kernel - Fix more wiring / fictitious bugs w/recent VM work
[dragonfly.git] / sys / vm / vm_page.c
CommitLineData
984263bc 1/*
16b1cc2d 2 * Copyright (c) 2003-2019 The DragonFly Project. All rights reserved.
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3 * Copyright (c) 1991 Regents of the University of California.
4 * 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 *
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9 * This code is derived from software contributed to The DragonFly Project
10 * by Matthew Dillon <dillon@backplane.com>
11 *
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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.
dc71b7ab 20 * 3. Neither the name of the University nor the names of its contributors
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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 */
984263bc 66/*
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67 * Resident memory management module. The module manipulates 'VM pages'.
68 * A VM page is the core building block for memory management.
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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>
cd3c66bd 77#include <sys/kernel.h>
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78#include <sys/alist.h>
79#include <sys/sysctl.h>
33ee48c4 80#include <sys/cpu_topology.h>
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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>
096e95c0 93#include <vm/swap_pager.h>
984263bc 94
480c83b6 95#include <machine/inttypes.h>
8e5e6f1b 96#include <machine/md_var.h>
b524ca76 97#include <machine/specialreg.h>
df47a6f0 98#include <machine/bus_dma.h>
8e5e6f1b 99
bb6811be 100#include <vm/vm_page2.h>
b12defdc 101#include <sys/spinlock2.h>
bb6811be 102
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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)
906c754c 116
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117static void vm_page_queue_init(void);
118static void vm_page_free_wakeup(void);
85946b6c 119static vm_page_t vm_page_select_cache(u_short pg_color);
74232d8e 120static vm_page_t _vm_page_list_find2(int basequeue, int index);
b12defdc 121static void _vm_page_deactivate_locked(vm_page_t m, int athead);
c70d4562 122static void vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes);
984263bc 123
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124/*
125 * Array of tailq lists
126 */
b396bb03 127struct vpgqueues vm_page_queues[PQ_COUNT];
984263bc 128
e6b81333 129static volatile int vm_pages_waiting;
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130static struct alist vm_contig_alist;
131static struct almeta vm_contig_ameta[ALIST_RECORDS_65536];
ba87a4ab 132static struct spinlock vm_contig_spin = SPINLOCK_INITIALIZER(&vm_contig_spin, "vm_contig_spin");
79d182b0 133
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134static struct vm_page **vm_page_hash;
135
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136static u_long vm_dma_reserved = 0;
137TUNABLE_ULONG("vm.dma_reserved", &vm_dma_reserved);
138SYSCTL_ULONG(_vm, OID_AUTO, dma_reserved, CTLFLAG_RD, &vm_dma_reserved, 0,
139 "Memory reserved for DMA");
140SYSCTL_UINT(_vm, OID_AUTO, dma_free_pages, CTLFLAG_RD,
141 &vm_contig_alist.bl_free, 0, "Memory reserved for DMA");
906c754c 142
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143static int vm_contig_verbose = 0;
144TUNABLE_INT("vm.contig_verbose", &vm_contig_verbose);
145
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146RB_GENERATE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare,
147 vm_pindex_t, pindex);
148
984263bc 149static void
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150vm_page_queue_init(void)
151{
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152 int i;
153
de71fd3f 154 for (i = 0; i < PQ_L2_SIZE; i++)
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155 vm_page_queues[PQ_FREE+i].cnt_offset =
156 offsetof(struct vmstats, v_free_count);
de71fd3f 157 for (i = 0; i < PQ_L2_SIZE; i++)
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158 vm_page_queues[PQ_CACHE+i].cnt_offset =
159 offsetof(struct vmstats, v_cache_count);
027193eb 160 for (i = 0; i < PQ_L2_SIZE; i++)
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161 vm_page_queues[PQ_INACTIVE+i].cnt_offset =
162 offsetof(struct vmstats, v_inactive_count);
027193eb 163 for (i = 0; i < PQ_L2_SIZE; i++)
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164 vm_page_queues[PQ_ACTIVE+i].cnt_offset =
165 offsetof(struct vmstats, v_active_count);
027193eb 166 for (i = 0; i < PQ_L2_SIZE; i++)
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167 vm_page_queues[PQ_HOLD+i].cnt_offset =
168 offsetof(struct vmstats, v_active_count);
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169 /* PQ_NONE has no queue */
170
b12defdc 171 for (i = 0; i < PQ_COUNT; i++) {
984263bc 172 TAILQ_INIT(&vm_page_queues[i].pl);
ba87a4ab 173 spin_init(&vm_page_queues[i].spin, "vm_page_queue_init");
b12defdc 174 }
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175}
176
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177/*
178 * note: place in initialized data section? Is this necessary?
179 */
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180vm_pindex_t first_page = 0;
181vm_pindex_t vm_page_array_size = 0;
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182vm_page_t vm_page_array = NULL;
183vm_paddr_t vm_low_phys_reserved;
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184
185/*
de71fd3f 186 * (low level boot)
984263bc 187 *
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188 * Sets the page size, perhaps based upon the memory size.
189 * Must be called before any use of page-size dependent functions.
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190 */
191void
192vm_set_page_size(void)
193{
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194 if (vmstats.v_page_size == 0)
195 vmstats.v_page_size = PAGE_SIZE;
196 if (((vmstats.v_page_size - 1) & vmstats.v_page_size) != 0)
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197 panic("vm_set_page_size: page size not a power of two");
198}
199
200/*
de71fd3f 201 * (low level boot)
984263bc 202 *
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203 * Add a new page to the freelist for use by the system. New pages
204 * are added to both the head and tail of the associated free page
205 * queue in a bottom-up fashion, so both zero'd and non-zero'd page
206 * requests pull 'recent' adds (higher physical addresses) first.
161399b3 207 *
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208 * Beware that the page zeroing daemon will also be running soon after
209 * boot, moving pages from the head to the tail of the PQ_FREE queues.
210 *
654a39f0 211 * Must be called in a critical section.
984263bc 212 */
79d182b0 213static void
6ef943a3 214vm_add_new_page(vm_paddr_t pa)
984263bc 215{
161399b3 216 struct vpgqueues *vpq;
de71fd3f 217 vm_page_t m;
984263bc 218
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219 m = PHYS_TO_VM_PAGE(pa);
220 m->phys_addr = pa;
221 m->flags = 0;
b524ca76 222 m->pat_mode = PAT_WRITE_BACK;
75979118 223 m->pc = (pa >> PAGE_SHIFT);
c7f9edd8 224
85946b6c 225 /*
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226 * Twist for cpu localization in addition to page coloring, so
227 * different cpus selecting by m->queue get different page colors.
85946b6c 228 */
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229 m->pc ^= ((pa >> PAGE_SHIFT) / PQ_L2_SIZE);
230 m->pc ^= ((pa >> PAGE_SHIFT) / (PQ_L2_SIZE * PQ_L2_SIZE));
231 m->pc &= PQ_L2_MASK;
c7f9edd8 232
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233 /*
234 * Reserve a certain number of contiguous low memory pages for
235 * contigmalloc() to use.
236 */
237 if (pa < vm_low_phys_reserved) {
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238 atomic_add_long(&vmstats.v_page_count, 1);
239 atomic_add_long(&vmstats.v_dma_pages, 1);
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240 m->queue = PQ_NONE;
241 m->wire_count = 1;
b7ea2f3f 242 atomic_add_long(&vmstats.v_wire_count, 1);
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243 alist_free(&vm_contig_alist, pa >> PAGE_SHIFT, 1);
244 return;
245 }
246
247 /*
248 * General page
249 */
984263bc 250 m->queue = m->pc + PQ_FREE;
26bcc0c0 251 KKASSERT(m->dirty == 0);
de71fd3f 252
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253 atomic_add_long(&vmstats.v_page_count, 1);
254 atomic_add_long(&vmstats.v_free_count, 1);
161399b3 255 vpq = &vm_page_queues[m->queue];
afd2da4d 256 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
b12defdc 257 ++vpq->lcnt;
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258}
259
260/*
de71fd3f 261 * (low level boot)
984263bc 262 *
de71fd3f 263 * Initializes the resident memory module.
984263bc 264 *
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265 * Preallocates memory for critical VM structures and arrays prior to
266 * kernel_map becoming available.
26bcc0c0 267 *
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268 * Memory is allocated from (virtual2_start, virtual2_end) if available,
269 * otherwise memory is allocated from (virtual_start, virtual_end).
270 *
271 * On x86-64 (virtual_start, virtual_end) is only 2GB and may not be
272 * large enough to hold vm_page_array & other structures for machines with
273 * large amounts of ram, so we want to use virtual2* when available.
984263bc 274 */
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275void
276vm_page_startup(void)
984263bc 277{
da23a592 278 vm_offset_t vaddr = virtual2_start ? virtual2_start : virtual_start;
984263bc 279 vm_offset_t mapped;
b7ea2f3f 280 vm_pindex_t npages;
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281 vm_paddr_t page_range;
282 vm_paddr_t new_end;
984263bc 283 int i;
6ef943a3 284 vm_paddr_t pa;
6ef943a3 285 vm_paddr_t last_pa;
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286 vm_paddr_t end;
287 vm_paddr_t biggestone, biggestsize;
6ef943a3 288 vm_paddr_t total;
6ba5daf8 289 vm_page_t m;
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290
291 total = 0;
292 biggestsize = 0;
293 biggestone = 0;
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294 vaddr = round_page(vaddr);
295
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296 /*
297 * Make sure ranges are page-aligned.
298 */
299 for (i = 0; phys_avail[i].phys_end; ++i) {
300 phys_avail[i].phys_beg = round_page64(phys_avail[i].phys_beg);
301 phys_avail[i].phys_end = trunc_page64(phys_avail[i].phys_end);
302 if (phys_avail[i].phys_end < phys_avail[i].phys_beg)
303 phys_avail[i].phys_end = phys_avail[i].phys_beg;
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304 }
305
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306 /*
307 * Locate largest block
308 */
309 for (i = 0; phys_avail[i].phys_end; ++i) {
310 vm_paddr_t size = phys_avail[i].phys_end -
311 phys_avail[i].phys_beg;
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312
313 if (size > biggestsize) {
314 biggestone = i;
315 biggestsize = size;
316 }
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317 total += size;
318 }
6ba5daf8 319 --i; /* adjust to last entry for use down below */
984263bc 320
77c48adb 321 end = phys_avail[biggestone].phys_end;
1f804340 322 end = trunc_page(end);
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323
324 /*
325 * Initialize the queue headers for the free queue, the active queue
326 * and the inactive queue.
