1 /* $NetBSD: vm.c,v 1.196 2023/04/22 13:53:53 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 2007-2011 Antti Kantee. All Rights Reserved. 5 * 6 * Development of this software was supported by 7 * The Finnish Cultural Foundation and the Research Foundation of 8 * The Helsinki University of Technology. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 20 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 22 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Virtual memory emulation routines. 34 */ 35 36 /* 37 * XXX: we abuse pg->uanon for the virtual address of the storage 38 * for each page. phys_addr would fit the job description better, 39 * except that it will create unnecessary lossage on some platforms 40 * due to not being a pointer type. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.196 2023/04/22 13:53:53 riastradh Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/atomic.h> 48 #include <sys/buf.h> 49 #include <sys/kernel.h> 50 #include <sys/kmem.h> 51 #include <sys/vmem.h> 52 #include <sys/mman.h> 53 #include <sys/null.h> 54 #include <sys/vnode.h> 55 #include <sys/radixtree.h> 56 #include <sys/module.h> 57 58 #include <machine/pmap.h> 59 60 #if defined(__i386__) || defined(__x86_64__) 61 /* 62 * This file abuses the pmap abstraction to create its own statically 63 * allocated struct pmap object, even though it can't do anything 64 * useful with such a thing from userland. On x86 the struct pmap 65 * definition is private, so we have to go to extra effort to abuse it 66 * there. This should be fixed -- all of the struct pmap definitions 67 * should be private, and then rump can furnish its own fake struct 68 * pmap without clashing with anything. 69 */ 70 #include <machine/pmap_private.h> 71 #endif 72 73 #include <uvm/uvm.h> 74 #include <uvm/uvm_ddb.h> 75 #include <uvm/uvm_pdpolicy.h> 76 #include <uvm/uvm_prot.h> 77 #include <uvm/uvm_readahead.h> 78 #include <uvm/uvm_device.h> 79 80 #include <rump-sys/kern.h> 81 #include <rump-sys/vfs.h> 82 83 #include <rump/rumpuser.h> 84 85 kmutex_t vmpage_lruqueue_lock; /* non-free page lock */ 86 kmutex_t uvm_swap_data_lock; 87 88 struct uvmexp uvmexp; 89 struct uvm uvm; 90 91 #ifdef __uvmexp_pagesize 92 const int * const uvmexp_pagesize = &uvmexp.pagesize; 93 const int * const uvmexp_pagemask = &uvmexp.pagemask; 94 const int * const uvmexp_pageshift = &uvmexp.pageshift; 95 #endif 96 97 static struct vm_map kernel_map_store; 98 struct vm_map *kernel_map = &kernel_map_store; 99 100 static struct vm_map module_map_store; 101 102 static struct pmap pmap_kernel; 103 struct pmap rump_pmap_local; 104 struct pmap *const kernel_pmap_ptr = &pmap_kernel; 105 106 vmem_t *kmem_arena; 107 vmem_t *kmem_va_arena; 108 109 static unsigned int pdaemon_waiters; 110 static kmutex_t pdaemonmtx; 111 static kcondvar_t pdaemoncv, oomwait; 112 113 /* all local non-proc0 processes share this vmspace */ 114 struct vmspace *rump_vmspace_local; 115 116 unsigned long rump_physmemlimit = RUMPMEM_UNLIMITED; 117 static unsigned long pdlimit = RUMPMEM_UNLIMITED; /* page daemon memlimit */ 118 static unsigned long curphysmem; 119 static unsigned long dddlim; /* 90% of memory limit used */ 120 #define NEED_PAGEDAEMON() \ 121 (rump_physmemlimit != RUMPMEM_UNLIMITED && curphysmem > dddlim) 122 #define PDRESERVE (2*MAXPHYS) 123 124 /* 125 * Try to free two pages worth of pages from objects. 126 * If this successfully frees a full page cache page, we'll 127 * free the released page plus PAGE_SIZE/sizeof(vm_page). 128 */ 129 #define PAGEDAEMON_OBJCHUNK (2*PAGE_SIZE / sizeof(struct vm_page)) 130 131 /* 132 * Keep a list of least recently used pages. Since the only way a 133 * rump kernel can "access" a page is via lookup, we put the page 134 * at the back of queue every time a lookup for it is done. If the 135 * page is in front of this global queue and we're short of memory, 136 * it's a candidate for pageout. 137 */ 138 static struct pglist vmpage_lruqueue; 139 static unsigned vmpage_onqueue; 140 141 /* 142 * vm pages 143 */ 144 145 static int 146 pgctor(void *arg, void *obj, int flags) 147 { 148 struct vm_page *pg = obj; 149 150 memset(pg, 0, sizeof(*pg)); 151 pg->uanon = rump_hypermalloc(PAGE_SIZE, PAGE_SIZE, 152 (flags & PR_WAITOK) == PR_WAITOK, "pgalloc"); 153 return pg->uanon == NULL; 154 } 155 156 static void 157 pgdtor(void *arg, void *obj) 158 { 159 struct vm_page *pg = obj; 160 161 rump_hyperfree(pg->uanon, PAGE_SIZE); 162 } 163 164 static struct pool_cache pagecache; 165 166 /* stub for UVM_OBJ_IS_VNODE */ 167 struct uvm_pagerops rump_uvm_vnodeops; 168 __weak_alias(uvm_vnodeops,rump_uvm_vnodeops); 169 170 /* 171 * Called with the object locked. We don't support anons. 