can be used to track down problems 1509 * such a process setting "PG_BUSY" and never releasing it. 1510 * => page's object [if any] must be locked 1511 * => if "tag" is NULL then we are releasing page ownership 1512 */ 1513 void 1514 uvm_page_own(struct vm_page *pg, const char *tag) 1515 { 1516 struct uvm_object *uobj; 1517 struct vm_anon *anon; 1518 1519 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); 1520 1521 uobj = pg->uobject; 1522 anon = pg->uanon; 1523 if (uobj != NULL) { 1524 LOCK_ASSERT(simple_lock_held(&uobj->vmobjlock)); 1525 } else if (anon != NULL) { 1526 LOCK_ASSERT(simple_lock_held(&anon->an_lock)); 1527 } 1528 1529 KASSERT((pg->flags & PG_WANTED) == 0); 1530 1531 /* gain ownership? */ 1532 if (tag) { 1533 KASSERT((pg->flags & PG_BUSY) != 0); 1534 if (pg->owner_tag) { 1535 printf("uvm_page_own: page %p already owned " 1536 "by proc %d [%s]\n", pg, 1537 pg->owner, pg->owner_tag); 1538 panic("uvm_page_own"); 1539 } 1540 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1541 pg->lowner = (curlwp) ? curlwp->l_lid : (lwpid_t) -1; 1542 pg->owner_tag = tag; 1543 return; 1544 } 1545 1546 /* drop ownership */ 1547 KASSERT((pg->flags & PG_BUSY) == 0); 1548 if (pg->owner_tag == NULL) { 1549 printf("uvm_page_own: dropping ownership of an non-owned " 1550 "page (%p)\n", pg); 1551 panic("uvm_page_own"); 1552 } 1553 if (!uvmpdpol_pageisqueued_p(pg)) { 1554 KASSERT((pg->uanon == NULL && pg->uobject == NULL) || 1555 pg->wire_count > 0); 1556 } else { 1557 KASSERT(pg->wire_count == 0); 1558 } 1559 pg->owner_tag = NULL; 1560 } 1561 #endif 1562 1563 /* 1564 * uvm_pageidlezero: zero free pages while the system is idle. 1565 * 1566 * => try to complete one color bucket at a time, to reduce our impact 1567 * on the CPU cache. 1568 * => we loop until we either reach the target or there is a lwp ready to run. 1569 */ 1570 void 1571 uvm_pageidlezero(void) 1572 { 1573 struct vm_page *pg; 1574 struct pgfreelist *pgfl; 1575 int free_list, firstbucket; 1576 static int nextbucket; 1577 1578 KERNEL_LOCK(1, NULL); 1579 mutex_spin_enter(&uvm_fpageqlock); 1580 firstbucket = nextbucket; 1581 do { 1582 if (sched_curcpu_runnable_p()) { 1583 goto quit; 1584 } 1585 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1586 uvm.page_idle_zero = false; 1587 goto quit; 1588 } 1589 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1590 pgfl = &uvm.page_free[free_list]; 1591 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ 1592 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { 1593 if (sched_curcpu_runnable_p()) 1594 goto quit; 1595 1596 TAILQ_REMOVE(&pgfl->pgfl_buckets[ 1597 nextbucket].pgfl_queues[PGFL_UNKNOWN], 1598 pg, pageq); 1599 uvmexp.free--; 1600 mutex_spin_exit(&uvm_fpageqlock); 1601 KERNEL_UNLOCK_LAST(NULL); 1602 #ifdef PMAP_PAGEIDLEZERO 1603 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { 1604 1605 /* 1606 * The machine-dependent code detected 1607 * some reason for us to abort zeroing 1608 * pages, probably because there is a 1609 * process now ready to run. 1610 */ 1611 1612 KERNEL_LOCK(1, NULL); 1613 mutex_spin_enter(&uvm_fpageqlock); 1614 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1615 nextbucket].pgfl_queues[ 1616 PGFL_UNKNOWN], pg, pageq); 1617 uvmexp.free++; 1618 uvmexp.zeroaborts++; 1619 goto quit; 1620 } 1621 #else 1622 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1623 #endif /* PMAP_PAGEIDLEZERO */ 1624 pg->flags |= PG_ZERO; 1625 1626 KERNEL_LOCK(1, NULL); 1627 mutex_spin_enter(&uvm_fpageqlock); 1628 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ 1629 nextbucket].pgfl_queues[PGFL_ZEROS], 1630 pg, pageq); 1631 uvmexp.free++; 1632 uvmexp.zeropages++; 1633 } 1634 } 1635 nextbucket = (nextbucket + 1) & uvmexp.colormask; 1636 } while (nextbucket != firstbucket); 1637 quit: 1638 mutex_spin_exit(&uvm_fpageqlock); 1639 KERNEL_UNLOCK_LAST(NULL); 1640 } 1641 1642 /* 1643 * uvm_pagelookup: look up a page 1644 * 1645 * => caller should lock object to keep someone from pulling the page 1646 * out from under it 1647 */ 1648 1649 struct vm_page * 1650 uvm_pagelookup(struct uvm_object *obj, voff_t off) 1651 { 1652 struct