327 */
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328 vm_page_queue_init();
329
6abe3bd0 330#if !defined(_KERNEL_VIRTUAL)
8e5e6f1b 331 /*
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332 * VKERNELs don't support minidumps and as such don't need
333 * vm_page_dump
334 *
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335 * Allocate a bitmap to indicate that a random physical page
336 * needs to be included in a minidump.
337 *
338 * The amd64 port needs this to indicate which direct map pages
339 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
340 *
0a80a445 341 * However, x86 still needs this workspace internally within the
342 * minidump code. In theory, they are not needed on x86, but are
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343 * included should the sf_buf code decide to use them.
344 */
6ba5daf8 345 page_range = phys_avail[i].phys_end / PAGE_SIZE;
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346 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
347 end -= vm_page_dump_size;
348 vm_page_dump = (void *)pmap_map(&vaddr, end, end + vm_page_dump_size,
6f2099fe 349 VM_PROT_READ | VM_PROT_WRITE);
8e5e6f1b 350 bzero((void *)vm_page_dump, vm_page_dump_size);
6abe3bd0 351#endif
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352 /*
353 * Compute the number of pages of memory that will be available for
354 * use (taking into account the overhead of a page structure per
355 * page).
356 */
77c48adb 357 first_page = phys_avail[0].phys_beg / PAGE_SIZE;
6ba5daf8 358 page_range = phys_avail[i].phys_end / PAGE_SIZE - first_page;
1f804340 359 npages = (total - (page_range * sizeof(struct vm_page))) / PAGE_SIZE;
de71fd3f 360
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361#ifndef _KERNEL_VIRTUAL
362 /*
363 * (only applies to real kernels)
364 *
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365 * Reserve a large amount of low memory for potential 32-bit DMA
366 * space allocations. Once device initialization is complete we
367 * release most of it, but keep (vm_dma_reserved) memory reserved
368 * for later use. Typically for X / graphics. Through trial and
369 * error we find that GPUs usually requires ~60-100MB or so.
79d182b0 370 *
5a05c8a5 371 * By default, 128M is left in reserve on machines with 2G+ of ram.
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372 */
373 vm_low_phys_reserved = (vm_paddr_t)65536 << PAGE_SHIFT;
374 if (vm_low_phys_reserved > total / 4)
375 vm_low_phys_reserved = total / 4;
376 if (vm_dma_reserved == 0) {
5a05c8a5 377 vm_dma_reserved = 128 * 1024 * 1024; /* 128MB */
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378 if (vm_dma_reserved > total / 16)
379 vm_dma_reserved = total / 16;
380 }
381#endif
382 alist_init(&vm_contig_alist, 65536, vm_contig_ameta,
383 ALIST_RECORDS_65536);
384
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385 /*
386 * Initialize the mem entry structures now, and put them in the free
387 * queue.
388 */
efb8fa22 389 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024)
390 kprintf("initializing vm_page_array ");
984263bc 391 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
79d182b0 392 mapped = pmap_map(&vaddr, new_end, end, VM_PROT_READ | VM_PROT_WRITE);
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393 vm_page_array = (vm_page_t)mapped;
394
0e6594a8 395#if defined(__x86_64__) && !defined(_KERNEL_VIRTUAL)
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396 /*
397 * since pmap_map on amd64 returns stuff out of a direct-map region,
398 * we have to manually add these pages to the minidump tracking so
399 * that they can be dumped, including the vm_page_array.
400 */
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401 for (pa = new_end;
402 pa < phys_avail[biggestone].phys_end;
403 pa += PAGE_SIZE) {
8e5e6f1b 404 dump_add_page(pa);
77c48adb 405 }
8fdd3267 406#endif
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407
408 /*
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409 * Clear all of the page structures, run basic initialization so
410 * PHYS_TO_VM_PAGE() operates properly even on pages not in the
411 * map.
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412 */
413 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
414 vm_page_array_size = page_range;
efb8fa22 415 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024)
416 kprintf("size = 0x%zx\n", vm_page_array_size);
984263bc 417
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418 m = &vm_page_array[0];
419 pa = ptoa(first_page);
420 for (i = 0; i < page_range; ++i) {
421 spin_init(&m->spin, "vm_page");
422 m->phys_addr = pa;
423 pa += PAGE_SIZE;
424 ++m;
425 }
426
984263bc 427 /*
161399b3 428 * Construct the free queue(s) in ascending order (by physical
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429 * address) so that the first 16MB of physical memory is allocated
430 * last rather than first. On large-memory machines, this avoids
0bc821c6 431 * the exhaustion of low physical memory before isa_dma_init has run.
984263bc 432 */
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433 vmstats.v_page_count = 0;
434 vmstats.v_free_count = 0;
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435 for (i = 0; phys_avail[i].phys_end && npages > 0; ++i) {
436 pa = phys_avail[i].phys_beg;
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437 if (i == biggestone)
438 last_pa = new_end;
439 else
77c48adb 440 last_pa = phys_avail[i].phys_end;
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441 while (pa < last_pa && npages-- > 0) {
442 vm_add_new_page(pa);
443 pa += PAGE_SIZE;
444 }
445 }
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446 if (virtual2_start)
447 virtual2_start = vaddr;
448 else
449 virtual_start = vaddr;
75979118 450 mycpu->gd_vmstats = vmstats;
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451}
452
c7f9edd8 453/*
8e5d7c42
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454 * (called from early boot only)
455 *
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456 * Reorganize VM pages based on numa data. May be called as many times as
457 * necessary. Will reorganize the vm_page_t page color and related queue(s)
458 * to allow vm_page_alloc() to choose pages based on socket affinity.
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459 *
460 * NOTE: This function is only called while we are still in UP mode, so
461 * we only need a critical section to protect the queues (which
462 * saves a lot of time, there are likely a ton of pages).
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463 */
464void
465vm_numa_organize(vm_paddr_t ran_beg, vm_paddr_t bytes, int physid)
466{
467 vm_paddr_t scan_beg;
468 vm_paddr_t scan_end;
469 vm_paddr_t ran_end;
470 struct vpgqueues *vpq;
471 vm_page_t m;
6f2099fe 472 vm_page_t mend;
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473 int socket_mod;
474 int socket_value;
8e5d7c42 475 int i;
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476
477 /*
478 * Check if no physical information, or there was only one socket
479 * (so don't waste time doing nothing!).
480 */
481 if (cpu_topology_phys_ids <= 1 ||
482 cpu_topology_core_ids == 0) {
483 return;
484 }
485
486 /*
487 * Setup for our iteration. Note that ACPI may iterate CPU
488 * sockets starting at 0 or 1 or some other number. The
489 * cpu_topology code mod's it against the socket count.
490 */
491 ran_end = ran_beg + bytes;
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492
493 socket_mod = PQ_L2_SIZE / cpu_topology_phys_ids;
b97d93a4 494 socket_value = (physid % cpu_topology_phys_ids) * socket_mod;
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495 mend = &vm_page_array[vm_page_array_size];
496
497 crit_enter();
c7f9edd8 498
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499 /*
500 * Adjust cpu_topology's phys_mem parameter
501 */
502 if (root_cpu_node)
503 vm_numa_add_topology_mem(root_cpu_node, physid, (long)bytes);
504
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505 /*
506 * Adjust vm_page->pc and requeue all affected pages. The
507 * allocator will then be able to localize memory allocations
508 * to some degree.
509 */
510 for (i = 0; phys_avail[i].phys_end; ++i) {
511 scan_beg = phys_avail[i].phys_beg;
512 scan_end = phys_avail[i].phys_end;
513 if (scan_end <= ran_beg)
514 continue;
515 if (scan_beg >= ran_end)
516 continue;
517 if (scan_beg < ran_beg)
518 scan_beg = ran_beg;
519 if (scan_end > ran_end)
520 scan_end = ran_end;
6f2099fe 521 if (atop(scan_end) > first_page + vm_page_array_size)
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522 scan_end = ptoa(first_page + vm_page_array_size);
523
524 m = PHYS_TO_VM_PAGE(scan_beg);
525 while (scan_beg < scan_end) {
6f2099fe 526 KKASSERT(m < mend);
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527 if (m->queue != PQ_NONE) {
528 vpq = &vm_page_queues[m->queue];
529 TAILQ_REMOVE(&vpq->pl, m, pageq);
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530 --vpq->lcnt;
531 /* queue doesn't change, no need to adj cnt */
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532 m->queue -= m->pc;
533 m->pc %= socket_mod;
534 m->pc += socket_value;
535 m->pc &= PQ_L2_MASK;
536 m->queue += m->pc;
537 vpq = &vm_page_queues[m->queue];
538 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
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539 ++vpq->lcnt;
540 /* queue doesn't change, no need to adj cnt */
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541 } else {
542 m->pc %= socket_mod;
543 m->pc += socket_value;
544 m->pc &= PQ_L2_MASK;
545 }
546 scan_beg += PAGE_SIZE;
547 ++m;
548 }
549 }
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550
551 crit_exit();
552}
553
554/*
555 * (called from early boot only)
556 *
557 * Don't allow the NUMA organization to leave vm_page_queues[] nodes
558 * completely empty for a logical cpu. Doing so would force allocations
559 * on that cpu to always borrow from a nearby cpu, create unnecessary
560 * contention, and cause vm_page_alloc() to iterate more queues and run more
561 * slowly.
562 *
563 * This situation can occur when memory sticks are not entirely populated,
564 * populated at different densities, or in naturally assymetric systems
565 * such as the 2990WX. There could very well be many vm_page_queues[]
566 * entries with *NO* pages assigned to them.
567 *
568 * Fixing this up ensures that each logical CPU has roughly the same
569 * sized memory pool, and more importantly ensures that logical CPUs
570 * do not wind up with an empty memory pool.
571 *
572 * At them moment we just iterate the other queues and borrow pages,
573 * moving them into the queues for cpus with severe deficits even though
574 * the memory might not be local to those cpus. I am not doing this in
575 * a 'smart' way, its effectively UMA style (sorta, since its page-by-page
576 * whereas real UMA typically exchanges address bits 8-10 with high address
577 * bits). But it works extremely well and gives us fairly good deterministic
578 * results on the cpu cores associated with these secondary nodes.
579 */
580void
581vm_numa_organize_finalize(void)
582{
583 struct vpgqueues *vpq;
584 vm_page_t m;
585 long lcnt_lo;
586 long lcnt_hi;
587 int iter;
588 int i;
589 int scale_lim;
590
591 crit_enter();
592
593 /*
594 * Machines might not use an exact power of 2 for phys_ids,
595 * core_ids, ht_ids, etc. This can slightly reduce the actual
596 * range of indices in vm_page_queues[] that are nominally used.