172 */ 173 struct vm_page * 174 uvm_pagealloc_strat(struct uvm_object *uobj, voff_t off, struct vm_anon *anon, 175 int flags, int strat, int free_list) 176 { 177 struct vm_page *pg; 178 179 KASSERT(uobj && rw_write_held(uobj->vmobjlock)); 180 KASSERT(anon == NULL); 181 182 pg = pool_cache_get(&pagecache, PR_NOWAIT); 183 if (__predict_false(pg == NULL)) { 184 return NULL; 185 } 186 mutex_init(&pg->interlock, MUTEX_DEFAULT, IPL_NONE); 187 188 pg->offset = off; 189 pg->uobject = uobj; 190 191 if (radix_tree_insert_node(&uobj->uo_pages, off >> PAGE_SHIFT, 192 pg) != 0) { 193 pool_cache_put(&pagecache, pg); 194 return NULL; 195 } 196 197 if (UVM_OBJ_IS_VNODE(uobj)) { 198 if (uobj->uo_npages == 0) { 199 struct vnode *vp = (struct vnode *)uobj; 200 mutex_enter(vp->v_interlock); 201 vp->v_iflag |= VI_PAGES; 202 mutex_exit(vp->v_interlock); 203 } 204 pg->flags |= PG_FILE; 205 } 206 uobj->uo_npages++; 207 208 pg->flags = PG_CLEAN|PG_BUSY|PG_FAKE; 209 if (flags & UVM_PGA_ZERO) { 210 uvm_pagezero(pg); 211 } 212 213 /* 214 * Don't put anons on the LRU page queue. We can't flush them 215 * (there's no concept of swap in a rump kernel), so no reason 216 * to bother with them. 217 */ 218 if (!UVM_OBJ_IS_AOBJ(uobj)) { 219 atomic_inc_uint(&vmpage_onqueue); 220 mutex_enter(&vmpage_lruqueue_lock); 221 TAILQ_INSERT_TAIL(&vmpage_lruqueue, pg, pageq.queue); 222 mutex_exit(&vmpage_lruqueue_lock); 223 } else { 224 pg->flags |= PG_AOBJ; 225 } 226 227 return pg; 228 } 229 230 /* 231 * Release a page. 232 * 233 * Called with the vm object locked. 234 */ 235 void 236 uvm_pagefree(struct vm_page *pg) 237 { 238 struct uvm_object *uobj = pg->uobject; 239 struct vm_page *pg2 __unused; 240 241 KASSERT(rw_write_held(uobj->vmobjlock)); 242 243 mutex_enter(&pg->interlock); 244 uvm_pagewakeup(pg); 245 mutex_exit(&pg->interlock); 246 247 uobj->uo_npages--; 248 pg2 = radix_tree_remove_node(&uobj->uo_pages, pg->offset >> PAGE_SHIFT); 249 KASSERT(pg == pg2); 250 251 if (!UVM_OBJ_IS_AOBJ(uobj)) { 252 mutex_enter(&vmpage_lruqueue_lock); 253 TAILQ_REMOVE(&vmpage_lruqueue, pg, pageq.queue); 254 mutex_exit(&vmpage_lruqueue_lock); 255 atomic_dec_uint(&vmpage_onqueue); 256 } 257 258 if (UVM_OBJ_IS_VNODE(uobj) && uobj->uo_npages == 0) { 259 struct vnode *vp = (struct vnode *)uobj; 260 mutex_enter(vp->v_interlock); 261 vp->v_iflag &= ~VI_PAGES; 262 mutex_exit(vp->v_interlock); 263 } 264 265 mutex_destroy(&pg->interlock); 266 pool_cache_put(&pagecache, pg); 267 } 268 269 void 270 uvm_pagezero(struct vm_page *pg) 271 { 272 273 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 274 memset((void *)pg->uanon, 0, PAGE_SIZE); 275 } 276 277 /* 278 * uvm_page_owner_locked_p: return true if object associated with page is 279 * locked. this is a weak check for runtime assertions only. 280 */ 281 282 bool 283 uvm_page_owner_locked_p(struct vm_page *pg, bool exclusive) 284 { 285 286 if (exclusive) 287 return rw_write_held(pg->uobject->vmobjlock); 288 else 289 return rw_lock_held(pg->uobject->vmobjlock); 290 } 291 292 /* 293 * Misc routines 294 */ 295 296 static kmutex_t pagermtx; 297 298 void 299 uvm_init(void) 300 { 301 char buf[64]; 302 303 if (rumpuser_getparam("RUMP_MEMLIMIT", buf, sizeof(buf)) == 0) { 304 unsigned long tmp; 305 char *ep; 306 int mult; 307 308 tmp = strtoul(buf, &ep, 10); 309 if (strlen(ep) > 1) 310 panic("uvm_init: invalid RUMP_MEMLIMIT: %s", buf); 311 312 /* mini-dehumanize-number */ 313 mult = 1; 314 switch (*ep) { 315 case 'k': 316 mult = 1024; 317 break; 318 case 'm': 319 mult = 1024*1024; 320 break; 321 case 'g': 322 mult = 1024*1024*1024; 323 break; 324 case 0: 325 break; 326 default: 327 panic("uvm_init: invalid RUMP_MEMLIMIT: %s", buf); 328 } 329 rump_physmemlimit = tmp * mult; 330 331 if (rump_physmemlimit / mult != tmp) 332 panic("uvm_init: RUMP_MEMLIMIT overflow: %s", buf); 333 334 /* reserve some memory for the pager */ 335 if (rump_physmemlimit <= PDRESERVE) 336 panic("uvm_init: system reserves %d bytes of mem, " 337 "only %lu bytes given", 338 PDRESERVE, rump_physmemlimit); 339 pdlimit = rump_physmemlimit; 340 rump_physmemlimit -= PDRESERVE; 341 342 if (pdlimit < 1024*1024) 343 printf("uvm_init: WARNING: <1MB RAM limit, " 344 "hope you know what you're doing\n"); 345 346 #define