vm_page *pg; 1653 struct pglist *buck; 1654 kmutex_t *lock; 1655 u_int hash; 1656 1657 LOCK_ASSERT(simple_lock_held(&obj->vmobjlock)); 1658 1659 hash = uvm_pagehash(obj, off); 1660 buck = &uvm.page_hash[hash]; 1661 lock = uvm_hashlock(hash); 1662 mutex_spin_enter(lock); 1663 TAILQ_FOREACH(pg, buck, hashq) { 1664 if (pg->uobject == obj && pg->offset == off) { 1665 break; 1666 } 1667 } 1668 mutex_spin_exit(lock); 1669 KASSERT(pg == NULL || obj->uo_npages != 0); 1670 KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 1671 (pg->flags & PG_BUSY) != 0); 1672 return(pg); 1673 } 1674 1675 /* 1676 * uvm_pagewire: wire the page, thus removing it from the daemon's grasp 1677 * 1678 * => caller must lock page queues 1679 */ 1680 1681 void 1682 uvm_pagewire(struct vm_page *pg) 1683 { 1684 UVM_LOCK_ASSERT_PAGEQ(); 1685 #if defined(READAHEAD_STATS) 1686 if ((pg->pqflags & PQ_READAHEAD) != 0) { 1687 uvm_ra_hit.ev_count++; 1688 pg->pqflags &= ~PQ_READAHEAD; 1689 } 1690 #endif /* defined(READAHEAD_STATS) */ 1691 if (pg->wire_count == 0) { 1692 uvm_pagedequeue(pg); 1693 uvmexp.wired++; 1694 } 1695 pg->wire_count++; 1696 } 1697 1698 /* 1699 * uvm_pageunwire: unwire the page. 1700 * 1701 * => activate if wire count goes to zero. 1702 * => caller must lock page queues 1703 */ 1704 1705 void 1706 uvm_pageunwire(struct vm_page *pg) 1707 { 1708 UVM_LOCK_ASSERT_PAGEQ(); 1709 pg->wire_count--; 1710 if (pg->wire_count == 0) { 1711 uvm_pageactivate(pg); 1712 uvmexp.wired--; 1713 } 1714 } 1715 1716 /* 1717 * uvm_pagedeactivate: deactivate page 1718 * 1719 * => caller must lock page queues 1720 * => caller must check to make sure page is not wired 1721 * => object that page belongs to must be locked (so we can adjust pg->flags) 1722 * => caller must clear the reference on the page before calling 1723 */ 1724 1725 void 1726 uvm_pagedeactivate(struct vm_page *pg) 1727 { 1728 1729 UVM_LOCK_ASSERT_PAGEQ(); 1730 KASSERT(pg->wire_count != 0 || uvmpdpol_pageisqueued_p(pg)); 1731 uvmpdpol_pagedeactivate(pg); 1732 } 1733 1734 /* 1735 * uvm_pageactivate: activate page 1736 * 1737 * => caller must lock page queues 1738 */ 1739 1740 void 1741 uvm_pageactivate(struct vm_page *pg) 1742 { 1743 1744 UVM_LOCK_ASSERT_PAGEQ(); 1745 #if defined(READAHEAD_STATS) 1746 if ((pg->pqflags & PQ_READAHEAD) != 0) { 1747 uvm_ra_hit.ev_count++; 1748 pg->pqflags &= ~PQ_READAHEAD; 1749 } 1750 #endif /* defined(READAHEAD_STATS) */ 1751 if (pg->wire_count != 0) { 1752 return; 1753 } 1754 uvmpdpol_pageactivate(pg); 1755 } 1756 1757 /* 1758 * uvm_pagedequeue: remove a page from any paging queue 1759 */ 1760 1761 void 1762 uvm_pagedequeue(struct vm_page *pg) 1763 { 1764 1765 if (uvmpdpol_pageisqueued_p(pg)) { 1766 UVM_LOCK_ASSERT_PAGEQ(); 1767 } 1768 1769 uvmpdpol_pagedequeue(pg); 1770 } 1771 1772 /* 1773 * uvm_pageenqueue: add a page to a paging queue without activating. 1774 * used where a page is not really demanded (yet). eg. read-ahead 1775 */ 1776 1777 void 1778 uvm_pageenqueue(struct vm_page *pg) 1779 { 1780 1781 UVM_LOCK_ASSERT_PAGEQ(); 1782 if (pg->wire_count != 0) { 1783 return; 1784 } 1785 uvmpdpol_pageenqueue(pg); 1786 } 1787 1788 /* 1789 * uvm_pagezero: zero fill a page 1790 * 1791 * => if page is part of an object then the object should be locked 1792 * to protect pg->flags. 1793 */ 1794 1795 void 1796 uvm_pagezero(struct vm_page *pg) 1797 { 1798 pg->flags &= ~PG_CLEAN; 1799 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1800 } 1801 1802 /* 1803 * uvm_pagecopy: copy a page 1804 * 1805 * => if page is part of an object then the object should be locked 1806 * to protect pg->flags. 1807 */ 1808 1809 void 1810 uvm_pagecopy(struct vm_page *src, struct vm_page *dst) 1811 { 1812 1813 dst->flags &= ~PG_CLEAN; 1814 pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst)); 1815 } 1816 1817 /* 1818 * uvm_page_lookup_freelist: look up the free list for the specified page 1819 */ 1820 1821 int 1822 uvm_page_lookup_freelist(struct vm_page *pg) 1823 { 1824 int lcv; 1825 1826 lcv = vm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL); 1827 KASSERT(lcv != -1); 1828 return (vm_physmem[lcv].free_list); 1829 } 1830