597 */
598 if (cpu_topology_ht_ids) {
599 scale_lim = PQ_L2_SIZE / cpu_topology_phys_ids;
600 scale_lim = scale_lim / cpu_topology_core_ids;
601 scale_lim = scale_lim / cpu_topology_ht_ids;
602 scale_lim = scale_lim * cpu_topology_ht_ids;
603 scale_lim = scale_lim * cpu_topology_core_ids;
604 scale_lim = scale_lim * cpu_topology_phys_ids;
605 } else {
606 scale_lim = PQ_L2_SIZE;
607 }
608
609 /*
610 * Calculate an average, set hysteresis for balancing from
611 * 10% below the average to the average.
612 */
613 lcnt_hi = 0;
614 for (i = 0; i < scale_lim; ++i) {
615 lcnt_hi += vm_page_queues[i].lcnt;
616 }
617 lcnt_hi /= scale_lim;
618 lcnt_lo = lcnt_hi - lcnt_hi / 10;
619
620 kprintf("vm_page: avg %ld pages per queue, %d queues\n",
621 lcnt_hi, scale_lim);
622
623 iter = 0;
624 for (i = 0; i < scale_lim; ++i) {
625 vpq = &vm_page_queues[PQ_FREE + i];
626 while (vpq->lcnt < lcnt_lo) {
627 struct vpgqueues *vptmp;
628
629 iter = (iter + 1) & PQ_L2_MASK;
630 vptmp = &vm_page_queues[PQ_FREE + iter];
631 if (vptmp->lcnt < lcnt_hi)
632 continue;
633 m = TAILQ_FIRST(&vptmp->pl);
634 KKASSERT(m->queue == PQ_FREE + iter);
635 TAILQ_REMOVE(&vptmp->pl, m, pageq);
636 --vptmp->lcnt;
637 /* queue doesn't change, no need to adj cnt */
638 m->queue -= m->pc;
639 m->pc = i;
640 m->queue += m->pc;
641 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
642 ++vpq->lcnt;
643 }
644 }
6f2099fe 645 crit_exit();
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646}
647
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648static
649void
650vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes)
651{
652 int cpuid;
653 int i;
654
655 switch(cpup->type) {
656 case PACKAGE_LEVEL:
657 cpup->phys_mem += bytes;
658 break;
659 case CHIP_LEVEL:
660 /*
661 * All members should have the same chipid, so we only need
662 * to pull out one member.
663 */
664 if (CPUMASK_TESTNZERO(cpup->members)) {
665 cpuid = BSFCPUMASK(cpup->members);
666 if (physid ==
667 get_chip_ID_from_APICID(CPUID_TO_APICID(cpuid))) {
668 cpup->phys_mem += bytes;
669 }
670 }
671 break;
672 case CORE_LEVEL:
673 case THREAD_LEVEL:
674 /*
675 * Just inherit from the parent node
676 */
677 cpup->phys_mem = cpup->parent_node->phys_mem;
678 break;
679 }
680 for (i = 0; i < MAXCPU && cpup->child_node[i]; ++i)
681 vm_numa_add_topology_mem(cpup->child_node[i], physid, bytes);
682}
683
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684/*
685 * We tended to reserve a ton of memory for contigmalloc(). Now that most
686 * drivers have initialized we want to return most the remaining free
687 * reserve back to the VM page queues so they can be used for normal
688 * allocations.
689 *
690 * We leave vm_dma_reserved bytes worth of free pages in the reserve pool.
691 */
692static void
693vm_page_startup_finish(void *dummy __unused)
694{
695 alist_blk_t blk;
696 alist_blk_t rblk;
697 alist_blk_t count;
698 alist_blk_t xcount;
699 alist_blk_t bfree;
700 vm_page_t m;
70f3bb08 701 vm_page_t *mp;
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702
703 spin_lock(&vm_contig_spin);
704 for (;;) {
705 bfree = alist_free_info(&vm_contig_alist, &blk, &count);
706 if (bfree <= vm_dma_reserved / PAGE_SIZE)
707 break;
708 if (count == 0)
709 break;
710
711 /*
712 * Figure out how much of the initial reserve we have to
713 * free in order to reach our target.
714 */
715 bfree -= vm_dma_reserved / PAGE_SIZE;
716 if (count > bfree) {
717 blk += count - bfree;
718 count = bfree;
719 }
720
721 /*
722 * Calculate the nearest power of 2 <= count.
723 */
724 for (xcount = 1; xcount <= count; xcount <<= 1)
725 ;
726 xcount >>= 1;
727 blk += count - xcount;
728 count = xcount;
729
730 /*
731 * Allocate the pages from the alist, then free them to
732 * the normal VM page queues.
733 *
734 * Pages allocated from the alist are wired. We have to
735 * busy, unwire, and free them. We must also adjust
736 * vm_low_phys_reserved before freeing any pages to prevent
737 * confusion.
738 */
739 rblk = alist_alloc(&vm_contig_alist, blk, count);
740 if (rblk != blk) {
741 kprintf("vm_page_startup_finish: Unable to return "
742 "dma space @0x%08x/%d -> 0x%08x\n",
743 blk, count, rblk);
744 break;
745 }
85a76f5f 746 atomic_add_long(&vmstats.v_dma_pages, -(long)count);
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747 spin_unlock(&vm_contig_spin);
748
749 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT);
750 vm_low_phys_reserved = VM_PAGE_TO_PHYS(m);
751 while (count) {
752 vm_page_busy_wait(m, FALSE, "cpgfr");
753 vm_page_unwire(m, 0);
754 vm_page_free(m);
755 --count;
756 ++m;
757 }
758 spin_lock(&vm_contig_spin);
759 }
760 spin_unlock(&vm_contig_spin);
761
762 /*
763 * Print out how much DMA space drivers have already allocated and
764 * how much is left over.
765 */
766 kprintf("DMA space used: %jdk, remaining available: %jdk\n",
767 (intmax_t)(vmstats.v_dma_pages - vm_contig_alist.bl_free) *
768 (PAGE_SIZE / 1024),
769 (intmax_t)vm_contig_alist.bl_free * (PAGE_SIZE / 1024));
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770
771 /*
772 * hash table for vm_page_lookup_quick()
773 */
774 mp = (void *)kmem_alloc3(&kernel_map,
775 vm_page_array_size * sizeof(vm_page_t),
776 VM_SUBSYS_VMPGHASH, KM_CPU(0));
777 bzero(mp, vm_page_array_size * sizeof(vm_page_t));
778 cpu_sfence();
779 vm_page_hash = mp;
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780}
781SYSINIT(vm_pgend, SI_SUB_PROC0_POST, SI_ORDER_ANY,
f3f3eadb 782 vm_page_startup_finish, NULL);
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783
784
984263bc 785/*
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786 * Scan comparison function for Red-Black tree scans. An inclusive
787 * (start,end) is expected. Other fields are not used.
984263bc 788 */
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789int
790rb_vm_page_scancmp(struct vm_page *p, void *data)
984263bc 791{
1f804340 792 struct rb_vm_page_scan_info *info = data;
984263bc 793
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794 if (p->pindex < info->start_pindex)
795 return(-1);
796 if (p->pindex > info->end_pindex)
797 return(1);
798 return(0);
799}
800
801int
802rb_vm_page_compare(struct vm_page *p1, struct vm_page *p2)
803{
804 if (p1->pindex < p2->pindex)
805 return(-1);
806 if (p1->pindex > p2->pindex)
807 return(1);
808 return(0);
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809}
810
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811void
812vm_page_init(vm_page_t m)
813{
814 /* do nothing for now. Called from pmap_page_init() */
815}
816
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817/*
818 * Each page queue has its own spin lock, which is fairly optimal for
819 * allocating and freeing pages at least.
820 *
821 * The caller must hold the vm_page_spin_lock() before locking a vm_page's
822 * queue spinlock via this function. Also note that m->queue cannot change
823 * unless both the page and queue are locked.
824 */
825static __inline
826void
827_vm_page_queue_spin_lock(vm_page_t m)
828{
829 u_short queue;
830
831 queue = m->queue;
832 if (queue != PQ_NONE) {
833 spin_lock(&vm_page_queues[queue].spin);
834 KKASSERT(queue == m->queue);
835 }
836}
837
838static __inline
839void
840_vm_page_queue_spin_unlock(vm_page_t m)
841{
842 u_short queue;
843
844 queue = m->queue;
845 cpu_ccfence();
846 if (queue != PQ_NONE)
847 spin_unlock(&vm_page_queues[queue].spin);
848}
849
850static __inline
851void
852_vm_page_queues_spin_lock(u_short queue)
853{
854 cpu_ccfence();
855 if (queue != PQ_NONE)
856 spin_lock(&vm_page_queues[queue].spin);
857}
858
859
860static __inline
861void
862_vm_page_queues_spin_unlock(u_short queue)
863{
864 cpu_ccfence();
865 if (queue != PQ_NONE)
866 spin_unlock(&vm_page_queues[queue].spin);
867}
868
869void
870vm_page_queue_spin_lock(vm_page_t m)
871{
872 _vm_page_queue_spin_lock(m);
873}
874
875void
876vm_page_queues_spin_lock(u_short queue)
877{
878 _vm_page_queues_spin_lock(queue);
879}
880
881void
882vm_page_queue_spin_unlock(vm_page_t m)
883{
884 _vm_page_queue_spin_unlock(m);
885}
886
887void
888vm_page_queues_spin_unlock(u_short queue)
889{
890 _vm_page_queues_spin_unlock(queue);
891}
892
893/*
894 * This locks the specified vm_page and its queue in the proper order
895 * (page first, then queue). The queue may change so the caller must
896 * recheck on return.
897 */
898static __inline
899void
900_vm_page_and_queue_spin_lock(vm_page_t m)
901{
902 vm_page_spin_lock(m);
903 _vm_page_queue_spin_lock(m);
904}
905
906static __inline
907void
908_vm_page_and_queue_spin_unlock(vm_page_t m)
909{
910 _vm_page_queues_spin_unlock(m->queue);
911 vm_page_spin_unlock(m);
912}
913
914void
915vm_page_and_queue_spin_unlock(vm_page_t m)
916{
917 _vm_page_and_queue_spin_unlock(m);
918}
919
920void
921vm_page_and_queue_spin_lock(vm_page_t m)
922{
923 _vm_page_and_queue_spin_lock(m);
924}
925
926/*
927 * Helper function removes vm_page from its current queue.