HUMANIZE_BYTES 9 347 CTASSERT(sizeof(buf) >= HUMANIZE_BYTES); 348 format_bytes(buf, HUMANIZE_BYTES, rump_physmemlimit); 349 #undef HUMANIZE_BYTES 350 dddlim = 9 * (rump_physmemlimit / 10); 351 } else { 352 strlcpy(buf, "unlimited (host limit)", sizeof(buf)); 353 } 354 aprint_verbose("total memory = %s\n", buf); 355 356 TAILQ_INIT(&vmpage_lruqueue); 357 358 if (rump_physmemlimit == RUMPMEM_UNLIMITED) { 359 uvmexp.npages = physmem; 360 } else { 361 uvmexp.npages = pdlimit >> PAGE_SHIFT; 362 uvmexp.reserve_pagedaemon = PDRESERVE >> PAGE_SHIFT; 363 uvmexp.freetarg = (rump_physmemlimit-dddlim) >> PAGE_SHIFT; 364 } 365 /* 366 * uvmexp.free is not used internally or updated. The reason is 367 * that the memory hypercall allocator is allowed to allocate 368 * non-page sized chunks. We use a byte count in curphysmem 369 * instead. 370 */ 371 uvmexp.free = uvmexp.npages; 372 373 #ifndef __uvmexp_pagesize 374 uvmexp.pagesize = PAGE_SIZE; 375 uvmexp.pagemask = PAGE_MASK; 376 uvmexp.pageshift = PAGE_SHIFT; 377 #else 378 #define FAKE_PAGE_SHIFT 12 379 uvmexp.pageshift = FAKE_PAGE_SHIFT; 380 uvmexp.pagesize = 1<<FAKE_PAGE_SHIFT; 381 uvmexp.pagemask = (1<<FAKE_PAGE_SHIFT)-1; 382 #undef FAKE_PAGE_SHIFT 383 #endif 384 385 mutex_init(&pagermtx, MUTEX_DEFAULT, IPL_NONE); 386 mutex_init(&vmpage_lruqueue_lock, MUTEX_DEFAULT, IPL_NONE); 387 mutex_init(&uvm_swap_data_lock, MUTEX_DEFAULT, IPL_NONE); 388 mutex_init(&pdaemonmtx, MUTEX_DEFAULT, IPL_NONE); 389 390 cv_init(&pdaemoncv, "pdaemon"); 391 cv_init(&oomwait, "oomwait"); 392 393 module_map = &module_map_store; 394 395 kernel_map->pmap = pmap_kernel(); 396 397 pool_subsystem_init(); 398 399 kmem_arena = vmem_create("kmem", 0, 1024*1024, PAGE_SIZE, 400 NULL, NULL, NULL, 401 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 402 403 vmem_subsystem_init(kmem_arena); 404 405 kmem_va_arena = vmem_create("kva", 0, 0, PAGE_SIZE, 406 vmem_alloc, vmem_free, kmem_arena, 407 8 * PAGE_SIZE, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 408 409 pool_cache_bootstrap(&pagecache, sizeof(struct vm_page), 0, 0, 0, 410 "page$", NULL, IPL_NONE, pgctor, pgdtor, NULL); 411 412 radix_tree_init(); 413 414 /* create vmspace used by local clients */ 415 rump_vmspace_local = kmem_zalloc(sizeof(*rump_vmspace_local), KM_SLEEP); 416 uvmspace_init(rump_vmspace_local, &rump_pmap_local, 0, 0, false); 417 } 418 419 void 420 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax, 421 bool topdown) 422 { 423 424 vm->vm_map.pmap = pmap; 425 vm->vm_refcnt = 1; 426 } 427 428 int 429 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 430 bool new_pageable, int lockflags) 431 { 432 return 0; 433 } 434 435 void 436 uvm_pagewire(struct vm_page *pg) 437 { 438 439 /* nada */ 440 } 441 442 void 443 uvm_pageunwire(struct vm_page *pg) 444 { 445 446 /* nada */ 447 } 448 449 int 450 uvm_availmem(bool cached) 451 { 452 453 return uvmexp.free; 454 } 455 456 void 457 uvm_pagelock(struct vm_page *pg) 458 { 459 460 mutex_enter(&pg->interlock); 461 } 462 463 void 464 uvm_pagelock2(struct vm_page *pg1, struct vm_page *pg2) 465 { 466 467 if (pg1 < pg2) { 468 mutex_enter(&pg1->interlock); 469 mutex_enter(&pg2->interlock); 470 } else { 471 mutex_enter(&pg2->interlock); 472 mutex_enter(&pg1->interlock); 473 } 474 } 475 476 void 477 uvm_pageunlock(struct vm_page *pg) 478 { 479 480 mutex_exit(&pg->interlock); 481 } 482 483 void 484 uvm_pageunlock2(struct vm_page *pg1, struct vm_page *pg2) 485 { 486 487 mutex_exit(&pg1->interlock); 488 mutex_exit(&pg2->interlock); 489 } 490 491 /* where's your schmonz now? */ 492 #define PUNLIMIT(a) \ 493 p->p_rlimit[a].rlim_cur = p->p_rlimit[a].rlim_max = RLIM_INFINITY; 494 void 495 uvm_init_limits(struct proc *p) 496 { 497 498 #ifndef DFLSSIZ 499 #define DFLSSIZ (16*1024*1024) 500 #endif 501 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 502 p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; 503 PUNLIMIT(RLIMIT_DATA); 504 PUNLIMIT(RLIMIT_RSS); 505 PUNLIMIT(RLIMIT_AS); 506 /* nice, cascade */ 507 } 508 #undef PUNLIMIT 509 510 /* 511 * This satisfies the "disgusting mmap hack" used by proplib. 