1 /* 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * Copyright (c) 2003-2011 The DragonFly Project. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * The Mach Operating System project at Carnegie-Mellon University. 8 * 9 * This code is derived from software contributed to The DragonFly Project 10 * by Matthew Dillon <dillon@backplane.com> 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 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 37 * $FreeBSD: src/sys/vm/vm_page.c,v 1.147.2.18 2002/03/10 05:03:19 alc Exp $ 38 */ 39 40 /* 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 */ 66 /* 67 * Resident memory management module. The module manipulates 'VM pages'. 68 * A VM page is the core building block for memory management. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/malloc.h> 74 #include <sys/proc.h> 75 #include <sys/vmmeter.h> 76 #include <sys/vnode.h> 77 #include <sys/kernel.h> 78 #include <sys/alist.h> 79 #include <sys/sysctl.h> 80 #include <sys/cpu_topology.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_param.h> 84 #include <sys/lock.h> 85 #include <vm/vm_kern.h> 86 #include <vm/pmap.h> 87 #include <vm/vm_map.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_page.h> 90 #include <vm/vm_pageout.h> 91 #include <vm/vm_pager.h> 92 #include <vm/vm_extern.h> 93 #include <vm/swap_pager.h> 94 95 #include <machine/inttypes.h> 96 #include <machine/md_var.h> 97 #include <machine/specialreg.h> 98 #include <machine/bus_dma.h> 99 100 #include <vm/vm_page2.h> 101 #include <sys/spinlock2.h> 102 103 /* 104 * SET - Minimum required set associative size, must be a power of 2. We 105 * want this to match or exceed the set-associativeness of the cpu. 106 * 107 * GRP - A larger set that allows bleed-over into the domains of other 108 * nearby cpus. Also must be a power of 2. Used by the page zeroing 109 * code to smooth things out a bit. 110 */ 111 #define PQ_SET_ASSOC 16 112 #define PQ_SET_ASSOC_MASK (PQ_SET_ASSOC - 1) 113 114 #define PQ_GRP_ASSOC (PQ_SET_ASSOC * 2) 115 #define PQ_GRP_ASSOC_MASK (PQ_GRP_ASSOC - 1) 116 117 static void vm_page_queue_init(void); 118 static void vm_page_free_wakeup(void); 119 static vm_page_t vm_page_select_cache(u_short pg_color); 120 static vm_page_t _vm_page_list_find2(int basequeue, int index); 121 static void _vm_page_deactivate_locked(vm_page_t m, int athead); 122 static void vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes); 123 124 /* 125 * Array of tailq lists 126 */ 127 __cachealign struct vpgqueues vm_page_queues[PQ_COUNT]; 128 129 static volatile int vm_pages_waiting; 130 static struct alist vm_contig_alist; 131 static struct almeta vm_contig_ameta[ALIST_RECORDS_65536]; 132 static struct spinlock vm_contig_spin = SPINLOCK_INITIALIZER(&vm_contig_spin, "vm_contig_spin"); 133 134 static u_long vm_dma_reserved = 0; 135 TUNABLE_ULONG("vm.dma_reserved", &vm_dma_reserved); 136 SYSCTL_ULONG(_vm, OID_AUTO, dma_reserved, CTLFLAG_RD, &vm_dma_reserved, 0, 137 "Memory reserved for DMA"); 138 SYSCTL_UINT(_vm, OID_AUTO, dma_free_pages, CTLFLAG_RD, 139 &vm_contig_alist.bl_free, 0, "Memory reserved for DMA"); 140 141 static int vm_contig_verbose = 0; 142 TUNABLE_INT("vm.contig_verbose", &vm_contig_verbose); 143 144 RB_GENERATE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare, 145 vm_pindex_t, pindex); 146 147 static void 148 vm_page_queue_init(void) 149 { 150 int i; 151 152 for (i = 0; i < PQ_L2_SIZE; i++) 153 vm_page_queues[PQ_FREE+i].cnt_offset = 154 offsetof(struct vmstats, v_free_count); 155 for (i = 0; i < PQ_L2_SIZE; i++) 156 vm_page_queues[PQ_CACHE+i].cnt_offset = 157 offsetof(struct vmstats, v_cache_count); 158 for (i = 0; i < PQ_L2_SIZE; i++) 159 vm_page_queues[PQ_INACTIVE+i].cnt_offset = 160 offsetof(struct vmstats, v_inactive_count); 161 for (i = 0; i < PQ_L2_SIZE; i++) 162 vm_page_queues[PQ_ACTIVE+i].cnt_offset = 163 offsetof(struct vmstats, v_active_count); 164 for (i = 0; i < PQ_L2_SIZE; i++) 165 vm_page_queues[PQ_HOLD+i].cnt_offset = 166 offsetof(struct vmstats, v_active_count); 167 /* PQ_NONE has no queue */ 168 169 for (i = 0; i < PQ_COUNT; i++) { 170 TAILQ_INIT(&vm_page_queues[i].pl); 171 spin_init(&vm_page_queues[i].spin, "vm_page_queue_init"); 172 } 173 } 174 175 /* 176 * note: place in initialized data section? Is this necessary? 177 */ 178 vm_pindex_t first_page = 0; 179 vm_pindex_t vm_page_array_size = 0; 180 vm_page_t vm_page_array = NULL; 181 vm_paddr_t vm_low_phys_reserved; 182 183 /* 184 * (low level boot) 185 * 186 * Sets the page size, perhaps based upon the memory size. 187 * Must be called before any use of page-size dependent functions. 188 */ 189 void 190 vm_set_page_size(void) 191 { 192 if (vmstats.v_page_size == 0) 193 vmstats.v_page_size = PAGE_SIZE; 194 if (((vmstats.v_page_size - 1) & vmstats.v_page_size) != 0) 195 panic("vm_set_page_size: page size not a power of two"); 196 } 197 198 /* 199 * (low level boot) 200 * 201 * Add a new page to the freelist for use by the system. New pages 202 * are added to both the head and tail of the associated free page 203 * queue in a bottom-up fashion, so both zero'd and non-zero'd page 204 * requests pull 'recent' adds (higher physical addresses) first. 205 * 206 * Beware that the page zeroing daemon will also be running soon after 207 * boot, moving pages from the head to the tail of the PQ_FREE queues. 208 * 209 * Must be called in a critical section. 210 */ 211 static void 212 vm_add_new_page(vm_paddr_t pa) 213 { 214 struct vpgqueues *vpq; 215 vm_page_t m; 216 217 m = PHYS_TO_VM_PAGE(pa); 218 m->phys_addr = pa; 219 m->flags = 0; 220 m->pat_mode = PAT_WRITE_BACK; 221 m->pc = (pa >> PAGE_SHIFT); 222 223 /* 224 * Twist for cpu localization in addition to page coloring, so 225 * different cpus selecting by m->queue get different page colors. 226 */ 227 m->pc ^= ((pa >> PAGE_SHIFT) / PQ_L2_SIZE); 228 m->pc ^= ((pa >> PAGE_SHIFT) / (PQ_L2_SIZE * PQ_L2_SIZE)); 229 m->pc &= PQ_L2_MASK; 230 231 /* 232 * Reserve a certain number of contiguous low memory pages for 233 * contigmalloc() to use. 234 */ 235 if (pa < vm_low_phys_reserved) { 236 atomic_add_long(&vmstats.v_page_count, 1); 237 atomic_add_long(&vmstats.v_dma_pages, 1); 238 m->queue = PQ_NONE; 239 m->wire_count = 1; 240 atomic_add_long(&vmstats.v_wire_count, 1); 241 alist_free(&vm_contig_alist, pa >> PAGE_SHIFT, 1); 242 return; 243 } 244 245 /* 246 * General page 247 */ 248 m->queue = m->pc + PQ_FREE; 249 KKASSERT(m->dirty == 0); 250 251 atomic_add_long(&vmstats.v_page_count, 1); 252 atomic_add_long(&vmstats.v_free_count, 1); 253 vpq = &vm_page_queues[m->queue]; 254 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq); 255 ++vpq->lcnt; 256 } 257 258 /* 259 * (low level boot) 260 * 261 * Initializes the resident memory module. 262 * 263 * Preallocates memory for critical VM structures and arrays prior to 264 * kernel_map becoming available. 265 * 266 * Memory is allocated from (virtual2_start, virtual2_end) if available, 267 * otherwise memory is allocated from (virtual_start, virtual_end). 268 * 269 * On x86-64 (virtual_start, virtual_end) is only 2GB and may not be 270 * large enough to hold vm_page_array & other structures for machines with 271 * large amounts of ram, so we want to use virtual2* when available. 272 */ 273 void 274 vm_page_startup(void) 275 { 276 vm_offset_t vaddr = virtual2_start ? virtual2_start : virtual_start; 277 vm_offset_t mapped; 278 vm_pindex_t npages; 279 vm_paddr_t page_range; 280 vm_paddr_t new_end; 281 int i; 282 vm_paddr_t pa; 283 vm_paddr_t last_pa; 284 vm_paddr_t end; 285 vm_paddr_t biggestone, biggestsize; 286 vm_paddr_t total; 287 vm_page_t m; 288 289 total = 0; 290 biggestsize = 0; 291 biggestone = 0; 292 vaddr = round_page(vaddr); 293 294 /* 295 * Make sure ranges are page-aligned. 296 */ 297 for (i = 0; phys_avail[i].phys_end; ++i) { 298 phys_avail[i].phys_beg = round_page64(phys_avail[i].phys_beg); 299 phys_avail[i].phys_end = trunc_page64(phys_avail[i].phys_end); 300 if (phys_avail[i].phys_end < phys_avail[i].phys_beg) 301 phys_avail[i].phys_end = phys_avail[i].phys_beg; 302 } 303 304 /* 305 * Locate largest block 306 */ 307 for (i = 0; phys_avail[i].phys_end; ++i) { 308 vm_paddr_t size = phys_avail[i].phys_end - 309 phys_avail[i].phys_beg; 310 311 if (size > biggestsize) { 312 biggestone = i; 313 biggestsize = size; 314 } 315 total += size; 316 } 317 --i; /* adjust to last entry for use down below */ 318 319 end = phys_avail[biggestone].phys_end; 320 end = trunc_page(end); 321 322 /* 323 * Initialize the queue headers for the free queue, the active queue 324 * and the inactive queue. 325 */ 326 vm_page_queue_init(); 327 328 #if !defined(_KERNEL_VIRTUAL) 329 /* 330 * VKERNELs don't support minidumps and as such don't need 331 * vm_page_dump 332 * 333 * Allocate a bitmap to indicate that a random physical page 334 * needs to be included in a minidump. 335 * 336 * The amd64 port needs this to indicate which direct map pages 337 * need to be dumped, via calls to dump_add_page()/dump_drop_page(). 338 * 339 * However, x86 still needs this workspace internally within the 340 * minidump code. In theory, they are not needed on x86, but are 341 * included should the sf_buf code decide to use them. 342 */ 343 page_range = phys_avail[i].phys_end / PAGE_SIZE; 344 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY); 345 end -= vm_page_dump_size; 346 vm_page_dump = (void *)pmap_map(&vaddr, end, end + vm_page_dump_size, 347 VM_PROT_READ | VM_PROT_WRITE); 348 bzero((void *)vm_page_dump, vm_page_dump_size); 349 #endif 350 /* 351 * Compute the number of pages of memory that will be available for 352 * use (taking into account the overhead of a page structure per 353 * page). 354 */ 355 first_page = phys_avail[0].phys_beg / PAGE_SIZE; 356 page_range = phys_avail[i].phys_end / PAGE_SIZE - first_page; 357 npages = (total - (page_range * sizeof(struct vm_page))) / PAGE_SIZE; 358 359 #ifndef _KERNEL_VIRTUAL 360 /* 361 * (only applies to real kernels) 362 * 363 * Reserve a large amount of low memory for potential 32-bit DMA 364 * space allocations. Once device initialization is complete we 365 * release most of it, but keep (vm_dma_reserved) memory reserved 366 * for later use. Typically for X / graphics. Through trial and 367 * error we find that GPUs usually requires ~60-100MB or so. 368 * 369 * By default, 128M is left in reserve on machines with 2G+ of ram. 370 */ 371 vm_low_phys_reserved = (vm_paddr_t)65536 << PAGE_SHIFT; 372 if (vm_low_phys_reserved > total / 4) 373 vm_low_phys_reserved = total / 4; 374 if (vm_dma_reserved == 0) { 375 vm_dma_reserved = 128 * 1024 * 1024; /* 128MB */ 376 if (vm_dma_reserved > total / 16) 377 vm_dma_reserved = total / 16; 378 } 379 #endif 380 alist_init(&vm_contig_alist, 65536, vm_contig_ameta, 381 ALIST_RECORDS_65536); 382 383 /* 384 * Initialize the mem entry structures now, and put them in the free 385 * queue. 386 */ 387 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024) 388 kprintf("initializing vm_page_array "); 389 new_end = trunc_page(end - page_range * sizeof(struct vm_page)); 390 mapped = pmap_map(&vaddr, new_end, end, VM_PROT_READ | VM_PROT_WRITE); 391 vm_page_array = (vm_page_t)mapped; 392 393 #if defined(__x86_64__) && !defined(_KERNEL_VIRTUAL) 394 /* 395 * since pmap_map on amd64 returns stuff out of a direct-map region, 396 * we have to manually add these pages to the minidump tracking so 397 * that they can be dumped, including the vm_page_array. 398 */ 399 for (pa = new_end; 400 pa < phys_avail[biggestone].phys_end; 401 pa += PAGE_SIZE) { 402 dump_add_page(pa); 403 } 404 #endif 405 406 /* 407 * Clear all of the page structures, run basic initialization so 408 * PHYS_TO_VM_PAGE() operates properly even on pages not in the 409 * map. 410 */ 411 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 412 vm_page_array_size = page_range; 413 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024) 414 kprintf("size = 0x%zx\n", vm_page_array_size); 415 416 m = &vm_page_array[0]; 417 pa = ptoa(first_page); 418 for (i = 0; i < page_range; ++i) { 419 spin_init(&m->spin, "vm_page"); 420 m->phys_addr = pa; 421 pa += PAGE_SIZE; 422 ++m; 423 } 424 425 /* 426 * Construct the free queue(s) in ascending order (by physical 427 * address) so that the first 16MB of physical memory is allocated 428 * last rather than first. On large-memory machines, this avoids 429 * the exhaustion of low physical memory before isa_dma_init has run. 430 */ 431 vmstats.v_page_count = 0; 432 vmstats.v_free_count = 0; 433 for (i = 0; phys_avail[i].phys_end && npages > 0; ++i) { 434 pa = phys_avail[i].phys_beg; 435 if (i == biggestone) 436 last_pa = new_end; 437 else 438 last_pa = phys_avail[i].phys_end; 439 while (pa < last_pa && npages-- > 0) { 440 vm_add_new_page(pa); 441 pa += PAGE_SIZE; 442 } 443 } 444 if (virtual2_start) 445 virtual2_start = vaddr; 446 else 447 virtual_start = vaddr; 448 mycpu->gd_vmstats = vmstats; 449 } 450 451 /* 452 * (called from early boot only) 453 * 454 * Reorganize VM pages based on numa data. May be called as many times as 455 * necessary. Will reorganize the vm_page_t page color and related queue(s) 456 * to allow vm_page_alloc() to choose pages based on socket affinity. 