928 * Returns the base queue the page used to be on.
929 *
930 * The vm_page and the queue must be spinlocked.
931 * This function will unlock the queue but leave the page spinlocked.
932 */
933static __inline u_short
934_vm_page_rem_queue_spinlocked(vm_page_t m)
935{
936 struct vpgqueues *pq;
937 u_short queue;
33ee48c4 938 u_short oqueue;
b7ea2f3f 939 long *cnt;
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940
941 queue = m->queue;
942 if (queue != PQ_NONE) {
943 pq = &vm_page_queues[queue];
944 TAILQ_REMOVE(&pq->pl, m, pageq);
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MD
945
946 /*
947 * Adjust our pcpu stats. In order for the nominal low-memory
948 * algorithms to work properly we don't let any pcpu stat get
949 * too negative before we force it to be rolled-up into the
950 * global stats. Otherwise our pageout and vm_wait tests
951 * will fail badly.
952 *
953 * The idea here is to reduce unnecessary SMP cache
954 * mastership changes in the global vmstats, which can be
955 * particularly bad in multi-socket systems.
956 */
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MD
957 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset);
958 atomic_add_long(cnt, -1);
5ba14d44 959 if (*cnt < -VMMETER_SLOP_COUNT) {
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MD
960 u_long copy = atomic_swap_long(cnt, 0);
961 cnt = (long *)((char *)&vmstats + pq->cnt_offset);
962 atomic_add_long(cnt, copy);
963 cnt = (long *)((char *)&mycpu->gd_vmstats +
75979118 964 pq->cnt_offset);
b7ea2f3f 965 atomic_add_long(cnt, copy);
5ba14d44 966 }
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967 pq->lcnt--;
968 m->queue = PQ_NONE;
33ee48c4 969 oqueue = queue;
6f2099fe 970 queue -= m->pc;
33ee48c4 971 vm_page_queues_spin_unlock(oqueue); /* intended */
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972 }
973 return queue;
974}
975
976/*
635c9c15
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977 * Helper function places the vm_page on the specified queue. Generally
978 * speaking only PQ_FREE pages are placed at the head, to allow them to
979 * be allocated sooner rather than later on the assumption that they
980 * are cache-hot.
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981 *
982 * The vm_page must be spinlocked.
0ca81fbe 983 * The vm_page must NOT be FICTITIOUS (that would be a disaster)
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984 * This function will return with both the page and the queue locked.
985 */
986static __inline void
987_vm_page_add_queue_spinlocked(vm_page_t m, u_short queue, int athead)
988{
989 struct vpgqueues *pq;
b7ea2f3f 990 u_long *cnt;
b12defdc 991
0ca81fbe 992 KKASSERT(m->queue == PQ_NONE && (m->flags & PG_FICTITIOUS) == 0);
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993
994 if (queue != PQ_NONE) {
995 vm_page_queues_spin_lock(queue);
996 pq = &vm_page_queues[queue];
997 ++pq->lcnt;
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998
999 /*
1000 * Adjust our pcpu stats. If a system entity really needs
1001 * to incorporate the count it will call vmstats_rollup()
1002 * to roll it all up into the global vmstats strufture.
1003 */
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1004 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset);
1005 atomic_add_long(cnt, 1);
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1006
1007 /*
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1008 * PQ_FREE is always handled LIFO style to try to provide
1009 * cache-hot pages to programs.
b12defdc 1010 */
5ba14d44 1011 m->queue = queue;
b12defdc 1012 if (queue - m->pc == PQ_FREE) {
afd2da4d 1013 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
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MD
1014 } else if (athead) {
1015 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
1016 } else {
1017 TAILQ_INSERT_TAIL(&pq->pl, m, pageq);
1018 }
1019 /* leave the queue spinlocked */
1020 }
1021}
1022
1023/*
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1024 * Wait until page is no longer BUSY. If also_m_busy is TRUE we wait
1025 * until the page is no longer BUSY or SBUSY (busy_count field is 0).
1026 *
1027 * Returns TRUE if it had to sleep, FALSE if we did not. Only one sleep
1028 * call will be made before returning.
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1029 *
1030 * This function does NOT busy the page and on return the page is not
1031 * guaranteed to be available.
1032 */
1033void
1034vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg)
1035{
bc0aa189 1036 u_int32_t busy_count;
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1037
1038 for (;;) {
bc0aa189 1039 busy_count = m->busy_count;
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1040 cpu_ccfence();
1041
bc0aa189
MD
1042 if ((busy_count & PBUSY_LOCKED) == 0 &&
1043 (also_m_busy == 0 || (busy_count & PBUSY_MASK) == 0)) {
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MD
1044 break;
1045 }
1046 tsleep_interlock(m, 0);
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1047 if (atomic_cmpset_int(&m->busy_count, busy_count,
1048 busy_count | PBUSY_WANTED)) {
1049 atomic_set_int(&m->flags, PG_REFERENCED);
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1050 tsleep(m, PINTERLOCKED, msg, 0);
1051 break;
1052 }
1053 }
1054}
1055
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1056/*
1057 * This calculates and returns a page color given an optional VM object and
1058 * either a pindex or an iterator. We attempt to return a cpu-localized
1059 * pg_color that is still roughly 16-way set-associative. The CPU topology
1060 * is used if it was probed.
1061 *
1062 * The caller may use the returned value to index into e.g. PQ_FREE when
1063 * allocating a page in order to nominally obtain pages that are hopefully
1064 * already localized to the requesting cpu. This function is not able to
1065 * provide any sort of guarantee of this, but does its best to improve
1066 * hardware cache management performance.
1067 *
1068 * WARNING! The caller must mask the returned value with PQ_L2_MASK.
1069 */
1070u_short
070a58b3 1071vm_get_pg_color(int cpuid, vm_object_t object, vm_pindex_t pindex)
9002b0d5
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1072{
1073 u_short pg_color;
9002b0d5
MD
1074 int object_pg_color;
1075
8e5d7c42
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1076 /*
1077 * WARNING! cpu_topology_core_ids might not be a power of two.
1078 * We also shouldn't make assumptions about
1079 * cpu_topology_phys_ids either.
1080 *
1081 * WARNING! ncpus might not be known at this time (during early
1082 * boot), and might be set to 1.
1083 *
1084 * General format: [phys_id][core_id][cpuid][set-associativity]
1085 * (but uses modulo, so not necessarily precise bit masks)
1086 */
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1087 object_pg_color = object ? object->pg_color : 0;
1088
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1089 if (cpu_topology_ht_ids) {
1090 int phys_id;
1091 int core_id;
1092 int ht_id;
1093 int physcale;
1094 int grpscale;
1095 int cpuscale;
9002b0d5 1096
75979118 1097 /*
8e5d7c42 1098 * Translate cpuid to socket, core, and hyperthread id.
75979118 1099 */
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1100 phys_id = get_cpu_phys_id(cpuid);
1101 core_id = get_cpu_core_id(cpuid);
1102 ht_id = get_cpu_ht_id(cpuid);
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1103
1104 /*
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1105 * Calculate pg_color for our array index.
1106 *
1107 * physcale - socket multiplier.
1108 * grpscale - core multiplier (cores per socket)
1109 * cpu* - cpus per core
1110 *
1111 * WARNING! In early boot, ncpus has not yet been
1112 * initialized and may be set to (1).
1113 *
1114 * WARNING! physcale must match the organization that
1115 * vm_numa_organize() creates to ensure that
1116 * we properly localize allocations to the
1117 * requested cpuid.
75979118 1118 */
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1119 physcale = PQ_L2_SIZE / cpu_topology_phys_ids;
1120 grpscale = physcale / cpu_topology_core_ids;
1121 cpuscale = grpscale / cpu_topology_ht_ids;
1122
1123 pg_color = phys_id * physcale;
1124 pg_color += core_id * grpscale;
1125 pg_color += ht_id * cpuscale;
1126 pg_color += (pindex + object_pg_color) % cpuscale;
1127
1128#if 0
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MD
1129 if (grpsize >= 8) {
1130 pg_color += (pindex + object_pg_color) % grpsize;
9002b0d5 1131 } else {
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MD
1132 if (grpsize <= 2) {
1133 grpsize = 8;
9002b0d5 1134 } else {
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MD
1135 /* 3->9, 4->8, 5->10, 6->12, 7->14 */
1136 grpsize += grpsize;
1137 if (grpsize < 8)
1138 grpsize += grpsize;
9002b0d5 1139 }
75979118 1140 pg_color += (pindex + object_pg_color) % grpsize;
9002b0d5 1141 }
8e5d7c42 1142#endif
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MD
1143 } else {
1144 /*
1145 * Unknown topology, distribute things evenly.
8e5d7c42
MD
1146 *
1147 * WARNING! In early boot, ncpus has not yet been
1148 * initialized and may be set to (1).
9002b0d5 1149 */
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MD
1150 int cpuscale;
1151
1152 cpuscale = PQ_L2_SIZE / ncpus;
1153
1154 pg_color = cpuid * cpuscale;
1155 pg_color += (pindex + object_pg_color) % cpuscale;
9002b0d5 1156 }
75979118 1157 return (pg_color & PQ_L2_MASK);
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MD
1158}
1159
b12defdc 1160/*
bc0aa189
MD
1161 * Wait until BUSY can be set, then set it. If also_m_busy is TRUE we
1162 * also wait for m->busy_count to become 0 before setting PBUSY_LOCKED.
b12defdc
MD
1163 */
1164void
1165VM_PAGE_DEBUG_EXT(vm_page_busy_wait)(vm_page_t m,
1166 int also_m_busy, const char *msg
1167 VM_PAGE_DEBUG_ARGS)
1168{
bc0aa189 1169 u_int32_t busy_count;
b12defdc
MD
1170
1171 for (;;) {
bc0aa189 1172 busy_count = m->busy_count;
b12defdc 1173 cpu_ccfence();
bc0aa189 1174 if (busy_count & PBUSY_LOCKED) {
b12defdc 1175 tsleep_interlock(m, 0);
bc0aa189
MD
1176 if (atomic_cmpset_int(&m->busy_count, busy_count,
1177 busy_count | PBUSY_WANTED)) {
1178 atomic_set_int(&m->flags, PG_REFERENCED);
b12defdc
MD
1179 tsleep(m, PINTERLOCKED, msg, 0);
1180 }
bc0aa189 1181 } else if (also_m_busy && busy_count) {
b12defdc 1182 tsleep_interlock(m, 0);
bc0aa189
MD
1183 if (atomic_cmpset_int(&m->busy_count, busy_count,
1184 busy_count | PBUSY_WANTED)) {
1185 atomic_set_int(&m->flags, PG_REFERENCED);
b12defdc
MD
1186 tsleep(m, PINTERLOCKED, msg, 0);
1187 }
1188 } else {
bc0aa189
MD
1189 if (atomic_cmpset_int(&m->busy_count, busy_count,
1190 busy_count | PBUSY_LOCKED)) {
b12defdc
MD
1191#ifdef VM_PAGE_DEBUG
1192 m->busy_func = func;
1193 m->busy_line = lineno;
1194#endif
1195 break;
1196 }
1197 }
1198 }
1199}
1200
1201/*
bc0aa189
MD
1202 * Attempt to set BUSY. If also_m_busy is TRUE we only succeed if
1203 * m->busy_count is also 0.
b12defdc
MD
1204 *
1205 * Returns non-zero on failure.