512 */ 513 int 514 uvm_mmap_anon(struct proc *p, void **addrp, size_t size) 515 { 516 int error; 517 518 /* no reason in particular, but cf. uvm_default_mapaddr() */ 519 if (*addrp != NULL) 520 panic("uvm_mmap() variant unsupported"); 521 522 if (RUMP_LOCALPROC_P(curproc)) { 523 error = rumpuser_anonmmap(NULL, size, 0, 0, addrp); 524 } else { 525 error = rump_sysproxy_anonmmap(RUMP_SPVM2CTL(p->p_vmspace), 526 size, addrp); 527 } 528 return error; 529 } 530 531 /* 532 * Stubs for things referenced from vfs_vnode.c but not used. 533 */ 534 const dev_t zerodev; 535 536 struct uvm_object * 537 udv_attach(dev_t device, vm_prot_t accessprot, voff_t off, vsize_t size) 538 { 539 return NULL; 540 } 541 542 struct pagerinfo { 543 vaddr_t pgr_kva; 544 int pgr_npages; 545 struct vm_page **pgr_pgs; 546 bool pgr_read; 547 548 LIST_ENTRY(pagerinfo) pgr_entries; 549 }; 550 static LIST_HEAD(, pagerinfo) pagerlist = LIST_HEAD_INITIALIZER(pagerlist); 551 552 /* 553 * Pager "map" in routine. Instead of mapping, we allocate memory 554 * and copy page contents there. The reason for copying instead of 555 * mapping is simple: we do not assume we are running on virtual 556 * memory. Even if we could emulate virtual memory in some envs 557 * such as userspace, copying is much faster than trying to awkardly 558 * cope with remapping (see "Design and Implementation" pp.95-98). 559 * The downside of the approach is that the pager requires MAXPHYS 560 * free memory to perform paging, but short of virtual memory or 561 * making the pager do I/O in page-sized chunks we cannot do much 562 * about that. 563 */ 564 vaddr_t 565 uvm_pagermapin(struct vm_page **pgs, int npages, int flags) 566 { 567 struct pagerinfo *pgri; 568 vaddr_t curkva; 569 int i; 570 571 /* allocate structures */ 572 pgri = kmem_alloc(sizeof(*pgri), KM_SLEEP); 573 pgri->pgr_kva = (vaddr_t)kmem_alloc(npages * PAGE_SIZE, KM_SLEEP); 574 pgri->pgr_npages = npages; 575 pgri->pgr_pgs = kmem_alloc(sizeof(struct vm_page *) * npages, KM_SLEEP); 576 pgri->pgr_read = (flags & UVMPAGER_MAPIN_READ) != 0; 577 578 /* copy contents to "mapped" memory */ 579 for (i = 0, curkva = pgri->pgr_kva; 580 i < npages; 581 i++, curkva += PAGE_SIZE) { 582 /* 583 * We need to copy the previous contents of the pages to 584 * the window even if we are reading from the 585 * device, since the device might not fill the contents of 586 * the full mapped range and we will end up corrupting 587 * data when we unmap the window. 588 */ 589 memcpy((void*)curkva, pgs[i]->uanon, PAGE_SIZE); 590 pgri->pgr_pgs[i] = pgs[i]; 591 } 592 593 mutex_enter(&pagermtx); 594 LIST_INSERT_HEAD(&pagerlist, pgri, pgr_entries); 595 mutex_exit(&pagermtx); 596 597 return pgri->pgr_kva; 598 } 599 600 /* 601 * map out the pager window. return contents from VA to page storage 602 * and free structures. 603 * 604 * Note: does not currently support partial frees 605 */ 606 void 607 uvm_pagermapout(vaddr_t kva, int npages) 608 { 609 struct pagerinfo *pgri; 610 vaddr_t curkva; 611 int i; 612 613 mutex_enter(&pagermtx); 614 LIST_FOREACH(pgri, &pagerlist, pgr_entries) { 615 if (pgri->pgr_kva == kva) 616 break; 617 } 618 KASSERT(pgri); 619 if (pgri->pgr_npages != npages) 620 panic("uvm_pagermapout: partial unmapping not supported"); 621 LIST_REMOVE(pgri, pgr_entries); 622 mutex_exit(&pagermtx); 623 624 if (pgri->pgr_read) { 625 for (i = 0, curkva = pgri->pgr_kva; 626 i < pgri->pgr_npages; 627 i++, curkva += PAGE_SIZE) { 628 memcpy(pgri->pgr_pgs[i]->uanon,(void*)curkva,PAGE_SIZE); 629 } 630 } 631 632 kmem_free(pgri->pgr_pgs, npages * sizeof(struct vm_page *)); 633 kmem_free((void*)pgri->pgr_kva, npages * PAGE_SIZE); 634 kmem_free(pgri, sizeof(*pgri)); 635 } 636 637 /* 638 * convert va in pager window to page structure. 639 * XXX: how expensive is this (global lock, list traversal)? 640 */ 641 struct vm_page * 642 uvm_pageratop(vaddr_t va) 643 { 644 struct pagerinfo *pgri; 645 struct vm_page *pg = NULL; 646 int i; 647 648 mutex_enter(&pagermtx); 649 LIST_FOREACH(pgri, &pagerlist, pgr_entries) { 650 if (pgri->pgr_kva <= va 651 && va < pgri->pgr_kva + pgri->pgr_npages*PAGE_SIZE) 652 break; 653 } 654 if (pgri) { 655 i = (va - pgri->pgr_kva) >> PAGE_SHIFT; 656 pg = pgri->pgr_pgs[i]; 657 } 658 mutex_exit(&pagermtx); 659 660 return pg; 661 } 662 663 /* 664 * Called with the vm object locked. 665 * 666 * Put vnode object pages at the end of the access queue to indicate 667 * they have been recently accessed and should not be immediate 668 * candidates for pageout. Do not do this for lookups done by 669 * the pagedaemon to mimic pmap_kentered mappings which don't track 670 * access information. 