457 * 458 * NOTE: This function is only called while we are still in UP mode, so 459 * we only need a critical section to protect the queues (which 460 * saves a lot of time, there are likely a ton of pages). 461 */ 462 void 463 vm_numa_organize(vm_paddr_t ran_beg, vm_paddr_t bytes, int physid) 464 { 465 vm_paddr_t scan_beg; 466 vm_paddr_t scan_end; 467 vm_paddr_t ran_end; 468 struct vpgqueues *vpq; 469 vm_page_t m; 470 vm_page_t mend; 471 int socket_mod; 472 int socket_value; 473 int i; 474 475 /* 476 * Check if no physical information, or there was only one socket 477 * (so don't waste time doing nothing!). 478 */ 479 if (cpu_topology_phys_ids <= 1 || 480 cpu_topology_core_ids == 0) { 481 return; 482 } 483 484 /* 485 * Setup for our iteration. Note that ACPI may iterate CPU 486 * sockets starting at 0 or 1 or some other number. The 487 * cpu_topology code mod's it against the socket count. 488 */ 489 ran_end = ran_beg + bytes; 490 491 socket_mod = PQ_L2_SIZE / cpu_topology_phys_ids; 492 socket_value = (physid % cpu_topology_phys_ids) * socket_mod; 493 mend = &vm_page_array[vm_page_array_size]; 494 495 crit_enter(); 496 497 /* 498 * Adjust cpu_topology's phys_mem parameter 499 */ 500 if (root_cpu_node) 501 vm_numa_add_topology_mem(root_cpu_node, physid, (long)bytes); 502 503 /* 504 * Adjust vm_page->pc and requeue all affected pages. The 505 * allocator will then be able to localize memory allocations 506 * to some degree. 507 */ 508 for (i = 0; phys_avail[i].phys_end; ++i) { 509 scan_beg = phys_avail[i].phys_beg; 510 scan_end = phys_avail[i].phys_end; 511 if (scan_end <= ran_beg) 512 continue; 513 if (scan_beg >= ran_end) 514 continue; 515 if (scan_beg < ran_beg) 516 scan_beg = ran_beg; 517 if (scan_end > ran_end) 518 scan_end = ran_end; 519 if (atop(scan_end) > first_page + vm_page_array_size) 520 scan_end = ptoa(first_page + vm_page_array_size); 521 522 m = PHYS_TO_VM_PAGE(scan_beg); 523 while (scan_beg < scan_end) { 524 KKASSERT(m < mend); 525 if (m->queue != PQ_NONE) { 526 vpq = &vm_page_queues[m->queue]; 527 TAILQ_REMOVE(&vpq->pl, m, pageq); 528 --vpq->lcnt; 529 /* queue doesn't change, no need to adj cnt */ 530 m->queue -= m->pc; 531 m->pc %= socket_mod; 532 m->pc += socket_value; 533 m->pc &= PQ_L2_MASK; 534 m->queue += m->pc; 535 vpq = &vm_page_queues[m->queue]; 536 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq); 537 ++vpq->lcnt; 538 /* queue doesn't change, no need to adj cnt */ 539 } else { 540 m->pc %= socket_mod; 541 m->pc += socket_value; 542 m->pc &= PQ_L2_MASK; 543 } 544 scan_beg += PAGE_SIZE; 545 ++m; 546 } 547 } 548 549 crit_exit(); 550 } 551 552 /* 553 * (called from early boot only) 554 * 555 * Don't allow the NUMA organization to leave vm_page_queues[] nodes 556 * completely empty for a logical cpu. Doing so would force allocations 557 * on that cpu to always borrow from a nearby cpu, create unnecessary 558 * contention, and cause vm_page_alloc() to iterate more queues and run more 559 * slowly. 560 * 561 * This situation can occur when memory sticks are not entirely populated, 562 * populated at different densities, or in naturally assymetric systems 563 * such as the 2990WX. There could very well be many vm_page_queues[] 564 * entries with *NO* pages assigned to them. 565 * 566 * Fixing this up ensures that each logical CPU has roughly the same 567 * sized memory pool, and more importantly ensures that logical CPUs 568 * do not wind up with an empty memory pool. 569 * 570 * At them moment we just iterate the other queues and borrow pages, 571 * moving them into the queues for cpus with severe deficits even though 572 * the memory might not be local to those cpus. I am not doing this in 573 * a 'smart' way, its effectively UMA style (sorta, since its page-by-page 574 * whereas real UMA typically exchanges address bits 8-10 with high address 575 * bits). But it works extremely well and gives us fairly good deterministic 576 * results on the cpu cores associated with these secondary nodes. 577 */ 578 void 579 vm_numa_organize_finalize(void) 580 { 581 struct vpgqueues *vpq; 582 vm_page_t m; 583 long lcnt_lo; 584 long lcnt_hi; 585 int iter; 586 int i; 587 int scale_lim; 588 589 crit_enter(); 590 591 /* 592 * Machines might not use an exact power of 2 for phys_ids, 593 * core_ids, ht_ids, etc. This can slightly reduce the actual 594 * range of indices in vm_page_queues[] that are nominally used. 595 */ 596 if (cpu_topology_ht_ids) { 597 scale_lim = PQ_L2_SIZE / cpu_topology_phys_ids; 598 scale_lim = scale_lim / cpu_topology_core_ids; 599 scale_lim = scale_lim / cpu_topology_ht_ids; 600 scale_lim = scale_lim * cpu_topology_ht_ids; 601 scale_lim = scale_lim * cpu_topology_core_ids; 602 scale_lim = scale_lim * cpu_topology_phys_ids; 603 } else { 604 scale_lim = PQ_L2_SIZE; 605 } 606 607 /* 608 * Calculate an average, set hysteresis for balancing from 609 * 10% below the average to the average. 610 */ 611 lcnt_hi = 0; 612 for (i = 0; i < scale_lim; ++i) { 613 lcnt_hi += vm_page_queues[i].lcnt; 614 } 615 lcnt_hi /= scale_lim; 616 lcnt_lo = lcnt_hi - lcnt_hi / 10; 617 618 kprintf("vm_page: avg %ld pages per queue, %d queues\n", 619 lcnt_hi, scale_lim); 620 621 iter = 0; 622 for (i = 0; i < scale_lim; ++i) { 623 vpq = &vm_page_queues[PQ_FREE + i]; 624 while (vpq->lcnt < lcnt_lo) { 625 struct vpgqueues *vptmp; 626 627 iter = (iter + 1) & PQ_L2_MASK; 628 vptmp = &vm_page_queues[PQ_FREE + iter]; 629 if (vptmp->lcnt < lcnt_hi) 630 continue; 631 m = TAILQ_FIRST(&vptmp->pl); 632 KKASSERT(m->queue == PQ_FREE + iter); 633 TAILQ_REMOVE(&vptmp->pl, m, pageq); 634 --vptmp->lcnt; 635 /* queue doesn't change, no need to adj cnt */ 636 m->queue -= m->pc; 637 m->pc = i; 638 m->queue += m->pc; 639 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq); 640 ++vpq->lcnt; 641 } 642 } 643 crit_exit(); 644 } 645 646 static 647 void 648 vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes) 649 { 650 int cpuid; 651 int i; 652 653 switch(cpup->type) { 654 case PACKAGE_LEVEL: 655 cpup->phys_mem += bytes; 656 break; 657 case CHIP_LEVEL: 658 /* 659 * All members should have the same chipid, so we only need 660 * to pull out one member. 661 */ 662 if (CPUMASK_TESTNZERO(cpup->members)) { 663 cpuid = BSFCPUMASK(cpup->members); 664 if (physid == 665 get_chip_ID_from_APICID(CPUID_TO_APICID(cpuid))) { 666 cpup->phys_mem += bytes; 667 } 668 } 669 break; 670 case CORE_LEVEL: 671 case THREAD_LEVEL: 672 /* 673 * Just inherit from the parent node 674 */ 675 cpup->phys_mem = cpup->parent_node->phys_mem; 676 break; 677 } 678 for (i = 0; i < MAXCPU && cpup->child_node[i]; ++i) 679 vm_numa_add_topology_mem(cpup->child_node[i], physid, bytes); 680 } 681 682 /* 683 * We tended to reserve a ton of memory for contigmalloc(). Now that most 684 * drivers have initialized we want to return most the remaining free 685 * reserve back to the VM page queues so they can be used for normal 686 * allocations. 687 * 688 * We leave vm_dma_reserved bytes worth of free pages in the reserve pool. 689 */ 690 static void 691 vm_page_startup_finish(void *dummy __unused) 692 { 693 alist_blk_t blk; 694 alist_blk_t rblk; 695 alist_blk_t count; 696 alist_blk_t xcount; 697 alist_blk_t bfree; 698 vm_page_t m; 699 700 spin_lock(&vm_contig_spin); 701 for (;;) { 702 bfree = alist_free_info(&vm_contig_alist, &blk, &count); 703 if (bfree <= vm_dma_reserved / PAGE_SIZE) 704 break; 705 if (count == 0) 706 break; 707 708 /* 709 * Figure out how much of the initial reserve we have to 710 * free in order to reach our target. 711 */ 712 bfree -= vm_dma_reserved / PAGE_SIZE; 713 if (count > bfree) { 714 blk += count - bfree; 715 count = bfree; 716 } 717 718 /* 719 * Calculate the nearest power of 2 <= count. 720 */ 721 for (xcount = 1; xcount <= count; xcount <<= 1) 722 ; 723 xcount >>= 1; 724 blk += count - xcount; 725 count = xcount; 726 727 /* 728 * Allocate the pages from the alist, then free them to 729 * the normal VM page queues. 730 * 731 * Pages allocated from the alist are wired. We have to 732 * busy, unwire, and free them. We must also adjust 733 * vm_low_phys_reserved before freeing any pages to prevent 734 * confusion. 735 */ 736 rblk = alist_alloc(&vm_contig_alist, blk, count); 737 if (rblk != blk) { 738 kprintf("vm_page_startup_finish: Unable to return " 739 "dma space @0x%08x/%d -> 0x%08x\n", 740 blk, count, rblk); 741 break; 742 } 743 atomic_add_long(&vmstats.v_dma_pages, -(long)count); 744 spin_unlock(&vm_contig_spin); 745 746 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT); 747 vm_low_phys_reserved = VM_PAGE_TO_PHYS(m); 748 while (count) { 749 vm_page_busy_wait(m, FALSE, "cpgfr"); 750 vm_page_unwire(m, 0); 751 vm_page_free(m); 752 --count; 753 ++m; 754 } 755 spin_lock(&vm_contig_spin); 756 } 757 spin_unlock(&vm_contig_spin); 758 759 /* 760 * Print out how much DMA space drivers have already allocated and 761 * how much is left over. 762 */ 763 kprintf("DMA space used: %jdk, remaining available: %jdk\n", 764 (intmax_t)(vmstats.v_dma_pages - vm_contig_alist.bl_free) * 765 (PAGE_SIZE / 1024), 766 (intmax_t)vm_contig_alist.bl_free * (PAGE_SIZE / 1024)); 767 } 768 SYSINIT(vm_pgend, SI_SUB_PROC0_POST, SI_ORDER_ANY, 769 vm_page_startup_finish, NULL); 770 771 772 /* 773 * Scan comparison function for Red-Black tree scans. An inclusive 774 * (start,end) is expected. Other fields are not used. 775 */ 776 int 777 rb_vm_page_scancmp(struct vm_page *p, void *data) 778 { 779 struct rb_vm_page_scan_info *info = data; 780 781 if (p->pindex < info->start_pindex) 782 return(-1); 783 if (p->pindex > info->end_pindex) 784 return(1); 785 return(0); 786 } 787 788 int 789 rb_vm_page_compare(struct vm_page *p1, struct vm_page *p2) 790 { 791 if (p1->pindex < p2->pindex) 792 return(-1); 793 if (p1->pindex > p2->pindex) 794 return(1); 795 return(0); 796 } 797 798 void 799 vm_page_init(vm_page_t m) 800 { 801 /* do nothing for now. Called from pmap_page_init() */ 802 } 803 804 /* 805 * Each page queue has its own spin lock, which is fairly optimal for 806 * allocating and freeing pages at least. 807 * 808 * The caller must hold the vm_page_spin_lock() before locking a vm_page's 809 * queue spinlock via this function. Also note that m->queue cannot change 810 * unless both the page and queue are locked. 811 */ 812 static __inline 813 void 814 _vm_page_queue_spin_lock(vm_page_t m) 815 { 816 u_short queue; 817 818 queue = m->queue; 819 if (queue != PQ_NONE) { 820 spin_lock(&vm_page_queues[queue].spin); 821 KKASSERT(queue == m->queue); 822 } 823 } 824 825 static __inline 826 void 827 _vm_page_queue_spin_unlock(vm_page_t m) 828 { 829 u_short queue; 830 831 queue = m->queue; 832 cpu_ccfence(); 833 if (queue != PQ_NONE) 834 spin_unlock(&vm_page_queues[queue].spin); 835 } 836 837 static __inline 838 void 839 _vm_page_queues_spin_lock(u_short queue) 840 { 841 cpu_ccfence(); 842 if (queue != PQ_NONE) 843 spin_lock(&vm_page_queues[queue].spin); 844 } 845 846 847 static __inline 848 void 849 _vm_page_queues_spin_unlock(u_short queue) 850 { 851 cpu_ccfence(); 852 if (queue != PQ_NONE) 853 spin_unlock(&vm_page_queues[queue].spin); 854 } 855 856 void 857 vm_page_queue_spin_lock(vm_page_t m) 858 { 859 _vm_page_queue_spin_lock(m); 860 } 861 862 void 863 vm_page_queues_spin_lock(u_short queue) 864 { 865 _vm_page_queues_spin_lock(queue); 866 } 867 868 void 869 vm_page_queue_spin_unlock(vm_page_t m) 870 { 871 _vm_page_queue_spin_unlock(m); 872 } 873 874 void 875 vm_page_queues_spin_unlock(u_short queue) 876 { 877 _vm_page_queues_spin_unlock(queue); 878 } 879 880 /* 881 * This locks the specified vm_page and its queue in the proper order 882 * (page first, then queue). The queue may change so the caller must 883 * recheck on return. 884 */ 885 static __inline 886 void 887 _vm_page_and_queue_spin_lock(vm_page_t m) 888 { 889 vm_page_spin_lock(m); 890 _vm_page_queue_spin_lock(m); 891 } 892 893 static __inline 894 void 895 _vm_page_and_queue_spin_unlock(vm_page_t m) 896 { 897 _vm_page_queues_spin_unlock(m->queue); 898 vm_page_spin_unlock(m); 899 } 900 901 void 902 vm_page_and_queue_spin_unlock(vm_page_t m) 903 { 904 _vm_page_and_queue_spin_unlock(m); 905 } 906 907 void 908 vm_page_and_queue_spin_lock(vm_page_t m) 909 { 910 _vm_page_and_queue_spin_lock(m); 911 } 912 913 /* 914 * Helper function removes vm_page from its current queue. 915 * Returns the base queue the page used to be on. 916 * 917 * The vm_page and the queue must be spinlocked. 918 * This function will unlock the queue but leave the page spinlocked. 