1206 */
1207int
1208VM_PAGE_DEBUG_EXT(vm_page_busy_try)(vm_page_t m, int also_m_busy
1209 VM_PAGE_DEBUG_ARGS)
1210{
bc0aa189 1211 u_int32_t busy_count;
b12defdc
MD
1212
1213 for (;;) {
bc0aa189 1214 busy_count = m->busy_count;
b12defdc 1215 cpu_ccfence();
bc0aa189 1216 if (busy_count & PBUSY_LOCKED)
b12defdc 1217 return TRUE;
bc0aa189 1218 if (also_m_busy && (busy_count & PBUSY_MASK) != 0)
b12defdc 1219 return TRUE;
bc0aa189
MD
1220 if (atomic_cmpset_int(&m->busy_count, busy_count,
1221 busy_count | PBUSY_LOCKED)) {
b12defdc
MD
1222#ifdef VM_PAGE_DEBUG
1223 m->busy_func = func;
1224 m->busy_line = lineno;
1225#endif
1226 return FALSE;
1227 }
1228 }
1229}
1230
1231/*
bc0aa189 1232 * Clear the BUSY flag and return non-zero to indicate to the caller
b12defdc
MD
1233 * that a wakeup() should be performed.
1234 *
b12defdc
MD
1235 * (inline version)
1236 */
1237static __inline
1238int
1239_vm_page_wakeup(vm_page_t m)
1240{
bc0aa189 1241 u_int32_t busy_count;
b12defdc 1242
16b1cc2d
MD
1243 busy_count = m->busy_count;
1244 cpu_ccfence();
b12defdc 1245 for (;;) {
16b1cc2d 1246 if (atomic_fcmpset_int(&m->busy_count, &busy_count,
bc0aa189
MD
1247 busy_count &
1248 ~(PBUSY_LOCKED | PBUSY_WANTED))) {
16b1cc2d 1249 return((int)(busy_count & PBUSY_WANTED));
b12defdc
MD
1250 }
1251 }
16b1cc2d 1252 /* not reached */
b12defdc
MD
1253}
1254
1255/*
bc0aa189 1256 * Clear the BUSY flag and wakeup anyone waiting for the page. This
b12defdc
MD
1257 * is typically the last call you make on a page before moving onto
1258 * other things.
1259 */
1260void
1261vm_page_wakeup(vm_page_t m)
1262{
bc0aa189
MD
1263 KASSERT(m->busy_count & PBUSY_LOCKED,
1264 ("vm_page_wakeup: page not busy!!!"));
16b1cc2d 1265 if (_vm_page_wakeup(m))
b12defdc 1266 wakeup(m);
b12defdc
MD
1267}
1268
573fb415 1269/*
16b1cc2d
MD
1270 * Hold a page, preventing reuse. This is typically only called on pages
1271 * in a known state (either held busy, special, or interlocked in some
1272 * manner). Holding a page does not ensure that it remains valid, it only
1273 * prevents reuse. The page must not already be on the FREE queue or in
1274 * any danger of being moved to the FREE queue concurrent with this call.
1275 *
1276 * Other parts of the system can still disassociate the page from its object
1277 * and attempt to free it, or perform read or write I/O on it and/or otherwise
1278 * manipulate the page, but if the page is held the VM system will leave the
1279 * page and its data intact and not cycle it through the FREE queue until
1280 * the last hold has been released.
1281 *
1282 * (see vm_page_wire() if you want to prevent the page from being
1283 * disassociated from its object too).
573fb415
MD
1284 */
1285void
1286vm_page_hold(vm_page_t m)
1287{
16b1cc2d
MD
1288 atomic_add_int(&m->hold_count, 1);
1289 KKASSERT(m->queue - m->pc != PQ_FREE);
1290#if 0
b12defdc
MD
1291 vm_page_spin_lock(m);
1292 atomic_add_int(&m->hold_count, 1);
1293 if (m->queue - m->pc == PQ_FREE) {
1294 _vm_page_queue_spin_lock(m);
1295 _vm_page_rem_queue_spinlocked(m);
027193eb 1296 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0);
b12defdc
MD
1297 _vm_page_queue_spin_unlock(m);
1298 }
1299 vm_page_spin_unlock(m);
16b1cc2d 1300#endif
573fb415
MD
1301}
1302
de71fd3f 1303/*
5cdc30e8
MD
1304 * The opposite of vm_page_hold(). If the page is on the HOLD queue
1305 * it was freed while held and must be moved back to the FREE queue.
16b1cc2d 1306 *
e05899ce
MD
1307 * To avoid racing against vm_page_free*() we must re-test conditions
1308 * after obtaining the spin-lock. The initial test can also race a
1309 * vm_page_free*() that is in the middle of moving a page to PQ_HOLD,
1310 * leaving the page on PQ_HOLD with hold_count == 0. Rather than
1311 * throw a spin-lock in the critical path, we rely on the pageout
1312 * daemon to clean-up these loose ends.
1313 *
1314 * More critically, the 'easy movement' between queues without busying
1315 * a vm_page is only allowed for PQ_FREE<->PQ_HOLD.
de71fd3f 1316 */
984263bc 1317void
573fb415 1318vm_page_unhold(vm_page_t m)
984263bc 1319{
5cdc30e8 1320 KASSERT(m->hold_count > 0 && m->queue - m->pc != PQ_FREE,
16b1cc2d
MD
1321 ("vm_page_unhold: pg %p illegal hold_count (%d) or "
1322 "on FREE queue (%d)",
5cdc30e8 1323 m, m->hold_count, m->queue - m->pc));
16b1cc2d 1324
e05899ce
MD
1325 if (atomic_fetchadd_int(&m->hold_count, -1) == 1 &&
1326 m->queue - m->pc == PQ_HOLD) {
16b1cc2d
MD
1327 vm_page_spin_lock(m);
1328 if (m->hold_count == 0 && m->queue - m->pc == PQ_HOLD) {
1329 _vm_page_queue_spin_lock(m);
1330 _vm_page_rem_queue_spinlocked(m);
1331 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1);
1332 _vm_page_queue_spin_unlock(m);
1333 }
1334 vm_page_spin_unlock(m);
97edb3b6 1335 }
984263bc
MD
1336}
1337
3023924a 1338/*
16b1cc2d
MD
1339 * Create a fictitious page with the specified physical address and
1340 * memory attribute. The memory attribute is the only the machine-
1341 * dependent aspect of a fictitious page that must be initialized.
3023924a 1342 */
3023924a
FT
1343void
1344vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1345{
1346
1347 if ((m->flags & PG_FICTITIOUS) != 0) {
1348 /*
1349 * The page's memattr might have changed since the
1350 * previous initialization. Update the pmap to the
1351 * new memattr.
1352 */
1353 goto memattr;
1354 }
1355 m->phys_addr = paddr;
1356 m->queue = PQ_NONE;
1357 /* Fictitious pages don't use "segind". */
1358 /* Fictitious pages don't use "order" or "pool". */
bc0aa189
MD
1359 m->flags = PG_FICTITIOUS | PG_UNMANAGED;
1360 m->busy_count = PBUSY_LOCKED;
3023924a 1361 m->wire_count = 1;
6ba5daf8 1362 spin_init(&m->spin, "fake_page");
3023924a
FT
1363 pmap_page_init(m);
1364memattr:
1365 pmap_page_set_memattr(m, memattr);
1366}
1367
984263bc 1368/*
573fb415 1369 * Inserts the given vm_page into the object and object list.
984263bc 1370 *
de71fd3f
MD
1371 * The pagetables are not updated but will presumably fault the page
1372 * in if necessary, or if a kernel page the caller will at some point
1373 * enter the page into the kernel's pmap. We are not allowed to block
1374 * here so we *can't* do this anyway.
984263bc 1375 *
de71fd3f 1376 * This routine may not block.
398c240d 1377 * This routine must be called with the vm_object held.
654a39f0 1378 * This routine must be called with a critical section held.
d2d8515b
MD
1379 *
1380 * This routine returns TRUE if the page was inserted into the object
1381 * successfully, and FALSE if the page already exists in the object.
984263bc 1382 */
d2d8515b 1383int
984263bc
MD
1384vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1385{
ce94514e 1386 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(object));
984263bc
MD
1387 if (m->object != NULL)
1388 panic("vm_page_insert: already inserted");
1389
95270b7e 1390 atomic_add_int(&object->generation, 1);
b12defdc 1391
984263bc 1392 /*
b12defdc
MD
1393 * Record the object/offset pair in this page and add the
1394 * pv_list_count of the page to the object.
1395 *
1396 * The vm_page spin lock is required for interactions with the pmap.
984263bc 1397 */
b12defdc 1398 vm_page_spin_lock(m);
984263bc
MD
1399 m->object = object;
1400 m->pindex = pindex;
d2d8515b
MD
1401 if (vm_page_rb_tree_RB_INSERT(&object->rb_memq, m)) {
1402 m->object = NULL;
1403 m->pindex = 0;
1404 vm_page_spin_unlock(m);
1405 return FALSE;
1406 }
6d538b47
MD
1407 ++object->resident_page_count;
1408 ++mycpu->gd_vmtotal.t_rm;
b12defdc 1409 vm_page_spin_unlock(m);
50a55c46 1410
984263bc
MD
1411 /*
1412 * Since we are inserting a new and possibly dirty page,
1413 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
1414 */
d86d27a8
MD
1415 if ((m->valid & m->dirty) ||
1416 (m->flags & (PG_WRITEABLE | PG_NEED_COMMIT)))
984263bc 1417 vm_object_set_writeable_dirty(object);
096e95c0
MD
1418
1419 /*
1420 * Checks for a swap assignment and sets PG_SWAPPED if appropriate.