671 */ 672 struct vm_page * 673 uvm_pagelookup(struct uvm_object *uobj, voff_t off) 674 { 675 struct vm_page *pg; 676 bool ispagedaemon = curlwp == uvm.pagedaemon_lwp; 677 678 pg = radix_tree_lookup_node(&uobj->uo_pages, off >> PAGE_SHIFT); 679 if (pg && !UVM_OBJ_IS_AOBJ(pg->uobject) && !ispagedaemon) { 680 mutex_enter(&vmpage_lruqueue_lock); 681 TAILQ_REMOVE(&vmpage_lruqueue, pg, pageq.queue); 682 TAILQ_INSERT_TAIL(&vmpage_lruqueue, pg, pageq.queue); 683 mutex_exit(&vmpage_lruqueue_lock); 684 } 685 686 return pg; 687 } 688 689 void 690 uvm_page_unbusy(struct vm_page **pgs, int npgs) 691 { 692 struct vm_page *pg; 693 int i, pageout_done; 694 695 KASSERT(npgs > 0); 696 697 pageout_done = 0; 698 for (i = 0; i < npgs; i++) { 699 pg = pgs[i]; 700 if (pg == NULL || pg == PGO_DONTCARE) { 701 continue; 702 } 703 704 #if 0 705 KASSERT(uvm_page_owner_locked_p(pg, true)); 706 #else 707 /* 708 * uvm_page_owner_locked_p() is not available in rump, 709 * and rump doesn't support amaps anyway. 710 */ 711 KASSERT(rw_write_held(pg->uobject->vmobjlock)); 712 #endif 713 KASSERT(pg->flags & PG_BUSY); 714 715 if (pg->flags & PG_PAGEOUT) { 716 pg->flags &= ~PG_PAGEOUT; 717 pg->flags |= PG_RELEASED; 718 pageout_done++; 719 atomic_inc_uint(&uvmexp.pdfreed); 720 } 721 if (pg->flags & PG_RELEASED) { 722 KASSERT(pg->uobject != NULL || 723 (pg->uanon != NULL && pg->uanon->an_ref > 0)); 724 pg->flags &= ~PG_RELEASED; 725 uvm_pagefree(pg); 726 } else { 727 KASSERT((pg->flags & PG_FAKE) == 0); 728 pg->flags &= ~PG_BUSY; 729 uvm_pagelock(pg); 730 uvm_pagewakeup(pg); 731 uvm_pageunlock(pg); 732 UVM_PAGE_OWN(pg, NULL); 733 } 734 } 735 if (pageout_done != 0) { 736 uvm_pageout_done(pageout_done); 737 } 738 } 739 740 void 741 uvm_pagewait(struct vm_page *pg, krwlock_t *lock, const char *wmesg) 742 { 743 744 KASSERT(rw_lock_held(lock)); 745 KASSERT((pg->flags & PG_BUSY) != 0); 746 747 mutex_enter(&pg->interlock); 748 pg->pqflags |= PQ_WANTED; 749 rw_exit(lock); 750 UVM_UNLOCK_AND_WAIT(pg, &pg->interlock, false, wmesg, 0); 751 } 752 753 void 754 uvm_pagewakeup(struct vm_page *pg) 755 { 756 757 KASSERT(mutex_owned(&pg->interlock)); 758 759 if ((pg->pqflags & PQ_WANTED) != 0) { 760 pg->pqflags &= ~PQ_WANTED; 761 wakeup(pg); 762 } 763 } 764 765 void 766 uvm_estimatepageable(int *active, int *inactive) 767 { 768 769 /* XXX: guessing game */ 770 *active = 1024; 771 *inactive = 1024; 772 } 773 774 int 775 uvm_loan(struct vm_map *map, vaddr_t start, vsize_t len, void *v, int flags) 776 { 777 778 panic("%s: unimplemented", __func__); 779 } 780 781 void 782 uvm_unloan(void *v, int npages, int flags) 783 { 784 785 panic("%s: unimplemented", __func__); 786 } 787 788 int 789 uvm_loanuobjpages(struct uvm_object *uobj, voff_t pgoff, int orignpages, 790 struct vm_page **opp) 791 { 792 793 return EBUSY; 794 } 795 796 struct vm_page * 797 uvm_loanbreak(struct vm_page *pg) 798 { 799 800 panic("%s: unimplemented", __func__); 801 } 802 803 void 804 ubc_purge(struct uvm_object *uobj) 805 { 806 807 } 808 809 vaddr_t 810 uvm_default_mapaddr(struct proc *p, vaddr_t base, vsize_t sz, int topdown) 811 { 812 813 return 0; 814 } 815 816 int 817 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 818 vm_prot_t prot, bool set_max) 819 { 820 821 return EOPNOTSUPP; 822 } 823 824 int 825 uvm_map(struct vm_map *map, vaddr_t *startp, vsize_t size, 826 struct uvm_object *uobj, voff_t uoffset, vsize_t align, 827 uvm_flag_t flags) 828 { 829 830 *startp = (vaddr_t)rump_hypermalloc(size, align, true, "uvm_map"); 831 return *startp != 0 ? 0 : ENOMEM; 832 } 833 834 void 835 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 836 { 837 838 rump_hyperfree((void*)start, end-start); 839 } 840 841 842 /* 843 * UVM km 844 */ 845 846 vaddr_t 847 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 848 { 849 void *rv, *desired = NULL; 850 int alignbit, error; 851 852 #ifdef __x86_64__ 853 /* 854 * On amd64, allocate all module memory from the lowest 2GB. 855 * This is because NetBSD kernel modules are compiled 856 * with -mcmodel=kernel and reserve only 4 bytes for 857 * offsets. If we load code compiled with -mcmodel=kernel 858 * anywhere except the lowest or highest 2GB, it will not 859 * work. Since userspace does not have access to the highest 860 * 2GB, use the lowest 2GB. 861 * 862 * Note: this assumes the rump kernel resides in 863 * the lowest 2GB as well. 864 * 865 * Note2: yes, it's a quick hack, but since this the only 866 * place where we care about the map we're allocating from, 867 * just use a simple "if" instead of coming up with a fancy 868 * generic solution. 