919 */ 920 static __inline u_short 921 _vm_page_rem_queue_spinlocked(vm_page_t m) 922 { 923 struct vpgqueues *pq; 924 u_short queue; 925 u_short oqueue; 926 long *cnt; 927 928 queue = m->queue; 929 if (queue != PQ_NONE) { 930 pq = &vm_page_queues[queue]; 931 TAILQ_REMOVE(&pq->pl, m, pageq); 932 933 /* 934 * Adjust our pcpu stats. In order for the nominal low-memory 935 * algorithms to work properly we don't let any pcpu stat get 936 * too negative before we force it to be rolled-up into the 937 * global stats. Otherwise our pageout and vm_wait tests 938 * will fail badly. 939 * 940 * The idea here is to reduce unnecessary SMP cache 941 * mastership changes in the global vmstats, which can be 942 * particularly bad in multi-socket systems. 943 */ 944 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset); 945 atomic_add_long(cnt, -1); 946 if (*cnt < -VMMETER_SLOP_COUNT) { 947 u_long copy = atomic_swap_long(cnt, 0); 948 cnt = (long *)((char *)&vmstats + pq->cnt_offset); 949 atomic_add_long(cnt, copy); 950 cnt = (long *)((char *)&mycpu->gd_vmstats + 951 pq->cnt_offset); 952 atomic_add_long(cnt, copy); 953 } 954 pq->lcnt--; 955 m->queue = PQ_NONE; 956 oqueue = queue; 957 queue -= m->pc; 958 vm_page_queues_spin_unlock(oqueue); /* intended */ 959 } 960 return queue; 961 } 962 963 /* 964 * Helper function places the vm_page on the specified queue. Generally 965 * speaking only PQ_FREE pages are placed at the head, to allow them to 966 * be allocated sooner rather than later on the assumption that they 967 * are cache-hot. 968 * 969 * The vm_page must be spinlocked. 970 * This function will return with both the page and the queue locked. 971 */ 972 static __inline void 973 _vm_page_add_queue_spinlocked(vm_page_t m, u_short queue, int athead) 974 { 975 struct vpgqueues *pq; 976 u_long *cnt; 977 978 KKASSERT(m->queue == PQ_NONE); 979 980 if (queue != PQ_NONE) { 981 vm_page_queues_spin_lock(queue); 982 pq = &vm_page_queues[queue]; 983 ++pq->lcnt; 984 985 /* 986 * Adjust our pcpu stats. If a system entity really needs 987 * to incorporate the count it will call vmstats_rollup() 988 * to roll it all up into the global vmstats strufture. 989 */ 990 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset); 991 atomic_add_long(cnt, 1); 992 993 /* 994 * PQ_FREE is always handled LIFO style to try to provide 995 * cache-hot pages to programs. 996 */ 997 m->queue = queue; 998 if (queue - m->pc == PQ_FREE) { 999 TAILQ_INSERT_HEAD(&pq->pl, m, pageq); 1000 } else if (athead) { 1001 TAILQ_INSERT_HEAD(&pq->pl, m, pageq); 1002 } else { 1003 TAILQ_INSERT_TAIL(&pq->pl, m, pageq); 1004 } 1005 /* leave the queue spinlocked */ 1006 } 1007 } 1008 1009 /* 1010 * Wait until page is no longer BUSY. If also_m_busy is TRUE we wait 1011 * until the page is no longer BUSY or SBUSY (busy_count field is 0). 1012 * 1013 * Returns TRUE if it had to sleep, FALSE if we did not. Only one sleep 1014 * call will be made before returning. 1015 * 1016 * This function does NOT busy the page and on return the page is not 1017 * guaranteed to be available. 1018 */ 1019 void 1020 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 1021 { 1022 u_int32_t busy_count; 1023 1024 for (;;) { 1025 busy_count = m->busy_count; 1026 cpu_ccfence(); 1027 1028 if ((busy_count & PBUSY_LOCKED) == 0 && 1029 (also_m_busy == 0 || (busy_count & PBUSY_MASK) == 0)) { 1030 break; 1031 } 1032 tsleep_interlock(m, 0); 1033 if (atomic_cmpset_int(&m->busy_count, busy_count, 1034 busy_count | PBUSY_WANTED)) { 1035 atomic_set_int(&m->flags, PG_REFERENCED); 1036 tsleep(m, PINTERLOCKED, msg, 0); 1037 break; 1038 } 1039 } 1040 } 1041 1042 /* 1043 * This calculates and returns a page color given an optional VM object and 1044 * either a pindex or an iterator. We attempt to return a cpu-localized 1045 * pg_color that is still roughly 16-way set-associative. The CPU topology 1046 * is used if it was probed. 1047 * 1048 * The caller may use the returned value to index into e.g. PQ_FREE when 1049 * allocating a page in order to nominally obtain pages that are hopefully 1050 * already localized to the requesting cpu. This function is not able to 1051 * provide any sort of guarantee of this, but does its best to improve 1052 * hardware cache management performance. 1053 * 1054 * WARNING! The caller must mask the returned value with PQ_L2_MASK. 1055 */ 1056 u_short 1057 vm_get_pg_color(int cpuid, vm_object_t object, vm_pindex_t pindex) 1058 { 1059 u_short pg_color; 1060 int object_pg_color; 1061 1062 /* 1063 * WARNING! cpu_topology_core_ids might not be a power of two. 1064 * We also shouldn't make assumptions about 1065 * cpu_topology_phys_ids either. 1066 * 1067 * WARNING! ncpus might not be known at this time (during early 1068 * boot), and might be set to 1. 1069 * 1070 * General format: [phys_id][core_id][cpuid][set-associativity] 1071 * (but uses modulo, so not necessarily precise bit masks) 1072 */ 1073 object_pg_color = object ? object->pg_color : 0; 1074 1075 if (cpu_topology_ht_ids) { 1076 int phys_id; 1077 int core_id; 1078 int ht_id; 1079 int physcale; 1080 int grpscale; 1081 int cpuscale; 1082 1083 /* 1084 * Translate cpuid to socket, core, and hyperthread id. 1085 */ 1086 phys_id = get_cpu_phys_id(cpuid); 1087 core_id = get_cpu_core_id(cpuid); 1088 ht_id = get_cpu_ht_id(cpuid); 1089 1090 /* 1091 * Calculate pg_color for our array index. 1092 * 1093 * physcale - socket multiplier. 1094 * grpscale - core multiplier (cores per socket) 1095 * cpu* - cpus per core 1096 * 1097 * WARNING! In early boot, ncpus has not yet been 1098 * initialized and may be set to (1). 1099 * 1100 * WARNING! physcale must match the organization that 1101 * vm_numa_organize() creates to ensure that 1102 * we properly localize allocations to the 1103 * requested cpuid. 1104 */ 1105 physcale = PQ_L2_SIZE / cpu_topology_phys_ids; 1106 grpscale = physcale / cpu_topology_core_ids; 1107 cpuscale = grpscale / cpu_topology_ht_ids; 1108 1109 pg_color = phys_id * physcale; 1110 pg_color += core_id * grpscale; 1111 pg_color += ht_id * cpuscale; 1112 pg_color += (pindex + object_pg_color) % cpuscale; 1113 1114 #if 0 1115 if (grpsize >= 8) { 1116 pg_color += (pindex + object_pg_color) % grpsize; 1117 } else { 1118 if (grpsize <= 2) { 1119 grpsize = 8; 1120 } else { 1121 /* 3->9, 4->8, 5->10, 6->12, 7->14 */ 1122 grpsize += grpsize; 1123 if (grpsize < 8) 1124 grpsize += grpsize; 1125 } 1126 pg_color += (pindex + object_pg_color) % grpsize; 1127 } 1128 #endif 1129 } else { 1130 /* 1131 * Unknown topology, distribute things evenly. 1132 * 1133 * WARNING! In early boot, ncpus has not yet been 1134 * initialized and may be set to (1). 1135 */ 1136 int cpuscale; 1137 1138 cpuscale = PQ_L2_SIZE / ncpus; 1139 1140 pg_color = cpuid * cpuscale; 1141 pg_color += (pindex + object_pg_color) % cpuscale; 1142 } 1143 return (pg_color & PQ_L2_MASK); 1144 } 1145 1146 /* 1147 * Wait until BUSY can be set, then set it. If also_m_busy is TRUE we 1148 * also wait for m->busy_count to become 0 before setting PBUSY_LOCKED. 1149 */ 1150 void 1151 VM_PAGE_DEBUG_EXT(vm_page_busy_wait)(vm_page_t m, 1152 int also_m_busy, const char *msg 1153 VM_PAGE_DEBUG_ARGS) 1154 { 1155 u_int32_t busy_count; 1156 1157 for (;;) { 1158 busy_count = m->busy_count; 1159 cpu_ccfence(); 1160 if (busy_count & PBUSY_LOCKED) { 1161 tsleep_interlock(m, 0); 1162 if (atomic_cmpset_int(&m->busy_count, busy_count, 1163 busy_count | PBUSY_WANTED)) { 1164 atomic_set_int(&m->flags, PG_REFERENCED); 1165 tsleep(m, PINTERLOCKED, msg, 0); 1166 } 1167 } else if (also_m_busy && busy_count) { 1168 tsleep_interlock(m, 0); 1169 if (atomic_cmpset_int(&m->busy_count, busy_count, 1170 busy_count | PBUSY_WANTED)) { 1171 atomic_set_int(&m->flags, PG_REFERENCED); 1172 tsleep(m, PINTERLOCKED, msg, 0); 1173 } 1174 } else { 1175 if (atomic_cmpset_int(&m->busy_count, busy_count, 1176 busy_count | PBUSY_LOCKED)) { 1177 #ifdef VM_PAGE_DEBUG 1178 m->busy_func = func; 1179 m->busy_line = lineno; 1180 #endif 1181 break; 1182 } 1183 } 1184 } 1185 } 1186 1187 /* 1188 * Attempt to set BUSY. If also_m_busy is TRUE we only succeed if 1189 * m->busy_count is also 0. 1190 * 1191 * Returns non-zero on failure. 1192 */ 1193 int 1194 VM_PAGE_DEBUG_EXT(vm_page_busy_try)(vm_page_t m, int also_m_busy 1195 VM_PAGE_DEBUG_ARGS) 1196 { 1197 u_int32_t busy_count; 1198 1199 for (;;) { 1200 busy_count = m->busy_count; 1201 cpu_ccfence(); 1202 if (busy_count & PBUSY_LOCKED) 1203 return TRUE; 1204 if (also_m_busy && (busy_count & PBUSY_MASK) != 0) 1205 return TRUE; 1206 if (atomic_cmpset_int(&m->busy_count, busy_count, 1207 busy_count | PBUSY_LOCKED)) { 1208 #ifdef VM_PAGE_DEBUG 1209 m->busy_func = func; 1210 m->busy_line = lineno; 1211 #endif 1212 return FALSE; 1213 } 1214 } 1215 } 1216 1217 /* 1218 * Clear the BUSY flag and return non-zero to indicate to the caller 1219 * that a wakeup() should be performed. 1220 * 1221 * The vm_page must be spinlocked and will remain spinlocked on return. 1222 * The related queue must NOT be spinlocked (which could deadlock us). 1223 * 1224 * (inline version) 1225 */ 1226 static __inline 1227 int 1228 _vm_page_wakeup(vm_page_t m) 1229 { 1230 u_int32_t busy_count; 1231 1232 for (;;) { 1233 busy_count = m->busy_count; 1234 cpu_ccfence(); 1235 if (atomic_cmpset_int(&m->busy_count, busy_count, 1236 busy_count & 1237 ~(PBUSY_LOCKED | PBUSY_WANTED))) { 1238 break; 1239 } 1240 } 1241 return((int)(busy_count & PBUSY_WANTED)); 1242 } 1243 1244 /* 1245 * Clear the BUSY flag and wakeup anyone waiting for the page. This 1246 * is typically the last call you make on a page before moving onto 1247 * other things. 1248 */ 1249 void 1250 vm_page_wakeup(vm_page_t m) 1251 { 1252 KASSERT(m->busy_count & PBUSY_LOCKED, 1253 ("vm_page_wakeup: page not busy!!!")); 1254 vm_page_spin_lock(m); 1255 if (_vm_page_wakeup(m)) { 1256 vm_page_spin_unlock(m); 1257 wakeup(m); 1258 } else { 1259 vm_page_spin_unlock(m); 1260 } 1261 } 1262 1263 /* 1264 * Holding a page keeps it from being reused. Other parts of the system 1265 * can still disassociate the page from its current object and free it, or 1266 * perform read or write I/O on it and/or otherwise manipulate the page, 1267 * but if the page is held the VM system will leave the page and its data 1268 * intact and not reuse the page for other purposes until the last hold 1269 * reference is released. (see vm_page_wire() if you want to prevent the 1270 * page from being disassociated from its object too). 1271 * 1272 * The caller must still validate the contents of the page and, if necessary, 1273 * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete 1274 * before manipulating the page. 1275 * 1276 * XXX get vm_page_spin_lock() here and move FREE->HOLD if necessary 1277 */ 1278 void 1279 vm_page_hold(vm_page_t m) 1280 { 1281 vm_page_spin_lock(m); 1282 atomic_add_int(&m->hold_count, 1); 1283 if (m->queue - m->pc == PQ_FREE) { 1284 _vm_page_queue_spin_lock(m); 1285 _vm_page_rem_queue_spinlocked(m); 1286 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0); 1287 _vm_page_queue_spin_unlock(m); 1288 } 1289 vm_page_spin_unlock(m); 1290 } 1291 1292 /* 1293 * The opposite of vm_page_hold(). If the page is on the HOLD queue 1294 * it was freed while held and must be moved back to the FREE queue. 1295 */ 1296 void 1297 vm_page_unhold(vm_page_t m) 1298 { 1299 KASSERT(m->hold_count > 0 && m->queue - m->pc != PQ_FREE, 1300 ("vm_page_unhold: pg %p illegal hold_count (%d) or on FREE queue (%d)", 1301 m, m->hold_count, m->queue - m->pc)); 1302 vm_page_spin_lock(m); 1303 atomic_add_int(&m->hold_count, -1); 1304 if (m->hold_count == 0 && m->queue - m->pc == PQ_HOLD) { 1305 _vm_page_queue_spin_lock(m); 1306 _vm_page_rem_queue_spinlocked(m); 1307 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1); 1308 _vm_page_queue_spin_unlock(m); 1309 } 1310 vm_page_spin_unlock(m); 1311 } 1312 1313 /* 1314 * vm_page_getfake: 1315 * 1316 * Create a fictitious page with the specified physical address and 1317 * memory attribute. The memory attribute is the only the machine- 1318 * dependent aspect of a fictitious page that must be initialized. 1319 */ 1320 1321 void 1322 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 1323 { 1324 1325 if ((m->flags & PG_FICTITIOUS) != 0) { 1326 /* 1327 * The page's memattr might have changed since the 1328 * previous initialization. Update the pmap to the 1329 * new memattr. 1330 */ 1331 goto memattr; 1332 } 1333 m->phys_addr = paddr; 1334 m->queue = PQ_NONE; 1335 /* Fictitious pages don't use "segind". */ 1336 /* Fictitious pages don't use "order" or "pool". */ 1337 m->flags = PG_FICTITIOUS | PG_UNMANAGED; 1338 m->busy_count = PBUSY_LOCKED; 1339 m->wire_count = 1; 1340 spin_init(&m->spin, "fake_page"); 1341 pmap_page_init(m); 1342 memattr: 1343 pmap_page_set_memattr(m, memattr); 1344 } 1345 1346 /* 1347 * Inserts the given vm_page into the object and object list. 1348 * 1349 * The pagetables are not updated but will presumably fault the page 1350 * in if necessary, or if a kernel page the caller will at some point 1351 * enter the page into the kernel's pmap. We are not allowed to block 1352 * here so we *can't* do this anyway. 