1421 */
1422 swap_pager_page_inserted(m);
d2d8515b 1423 return TRUE;
984263bc
MD
1424}
1425
1426/*
b12defdc 1427 * Removes the given vm_page_t from the (object,index) table
984263bc 1428 *
de71fd3f
MD
1429 * The underlying pmap entry (if any) is NOT removed here.
1430 * This routine may not block.
9765affa 1431 *
9ad0147b
MD
1432 * The page must be BUSY and will remain BUSY on return.
1433 * No other requirements.
9765affa 1434 *
9ad0147b
MD
1435 * NOTE: FreeBSD side effect was to unbusy the page on return. We leave
1436 * it busy.
984263bc 1437 */
984263bc
MD
1438void
1439vm_page_remove(vm_page_t m)
1440{
1441 vm_object_t object;
1442
654a39f0 1443 if (m->object == NULL) {
984263bc 1444 return;
654a39f0 1445 }
984263bc 1446
bc0aa189 1447 if ((m->busy_count & PBUSY_LOCKED) == 0)
984263bc 1448 panic("vm_page_remove: page not busy");
984263bc 1449
984263bc
MD
1450 object = m->object;
1451
398c240d
VS
1452 vm_object_hold(object);
1453
984263bc 1454 /*
1f804340 1455 * Remove the page from the object and update the object.
b12defdc
MD
1456 *
1457 * The vm_page spin lock is required for interactions with the pmap.
984263bc 1458 */
b12defdc 1459 vm_page_spin_lock(m);
1f804340 1460 vm_page_rb_tree_RB_REMOVE(&object->rb_memq, m);
6d538b47
MD
1461 --object->resident_page_count;
1462 --mycpu->gd_vmtotal.t_rm;
984263bc 1463 m->object = NULL;
95270b7e 1464 atomic_add_int(&object->generation, 1);
b12defdc 1465 vm_page_spin_unlock(m);
1f804340 1466
b12defdc 1467 vm_object_drop(object);
984263bc
MD
1468}
1469
70f3bb08
MD
1470/*
1471 * Calculate the hash position for the vm_page hash heuristic.
1472 */
1473static __inline
1474struct vm_page **
1475vm_page_hash_hash(vm_object_t object, vm_pindex_t pindex)
1476{
1477 size_t hi;
1478
1479 hi = (uintptr_t)object % (uintptr_t)vm_page_array_size + pindex;
1480 hi %= vm_page_array_size;
1481 return (&vm_page_hash[hi]);
1482}
1483
1484/*
1485 * Heuristical page lookup that does not require any locks. Returns
1486 * a soft-busied page on success, NULL on failure.
1487 *
1488 * Caller must lookup the page the slow way if NULL is returned.
1489 */
1490vm_page_t
1491vm_page_hash_get(vm_object_t object, vm_pindex_t pindex)
1492{
1493 struct vm_page **mp;
1494 vm_page_t m;
1495
1496 if (vm_page_hash == NULL)
1497 return NULL;
1498 mp = vm_page_hash_hash(object, pindex);
1499 m = *mp;
1500 cpu_ccfence();
1501 if (m == NULL)
1502 return NULL;
1503 if (m->object != object || m->pindex != pindex)
1504 return NULL;
1505 if (vm_page_sbusy_try(m))
1506 return NULL;
1507 if (m->object != object || m->pindex != pindex) {
1508 vm_page_wakeup(m);
1509 return NULL;
1510 }
1511 return m;
1512}
1513
1514/*
1515 * Enter page onto vm_page_hash[]. This is a heuristic, SMP collisions
1516 * are allowed.
1517 */
1518static __inline
1519void
1520vm_page_hash_enter(vm_page_t m)
1521{
1522 struct vm_page **mp;
1523
1524 if (vm_page_hash &&
1525 m > &vm_page_array[0] &&
1526 m < &vm_page_array[vm_page_array_size]) {
1527 mp = vm_page_hash_hash(m->object, m->pindex);
1528 if (*mp != m)
1529 *mp = m;
1530 }
1531}
1532
984263bc 1533/*
de71fd3f
MD
1534 * Locate and return the page at (object, pindex), or NULL if the
1535 * page could not be found.
1536 *
b12defdc 1537 * The caller must hold the vm_object token.
984263bc 1538 */
984263bc
MD
1539vm_page_t
1540vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1541{
1542 vm_page_t m;
984263bc
MD
1543
1544 /*
1545 * Search the hash table for this object/offset pair
1546 */
b12defdc 1547 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1f804340 1548 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
70f3bb08
MD
1549 if (m) {
1550 KKASSERT(m->object == object && m->pindex == pindex);
1551 vm_page_hash_enter(m);
1552 }
1f804340 1553 return(m);
984263bc
MD
1554}
1555
b12defdc
MD
1556vm_page_t
1557VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_wait)(struct vm_object *object,
1558 vm_pindex_t pindex,
1559 int also_m_busy, const char *msg
1560 VM_PAGE_DEBUG_ARGS)
1561{
bc0aa189 1562 u_int32_t busy_count;
b12defdc
MD
1563 vm_page_t m;
1564
1565 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1566 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1567 while (m) {
1568 KKASSERT(m->object == object && m->pindex == pindex);
bc0aa189 1569 busy_count = m->busy_count;
b12defdc 1570 cpu_ccfence();
bc0aa189 1571 if (busy_count & PBUSY_LOCKED) {
b12defdc 1572 tsleep_interlock(m, 0);
bc0aa189
MD
1573 if (atomic_cmpset_int(&m->busy_count, busy_count,
1574 busy_count | PBUSY_WANTED)) {
1575 atomic_set_int(&m->flags, PG_REFERENCED);
b12defdc
MD
1576 tsleep(m, PINTERLOCKED, msg, 0);
1577 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq,
1578 pindex);
1579 }
bc0aa189 1580 } else if (also_m_busy && busy_count) {
b12defdc 1581 tsleep_interlock(m, 0);
bc0aa189
MD
1582 if (atomic_cmpset_int(&m->busy_count, busy_count,
1583 busy_count | PBUSY_WANTED)) {
1584 atomic_set_int(&m->flags, PG_REFERENCED);
b12defdc
MD
1585 tsleep(m, PINTERLOCKED, msg, 0);
1586 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq,
1587 pindex);
1588 }
bc0aa189
MD
1589 } else if (atomic_cmpset_int(&m->busy_count, busy_count,
1590 busy_count | PBUSY_LOCKED)) {
b12defdc
MD
1591#ifdef VM_PAGE_DEBUG
1592 m->busy_func = func;
1593 m->busy_line = lineno;
1594#endif
70f3bb08 1595 vm_page_hash_enter(m);
b12defdc
MD
1596 break;
1597 }
1598 }
1599 return m;
1600}
1601
984263bc 1602/*
b12defdc 1603 * Attempt to lookup and busy a page.
984263bc 1604 *
b12defdc 1605 * Returns NULL if the page could not be found
984263bc 1606 *
b12defdc
MD
1607 * Returns a vm_page and error == TRUE if the page exists but could not
1608 * be busied.
984263bc 1609 *
b12defdc
MD
1610 * Returns a vm_page and error == FALSE on success.
1611 */
1612vm_page_t
1613VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_try)(struct vm_object *object,
1614 vm_pindex_t pindex,
1615 int also_m_busy, int *errorp
1616 VM_PAGE_DEBUG_ARGS)
1617{
bc0aa189 1618 u_int32_t busy_count;
b12defdc
MD
1619 vm_page_t m;
1620
1621 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1622 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1623 *errorp = FALSE;
1624 while (m) {
1625 KKASSERT(m->object == object && m->pindex == pindex);
bc0aa189 1626 busy_count = m->busy_count;
b12defdc 1627 cpu_ccfence();
bc0aa189 1628 if (busy_count & PBUSY_LOCKED) {
b12defdc
MD
1629 *errorp = TRUE;
1630 break;
1631 }
bc0aa189 1632 if (also_m_busy && busy_count) {
b12defdc
MD
1633 *errorp = TRUE;
1634 break;
1635 }
bc0aa189
MD
1636 if (atomic_cmpset_int(&m->busy_count, busy_count,
1637 busy_count | PBUSY_LOCKED)) {
b12defdc
MD
1638#ifdef VM_PAGE_DEBUG
1639 m->busy_func = func;
1640 m->busy_line = lineno;
1641#endif
70f3bb08 1642 vm_page_hash_enter(m);
b12defdc
MD
1643 break;
1644 }
1645 }
1646 return m;
1647}
1648
bc0aa189
MD
1649/*
1650 * Returns a page that is only soft-busied for use by the caller in
1651 * a read-only fashion. Returns NULL if the page could not be found,
1652 * the soft busy could not be obtained, or the page data is invalid.
1653 */
1654vm_page_t
eae4df88
MD
1655vm_page_lookup_sbusy_try(struct vm_object *object, vm_pindex_t pindex,
1656 int pgoff, int pgbytes)
bc0aa189
MD
1657{
1658 vm_page_t m;
1659
1660 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1661 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1662 if (m) {
eae4df88
MD
1663 if ((m->valid != VM_PAGE_BITS_ALL &&
1664 !vm_page_is_valid(m, pgoff, pgbytes)) ||
bc0aa189
MD
1665 (m->flags & PG_FICTITIOUS)) {
1666 m = NULL;
1667 } else if (vm_page_sbusy_try(m)) {
1668 m = NULL;
eae4df88
MD
1669 } else if ((m->valid != VM_PAGE_BITS_ALL &&
1670 !vm_page_is_valid(m, pgoff, pgbytes)) ||
bc0aa189
MD
1671 (m->flags & PG_FICTITIOUS)) {
1672 vm_page_sbusy_drop(m);
1673 m = NULL;
70f3bb08
MD
1674 } else {
1675 vm_page_hash_enter(m);
bc0aa189
MD
1676 }
1677 }
1678 return m;
1679}
1680
b12defdc
MD
1681/*
1682 * Caller must hold the related vm_object
1683 */
1684vm_page_t
1685vm_page_next(vm_page_t m)
1686{
1687 vm_page_t next;
1688
1689 next = vm_page_rb_tree_RB_NEXT(m);
1690 if (next && next->pindex != m->pindex + 1)
1691 next = NULL;
1692 return (next);
1693}
1694
1695/*
1696 * vm_page_rename()
1697 *
1698 * Move the given vm_page from its current object to the specified
1699 * target object/offset. The page must be busy and will remain so
1700 * on return.