869 */ 870 if (map == module_map) { 871 desired = (void *)(0x80000000 - size); 872 } 873 #endif 874 875 if (__predict_false(map == module_map)) { 876 alignbit = 0; 877 if (align) { 878 alignbit = ffs(align)-1; 879 } 880 error = rumpuser_anonmmap(desired, size, alignbit, 881 flags & UVM_KMF_EXEC, &rv); 882 } else { 883 error = rumpuser_malloc(size, align, &rv); 884 } 885 886 if (error) { 887 if (flags & (UVM_KMF_CANFAIL | UVM_KMF_NOWAIT)) 888 return 0; 889 else 890 panic("uvm_km_alloc failed"); 891 } 892 893 if (flags & UVM_KMF_ZERO) 894 memset(rv, 0, size); 895 896 return (vaddr_t)rv; 897 } 898 899 void 900 uvm_km_free(struct vm_map *map, vaddr_t vaddr, vsize_t size, uvm_flag_t flags) 901 { 902 903 if (__predict_false(map == module_map)) 904 rumpuser_unmap((void *)vaddr, size); 905 else 906 rumpuser_free((void *)vaddr, size); 907 } 908 909 int 910 uvm_km_protect(struct vm_map *map, vaddr_t vaddr, vsize_t size, vm_prot_t prot) 911 { 912 return 0; 913 } 914 915 struct vm_map * 916 uvm_km_suballoc(struct vm_map *map, vaddr_t *minaddr, vaddr_t *maxaddr, 917 vsize_t size, int pageable, bool fixed, struct vm_map *submap) 918 { 919 920 return (struct vm_map *)417416; 921 } 922 923 int 924 uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 925 vmem_addr_t *addr) 926 { 927 vaddr_t va; 928 va = (vaddr_t)rump_hypermalloc(size, PAGE_SIZE, 929 (flags & VM_SLEEP), "kmalloc"); 930 931 if (va) { 932 *addr = va; 933 return 0; 934 } else { 935 return ENOMEM; 936 } 937 } 938 939 void 940 uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 941 { 942 943 rump_hyperfree((void *)addr, size); 944 } 945 946 /* 947 * VM space locking routines. We don't really have to do anything, 948 * since the pages are always "wired" (both local and remote processes). 949 */ 950 int 951 uvm_vslock(struct vmspace *vs, void *addr, size_t len, vm_prot_t access) 952 { 953 954 return 0; 955 } 956 957 void 958 uvm_vsunlock(struct vmspace *vs, void *addr, size_t len) 959 { 960 961 } 962 963 /* 964 * For the local case the buffer mappers don't need to do anything. 965 * For the remote case we need to reserve space and copy data in or 966 * out, depending on B_READ/B_WRITE. 967 */ 968 int 969 vmapbuf(struct buf *bp, vsize_t len) 970 { 971 int error = 0; 972 973 bp->b_saveaddr = bp->b_data; 974 975 /* remote case */ 976 if (!RUMP_LOCALPROC_P(curproc)) { 977 bp->b_data = rump_hypermalloc(len, 0, true, "vmapbuf"); 978 if (BUF_ISWRITE(bp)) { 979 error = copyin(bp->b_saveaddr, bp->b_data, len); 980 if (error) { 981 rump_hyperfree(bp->b_data, len); 982 bp->b_data = bp->b_saveaddr; 983 bp->b_saveaddr = 0; 984 } 985 } 986 } 987 988 return error; 989 } 990 991 void 992 vunmapbuf(struct buf *bp, vsize_t len) 993 { 994 995 /* remote case */ 996 if (!RUMP_LOCALPROC_P(bp->b_proc)) { 997 if (BUF_ISREAD(bp)) { 998 bp->b_error = copyout_proc(bp->b_proc, 999 bp->b_data, bp->b_saveaddr, len); 1000 } 1001 rump_hyperfree(bp->b_data, len); 1002 } 1003 1004 bp->b_data = bp->b_saveaddr; 1005 bp->b_saveaddr = 0; 1006 } 1007 1008 void 1009 uvmspace_addref(struct vmspace *vm) 1010 { 1011 1012 /* 1013 * No dynamically allocated vmspaces exist. 1014 */ 1015 } 1016 1017 void 1018 uvmspace_free(struct vmspace *vm) 1019 { 1020 1021 /* nothing for now */ 1022 } 1023 1024 /* 1025 * page life cycle stuff. it really doesn't exist, so just stubs. 1026 */ 1027 1028 void 1029 uvm_pageactivate(struct vm_page *pg) 1030 { 1031 1032 /* nada */ 1033 } 1034 1035 void 1036 uvm_pagedeactivate(struct vm_page *pg) 1037 { 1038 1039 /* nada */ 1040 } 1041 1042 void 1043 uvm_pagedequeue(struct vm_page *pg) 1044 { 1045 1046 /* nada*/ 1047 } 1048 1049 void 1050 uvm_pageenqueue(struct vm_page *pg) 1051 { 1052 1053 /* nada */ 1054 } 1055 1056 void 1057 uvmpdpol_anfree(struct vm_anon *an) 1058 { 1059 1060 /* nada */ 1061 } 1062 1063 /* 1064 * Physical address accessors. 1065 */ 1066 1067 struct vm_page * 1068 uvm_phys_to_vm_page(paddr_t pa) 1069 { 1070 1071 return NULL; 1072 } 1073 1074 paddr_t 1075 uvm_vm_page_to_phys(const struct vm_page *pg) 1076 { 1077 1078 return 0; 1079 } 1080 1081 vaddr_t 1082 uvm_uarea_alloc(void) 1083 { 1084 1085 /* non-zero */ 1086 return (vaddr_t)11; 1087 } 1088 1089 void 1090 uvm_uarea_free(vaddr_t uarea) 1091 { 1092 1093 /* nata, so creamy */ 1094 } 1095 1096 /* 1097 * Routines related to the Page Baroness. 