1353 * 1354 * This routine may not block. 1355 * This routine must be called with the vm_object held. 1356 * This routine must be called with a critical section held. 1357 * 1358 * This routine returns TRUE if the page was inserted into the object 1359 * successfully, and FALSE if the page already exists in the object. 1360 */ 1361 int 1362 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex) 1363 { 1364 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(object)); 1365 if (m->object != NULL) 1366 panic("vm_page_insert: already inserted"); 1367 1368 atomic_add_int(&object->generation, 1); 1369 1370 /* 1371 * Record the object/offset pair in this page and add the 1372 * pv_list_count of the page to the object. 1373 * 1374 * The vm_page spin lock is required for interactions with the pmap. 1375 */ 1376 vm_page_spin_lock(m); 1377 m->object = object; 1378 m->pindex = pindex; 1379 if (vm_page_rb_tree_RB_INSERT(&object->rb_memq, m)) { 1380 m->object = NULL; 1381 m->pindex = 0; 1382 vm_page_spin_unlock(m); 1383 return FALSE; 1384 } 1385 ++object->resident_page_count; 1386 ++mycpu->gd_vmtotal.t_rm; 1387 vm_page_spin_unlock(m); 1388 1389 /* 1390 * Since we are inserting a new and possibly dirty page, 1391 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags. 1392 */ 1393 if ((m->valid & m->dirty) || 1394 (m->flags & (PG_WRITEABLE | PG_NEED_COMMIT))) 1395 vm_object_set_writeable_dirty(object); 1396 1397 /* 1398 * Checks for a swap assignment and sets PG_SWAPPED if appropriate. 1399 */ 1400 swap_pager_page_inserted(m); 1401 return TRUE; 1402 } 1403 1404 /* 1405 * Removes the given vm_page_t from the (object,index) table 1406 * 1407 * The underlying pmap entry (if any) is NOT removed here. 1408 * This routine may not block. 1409 * 1410 * The page must be BUSY and will remain BUSY on return. 1411 * No other requirements. 1412 * 1413 * NOTE: FreeBSD side effect was to unbusy the page on return. We leave 1414 * it busy. 1415 */ 1416 void 1417 vm_page_remove(vm_page_t m) 1418 { 1419 vm_object_t object; 1420 1421 if (m->object == NULL) { 1422 return; 1423 } 1424 1425 if ((m->busy_count & PBUSY_LOCKED) == 0) 1426 panic("vm_page_remove: page not busy"); 1427 1428 object = m->object; 1429 1430 vm_object_hold(object); 1431 1432 /* 1433 * Remove the page from the object and update the object. 1434 * 1435 * The vm_page spin lock is required for interactions with the pmap. 1436 */ 1437 vm_page_spin_lock(m); 1438 vm_page_rb_tree_RB_REMOVE(&object->rb_memq, m); 1439 --object->resident_page_count; 1440 --mycpu->gd_vmtotal.t_rm; 1441 m->object = NULL; 1442 atomic_add_int(&object->generation, 1); 1443 vm_page_spin_unlock(m); 1444 1445 vm_object_drop(object); 1446 } 1447 1448 /* 1449 * Locate and return the page at (object, pindex), or NULL if the 1450 * page could not be found. 1451 * 1452 * The caller must hold the vm_object token. 1453 */ 1454 vm_page_t 1455 vm_page_lookup(vm_object_t object, vm_pindex_t pindex) 1456 { 1457 vm_page_t m; 1458 1459 /* 1460 * Search the hash table for this object/offset pair 1461 */ 1462 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 1463 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex); 1464 KKASSERT(m == NULL || (m->object == object && m->pindex == pindex)); 1465 return(m); 1466 } 1467 1468 vm_page_t 1469 VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_wait)(struct vm_object *object, 1470 vm_pindex_t pindex, 1471 int also_m_busy, const char *msg 1472 VM_PAGE_DEBUG_ARGS) 1473 { 1474 u_int32_t busy_count; 1475 vm_page_t m; 1476 1477 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 1478 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex); 1479 while (m) { 1480 KKASSERT(m->object == object && m->pindex == pindex); 1481 busy_count = m->busy_count; 1482 cpu_ccfence(); 1483 if (busy_count & PBUSY_LOCKED) { 1484 tsleep_interlock(m, 0); 1485 if (atomic_cmpset_int(&m->busy_count, busy_count, 1486 busy_count | PBUSY_WANTED)) { 1487 atomic_set_int(&m->flags, PG_REFERENCED); 1488 tsleep(m, PINTERLOCKED, msg, 0); 1489 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, 1490 pindex); 1491 } 1492 } else if (also_m_busy && busy_count) { 1493 tsleep_interlock(m, 0); 1494 if (atomic_cmpset_int(&m->busy_count, busy_count, 1495 busy_count | PBUSY_WANTED)) { 1496 atomic_set_int(&m->flags, PG_REFERENCED); 1497 tsleep(m, PINTERLOCKED, msg, 0); 1498 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, 1499 pindex); 1500 } 1501 } else if (atomic_cmpset_int(&m->busy_count, busy_count, 1502 busy_count | PBUSY_LOCKED)) { 1503 #ifdef VM_PAGE_DEBUG 1504 m->busy_func = func; 1505 m->busy_line = lineno; 1506 #endif 1507 break; 1508 } 1509 } 1510 return m; 1511 } 1512 1513 /* 1514 * Attempt to lookup and busy a page. 1515 * 1516 * Returns NULL if the page could not be found 1517 * 1518 * Returns a vm_page and error == TRUE if the page exists but could not 1519 * be busied. 1520 * 1521 * Returns a vm_page and error == FALSE on success. 1522 */ 1523 vm_page_t 1524 VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_try)(struct vm_object *object, 1525 vm_pindex_t pindex, 1526 int also_m_busy, int *errorp 1527 VM_PAGE_DEBUG_ARGS) 1528 { 1529 u_int32_t busy_count; 1530 vm_page_t m; 1531 1532 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 1533 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex); 1534 *errorp = FALSE; 1535 while (m) { 1536 KKASSERT(m->object == object && m->pindex == pindex); 1537 busy_count = m->busy_count; 1538 cpu_ccfence(); 1539 if (busy_count & PBUSY_LOCKED) { 1540 *errorp = TRUE; 1541 break; 1542 } 1543 if (also_m_busy && busy_count) { 1544 *errorp = TRUE; 1545 break; 1546 } 1547 if (atomic_cmpset_int(&m->busy_count, busy_count, 1548 busy_count | PBUSY_LOCKED)) { 1549 #ifdef VM_PAGE_DEBUG 1550 m->busy_func = func; 1551 m->busy_line = lineno; 1552 #endif 1553 break; 1554 } 1555 } 1556 return m; 1557 } 1558 1559 /* 1560 * Returns a page that is only soft-busied for use by the caller in 1561 * a read-only fashion. Returns NULL if the page could not be found, 1562 * the soft busy could not be obtained, or the page data is invalid. 1563 */ 1564 vm_page_t 1565 vm_page_lookup_sbusy_try(struct vm_object *object, vm_pindex_t pindex, 1566 int pgoff, int pgbytes) 1567 { 1568 vm_page_t m; 1569 1570 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 1571 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex); 1572 if (m) { 1573 if ((m->valid != VM_PAGE_BITS_ALL && 1574 !vm_page_is_valid(m, pgoff, pgbytes)) || 1575 (m->flags & PG_FICTITIOUS)) { 1576 m = NULL; 1577 } else if (vm_page_sbusy_try(m)) { 1578 m = NULL; 1579 } else if ((m->valid != VM_PAGE_BITS_ALL && 1580 !vm_page_is_valid(m, pgoff, pgbytes)) || 1581 (m->flags & PG_FICTITIOUS)) { 1582 vm_page_sbusy_drop(m); 1583 m = NULL; 1584 } 1585 } 1586 return m; 1587 } 1588 1589 /* 1590 * Caller must hold the related vm_object 1591 */ 1592 vm_page_t 1593 vm_page_next(vm_page_t m) 1594 { 1595 vm_page_t next; 1596 1597 next = vm_page_rb_tree_RB_NEXT(m); 1598 if (next && next->pindex != m->pindex + 1) 1599 next = NULL; 1600 return (next); 1601 } 1602 1603 /* 1604 * vm_page_rename() 1605 * 1606 * Move the given vm_page from its current object to the specified 1607 * target object/offset. The page must be busy and will remain so 1608 * on return. 1609 * 1610 * new_object must be held. 1611 * This routine might block. XXX ? 1612 * 1613 * NOTE: Swap associated with the page must be invalidated by the move. We 1614 * have to do this for several reasons: (1) we aren't freeing the 1615 * page, (2) we are dirtying the page, (3) the VM system is probably 1616 * moving the page from object A to B, and will then later move 1617 * the backing store from A to B and we can't have a conflict. 1618 * 1619 * NOTE: We *always* dirty the page. It is necessary both for the 1620 * fact that we moved it, and because we may be invalidating 1621 * swap. If the page is on the cache, we have to deactivate it 1622 * or vm_page_dirty() will panic. Dirty pages are not allowed 1623 * on the cache. 1624 */ 1625 void 1626 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex) 1627 { 1628 KKASSERT(m->busy_count & PBUSY_LOCKED); 1629 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(new_object)); 1630 if (m->object) { 1631 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(m->object)); 1632 vm_page_remove(m); 1633 } 1634 if (vm_page_insert(m, new_object, new_pindex) == FALSE) { 1635 panic("vm_page_rename: target exists (%p,%"PRIu64")", 1636 new_object, new_pindex); 1637 } 1638 if (m->queue - m->pc == PQ_CACHE) 1639 vm_page_deactivate(m); 1640 vm_page_dirty(m); 1641 } 1642 1643 /* 1644 * vm_page_unqueue() without any wakeup. This routine is used when a page 1645 * is to remain BUSYied by the caller. 1646 * 1647 * This routine may not block. 1648 */ 1649 void 1650 vm_page_unqueue_nowakeup(vm_page_t m) 1651 { 1652 vm_page_and_queue_spin_lock(m); 1653 (void)_vm_page_rem_queue_spinlocked(m); 1654 vm_page_spin_unlock(m); 1655 } 1656 1657 /* 1658 * vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon 1659 * if necessary. 1660 * 1661 * This routine may not block. 1662 */ 1663 void 1664 vm_page_unqueue(vm_page_t m) 1665 { 1666 u_short queue; 1667 1668 vm_page_and_queue_spin_lock(m); 1669 queue = _vm_page_rem_queue_spinlocked(m); 1670 if (queue == PQ_FREE || queue == PQ_CACHE) { 1671 vm_page_spin_unlock(m); 1672 pagedaemon_wakeup(); 1673 } else { 1674 vm_page_spin_unlock(m); 1675 } 1676 } 1677 1678 /* 1679 * vm_page_list_find() 1680 * 1681 * Find a page on the specified queue with color optimization. 1682 * 1683 * The page coloring optimization attempts to locate a page that does 1684 * not overload other nearby pages in the object in the cpu's L1 or L2 1685 * caches. We need this optimization because cpu caches tend to be 1686 * physical caches, while object spaces tend to be virtual. 1687 * 1688 * The page coloring optimization also, very importantly, tries to localize 1689 * memory to cpus and physical sockets. 1690 * 1691 * Each PQ_FREE and PQ_CACHE color queue has its own spinlock and the 1692 * algorithm is adjusted to localize allocations on a per-core basis. 1693 * This is done by 'twisting' the colors. 1694 * 1695 * The page is returned spinlocked and removed from its queue (it will 1696 * be on PQ_NONE), or NULL. The page is not BUSY'd. The caller 1697 * is responsible for dealing with the busy-page case (usually by 1698 * deactivating the page and looping). 1699 * 1700 * NOTE: This routine is carefully inlined. A non-inlined version 1701 * is available for outside callers but the only critical path is 1702 * from within this source file. 1703 * 1704 * NOTE: This routine assumes that the vm_pages found in PQ_CACHE and PQ_FREE 1705 * represent stable storage, allowing us to order our locks vm_page 1706 * first, then queue. 1707 */ 1708 static __inline 1709 vm_page_t 1710 _vm_page_list_find(int basequeue, int index) 1711 { 1712 struct vpgqueues *pq; 1713 vm_page_t m; 1714 1715 index &= PQ_L2_MASK; 1716 pq = &vm_page_queues[basequeue + index]; 1717 1718 /* 1719 * Try this cpu's colored queue first. Test for a page unlocked, 1720 * then lock the queue and locate a page. Note that the lock order 1721 * is reversed, but we do not want to dwadle on the page spinlock 1722 * anyway as it is held significantly longer than the queue spinlock. 1723 */ 1724 if (TAILQ_FIRST(&pq->pl)) { 1725 spin_lock(&pq->spin); 1726 TAILQ_FOREACH(m, &pq->pl, pageq) { 1727 if (spin_trylock(&m->spin) == 0) 1728 continue; 1729 KKASSERT(m->queue == basequeue + index); 1730 _vm_page_rem_queue_spinlocked(m); 1731 return(m); 1732 } 1733 spin_unlock(&pq->spin); 1734 } 1735 1736 /* 1737 * If we are unable to get a page, do a more involved NUMA-aware 1738 * search. 1739 */ 1740 m = _vm_page_list_find2(basequeue, index); 1741 return(m); 1742 } 1743 1744 /* 1745 * If we could not find the page in the desired queue try to find it in 1746 * a nearby (NUMA-aware) queue. 1747 */ 1748 static vm_page_t 1749 _vm_page_list_find2(int basequeue, int index) 1750 { 1751 struct vpgqueues *pq; 1752 vm_page_t m = NULL; 1753 int pqmask = PQ_SET_ASSOC_MASK >> 1; 1754 int pqi; 1755 int i; 1756 1757 index &= PQ_L2_MASK; 1758 pq = &vm_page_queues[basequeue]; 1759 1760 /* 1761 * Run local sets of 16, 32, 64, 128, and the whole queue if all 1762 * else fails (PQ_L2_MASK which is 255). 1763 * 1764 * Test each queue unlocked first, then lock the queue and locate 1765 * a page. Note that the lock order is reversed, but we do not want 1766 * to dwadle on the page spinlock anyway as it is held significantly 1767 * longer than the queue spinlock. 