984263bc 1701 *
b12defdc
MD
1702 * new_object must be held.
1703 * This routine might block. XXX ?
1704 *
1705 * NOTE: Swap associated with the page must be invalidated by the move. We
de71fd3f
MD
1706 * have to do this for several reasons: (1) we aren't freeing the
1707 * page, (2) we are dirtying the page, (3) the VM system is probably
1708 * moving the page from object A to B, and will then later move
1709 * the backing store from A to B and we can't have a conflict.
984263bc 1710 *
b12defdc 1711 * NOTE: We *always* dirty the page. It is necessary both for the
de71fd3f
MD
1712 * fact that we moved it, and because we may be invalidating
1713 * swap. If the page is on the cache, we have to deactivate it
1714 * or vm_page_dirty() will panic. Dirty pages are not allowed
1715 * on the cache.
984263bc 1716 */
984263bc
MD
1717void
1718vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1719{
bc0aa189 1720 KKASSERT(m->busy_count & PBUSY_LOCKED);
ce94514e 1721 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(new_object));
b12defdc 1722 if (m->object) {
ce94514e 1723 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(m->object));
b12defdc
MD
1724 vm_page_remove(m);
1725 }
d2d8515b 1726 if (vm_page_insert(m, new_object, new_pindex) == FALSE) {
480c83b6 1727 panic("vm_page_rename: target exists (%p,%"PRIu64")",
d2d8515b
MD
1728 new_object, new_pindex);
1729 }
984263bc
MD
1730 if (m->queue - m->pc == PQ_CACHE)
1731 vm_page_deactivate(m);
1732 vm_page_dirty(m);
984263bc
MD
1733}
1734
1735/*
de71fd3f 1736 * vm_page_unqueue() without any wakeup. This routine is used when a page
5cdc30e8 1737 * is to remain BUSYied by the caller.
984263bc 1738 *
de71fd3f 1739 * This routine may not block.
984263bc 1740 */
984263bc
MD
1741void
1742vm_page_unqueue_nowakeup(vm_page_t m)
1743{
b12defdc
MD
1744 vm_page_and_queue_spin_lock(m);
1745 (void)_vm_page_rem_queue_spinlocked(m);
1746 vm_page_spin_unlock(m);
984263bc
MD
1747}
1748
1749/*
de71fd3f
MD
1750 * vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon
1751 * if necessary.
984263bc 1752 *
de71fd3f 1753 * This routine may not block.
984263bc 1754 */
984263bc
MD
1755void
1756vm_page_unqueue(vm_page_t m)
1757{
b12defdc 1758 u_short queue;
de71fd3f 1759
b12defdc
MD
1760 vm_page_and_queue_spin_lock(m);
1761 queue = _vm_page_rem_queue_spinlocked(m);
1762 if (queue == PQ_FREE || queue == PQ_CACHE) {
1763 vm_page_spin_unlock(m);
1764 pagedaemon_wakeup();
1765 } else {
1766 vm_page_spin_unlock(m);
984263bc
MD
1767 }
1768}
1769
984263bc 1770/*
de71fd3f 1771 * vm_page_list_find()
984263bc 1772 *
de71fd3f 1773 * Find a page on the specified queue with color optimization.
984263bc 1774 *
de71fd3f
MD
1775 * The page coloring optimization attempts to locate a page that does
1776 * not overload other nearby pages in the object in the cpu's L1 or L2
1777 * caches. We need this optimization because cpu caches tend to be
85946b6c
MD
1778 * physical caches, while object spaces tend to be virtual.
1779 *
9002b0d5
MD
1780 * The page coloring optimization also, very importantly, tries to localize
1781 * memory to cpus and physical sockets.
1782 *
53ddc8a1
MD
1783 * Each PQ_FREE and PQ_CACHE color queue has its own spinlock and the
1784 * algorithm is adjusted to localize allocations on a per-core basis.
85946b6c 1785 * This is done by 'twisting' the colors.
984263bc 1786 *
b12defdc 1787 * The page is returned spinlocked and removed from its queue (it will
bc0aa189 1788 * be on PQ_NONE), or NULL. The page is not BUSY'd. The caller
b12defdc
MD
1789 * is responsible for dealing with the busy-page case (usually by
1790 * deactivating the page and looping).
1791 *
1792 * NOTE: This routine is carefully inlined. A non-inlined version
1793 * is available for outside callers but the only critical path is
1794 * from within this source file.
984263bc 1795 *
b12defdc
MD
1796 * NOTE: This routine assumes that the vm_pages found in PQ_CACHE and PQ_FREE
1797 * represent stable storage, allowing us to order our locks vm_page
1798 * first, then queue.
984263bc 1799 */
74232d8e 1800static __inline
984263bc 1801vm_page_t
635c9c15 1802_vm_page_list_find(int basequeue, int index)
74232d8e 1803{
53ddc8a1 1804 struct vpgqueues *pq;
74232d8e
MD
1805 vm_page_t m;
1806
53ddc8a1
MD
1807 index &= PQ_L2_MASK;
1808 pq = &vm_page_queues[basequeue + index];
1809
1810 /*
1811 * Try this cpu's colored queue first. Test for a page unlocked,
1812 * then lock the queue and locate a page. Note that the lock order
1813 * is reversed, but we do not want to dwadle on the page spinlock
1814 * anyway as it is held significantly longer than the queue spinlock.
1815 */
1816 if (TAILQ_FIRST(&pq->pl)) {
1817 spin_lock(&pq->spin);
1818 TAILQ_FOREACH(m, &pq->pl, pageq) {
1819 if (spin_trylock(&m->spin) == 0)
1820 continue;
1821 KKASSERT(m->queue == basequeue + index);
b12defdc 1822 _vm_page_rem_queue_spinlocked(m);
53ddc8a1 1823 return(m);
b12defdc 1824 }
53ddc8a1 1825 spin_unlock(&pq->spin);
b12defdc 1826 }
53ddc8a1
MD
1827
1828 /*
1829 * If we are unable to get a page, do a more involved NUMA-aware
1830 * search.
1831 */
1832 m = _vm_page_list_find2(basequeue, index);
74232d8e
MD
1833 return(m);
1834}
1835
9002b0d5
MD
1836/*
1837 * If we could not find the page in the desired queue try to find it in
53ddc8a1 1838 * a nearby (NUMA-aware) queue.
9002b0d5 1839 */
74232d8e
MD
1840static vm_page_t
1841_vm_page_list_find2(int basequeue, int index)
984263bc 1842{
984263bc 1843 struct vpgqueues *pq;
9002b0d5
MD
1844 vm_page_t m = NULL;
1845 int pqmask = PQ_SET_ASSOC_MASK >> 1;
1846 int pqi;
1847 int i;
984263bc 1848
9002b0d5 1849 index &= PQ_L2_MASK;
984263bc
MD
1850 pq = &vm_page_queues[basequeue];
1851
1852 /*
9002b0d5
MD
1853 * Run local sets of 16, 32, 64, 128, and the whole queue if all
1854 * else fails (PQ_L2_MASK which is 255).
53ddc8a1
MD
1855 *
1856 * Test each queue unlocked first, then lock the queue and locate
1857 * a page. Note that the lock order is reversed, but we do not want
1858 * to dwadle on the page spinlock anyway as it is held significantly
1859 * longer than the queue spinlock.
984263bc 1860 */
9002b0d5
MD
1861 do {
1862 pqmask = (pqmask << 1) | 1;
1863 for (i = 0; i <= pqmask; ++i) {
1864 pqi = (index & ~pqmask) | ((index + i) & pqmask);
53ddc8a1
MD
1865 if (TAILQ_FIRST(&pq[pqi].pl)) {
1866 spin_lock(&pq[pqi].spin);
1867 TAILQ_FOREACH(m, &pq[pqi].pl, pageq) {
1868 if (spin_trylock(&m->spin) == 0)
1869 continue;
1870 KKASSERT(m->queue == basequeue + pqi);
b12defdc
MD
1871 _vm_page_rem_queue_spinlocked(m);
1872 return(m);
1873 }
53ddc8a1 1874 spin_unlock(&pq[pqi].spin);
b12defdc 1875 }
b12defdc 1876 }
9002b0d5
MD
1877 } while (pqmask != PQ_L2_MASK);
1878
984263bc
MD
1879 return(m);
1880}
1881
573fb415 1882/*
b12defdc
MD
1883 * Returns a vm_page candidate for allocation. The page is not busied so
1884 * it can move around. The caller must busy the page (and typically
1885 * deactivate it if it cannot be busied!)
1886 *
1887 * Returns a spinlocked vm_page that has been removed from its queue.
573fb415 1888 */
74232d8e 1889vm_page_t
635c9c15 1890vm_page_list_find(int basequeue, int index)
74232d8e 1891{
635c9c15 1892 return(_vm_page_list_find(basequeue, index));
74232d8e
MD
1893}
1894
984263bc 1895/*
b12defdc
MD
1896 * Find a page on the cache queue with color optimization, remove it
1897 * from the queue, and busy it. The returned page will not be spinlocked.
1898 *
1899 * A candidate failure will be deactivated. Candidates can fail due to
1900 * being busied by someone else, in which case they will be deactivated.
984263bc 1901 *
de71fd3f 1902 * This routine may not block.
b12defdc 1903 *
984263bc 1904 */
b12defdc 1905static vm_page_t
85946b6c 1906vm_page_select_cache(u_short pg_color)
984263bc
MD
1907{
1908 vm_page_t m;
1909
b12defdc 1910 for (;;) {
635c9c15 1911 m = _vm_page_list_find(PQ_CACHE, pg_color & PQ_L2_MASK);
b12defdc
MD
1912 if (m == NULL)
1913 break;
1914 /*
1915 * (m) has been removed from its queue and spinlocked
1916 */
1917 if (vm_page_busy_try(m, TRUE)) {
1918 _vm_page_deactivate_locked(m, 0);
1919 vm_page_spin_unlock(m);
b12defdc
MD
1920 } else {
1921 /*
1922 * We successfully busied the page
1923 */
9bf025db 1924 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT)) == 0 &&
b12defdc 1925 m->hold_count == 0 &&
9bf025db
MD
1926 m->wire_count == 0 &&
1927 (m->dirty & m->valid) == 0) {
b12defdc
MD
1928 vm_page_spin_unlock(m);
1929 pagedaemon_wakeup();
1930 return(m);
1931 }
9bf025db
MD
1932
1933 /*
1934 * The page cannot be recycled, deactivate it.