1098 */ 1099 1100 void 1101 uvm_wait(const char *msg) 1102 { 1103 1104 if (__predict_false(rump_threads == 0)) 1105 panic("pagedaemon missing (RUMP_THREADS = 0)"); 1106 1107 if (curlwp == uvm.pagedaemon_lwp) { 1108 /* is it possible for us to later get memory? */ 1109 if (!uvmexp.paging) 1110 panic("pagedaemon out of memory"); 1111 } 1112 1113 mutex_enter(&pdaemonmtx); 1114 pdaemon_waiters++; 1115 cv_signal(&pdaemoncv); 1116 cv_wait(&oomwait, &pdaemonmtx); 1117 mutex_exit(&pdaemonmtx); 1118 } 1119 1120 void 1121 uvm_pageout_start(int npages) 1122 { 1123 1124 mutex_enter(&pdaemonmtx); 1125 uvmexp.paging += npages; 1126 mutex_exit(&pdaemonmtx); 1127 } 1128 1129 void 1130 uvm_pageout_done(int npages) 1131 { 1132 1133 if (!npages) 1134 return; 1135 1136 mutex_enter(&pdaemonmtx); 1137 KASSERT(uvmexp.paging >= npages); 1138 uvmexp.paging -= npages; 1139 1140 if (pdaemon_waiters) { 1141 pdaemon_waiters = 0; 1142 cv_broadcast(&oomwait); 1143 } 1144 mutex_exit(&pdaemonmtx); 1145 } 1146 1147 static bool 1148 processpage(struct vm_page *pg) 1149 { 1150 struct uvm_object *uobj; 1151 1152 uobj = pg->uobject; 1153 if (rw_tryenter(uobj->vmobjlock, RW_WRITER)) { 1154 if ((pg->flags & PG_BUSY) == 0) { 1155 mutex_exit(&vmpage_lruqueue_lock); 1156 uobj->pgops->pgo_put(uobj, pg->offset, 1157 pg->offset + PAGE_SIZE, 1158 PGO_CLEANIT|PGO_FREE); 1159 KASSERT(!rw_write_held(uobj->vmobjlock)); 1160 return true; 1161 } else { 1162 rw_exit(uobj->vmobjlock); 1163 } 1164 } 1165 1166 return false; 1167 } 1168 1169 /* 1170 * The Diabolical pageDaemon Director (DDD). 1171 * 1172 * This routine can always use better heuristics. 1173 */ 1174 void 1175 uvm_pageout(void *arg) 1176 { 1177 struct vm_page *pg; 1178 struct pool *pp, *pp_first; 1179 int cleaned, skip, skipped; 1180 bool succ; 1181 1182 mutex_enter(&pdaemonmtx); 1183 for (;;) { 1184 if (pdaemon_waiters) { 1185 pdaemon_waiters = 0; 1186 cv_broadcast(&oomwait); 1187 } 1188 if (!NEED_PAGEDAEMON()) { 1189 kernel_map->flags &= ~VM_MAP_WANTVA; 1190 cv_wait(&pdaemoncv, &pdaemonmtx); 1191 } 1192 uvmexp.pdwoke++; 1193 1194 /* tell the world that we are hungry */ 1195 kernel_map->flags |= VM_MAP_WANTVA; 1196 mutex_exit(&pdaemonmtx); 1197 1198 /* 1199 * step one: reclaim the page cache. this should give 1200 * us the biggest earnings since whole pages are released 1201 * into backing memory. 1202 */ 1203 pool_cache_reclaim(&pagecache); 1204 if (!NEED_PAGEDAEMON()) { 1205 mutex_enter(&pdaemonmtx); 1206 continue; 1207 } 1208 1209 /* 1210 * Ok, so that didn't help. Next, try to hunt memory 1211 * by pushing out vnode pages. The pages might contain 1212 * useful cached data, but we need the memory. 1213 */ 1214 cleaned = 0; 1215 skip = 0; 1216 again: 1217 mutex_enter(&vmpage_lruqueue_lock); 1218 while (cleaned < PAGEDAEMON_OBJCHUNK) { 1219 skipped = 0; 1220 TAILQ_FOREACH(pg, &vmpage_lruqueue, pageq.queue) { 1221 1222 /* 1223 * skip over pages we _might_ have tried 1224 * to handle earlier. they might not be 1225 * exactly the same ones, but I'm not too 1226 * concerned. 1227 */ 1228 while (skipped++ < skip) 1229 continue; 1230 1231 if (processpage(pg)) { 1232 cleaned++; 1233 goto again; 1234 } 1235 1236 skip++; 1237 } 1238 break; 1239 } 1240 mutex_exit(&vmpage_lruqueue_lock); 1241 1242 /* 1243 * And of course we need to reclaim the page cache 1244 * again to actually release memory. 1245 */ 1246 pool_cache_reclaim(&pagecache); 1247 if (!NEED_PAGEDAEMON()) { 1248 mutex_enter(&pdaemonmtx); 1249 continue; 1250 } 1251 1252 /* 1253 * And then drain the pools. Wipe them out ... all of them. 1254 */ 1255 for (pp_first = NULL;;) { 1256 rump_vfs_drainbufs(10 /* XXX: estimate! */); 1257 1258 succ = pool_drain(&pp); 1259 if (succ || pp == pp_first) 1260 break; 1261 1262 if (pp_first == NULL) 1263 pp_first = pp; 1264 } 1265 1266 /* 1267 * Need to use PYEC on our bag of tricks. 1268 * Unfortunately, the wife just borrowed it. 1269 */ 1270 1271 mutex_enter(&pdaemonmtx); 1272 if (!succ && cleaned == 0 && pdaemon_waiters && 1273 uvmexp.paging == 0) { 1274 kpause("pddlk", false, hz, &pdaemonmtx); 1275 } 1276 } 1277 1278 panic("you can swap out any time you like, but you can never leave"); 1279 } 1280 1281 void 1282 uvm_kick_pdaemon() 1283 { 1284 1285 /* 1286 * Wake up the diabolical pagedaemon director if we are over 1287 * 90% of the memory limit. This is a complete and utter 1288 * stetson-harrison decision which you are allowed to finetune. 1289 * Don't bother locking. If we have some unflushed caches, 1290 * other waker-uppers will deal with the issue. 