1768 */ 1769 do { 1770 pqmask = (pqmask << 1) | 1; 1771 for (i = 0; i <= pqmask; ++i) { 1772 pqi = (index & ~pqmask) | ((index + i) & pqmask); 1773 if (TAILQ_FIRST(&pq[pqi].pl)) { 1774 spin_lock(&pq[pqi].spin); 1775 TAILQ_FOREACH(m, &pq[pqi].pl, pageq) { 1776 if (spin_trylock(&m->spin) == 0) 1777 continue; 1778 KKASSERT(m->queue == basequeue + pqi); 1779 _vm_page_rem_queue_spinlocked(m); 1780 return(m); 1781 } 1782 spin_unlock(&pq[pqi].spin); 1783 } 1784 } 1785 } while (pqmask != PQ_L2_MASK); 1786 1787 return(m); 1788 } 1789 1790 /* 1791 * Returns a vm_page candidate for allocation. The page is not busied so 1792 * it can move around. The caller must busy the page (and typically 1793 * deactivate it if it cannot be busied!) 1794 * 1795 * Returns a spinlocked vm_page that has been removed from its queue. 1796 */ 1797 vm_page_t 1798 vm_page_list_find(int basequeue, int index) 1799 { 1800 return(_vm_page_list_find(basequeue, index)); 1801 } 1802 1803 /* 1804 * Find a page on the cache queue with color optimization, remove it 1805 * from the queue, and busy it. The returned page will not be spinlocked. 1806 * 1807 * A candidate failure will be deactivated. Candidates can fail due to 1808 * being busied by someone else, in which case they will be deactivated. 1809 * 1810 * This routine may not block. 1811 * 1812 */ 1813 static vm_page_t 1814 vm_page_select_cache(u_short pg_color) 1815 { 1816 vm_page_t m; 1817 1818 for (;;) { 1819 m = _vm_page_list_find(PQ_CACHE, pg_color & PQ_L2_MASK); 1820 if (m == NULL) 1821 break; 1822 /* 1823 * (m) has been removed from its queue and spinlocked 1824 */ 1825 if (vm_page_busy_try(m, TRUE)) { 1826 _vm_page_deactivate_locked(m, 0); 1827 vm_page_spin_unlock(m); 1828 } else { 1829 /* 1830 * We successfully busied the page 1831 */ 1832 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT)) == 0 && 1833 m->hold_count == 0 && 1834 m->wire_count == 0 && 1835 (m->dirty & m->valid) == 0) { 1836 vm_page_spin_unlock(m); 1837 pagedaemon_wakeup(); 1838 return(m); 1839 } 1840 1841 /* 1842 * The page cannot be recycled, deactivate it. 1843 */ 1844 _vm_page_deactivate_locked(m, 0); 1845 if (_vm_page_wakeup(m)) { 1846 vm_page_spin_unlock(m); 1847 wakeup(m); 1848 } else { 1849 vm_page_spin_unlock(m); 1850 } 1851 } 1852 } 1853 return (m); 1854 } 1855 1856 /* 1857 * Find a free page. We attempt to inline the nominal case and fall back 1858 * to _vm_page_select_free() otherwise. A busied page is removed from 1859 * the queue and returned. 1860 * 1861 * This routine may not block. 1862 */ 1863 static __inline vm_page_t 1864 vm_page_select_free(u_short pg_color) 1865 { 1866 vm_page_t m; 1867 1868 for (;;) { 1869 m = _vm_page_list_find(PQ_FREE, pg_color & PQ_L2_MASK); 1870 if (m == NULL) 1871 break; 1872 if (vm_page_busy_try(m, TRUE)) { 1873 /* 1874 * Various mechanisms such as a pmap_collect can 1875 * result in a busy page on the free queue. We 1876 * have to move the page out of the way so we can 1877 * retry the allocation. If the other thread is not 1878 * allocating the page then m->valid will remain 0 and 1879 * the pageout daemon will free the page later on. 1880 * 1881 * Since we could not busy the page, however, we 1882 * cannot make assumptions as to whether the page 1883 * will be allocated by the other thread or not, 1884 * so all we can do is deactivate it to move it out 1885 * of the way. In particular, if the other thread 1886 * wires the page it may wind up on the inactive 1887 * queue and the pageout daemon will have to deal 1888 * with that case too. 1889 */ 1890 _vm_page_deactivate_locked(m, 0); 1891 vm_page_spin_unlock(m); 1892 } else { 1893 /* 1894 * Theoretically if we are able to busy the page 1895 * atomic with the queue removal (using the vm_page 1896 * lock) nobody else should be able to mess with the 1897 * page before us. 1898 */ 1899 KKASSERT((m->flags & (PG_UNMANAGED | 1900 PG_NEED_COMMIT)) == 0); 1901 KASSERT(m->hold_count == 0, ("m->hold_count is not zero " 1902 "pg %p q=%d flags=%08x hold=%d wire=%d", 1903 m, m->queue, m->flags, m->hold_count, m->wire_count)); 1904 KKASSERT(m->wire_count == 0); 1905 vm_page_spin_unlock(m); 1906 pagedaemon_wakeup(); 1907 1908 /* return busied and removed page */ 1909 return(m); 1910 } 1911 } 1912 return(m); 1913 } 1914 1915 /* 1916 * vm_page_alloc() 1917 * 1918 * Allocate and return a memory cell associated with this VM object/offset 1919 * pair. If object is NULL an unassociated page will be allocated. 1920 * 1921 * The returned page will be busied and removed from its queues. This 1922 * routine can block and may return NULL if a race occurs and the page 1923 * is found to already exist at the specified (object, pindex). 1924 * 1925 * VM_ALLOC_NORMAL allow use of cache pages, nominal free drain 1926 * VM_ALLOC_QUICK like normal but cannot use cache 1927 * VM_ALLOC_SYSTEM greater free drain 1928 * VM_ALLOC_INTERRUPT allow free list to be completely drained 1929 * VM_ALLOC_ZERO advisory request for pre-zero'd page only 1930 * VM_ALLOC_FORCE_ZERO advisory request for pre-zero'd page only 1931 * VM_ALLOC_NULL_OK ok to return NULL on insertion collision 1932 * (see vm_page_grab()) 1933 * VM_ALLOC_USE_GD ok to use per-gd cache 1934 * 1935 * VM_ALLOC_CPU(n) allocate using specified cpu localization 1936 * 1937 * The object must be held if not NULL 1938 * This routine may not block 1939 * 1940 * Additional special handling is required when called from an interrupt 1941 * (VM_ALLOC_INTERRUPT). We are not allowed to mess with the page cache 1942 * in this case. 1943 */ 1944 vm_page_t 1945 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req) 1946 { 1947 globaldata_t gd; 1948 vm_object_t obj; 1949 vm_page_t m; 1950 u_short pg_color; 1951 int cpuid_local; 1952 1953 #if 0 1954 /* 1955 * Special per-cpu free VM page cache. The pages are pre-busied 1956 * and pre-zerod for us. 1957 */ 1958 if (gd->gd_vmpg_count && (page_req & VM_ALLOC_USE_GD)) { 1959 crit_enter_gd(gd); 1960 if (gd->gd_vmpg_count) { 1961 m = gd->gd_vmpg_array[--gd->gd_vmpg_count]; 1962 crit_exit_gd(gd); 1963 goto done; 1964 } 1965 crit_exit_gd(gd); 1966 } 1967 #endif 1968 m = NULL; 1969 1970 /* 1971 * CPU LOCALIZATION 1972 * 1973 * CPU localization algorithm. Break the page queues up by physical 1974 * id and core id (note that two cpu threads will have the same core 1975 * id, and core_id != gd_cpuid). 1976 * 1977 * This is nowhere near perfect, for example the last pindex in a 1978 * subgroup will overflow into the next cpu or package. But this 1979 * should get us good page reuse locality in heavy mixed loads. 1980 * 1981 * (may be executed before the APs are started, so other GDs might 1982 * not exist!) 1983 */ 1984 if (page_req & VM_ALLOC_CPU_SPEC) 1985 cpuid_local = VM_ALLOC_GETCPU(page_req); 1986 else 1987 cpuid_local = mycpu->gd_cpuid; 1988 1989 pg_color = vm_get_pg_color(cpuid_local, object, pindex); 1990 1991 KKASSERT(page_req & 1992 (VM_ALLOC_NORMAL|VM_ALLOC_QUICK| 1993 VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM)); 1994 1995 /* 1996 * Certain system threads (pageout daemon, buf_daemon's) are 1997 * allowed to eat deeper into the free page list. 1998 */ 1999 if (curthread->td_flags & TDF_SYSTHREAD) 2000 page_req |= VM_ALLOC_SYSTEM; 2001 2002 /* 2003 * Impose various limitations. Note that the v_free_reserved test 2004 * must match the opposite of vm_page_count_target() to avoid 2005 * livelocks, be careful. 2006 */ 2007 loop: 2008 gd = mycpu; 2009 if (gd->gd_vmstats.v_free_count >= gd->gd_vmstats.v_free_reserved || 2010 ((page_req & VM_ALLOC_INTERRUPT) && 2011 gd->gd_vmstats.v_free_count > 0) || 2012 ((page_req & VM_ALLOC_SYSTEM) && 2013 gd->gd_vmstats.v_cache_count == 0 && 2014 gd->gd_vmstats.v_free_count > 2015 gd->gd_vmstats.v_interrupt_free_min) 2016 ) { 2017 /* 2018 * The free queue has sufficient free pages to take one out. 2019 */ 2020 m = vm_page_select_free(pg_color); 2021 } else if (page_req & VM_ALLOC_NORMAL) { 2022 /* 2023 * Allocatable from the cache (non-interrupt only). On 2024 * success, we must free the page and try again, thus 2025 * ensuring that vmstats.v_*_free_min counters are replenished. 2026 */ 2027 #ifdef INVARIANTS 2028 if (curthread->td_preempted) { 2029 kprintf("vm_page_alloc(): warning, attempt to allocate" 2030 " cache page from preempting interrupt\n"); 2031 m = NULL; 2032 } else { 2033 m = vm_page_select_cache(pg_color); 2034 } 2035 #else 2036 m = vm_page_select_cache(pg_color); 2037 #endif 2038 /* 2039 * On success move the page into the free queue and loop. 2040 * 2041 * Only do this if we can safely acquire the vm_object lock, 2042 * because this is effectively a random page and the caller 2043 * might be holding the lock shared, we don't want to 2044 * deadlock. 2045 */ 2046 if (m != NULL) { 2047 KASSERT(m->dirty == 0, 2048 ("Found dirty cache page %p", m)); 2049 if ((obj = m->object) != NULL) { 2050 if (vm_object_hold_try(obj)) { 2051 vm_page_protect(m, VM_PROT_NONE); 2052 vm_page_free(m); 2053 /* m->object NULL here */ 2054 vm_object_drop(obj); 2055 } else { 2056 vm_page_deactivate(m); 2057 vm_page_wakeup(m); 2058 } 2059 } else { 2060 vm_page_protect(m, VM_PROT_NONE); 2061 vm_page_free(m); 2062 } 2063 goto loop; 2064 } 2065 2066 /* 2067 * On failure return NULL 2068 */ 2069 atomic_add_int(&vm_pageout_deficit, 1); 2070 pagedaemon_wakeup(); 2071 return (NULL); 2072 } else { 2073 /* 2074 * No pages available, wakeup the pageout daemon and give up. 2075 */ 2076 atomic_add_int(&vm_pageout_deficit, 1); 2077 pagedaemon_wakeup(); 2078 return (NULL); 2079 } 2080 2081 /* 2082 * v_free_count can race so loop if we don't find the expected 2083 * page. 2084 */ 2085 if (m == NULL) { 2086 vmstats_rollup(); 2087 goto loop; 2088 } 2089 2090 /* 2091 * Good page found. The page has already been busied for us and 2092 * removed from its queues. 2093 */ 2094 KASSERT(m->dirty == 0, 2095 ("vm_page_alloc: free/cache page %p was dirty", m)); 2096 KKASSERT(m->queue == PQ_NONE); 2097 2098 #if 0 2099 done: 2100 #endif 2101 /* 2102 * Initialize the structure, inheriting some flags but clearing 2103 * all the rest. The page has already been busied for us. 2104 */ 2105 vm_page_flag_clear(m, ~PG_KEEP_NEWPAGE_MASK); 2106 2107 KKASSERT(m->wire_count == 0); 2108 KKASSERT((m->busy_count & PBUSY_MASK) == 0); 2109 m->act_count = 0; 2110 m->valid = 0; 2111 2112 /* 2113 * Caller must be holding the object lock (asserted by 2114 * vm_page_insert()). 2115 * 2116 * NOTE: Inserting a page here does not insert it into any pmaps 2117 * (which could cause us to block allocating memory). 2118 * 2119 * NOTE: If no object an unassociated page is allocated, m->pindex 2120 * can be used by the caller for any purpose. 2121 */ 2122 if (object) { 2123 if (vm_page_insert(m, object, pindex) == FALSE) { 2124 vm_page_free(m); 2125 if ((page_req & VM_ALLOC_NULL_OK) == 0) 2126 panic("PAGE RACE %p[%ld]/%p", 2127 object, (long)pindex, m); 2128 m = NULL; 2129 } 2130 } else { 2131 m->pindex = pindex; 2132 } 2133 2134 /* 2135 * Don't wakeup too often - wakeup the pageout daemon when 2136 * we would be nearly out of memory. 2137 */ 2138 pagedaemon_wakeup(); 2139 2140 /* 2141 * A BUSY page is returned. 2142 */ 2143 return (m); 2144 } 2145 2146 /* 2147 * Returns number of pages available in our DMA memory reserve 2148 * (adjusted with vm.dma_reserved=<value>m in /boot/loader.conf) 2149 */ 2150 vm_size_t 2151 vm_contig_avail_pages(void) 2152 { 2153 alist_blk_t blk; 2154 alist_blk_t count; 2155 alist_blk_t bfree; 2156 spin_lock(&vm_contig_spin); 2157 bfree = alist_free_info(&vm_contig_alist, &blk, &count); 2158 spin_unlock(&vm_contig_spin); 2159 2160 return bfree; 2161 } 2162 2163 /* 2164 * Attempt to allocate contiguous physical memory with the specified 2165 * requirements. 2166 */ 2167 vm_page_t 2168 vm_page_alloc_contig(vm_paddr_t low, vm_paddr_t high, 2169 unsigned long alignment, unsigned long boundary, 2170 unsigned long size, vm_memattr_t memattr) 2171 { 2172 alist_blk_t blk; 2173 vm_page_t m; 2174 vm_pindex_t i; 2175 #if 0 2176 static vm_pindex_t contig_rover; 2177 #endif 2178 2179 alignment >>= PAGE_SHIFT; 2180 if (alignment == 0) 2181 alignment = 1; 2182 boundary >>= PAGE_SHIFT; 2183 if (boundary == 0) 2184 boundary = 1; 2185 size = (size + PAGE_MASK) >> PAGE_SHIFT; 2186 2187 #if 0 2188 /* 2189 * Disabled temporarily until we find a solution for DRM (a flag 2190 * to always use the free space reserve, for performance). 2191 */ 2192 if (high == BUS_SPACE_MAXADDR && alignment <= PAGE_SIZE && 2193 boundary <= PAGE_SIZE && size == 1 && 2194 memattr == VM_MEMATTR_DEFAULT) { 2195 /* 2196 * Any page will work, use vm_page_alloc() 2197 * (e.g. when used from kmem_alloc_attr()) 2198 */ 2199 m = vm_page_alloc(NULL, (contig_rover++) & 0x7FFFFFFF, 2200 VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM | 2201 VM_ALLOC_INTERRUPT); 2202 m->valid = VM_PAGE_BITS_ALL; 2203 vm_page_wire(m); 2204 vm_page_wakeup(m); 2205 } else 2206 #endif 2207 { 2208 /* 2209 * Use the low-memory dma reserve 2210 */ 2211 spin_lock(&vm_contig_spin); 2212 blk = alist_alloc(&vm_contig_alist, 0, size); 2213 if (blk == ALIST_BLOCK_NONE) { 2214 spin_unlock(&vm_contig_spin); 2215 if (bootverbose) { 2216 kprintf("vm_page_alloc_contig: %ldk nospace\n", 2217 (size << PAGE_SHIFT) / 1024); 2218 print_backtrace(5); 2219 } 2220 return(NULL); 2221 } 2222 if (high && ((vm_paddr_t)(blk + size) << PAGE_SHIFT) > high) { 2223 alist_free(&vm_contig_alist, blk, size); 2224 spin_unlock(&vm_contig_spin); 2225 if (bootverbose) { 2226 kprintf("vm_page_alloc_contig: %ldk high " 2227 "%016jx failed\n", 2228 (size << PAGE_SHIFT) / 1024, 2229 (intmax_t)high); 2230 } 2231 return(NULL); 2232 } 2233 spin_unlock(&vm_contig_spin); 2234 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT); 2235 } 2236 if (vm_contig_verbose) { 2237 kprintf("vm_page_alloc_contig: %016jx/%ldk " 2238 "(%016jx-%016jx al=%lu bo=%lu pgs=%lu attr=%d\n", 2239 (intmax_t)m->phys_addr, 2240 (size << PAGE_SHIFT) / 1024, 2241 low, high, alignment, boundary, size, memattr); 2242 } 2243 if (memattr != VM_MEMATTR_DEFAULT) { 2244 for (i = 0;i < size; i++) 2245 pmap_page_set_memattr(&m[i], memattr); 2246 } 2247 return m; 2248 } 2249 2250 /* 2251 * Free contiguously allocated pages. The pages will be wired but not busy. 2252 * When freeing to the alist we leave them wired and not busy. 2253 */ 2254 void 2255 vm_page_free_contig(vm_page_t m, unsigned long size) 2256 { 2257 vm_paddr_t pa = VM_PAGE_TO_PHYS(m); 2258 vm_pindex_t start = pa >> PAGE_SHIFT; 2259 vm_pindex_t pages = (size + PAGE_MASK) >> PAGE_SHIFT; 2260 2261 if (vm_contig_verbose) { 2262 kprintf("vm_page_free_contig: %016jx/%ldk\n", 2263 (intmax_t)pa, size / 1024); 2264 } 2265 if (pa < vm_low_phys_reserved) { 2266 KKASSERT(pa + size <= vm_low_phys_reserved); 2267 spin_lock(&vm_contig_spin); 2268 alist_free(&vm_contig_alist, start, pages); 2269 spin_unlock(&vm_contig_spin); 2270 } else { 2271 while (pages) { 2272 vm_page_busy_wait(m, FALSE, "cpgfr"); 2273 vm_page_unwire(m, 0); 2274 vm_page_free(m); 2275 --pages; 2276 ++m; 2277 } 2278 2279 } 2280 } 2281 2282 2283 /* 2284 * Wait for sufficient free memory for nominal heavy memory use kernel 2285 * operations. 2286 * 2287 * WARNING! Be sure never to call this in any vm_pageout code path, which 2288 * will trivially deadlock the system. 2289 */ 2290 void 2291 vm_wait_nominal(void) 2292 { 2293 while (vm_page_count_min(0)) 2294 vm_wait(0); 2295 } 2296 2297 /* 2298 * Test if vm_wait_nominal() would block. 2299 */ 2300 int 2301 vm_test_nominal(void) 2302 { 2303 if (vm_page_count_min(0)) 2304 return(1); 2305 return(0); 2306 } 2307 2308 /* 2309 * Block until free pages are available for allocation, called in various 2310 * places before memory allocations. 2311 * 2312 * The caller may loop if vm_page_count_min() == FALSE so we cannot be 2313 * more generous then that. 2314 */ 2315 void 2316 vm_wait(int timo) 2317 { 2318 /* 2319 * never wait forever 2320 */ 2321 if (timo == 0) 2322 timo = hz; 2323 lwkt_gettoken(&vm_token); 2324 2325 if (curthread == pagethread || 2326 curthread == emergpager) { 2327 /* 2328 * The pageout daemon itself needs pages, this is bad. 2329 */ 2330 if (vm_page_count_min(0)) { 2331 vm_pageout_pages_needed = 1; 2332 tsleep(&vm_pageout_pages_needed, 0, "VMWait", timo); 2333 } 2334 } else { 2335 /* 2336 * Wakeup the pageout daemon if necessary and wait. 2337 * 2338 * Do not wait indefinitely for the target to be reached, 2339 * as load might prevent it from being reached any time soon. 2340 * But wait a little to try to slow down page allocations 2341 * and to give more important threads (the pagedaemon) 2342 * allocation priority. 2343 */ 2344 if (vm_page_count_target()) { 2345 if (vm_pages_needed == 0) { 2346 vm_pages_needed = 1; 2347 wakeup(&vm_pages_needed); 2348 } 2349 ++vm_pages_waiting; /* SMP race ok */ 2350 tsleep(&vmstats.v_free_count, 0, "vmwait", timo); 2351 } 2352 } 2353 lwkt_reltoken(&vm_token); 2354 } 2355 2356 /* 2357 * Block until free pages are available for allocation 2358 * 2359 * Called only from vm_fault so that processes page faulting can be 2360 * easily tracked. 2361 */ 2362 void 2363 vm_wait_pfault(void) 2364 { 2365 /* 2366 * Wakeup the pageout daemon if necessary and wait. 2367 * 2368 * Do not wait indefinitely for the target to be reached, 2369 * as load might prevent it from being reached any time soon. 2370 * But wait a little to try to slow down page allocations 2371 * and to give more important threads (the pagedaemon) 2372 * allocation priority. 2373 */ 2374 if (vm_page_count_min(0)) { 2375 lwkt_gettoken(&vm_token); 2376 while (vm_page_count_severe()) { 2377 if (vm_page_count_target()) { 2378 thread_t td; 2379 2380 if (vm_pages_needed == 0) { 2381 vm_pages_needed = 1; 2382 wakeup(&vm_pages_needed); 2383 } 2384 ++vm_pages_waiting; /* SMP race ok */ 2385 tsleep(&vmstats.v_free_count, 0, "pfault", hz); 2386 2387 /* 2388 * Do not stay stuck in the loop if the system is trying 2389 * to kill the process. 2390 */ 2391 td = curthread; 2392 if (td->td_proc && (td->td_proc->p_flags & P_LOWMEMKILL)) 2393 break; 2394 } 2395 } 2396 lwkt_reltoken(&vm_token); 2397 } 2398 } 2399 2400 /* 2401 * Put the specified page on the active list (if appropriate). Ensure 2402 * that act_count is at least ACT_INIT but do not otherwise mess with it. 2403 * 2404 * The caller should be holding the page busied ? XXX 2405 * This routine may not block. 2406 */ 2407 void 2408 vm_page_activate(vm_page_t m) 2409 { 2410 u_short oqueue; 2411 2412 vm_page_spin_lock(m); 2413 if (m->queue - m->pc != PQ_ACTIVE) { 2414 _vm_page_queue_spin_lock(m); 2415 oqueue = _vm_page_rem_queue_spinlocked(m); 2416 /* page is left spinlocked, queue is unlocked */ 2417 2418 if (oqueue == PQ_CACHE) 2419 mycpu->gd_cnt.v_reactivated++; 2420 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 2421 if (m->act_count < ACT_INIT) 2422 m->act_count = ACT_INIT; 2423 _vm_page_add_queue_spinlocked(m, PQ_ACTIVE + m->pc, 0); 2424 } 2425 _vm_page_and_queue_spin_unlock(m); 2426 if (oqueue == PQ_CACHE || oqueue == PQ_FREE) 2427 pagedaemon_wakeup(); 2428 } else { 2429 if (m->act_count < ACT_INIT) 2430 m->act_count = ACT_INIT; 2431 vm_page_spin_unlock(m); 2432 } 2433 } 2434 2435 /* 2436 * Helper routine for vm_page_free_toq() and vm_page_cache(). This 2437 * routine is called when a page has been added to the cache or free 2438 * queues. 2439 * 2440 * This routine may not block. 2441 */ 2442 static __inline void 2443 vm_page_free_wakeup(void) 2444 { 2445 globaldata_t gd = mycpu; 2446 2447 /* 2448 * If the pageout daemon itself needs pages, then tell it that 2449 * there are some free. 2450 */ 2451 if (vm_pageout_pages_needed && 2452 gd->gd_vmstats.v_cache_count + gd->gd_vmstats.v_free_count >= 2453 gd->gd_vmstats.v_pageout_free_min 2454 ) { 2455 vm_pageout_pages_needed = 0; 2456 wakeup(&vm_pageout_pages_needed); 2457 } 2458 2459 /* 2460 * Wakeup processes that are waiting on memory. 2461 * 2462 * Generally speaking we want to wakeup stuck processes as soon as 2463 * possible. !vm_page_count_min(0) is the absolute minimum point 2464 * where we can do this. Wait a bit longer to reduce degenerate 2465 * re-blocking (vm_page_free_hysteresis). The target check is just 2466 * to make sure the min-check w/hysteresis does not exceed the 2467 * normal target. 2468 */ 2469 if (vm_pages_waiting) { 2470 if (!vm_page_count_min(vm_page_free_hysteresis) || 2471 !vm_page_count_target()) { 2472 vm_pages_waiting = 0; 2473 wakeup(&vmstats.v_free_count); 2474 ++mycpu->gd_cnt.v_ppwakeups; 2475 } 2476 #if 0 2477 if (!vm_page_count_target()) { 2478 /* 2479 * Plenty of pages are free, wakeup everyone. 2480 */ 2481 vm_pages_waiting = 0; 2482 wakeup(&vmstats.v_free_count); 2483 ++mycpu->gd_cnt.v_ppwakeups; 2484 } else if (!vm_page_count_min(0)) { 2485 /* 2486 * Some pages are free, wakeup someone. 2487 */ 2488 int wcount = vm_pages_waiting; 2489 if (wcount > 0) 2490 --wcount; 2491 vm_pages_waiting = wcount; 2492 wakeup_one(&vmstats.v_free_count); 2493 ++mycpu->gd_cnt.v_ppwakeups; 2494 } 2495 #endif 2496 } 2497 } 2498 2499 /* 2500 * Returns the given page to the PQ_FREE or PQ_HOLD list and disassociates 2501 * it from its VM object. 2502 * 2503 * The vm_page must be BUSY on entry. BUSY will be released on 2504 * return (the page will have been freed). 2505 */ 2506 void 2507 vm_page_free_toq(vm_page_t m) 2508 { 2509 mycpu->gd_cnt.v_tfree++; 2510 KKASSERT((m->flags & PG_MAPPED) == 0); 2511 KKASSERT(m->busy_count & PBUSY_LOCKED); 2512 2513 if ((m->busy_count & PBUSY_MASK) || ((m->queue - m->pc) == PQ_FREE)) { 2514 kprintf("vm_page_free: pindex(%lu), busy %08x, " 2515 "hold(%d)\n", 2516 (u_long)m->pindex, m->busy_count, m->hold_count); 2517 if ((m->queue - m->pc) == PQ_FREE) 2518 panic("vm_page_free: freeing free page"); 2519 else 2520 panic("vm_page_free: freeing busy page"); 2521 } 2522 2523 /* 2524 * Remove from object, spinlock the page and its queues and 2525 * remove from any queue. No queue spinlock will be held 2526 * after this section (because the page was removed from any 2527 * queue). 2528 */ 2529 vm_page_remove(m); 2530 vm_page_and_queue_spin_lock(m); 2531 _vm_page_rem_queue_spinlocked(m); 2532 2533 /* 2534 * No further management of fictitious pages occurs beyond object 2535 * and queue removal. 2536 */ 2537 if ((m->flags & PG_FICTITIOUS) != 0) { 2538 vm_page_spin_unlock(m); 2539 vm_page_wakeup(m); 2540 return; 2541 } 2542 2543 m->valid = 0; 2544 vm_page_undirty(m); 2545 2546 if (m->wire_count != 0) { 2547 if (m->wire_count > 1) { 2548 panic( 2549 "vm_page_free: invalid wire count (%d), pindex: 0x%lx", 2550 m->wire_count, (long)m->pindex); 2551 } 2552 panic("vm_page_free: freeing wired page"); 2553 } 2554 2555 /* 2556 * Clear the UNMANAGED flag when freeing an unmanaged page. 2557 * Clear the NEED_COMMIT flag 2558 */ 2559 if (m->flags & PG_UNMANAGED) 2560 vm_page_flag_clear(m, PG_UNMANAGED); 2561 if (m->flags & PG_NEED_COMMIT) 2562 vm_page_flag_clear(m, PG_NEED_COMMIT); 2563 2564 if (m->hold_count != 0) { 2565 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0); 2566 } else { 2567 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1); 2568 } 2569 2570 /* 2571 * This sequence allows us to clear BUSY while still holding 2572 * its spin lock, which reduces contention vs allocators. We 2573 * must not leave the queue locked or _vm_page_wakeup() may 2574 * deadlock. 2575 */ 2576 _vm_page_queue_spin_unlock(m); 2577 if (_vm_page_wakeup(m)) { 2578 vm_page_spin_unlock(m); 2579 wakeup(m); 2580 } else { 2581 vm_page_spin_unlock(m); 2582 } 2583 vm_page_free_wakeup(); 2584 } 2585 2586 /* 2587 * vm_page_unmanage() 2588 * 2589 * Prevent PV management from being done on the page. The page is 2590 * removed from the paging queues as if it were wired, and as a 2591 * consequence of no longer being managed the pageout daemon will not 2592 * touch it (since there is no way to locate the pte mappings for the 2593 * page). madvise() calls that mess with the pmap will also no longer 2594 * operate on the page. 2595 * 2596 * Beyond that the page is still reasonably 'normal'. Freeing the page 2597 * will clear the flag. 2598 * 2599 * This routine is used by OBJT_PHYS objects - objects using unswappable 2600 * physical memory as backing store rather then swap-backed memory and 2601 * will eventually be extended to support 4MB unmanaged physical 2602 * mappings. 2603 * 2604 * Caller must be holding the page busy. 2605 */ 2606 void 2607 vm_page_unmanage(vm_page_t m) 2608 { 2609 KKASSERT(m->busy_count & PBUSY_LOCKED); 2610 if ((m->flags & PG_UNMANAGED) == 0) { 2611 if (m->wire_count == 0) 2612 vm_page_unqueue(m); 2613 } 2614 vm_page_flag_set(m, PG_UNMANAGED); 2615 } 2616 2617 /* 2618 * Mark this page as wired down by yet another map, removing it from 2619 * paging queues as necessary. 2620 * 2621 * Caller must be holding the page busy. 2622 */ 2623 void 2624 vm_page_wire(vm_page_t m) 2625 { 2626 /* 2627 * Only bump the wire statistics if the page is not already wired, 2628 * and only unqueue the page if it is on some queue (if it is unmanaged 2629 * it is already off the queues). Don't do anything with fictitious 2630 * pages because they are always wired. 2631 */ 2632 KKASSERT(m->busy_count & PBUSY_LOCKED); 2633 if ((m->flags & PG_FICTITIOUS) == 0) { 2634 if (atomic_fetchadd_int(&m->wire_count, 1) == 0) { 2635 if ((m->flags & PG_UNMANAGED) == 0) 2636 vm_page_unqueue(m); 2637 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count, 1); 2638 } 2639 KASSERT(m->wire_count != 0, 2640 ("vm_page_wire: wire_count overflow m=%p", m)); 2641 } 2642 } 2643 2644 /* 2645 * Release one wiring of this page, potentially enabling it to be paged again. 