1291 */ 1292 if (NEED_PAGEDAEMON()) { 1293 cv_signal(&pdaemoncv); 1294 } 1295 } 1296 1297 void * 1298 rump_hypermalloc(size_t howmuch, int alignment, bool waitok, const char *wmsg) 1299 { 1300 const unsigned long thelimit = 1301 curlwp == uvm.pagedaemon_lwp ? pdlimit : rump_physmemlimit; 1302 unsigned long newmem; 1303 void *rv; 1304 int error; 1305 1306 uvm_kick_pdaemon(); /* ouch */ 1307 1308 /* first we must be within the limit */ 1309 limitagain: 1310 if (thelimit != RUMPMEM_UNLIMITED) { 1311 newmem = atomic_add_long_nv(&curphysmem, howmuch); 1312 if (newmem > thelimit) { 1313 newmem = atomic_add_long_nv(&curphysmem, -howmuch); 1314 if (!waitok) { 1315 return NULL; 1316 } 1317 uvm_wait(wmsg); 1318 goto limitagain; 1319 } 1320 } 1321 1322 /* second, we must get something from the backend */ 1323 again: 1324 error = rumpuser_malloc(howmuch, alignment, &rv); 1325 if (__predict_false(error && waitok)) { 1326 uvm_wait(wmsg); 1327 goto again; 1328 } 1329 1330 return rv; 1331 } 1332 1333 void 1334 rump_hyperfree(void *what, size_t size) 1335 { 1336 1337 if (rump_physmemlimit != RUMPMEM_UNLIMITED) { 1338 atomic_add_long(&curphysmem, -size); 1339 } 1340 rumpuser_free(what, size); 1341 } 1342 1343 /* 1344 * UBC 1345 */ 1346 1347 #define PAGERFLAGS (PGO_SYNCIO | PGO_NOBLOCKALLOC | PGO_NOTIMESTAMP) 1348 1349 void 1350 ubc_zerorange(struct uvm_object *uobj, off_t off, size_t len, int flags) 1351 { 1352 struct vm_page **pgs; 1353 int maxpages = MIN(32, round_page(len) >> PAGE_SHIFT); 1354 int npages, i; 1355 1356 if (maxpages == 0) 1357 return; 1358 1359 pgs = kmem_alloc(maxpages * sizeof(pgs), KM_SLEEP); 1360 rw_enter(uobj->vmobjlock, RW_WRITER); 1361 while (len) { 1362 npages = MIN(maxpages, round_page(len) >> PAGE_SHIFT); 1363 memset(pgs, 0, npages * sizeof(struct vm_page *)); 1364 (void)uobj->pgops->pgo_get(uobj, trunc_page(off), 1365 pgs, &npages, 0, VM_PROT_READ | VM_PROT_WRITE, 1366 0, PAGERFLAGS | PGO_PASTEOF); 1367 KASSERT(npages > 0); 1368 1369 rw_enter(uobj->vmobjlock, RW_WRITER); 1370 for (i = 0; i < npages; i++) { 1371 struct vm_page *pg; 1372 uint8_t *start; 1373 size_t chunkoff, chunklen; 1374 1375 pg = pgs[i]; 1376 if (pg == NULL) 1377 break; 1378 1379 KASSERT(pg->uobject != NULL); 1380 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 1381 1382 chunkoff = off & PAGE_MASK; 1383 chunklen = MIN(PAGE_SIZE - chunkoff, len); 1384 start = (uint8_t *)pg->uanon + chunkoff; 1385 1386 memset(start, 0, chunklen); 1387 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 1388 1389 off += chunklen; 1390 len -= chunklen; 1391 } 1392 uvm_page_unbusy(pgs, npages); 1393 } 1394 rw_exit(uobj->vmobjlock); 1395 kmem_free(pgs, maxpages * sizeof(pgs)); 1396 } 1397 1398 #define len2npages(off, len) \ 1399 ((round_page(off+len) - trunc_page(off)) >> PAGE_SHIFT) 1400 1401 int 1402 ubc_uiomove(struct uvm_object *uobj, struct uio *uio, vsize_t todo, 1403 int advice, int flags) 1404 { 1405 struct vm_page **pgs; 1406 int npages = len2npages(uio->uio_offset, todo); 1407 size_t pgalloc; 1408 int i, rv, pagerflags; 1409 vm_prot_t prot; 1410 1411 pgalloc = npages * sizeof(pgs); 1412 pgs = kmem_alloc(pgalloc, KM_SLEEP); 1413 1414 pagerflags = PAGERFLAGS; 1415 if (flags & UBC_WRITE) 1416 pagerflags |= PGO_PASTEOF; 1417 if (flags & UBC_FAULTBUSY) 1418 pagerflags |= PGO_OVERWRITE; 1419 1420 prot = VM_PROT_READ; 1421 if (flags & UBC_WRITE) 1422 prot |= VM_PROT_WRITE; 1423 1424 rw_enter(uobj->vmobjlock, RW_WRITER); 1425 do { 1426 npages = len2npages(uio->uio_offset, todo); 1427 memset(pgs, 0, pgalloc); 1428 rv = uobj->pgops->pgo_get(uobj, trunc_page(uio->uio_offset), 1429 pgs, &npages, 0, prot, 0, pagerflags); 1430 if (rv) 1431 goto out; 1432 1433 rw_enter(uobj->vmobjlock, RW_WRITER); 1434 for (i = 0; i < npages; i++) { 1435 struct vm_page *pg; 1436 size_t xfersize; 1437 off_t pageoff; 1438 1439 pg = pgs[i]; 1440 if (pg == NULL) 1441 break; 1442 1443 KASSERT(pg->uobject != NULL); 1444 KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock); 1445 pageoff = uio->uio_offset & PAGE_MASK; 1446 1447 xfersize = MIN(MIN(todo, PAGE_SIZE), PAGE_SIZE-pageoff); 1448 KASSERT(xfersize > 0); 1449 rv = uiomove((uint8_t *)pg->uanon + pageoff, 1450 xfersize, uio); 1451 if (rv) { 1452 uvm_page_unbusy(pgs, npages); 1453 rw_exit(uobj->vmobjlock); 1454 goto out; 1455 } 1456 if (uio->uio_rw == UIO_WRITE) { 1457 pg->flags &= ~PG_FAKE; 1458 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 1459 } 1460 todo -= xfersize; 1461 } 1462 uvm_page_unbusy(pgs, npages); 1463 } while (todo); 1464 rw_exit(uobj->vmobjlock); 1465 1466 out: 1467 kmem_free(pgs, pgalloc); 1468 return rv; 1469 } 1470