2646 * 2647 * Many pages placed on the inactive queue should actually go 2648 * into the cache, but it is difficult to figure out which. What 2649 * we do instead, if the inactive target is well met, is to put 2650 * clean pages at the head of the inactive queue instead of the tail. 2651 * This will cause them to be moved to the cache more quickly and 2652 * if not actively re-referenced, freed more quickly. If we just 2653 * stick these pages at the end of the inactive queue, heavy filesystem 2654 * meta-data accesses can cause an unnecessary paging load on memory bound 2655 * processes. This optimization causes one-time-use metadata to be 2656 * reused more quickly. 2657 * 2658 * Pages marked PG_NEED_COMMIT are always activated and never placed on 2659 * the inactive queue. This helps the pageout daemon determine memory 2660 * pressure and act on out-of-memory situations more quickly. 2661 * 2662 * BUT, if we are in a low-memory situation we have no choice but to 2663 * put clean pages on the cache queue. 2664 * 2665 * A number of routines use vm_page_unwire() to guarantee that the page 2666 * will go into either the inactive or active queues, and will NEVER 2667 * be placed in the cache - for example, just after dirtying a page. 2668 * dirty pages in the cache are not allowed. 2669 * 2670 * This routine may not block. 2671 */ 2672 void 2673 vm_page_unwire(vm_page_t m, int activate) 2674 { 2675 KKASSERT(m->busy_count & PBUSY_LOCKED); 2676 if (m->flags & PG_FICTITIOUS) { 2677 /* do nothing */ 2678 } else if (m->wire_count <= 0) { 2679 panic("vm_page_unwire: invalid wire count: %d", m->wire_count); 2680 } else { 2681 if (atomic_fetchadd_int(&m->wire_count, -1) == 1) { 2682 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count,-1); 2683 if (m->flags & PG_UNMANAGED) { 2684 ; 2685 } else if (activate || (m->flags & PG_NEED_COMMIT)) { 2686 vm_page_spin_lock(m); 2687 _vm_page_add_queue_spinlocked(m, 2688 PQ_ACTIVE + m->pc, 0); 2689 _vm_page_and_queue_spin_unlock(m); 2690 } else { 2691 vm_page_spin_lock(m); 2692 vm_page_flag_clear(m, PG_WINATCFLS); 2693 _vm_page_add_queue_spinlocked(m, 2694 PQ_INACTIVE + m->pc, 0); 2695 ++vm_swapcache_inactive_heuristic; 2696 _vm_page_and_queue_spin_unlock(m); 2697 } 2698 } 2699 } 2700 } 2701 2702 /* 2703 * Move the specified page to the inactive queue. If the page has 2704 * any associated swap, the swap is deallocated. 2705 * 2706 * Normally athead is 0 resulting in LRU operation. athead is set 2707 * to 1 if we want this page to be 'as if it were placed in the cache', 2708 * except without unmapping it from the process address space. 2709 * 2710 * vm_page's spinlock must be held on entry and will remain held on return. 2711 * This routine may not block. 2712 */ 2713 static void 2714 _vm_page_deactivate_locked(vm_page_t m, int athead) 2715 { 2716 u_short oqueue; 2717 2718 /* 2719 * Ignore if already inactive. 2720 */ 2721 if (m->queue - m->pc == PQ_INACTIVE) 2722 return; 2723 _vm_page_queue_spin_lock(m); 2724 oqueue = _vm_page_rem_queue_spinlocked(m); 2725 2726 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) { 2727 if (oqueue == PQ_CACHE) 2728 mycpu->gd_cnt.v_reactivated++; 2729 vm_page_flag_clear(m, PG_WINATCFLS); 2730 _vm_page_add_queue_spinlocked(m, PQ_INACTIVE + m->pc, athead); 2731 if (athead == 0) 2732 ++vm_swapcache_inactive_heuristic; 2733 } 2734 /* NOTE: PQ_NONE if condition not taken */ 2735 _vm_page_queue_spin_unlock(m); 2736 /* leaves vm_page spinlocked */ 2737 } 2738 2739 /* 2740 * Attempt to deactivate a page. 2741 * 2742 * No requirements. 2743 */ 2744 void 2745 vm_page_deactivate(vm_page_t m) 2746 { 2747 vm_page_spin_lock(m); 2748 _vm_page_deactivate_locked(m, 0); 2749 vm_page_spin_unlock(m); 2750 } 2751 2752 void 2753 vm_page_deactivate_locked(vm_page_t m) 2754 { 2755 _vm_page_deactivate_locked(m, 0); 2756 } 2757 2758 /* 2759 * Attempt to move a busied page to PQ_CACHE, then unconditionally unbusy it. 2760 * 2761 * This function returns non-zero if it successfully moved the page to 2762 * PQ_CACHE. 2763 * 2764 * This function unconditionally unbusies the page on return. 2765 */ 2766 int 2767 vm_page_try_to_cache(vm_page_t m) 2768 { 2769 vm_page_spin_lock(m); 2770 if (m->dirty || m->hold_count || m->wire_count || 2771 (m->flags & (PG_UNMANAGED | PG_NEED_COMMIT))) { 2772 if (_vm_page_wakeup(m)) { 2773 vm_page_spin_unlock(m); 2774 wakeup(m); 2775 } else { 2776 vm_page_spin_unlock(m); 2777 } 2778 return(0); 2779 } 2780 vm_page_spin_unlock(m); 2781 2782 /* 2783 * Page busied by us and no longer spinlocked. Dirty pages cannot 2784 * be moved to the cache. 2785 */ 2786 vm_page_test_dirty(m); 2787 if (m->dirty || (m->flags & PG_NEED_COMMIT)) { 2788 vm_page_wakeup(m); 2789 return(0); 2790 } 2791 vm_page_cache(m); 2792 return(1); 2793 } 2794 2795 /* 2796 * Attempt to free the page. If we cannot free it, we do nothing. 2797 * 1 is returned on success, 0 on failure. 2798 * 2799 * No requirements. 2800 */ 2801 int 2802 vm_page_try_to_free(vm_page_t m) 2803 { 2804 vm_page_spin_lock(m); 2805 if (vm_page_busy_try(m, TRUE)) { 2806 vm_page_spin_unlock(m); 2807 return(0); 2808 } 2809 2810 /* 2811 * The page can be in any state, including already being on the free 2812 * queue. Check to see if it really can be freed. 2813 */ 2814 if (m->dirty || /* can't free if it is dirty */ 2815 m->hold_count || /* or held (XXX may be wrong) */ 2816 m->wire_count || /* or wired */ 2817 (m->flags & (PG_UNMANAGED | /* or unmanaged */ 2818 PG_NEED_COMMIT)) || /* or needs a commit */ 2819 m->queue - m->pc == PQ_FREE || /* already on PQ_FREE */ 2820 m->queue - m->pc == PQ_HOLD) { /* already on PQ_HOLD */ 2821 if (_vm_page_wakeup(m)) { 2822 vm_page_spin_unlock(m); 2823 wakeup(m); 2824 } else { 2825 vm_page_spin_unlock(m); 2826 } 2827 return(0); 2828 } 2829 vm_page_spin_unlock(m); 2830 2831 /* 2832 * We can probably free the page. 2833 * 2834 * Page busied by us and no longer spinlocked. Dirty pages will 2835 * not be freed by this function. We have to re-test the 2836 * dirty bit after cleaning out the pmaps. 2837 */ 2838 vm_page_test_dirty(m); 2839 if (m->dirty || (m->flags & PG_NEED_COMMIT)) { 2840 vm_page_wakeup(m); 2841 return(0); 2842 } 2843 vm_page_protect(m, VM_PROT_NONE); 2844 if (m->dirty || (m->flags & PG_NEED_COMMIT)) { 2845 vm_page_wakeup(m); 2846 return(0); 2847 } 2848 vm_page_free(m); 2849 return(1); 2850 } 2851 2852 /* 2853 * vm_page_cache 2854 * 2855 * Put the specified page onto the page cache queue (if appropriate). 2856 * 2857 * The page must be busy, and this routine will release the busy and 2858 * possibly even free the page. 2859 */ 2860 void 2861 vm_page_cache(vm_page_t m) 2862 { 2863 /* 2864 * Not suitable for the cache 2865 */ 2866 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT)) || 2867 (m->busy_count & PBUSY_MASK) || 2868 m->wire_count || m->hold_count) { 2869 vm_page_wakeup(m); 2870 return; 2871 } 2872 2873 /* 2874 * Already in the cache (and thus not mapped) 2875 */ 2876 if ((m->queue - m->pc) == PQ_CACHE) { 2877 KKASSERT((m->flags & PG_MAPPED) == 0); 2878 vm_page_wakeup(m); 2879 return; 2880 } 2881 2882 /* 2883 * Caller is required to test m->dirty, but note that the act of 2884 * removing the page from its maps can cause it to become dirty 2885 * on an SMP system due to another cpu running in usermode. 2886 */ 2887 if (m->dirty) { 2888 panic("vm_page_cache: caching a dirty page, pindex: %ld", 2889 (long)m->pindex); 2890 } 2891 2892 /* 2893 * Remove all pmaps and indicate that the page is not 2894 * writeable or mapped. Our vm_page_protect() call may 2895 * have blocked (especially w/ VM_PROT_NONE), so recheck 2896 * everything. 2897 */ 2898 vm_page_protect(m, VM_PROT_NONE); 2899 if ((m->flags & (PG_UNMANAGED | PG_MAPPED)) || 2900 (m->busy_count & PBUSY_MASK) || 2901 m->wire_count || m->hold_count) { 2902 vm_page_wakeup(m); 2903 } else if (m->dirty || (m->flags & PG_NEED_COMMIT)) { 2904 vm_page_deactivate(m); 2905 vm_page_wakeup(m); 2906 } else { 2907 _vm_page_and_queue_spin_lock(m); 2908 _vm_page_rem_queue_spinlocked(m); 2909 _vm_page_add_queue_spinlocked(m, PQ_CACHE + m->pc, 0); 2910 _vm_page_queue_spin_unlock(m); 2911 if (_vm_page_wakeup(m)) { 2912 vm_page_spin_unlock(m); 2913 wakeup(m); 2914 } else { 2915 vm_page_spin_unlock(m); 2916 } 2917 vm_page_free_wakeup(); 2918 } 2919 } 2920 2921 /* 2922 * vm_page_dontneed() 2923 * 2924 * Cache, deactivate, or do nothing as appropriate. This routine 2925 * is typically used by madvise() MADV_DONTNEED. 2926 * 2927 * Generally speaking we want to move the page into the cache so 2928 * it gets reused quickly. However, this can result in a silly syndrome 2929 * due to the page recycling too quickly. Small objects will not be 2930 * fully cached. On the otherhand, if we move the page to the inactive 2931 * queue we wind up with a problem whereby very large objects 2932 * unnecessarily blow away our inactive and cache queues. 2933 * 2934 * The solution is to move the pages based on a fixed weighting. We 2935 * either leave them alone, deactivate them, or move them to the cache, 2936 * where moving them to the cache has the highest weighting. 2937 * By forcing some pages into other queues we eventually force the 2938 * system to balance the queues, potentially recovering other unrelated 2939 * space from active. The idea is to not force this to happen too 2940 * often. 2941 * 2942 * The page must be busied. 2943 */ 2944 void 2945 vm_page_dontneed(vm_page_t m) 2946 { 2947 static int dnweight; 2948 int dnw; 2949 int head; 2950 2951 dnw = ++dnweight; 2952 2953 /* 2954 * occassionally leave the page alone 2955 */ 2956 if ((dnw & 0x01F0) == 0 || 2957 m->queue - m->pc == PQ_INACTIVE || 2958 m->queue - m->pc == PQ_CACHE 2959 ) { 2960 if (m->act_count >= ACT_INIT) 2961 --m->act_count; 2962 return; 2963 } 2964 2965 /* 2966 * If vm_page_dontneed() is inactivating a page, it must clear 2967 * the referenced flag; otherwise the pagedaemon will see references 2968 * on the page in the inactive queue and reactivate it. Until the 2969 * page can move to the cache queue, madvise's job is not done. 2970 */ 2971 vm_page_flag_clear(m, PG_REFERENCED); 2972 pmap_clear_reference(m); 2973 2974 if (m->dirty == 0) 2975 vm_page_test_dirty(m); 2976 2977 if (m->dirty || (dnw & 0x0070) == 0) { 2978 /* 2979 * Deactivate the page 3 times out of 32. 2980 */ 2981 head = 0; 2982 } else { 2983 /* 2984 * Cache the page 28 times out of every 32. Note that 2985 * the page is deactivated instead of cached, but placed 2986 * at the head of the queue instead of the tail. 2987 */ 2988 head = 1; 2989 } 2990 vm_page_spin_lock(m); 2991 _vm_page_deactivate_locked(m, head); 2992 vm_page_spin_unlock(m); 2993 } 2994 2995 /* 2996 * These routines manipulate the 'soft busy' count for a page. A soft busy 2997 * is almost like a hard BUSY except that it allows certain compatible 2998 * operations to occur on the page while it is busy. For example, a page 2999 * undergoing a write can still be mapped read-only. 3000 * 3001 * We also use soft-busy to quickly pmap_enter shared read-only pages 3002 * without having to hold the page locked. 3003 * 3004 * The soft-busy count can be > 1 in situations where multiple threads 3005 * are pmap_enter()ing the same page simultaneously, or when two buffer 3006 * cache buffers overlap the same page. 3007 * 3008 * The caller must hold the page BUSY when making these two calls. 3009 */ 3010 void 3011 vm_page_io_start(vm_page_t m) 3012 { 3013 uint32_t ocount; 3014 3015 ocount = atomic_fetchadd_int(&m->busy_count, 1); 3016 KKASSERT(ocount & PBUSY_LOCKED); 3017 } 3018 3019 void 3020 vm_page_io_finish(vm_page_t m) 3021 { 3022 uint32_t ocount; 3023 3024 ocount = atomic_fetchadd_int(&m->busy_count, -1); 3025 KKASSERT(ocount & PBUSY_MASK); 3026 #if 0 3027 if (((ocount - 1) & (PBUSY_LOCKED | PBUSY_MASK)) == 0) 3028 wakeup(m); 3029 #endif 3030 } 3031 3032 /* 3033 * Attempt to soft-busy a page. The page must not be PBUSY_LOCKED. 3034 * 3035 * We can't use fetchadd here because we might race a hard-busy and the 3036 * page freeing code asserts on a non-zero soft-busy count (even if only 3037 * temporary). 3038 * 3039 * Returns 0 on success, non-zero on failure. 3040 */ 3041 int 3042 vm_page_sbusy_try(vm_page_t m) 3043 { 3044 uint32_t ocount; 3045 3046 for (;;) { 3047 ocount = m->busy_count; 3048 cpu_ccfence(); 3049 if (ocount & PBUSY_LOCKED) 3050 return 1; 3051 if (atomic_cmpset_int(&m->busy_count, ocount, ocount + 1)) 3052 break; 3053 } 3054 return 0; 3055 #if 0 3056 if (m->busy_count & PBUSY_LOCKED) 3057 return 1; 3058 ocount = atomic_fetchadd_int(&m->busy_count, 1); 3059 if (ocount & PBUSY_LOCKED) { 3060 vm_page_sbusy_drop(m); 3061 return 1; 3062 } 3063 return 0; 3064 #endif 3065 } 3066 3067 /* 3068 * Indicate that a clean VM page requires a filesystem commit and cannot 3069 * be reused. Used by tmpfs. 3070 */ 3071 void 3072 vm_page_need_commit(vm_page_t m) 3073 { 3074 vm_page_flag_set(m, PG_NEED_COMMIT); 3075 vm_object_set_writeable_dirty(m->object); 3076 } 3077 3078 void 3079 vm_page_clear_commit(vm_page_t m) 3080 { 3081 vm_page_flag_clear(m, PG_NEED_COMMIT); 3082 } 3083 3084 /* 3085 * Grab a page, blocking if it is busy and allocating a page if necessary. 3086 * A busy page is returned or NULL. The page may or may not be valid and 3087 * might not be on a queue (the caller is responsible for the disposition of 3088 * the page). 3089 * 3090 * If VM_ALLOC_ZERO is specified and the grab must allocate a new page, the 3091 * page will be zero'd and marked valid. 3092 * 3093 * If VM_ALLOC_FORCE_ZERO is specified the page will be zero'd and marked 3094 * valid even if it already exists. 3095 * 3096 * If VM_ALLOC_RETRY is specified this routine will never return NULL. Also 3097 * note that VM_ALLOC_NORMAL must be specified if VM_ALLOC_RETRY is specified. 3098 * VM_ALLOC_NULL_OK is implied when VM_ALLOC_RETRY is specified. 3099 * 3100 * This routine may block, but if VM_ALLOC_RETRY is not set then NULL is 3101 * always returned if we had blocked. 3102 * 3103 * This routine may not be called from an interrupt. 3104 * 3105 * No other requirements. 3106 */ 3107 vm_page_t 3108 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags) 3109 { 3110 vm_page_t m; 3111 int error; 3112 int shared = 1; 3113 3114 KKASSERT(allocflags & 3115 (VM_ALLOC_NORMAL|VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM)); 3116 vm_object_hold_shared(object); 3117 for (;;) { 3118 m = vm_page_lookup_busy_try(object, pindex, TRUE, &error); 3119 if (error) { 3120 vm_page_sleep_busy(m, TRUE, "pgrbwt"); 3121 if ((allocflags & VM_ALLOC_RETRY) == 0) { 3122 m = NULL; 3123 break; 3124 } 3125 /* retry */ 3126 } else if (m == NULL) { 3127 if (shared) { 3128 vm_object_upgrade(object); 3129 shared = 0; 3130 } 3131 if (allocflags & VM_ALLOC_RETRY) 3132 allocflags |= VM_ALLOC_NULL_OK; 3133 m = vm_page_alloc(object, pindex, 3134 allocflags & ~VM_ALLOC_RETRY); 3135 if (m) 3136 break; 3137 vm_wait(0); 3138 if ((allocflags & VM_ALLOC_RETRY) == 0) 3139 goto failed; 3140 } else { 3141 /* m found */ 3142 break; 3143 } 3144 } 3145 3146 /* 3147 * If VM_ALLOC_ZERO an invalid page will be zero'd and set valid. 3148 * 3149 * If VM_ALLOC_FORCE_ZERO the page is unconditionally zero'd and set 3150 * valid even if already valid. 3151 * 3152 * NOTE! We have removed all of the PG_ZERO optimizations and also 3153 * removed the idle zeroing code. These optimizations actually 3154 * slow things down on modern cpus because the zerod area is 3155 * likely uncached, placing a memory-access burden on the 3156 * accesors taking the fault. 3157 * 3158 * By always zeroing the page in-line with the fault, no 3159 * dynamic ram reads are needed and the caches are hot, ready 3160 * for userland to access the memory. 3161 */ 3162 if (m->valid == 0) { 3163 if (allocflags & (VM_ALLOC_ZERO | VM_ALLOC_FORCE_ZERO)) { 3164 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 3165 m->valid = VM_PAGE_BITS_ALL; 3166 } 3167 } else if (allocflags & VM_ALLOC_FORCE_ZERO) { 3168 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 3169 m->valid = VM_PAGE_BITS_ALL; 3170 } 3171 failed: 3172 vm_object_drop(object); 3173 return(m); 3174 } 3175 3176 /* 3177 * Mapping function for valid bits or for dirty bits in 3178 * a page. May not block. 3179 * 3180 * Inputs are required to range within a page. 3181 * 3182 * No requirements. 3183 * Non blocking. 3184 */ 3185 int 3186 vm_page_bits(int base, int size) 3187 { 3188 int first_bit; 3189 int last_bit; 3190 3191 KASSERT( 3192 base + size <= PAGE_SIZE, 3193 ("vm_page_bits: illegal base/size %d/%d", base, size) 3194 ); 3195 3196 if (size == 0) /* handle degenerate case */ 3197 return(0); 3198 3199 first_bit = base >> DEV_BSHIFT; 3200 last_bit = (base + size - 1) >> DEV_BSHIFT; 3201 3202 return ((2 << last_bit) - (1 << first_bit)); 3203 } 3204 3205 /* 3206 * Sets portions of a page valid and clean. The arguments are expected 3207 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive 3208 * of any partial chunks touched by the range. The invalid portion of 3209 * such chunks will be zero'd. 3210 * 3211 * NOTE: When truncating a buffer vnode_pager_setsize() will automatically 3212 * align base to DEV_BSIZE so as not to mark clean a partially 3213 * truncated device block. Otherwise the dirty page status might be 3214 * lost. 3215 * 3216 * This routine may not block. 3217 * 3218 * (base + size) must be less then or equal to PAGE_SIZE. 3219 */ 3220 static void 3221 _vm_page_zero_valid(vm_page_t m, int base, int size) 3222 { 3223 int frag; 3224 int endoff; 3225 3226 if (size == 0) /* handle degenerate case */ 3227 return; 3228 3229 /* 3230 * If the base is not DEV_BSIZE aligned and the valid 3231 * bit is clear, we have to zero out a portion of the 3232 * first block. 3233 */ 3234 3235 if ((frag = base & ~(DEV_BSIZE - 1)) != base && 3236 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0 3237 ) { 3238 pmap_zero_page_area( 3239 VM_PAGE_TO_PHYS(m), 3240 frag, 3241 base - frag 3242 ); 3243 } 3244 3245 /* 3246 * If the ending offset is not DEV_BSIZE aligned and the 3247 * valid bit is clear, we have to zero out a portion of 3248 * the last block. 3249 */ 3250 3251 endoff = base + size; 3252 3253 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff && 3254 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0 3255 ) { 3256 pmap_zero_page_area( 3257 VM_PAGE_TO_PHYS(m), 3258 endoff, 3259 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)) 3260 ); 3261 } 3262 } 3263 3264 /* 3265 * Set valid, clear dirty bits. If validating the entire 3266 * page we can safely clear the pmap modify bit. We also 3267 * use this opportunity to clear the PG_NOSYNC flag. If a process 3268 * takes a write fault on a MAP_NOSYNC memory area the flag will 3269 * be set again. 3270 * 3271 * We set valid bits inclusive of any overlap, but we can only 3272 * clear dirty bits for DEV_BSIZE chunks that are fully within 3273 * the range. 3274 * 3275 * Page must be busied? 3276 * No other requirements. 3277 */ 3278 void 3279 vm_page_set_valid(vm_page_t m, int base, int size) 3280 { 3281 _vm_page_zero_valid(m, base, size); 3282 m->valid |= vm_page_bits(base, size); 3283 } 3284 3285 3286 /* 3287 * Set valid bits and clear dirty bits. 3288 * 3289 * Page must be busied by caller. 3290 * 3291 * NOTE: This function does not clear the pmap modified bit. 3292 * Also note that e.g. NFS may use a byte-granular base 3293 * and size. 3294 * 3295 * No other requirements. 3296 */ 3297 void 3298 vm_page_set_validclean(vm_page_t m, int base, int size) 3299 { 3300 int pagebits; 3301 3302 _vm_page_zero_valid(m, base, size); 3303 pagebits = vm_page_bits(base, size); 3304 m->valid |= pagebits; 3305 m->dirty &= ~pagebits; 3306 if (base == 0 && size == PAGE_SIZE) { 3307 /*pmap_clear_modify(m);*/ 3308 vm_page_flag_clear(m, PG_NOSYNC); 3309 } 3310 } 3311 3312 /* 3313 * Set valid & dirty. Used by buwrite() 3314 * 3315 * Page must be busied by caller. 3316 */ 3317 void 3318 vm_page_set_validdirty(vm_page_t m, int base, int size) 3319 { 3320 int pagebits; 3321 3322 pagebits = vm_page_bits(base, size); 3323 m->valid |= pagebits; 3324 m->dirty |= pagebits; 3325 if (m->object) 3326 vm_object_set_writeable_dirty(m->object); 3327 } 3328 3329 /* 3330 * Clear dirty bits. 3331 * 3332 * NOTE: This function does not clear the pmap modified bit. 3333 * Also note that e.g. NFS may use a byte-granular base 3334 * and size. 3335 * 3336 * Page must be busied? 3337 * No other requirements. 3338 */ 3339 void 3340 vm_page_clear_dirty(vm_page_t m, int base, int size) 3341 { 3342 m->dirty &= ~vm_page_bits(base, size); 3343 if (base == 0 && size == PAGE_SIZE) { 3344 /*pmap_clear_modify(m);*/ 3345 vm_page_flag_clear(m, PG_NOSYNC); 3346 } 3347 } 3348 3349 /* 3350 * Make the page all-dirty. 3351 * 3352 * Also make sure the related object and vnode reflect the fact that the 3353 * object may now contain a dirty page. 3354 * 3355 * Page must be busied? 3356 * No other requirements. 3357 */ 3358 void 3359 vm_page_dirty(vm_page_t m) 3360 { 3361 #ifdef INVARIANTS 3362 int pqtype = m->queue - m->pc; 3363 #endif 3364 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE, 3365 ("vm_page_dirty: page in free/cache queue!")); 3366 if (m->dirty != VM_PAGE_BITS_ALL) { 3367 m->dirty = VM_PAGE_BITS_ALL; 3368 if (m->object) 3369 vm_object_set_writeable_dirty(m->object); 3370 } 3371 } 3372 3373 /* 3374 * Invalidates DEV_BSIZE'd chunks within a page. Both the 3375 * valid and dirty bits for the effected areas are cleared. 3376 * 3377 * Page must be busied? 3378 * Does not block. 3379 * No other requirements. 3380 */ 3381 void 3382 vm_page_set_invalid(vm_page_t m, int base, int size) 3383 { 3384 int bits; 3385 3386 bits = vm_page_bits(base, size); 3387 m->valid &= ~bits; 3388 m->dirty &= ~bits; 3389 atomic_add_int(&m->object->generation, 1); 3390 } 3391 3392 /* 3393 * The kernel assumes that the invalid portions of a page contain 3394 * garbage, but such pages can be mapped into memory by user code. 3395 * When this occurs, we must zero out the non-valid portions of the 3396 * page so user code sees what it expects. 3397 * 3398 * Pages are most often semi-valid when the end of a file is mapped 3399 * into memory and the file's size is not page aligned. 3400 * 3401 * Page must be busied? 3402 * No other requirements. 3403 */ 3404 void 3405 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid) 3406 { 3407 int b; 3408 int i; 3409 3410 /* 3411 * Scan the valid bits looking for invalid sections that 3412 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the 3413 * valid bit may be set ) have already been zerod by 3414 * vm_page_set_validclean(). 3415 */ 3416 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) { 3417 if (i == (PAGE_SIZE / DEV_BSIZE) || 3418 (m->valid & (1 << i)) 3419 ) { 3420 if (i > b) { 3421 pmap_zero_page_area( 3422 VM_PAGE_TO_PHYS(m), 3423 b << DEV_BSHIFT, 3424 (i - b) << DEV_BSHIFT 3425 ); 3426 } 3427 b = i + 1; 3428 } 3429 } 3430 3431 /* 3432 * setvalid is TRUE when we can safely set the zero'd areas 3433 * as being valid. We can do this if there are no cache consistency 3434 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS. 3435 */ 3436 if (setvalid) 3437 m->valid = VM_PAGE_BITS_ALL; 3438 } 3439 3440 /* 3441 * Is a (partial) page valid? Note that the case where size == 0 3442 * will return FALSE in the degenerate case where the page is entirely 3443 * invalid, and TRUE otherwise. 3444 * 3445 * Does not block. 3446 * No other requirements. 3447 */ 3448 int 3449 vm_page_is_valid(vm_page_t m, int base, int size) 3450 { 3451 int bits = vm_page_bits(base, size); 3452 3453 if (m->valid && ((m->valid & bits) == bits)) 3454 return 1; 3455 else 3456 return 0; 3457 } 3458 3459 /* 3460 * update dirty bits from pmap/mmu. May not block. 3461 * 3462 * Caller must hold the page busy 3463 */ 3464 void 3465 vm_page_test_dirty(vm_page_t m) 3466 { 3467 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) { 3468 vm_page_dirty(m); 3469 } 3470 } 3471 3472 #include "opt_ddb.h" 3473 #ifdef DDB 3474 #include <ddb/ddb.h> 3475 3476 DB_SHOW_COMMAND(page, vm_page_print_page_info) 3477 { 3478 db_printf("vmstats.v_free_count: %ld\n", vmstats.v_free_count); 3479 db_printf("vmstats.v_cache_count: %ld\n", vmstats.v_cache_count); 3480 db_printf("vmstats.v_inactive_count: %ld\n", vmstats.v_inactive_count); 3481 db_printf("vmstats.v_active_count: %ld\n", vmstats.v_active_count); 3482 db_printf("vmstats.v_wire_count: %ld\n", vmstats.v_wire_count); 3483 db_printf("vmstats.v_free_reserved: %ld\n", vmstats.v_free_reserved); 3484 db_printf("vmstats.v_free_min: %ld\n", vmstats.v_free_min); 3485 db_printf("vmstats.v_free_target: %ld\n", vmstats.v_free_target); 3486 db_printf("vmstats.v_cache_min: %ld\n", vmstats.v_cache_min); 3487 db_printf("vmstats.v_inactive_target: %ld\n", 3488 vmstats.v_inactive_target); 3489 } 3490 3491 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info) 3492 { 3493 int i; 3494 db_printf("PQ_FREE:"); 3495 for (i = 0; i < PQ_L2_SIZE; i++) { 3496 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt); 3497 } 3498 db_printf("\n"); 3499 3500 db_printf("PQ_CACHE:"); 3501 for(i = 0; i < PQ_L2_SIZE; i++) { 3502 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt); 3503 } 3504 db_printf("\n"); 3505 3506 db_printf("PQ_ACTIVE:"); 3507 for(i = 0; i < PQ_L2_SIZE; i++) { 3508 db_printf(" %d", vm_page_queues[PQ_ACTIVE + i].lcnt); 3509 } 3510 db_printf("\n"); 3511 3512 db_printf("PQ_INACTIVE:"); 3513 for(i = 0; i < PQ_L2_SIZE; i++) { 3514 db_printf(" %d", vm_page_queues[PQ_INACTIVE + i].lcnt); 3515 } 3516 db_printf("\n"); 3517 } 3518 #endif /* DDB */ 3519