1935 */
b12defdc
MD
1936 _vm_page_deactivate_locked(m, 0);
1937 if (_vm_page_wakeup(m)) {
1938 vm_page_spin_unlock(m);
1939 wakeup(m);
1940 } else {
1941 vm_page_spin_unlock(m);
1942 }
984263bc 1943 }
984263bc 1944 }
b12defdc 1945 return (m);
984263bc
MD
1946}
1947
1948/*
635c9c15
MD
1949 * Find a free page. We attempt to inline the nominal case and fall back
1950 * to _vm_page_select_free() otherwise. A busied page is removed from
1951 * the queue and returned.
984263bc 1952 *
de71fd3f 1953 * This routine may not block.
984263bc 1954 */
984263bc 1955static __inline vm_page_t
635c9c15 1956vm_page_select_free(u_short pg_color)
984263bc
MD
1957{
1958 vm_page_t m;
1959
b12defdc 1960 for (;;) {
635c9c15 1961 m = _vm_page_list_find(PQ_FREE, pg_color & PQ_L2_MASK);
b12defdc
MD
1962 if (m == NULL)
1963 break;
1964 if (vm_page_busy_try(m, TRUE)) {
90244566
MD
1965 /*
1966 * Various mechanisms such as a pmap_collect can
1967 * result in a busy page on the free queue. We
1968 * have to move the page out of the way so we can
1969 * retry the allocation. If the other thread is not
1970 * allocating the page then m->valid will remain 0 and
1971 * the pageout daemon will free the page later on.
1972 *
1973 * Since we could not busy the page, however, we
1974 * cannot make assumptions as to whether the page
1975 * will be allocated by the other thread or not,
1976 * so all we can do is deactivate it to move it out
1977 * of the way. In particular, if the other thread
1978 * wires the page it may wind up on the inactive
1979 * queue and the pageout daemon will have to deal
1980 * with that case too.
1981 */
b12defdc
MD
1982 _vm_page_deactivate_locked(m, 0);
1983 vm_page_spin_unlock(m);
b12defdc 1984 } else {
90244566
MD
1985 /*
1986 * Theoretically if we are able to busy the page
1987 * atomic with the queue removal (using the vm_page
e05899ce
MD
1988 * lock) nobody else should have been able to mess
1989 * with the page before us.
1990 *
1991 * Assert the page state. Note that even though
1992 * wiring doesn't adjust queues, a page on the free
1993 * queue should never be wired at this point.
90244566 1994 */
9bf025db
MD
1995 KKASSERT((m->flags & (PG_UNMANAGED |
1996 PG_NEED_COMMIT)) == 0);
e05899ce
MD
1997 KASSERT(m->hold_count == 0,
1998 ("m->hold_count is not zero "
1999 "pg %p q=%d flags=%08x hold=%d wire=%d",
2000 m, m->queue, m->flags,
2001 m->hold_count, m->wire_count));
b12defdc
MD
2002 KKASSERT(m->wire_count == 0);
2003 vm_page_spin_unlock(m);
2004 pagedaemon_wakeup();
2005
2006 /* return busied and removed page */
2007 return(m);
2008 }
2009 }
984263bc
MD
2010 return(m);
2011}
2012
2013/*
de71fd3f 2014 * vm_page_alloc()
984263bc 2015 *
de71fd3f 2016 * Allocate and return a memory cell associated with this VM object/offset
85946b6c 2017 * pair. If object is NULL an unassociated page will be allocated.
984263bc 2018 *
d2d8515b
MD
2019 * The returned page will be busied and removed from its queues. This
2020 * routine can block and may return NULL if a race occurs and the page
2021 * is found to already exist at the specified (object, pindex).
de71fd3f 2022 *
dc1fd4b3 2023 * VM_ALLOC_NORMAL allow use of cache pages, nominal free drain
39208dbe 2024 * VM_ALLOC_QUICK like normal but cannot use cache
dc1fd4b3
MD
2025 * VM_ALLOC_SYSTEM greater free drain
2026 * VM_ALLOC_INTERRUPT allow free list to be completely drained
d2d8515b
MD
2027 * VM_ALLOC_ZERO advisory request for pre-zero'd page only
2028 * VM_ALLOC_FORCE_ZERO advisory request for pre-zero'd page only
2029 * VM_ALLOC_NULL_OK ok to return NULL on insertion collision
2030 * (see vm_page_grab())
54341a3b
MD
2031 * VM_ALLOC_USE_GD ok to use per-gd cache
2032 *
070a58b3
MD
2033 * VM_ALLOC_CPU(n) allocate using specified cpu localization
2034 *
d2d8515b 2035 * The object must be held if not NULL
85946b6c 2036 * This routine may not block
984263bc 2037 *
de71fd3f
MD
2038 * Additional special handling is required when called from an interrupt
2039 * (VM_ALLOC_INTERRUPT). We are not allowed to mess with the page cache
2040 * in this case.
984263bc 2041 */
984263bc
MD
2042vm_page_t
2043vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req)
2044{
75979118 2045 globaldata_t gd;
9d494b34 2046 vm_object_t obj;
54341a3b 2047 vm_page_t m;
85946b6c 2048 u_short pg_color;
070a58b3 2049 int cpuid_local;
984263bc 2050
54341a3b
MD
2051#if 0
2052 /*
2053 * Special per-cpu free VM page cache. The pages are pre-busied
2054 * and pre-zerod for us.
2055 */
2056 if (gd->gd_vmpg_count && (page_req & VM_ALLOC_USE_GD)) {
2057 crit_enter_gd(gd);
2058 if (gd->gd_vmpg_count) {
2059 m = gd->gd_vmpg_array[--gd->gd_vmpg_count];
2060 crit_exit_gd(gd);
2061 goto done;
2062 }
2063 crit_exit_gd(gd);
2064 }
2065#endif
2066 m = NULL;
2067
85946b6c 2068 /*
33ee48c4
MD
2069 * CPU LOCALIZATION
2070 *
2071 * CPU localization algorithm. Break the page queues up by physical
2072 * id and core id (note that two cpu threads will have the same core
2073 * id, and core_id != gd_cpuid).
2074 *
2075 * This is nowhere near perfect, for example the last pindex in a
2076 * subgroup will overflow into the next cpu or package. But this
2077 * should get us good page reuse locality in heavy mixed loads.
070a58b3
MD
2078 *
2079 * (may be executed before the APs are started, so other GDs might
2080 * not exist!)
85946b6c 2081 */
070a58b3
MD
2082 if (page_req & VM_ALLOC_CPU_SPEC)
2083 cpuid_local = VM_ALLOC_GETCPU(page_req);
2084 else
2085 cpuid_local = mycpu->gd_cpuid;
2086
2087 pg_color = vm_get_pg_color(cpuid_local, object, pindex);
33ee48c4 2088
dc1fd4b3 2089 KKASSERT(page_req &
39208dbe
MD
2090 (VM_ALLOC_NORMAL|VM_ALLOC_QUICK|
2091 VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
984263bc
MD
2092
2093 /*
4ecf7cc9
MD
2094 * Certain system threads (pageout daemon, buf_daemon's) are
2095 * allowed to eat deeper into the free page list.
984263bc 2096 */
4ecf7cc9 2097 if (curthread->td_flags & TDF_SYSTHREAD)
dc1fd4b3 2098 page_req |= VM_ALLOC_SYSTEM;
984263bc 2099
9cd626ca
MD
2100 /*
2101 * Impose various limitations. Note that the v_free_reserved test
2102 * must match the opposite of vm_page_count_target() to avoid
2103 * livelocks, be careful.
2104 */
984263bc 2105loop:
75979118
MD
2106 gd = mycpu;
2107 if (gd->gd_vmstats.v_free_count >= gd->gd_vmstats.v_free_reserved ||
2108 ((page_req & VM_ALLOC_INTERRUPT) &&
2109 gd->gd_vmstats.v_free_count > 0) ||
2110 ((page_req & VM_ALLOC_SYSTEM) &&
2111 gd->gd_vmstats.v_cache_count == 0 &&
2112 gd->gd_vmstats.v_free_count >
2113 gd->gd_vmstats.v_interrupt_free_min)
dc1fd4b3 2114 ) {
984263bc 2115 /*
dc1fd4b3 2116 * The free queue has sufficient free pages to take one out.
984263bc 2117 */
635c9c15 2118 m = vm_page_select_free(pg_color);
dc1fd4b3 2119 } else if (page_req & VM_ALLOC_NORMAL) {
984263bc 2120 /*
dc1fd4b3
MD
2121 * Allocatable from the cache (non-interrupt only). On
2122 * success, we must free the page and try again, thus
2123 * ensuring that vmstats.v_*_free_min counters are replenished.
984263bc 2124 */
dc1fd4b3
MD
2125#ifdef INVARIANTS
2126 if (curthread->td_preempted) {
086c1d7e 2127 kprintf("vm_page_alloc(): warning, attempt to allocate"
dc1fd4b3
MD
2128 " cache page from preempting interrupt\n");
2129 m = NULL;
2130 } else {
85946b6c 2131 m = vm_page_select_cache(pg_color);
dc1fd4b3
MD
2132 }
2133#else
85946b6c 2134 m = vm_page_select_cache(pg_color);
dc1fd4b3 2135#endif
984263bc 2136 /*
9765affa 2137 * On success move the page into the free queue and loop.
bdea739c
MD
2138 *
2139 * Only do this if we can safely acquire the vm_object lock,
2140 * because this is effectively a random page and the caller
2141 * might be holding the lock shared, we don't want to
2142 * deadlock.
984263bc 2143 */
dc1fd4b3
MD
2144 if (m != NULL) {
2145 KASSERT(m->dirty == 0,
d2d8515b 2146 ("Found dirty cache page %p", m));
9d494b34
MD
2147 if ((obj = m->object) != NULL) {
2148 if (vm_object_hold_try(obj)) {
bdea739c
MD
2149 vm_page_protect(m, VM_PROT_NONE);
2150 vm_page_free(m);
9d494b34
MD
2151 /* m->object NULL here */
2152 vm_object_drop(obj);
bdea739c
MD
2153 } else {
2154 vm_page_deactivate(m);
2155 vm_page_wakeup(m);
2156 }
2157 } else {
2158 vm_page_protect(m, VM_PROT_NONE);
2159 vm_page_free(m);
2160 }
dc1fd4b3
MD
2161 goto loop;
2162 }
2163
2164 /*
2165 * On failure return NULL
2166 */
534ee349 2167 atomic_add_int(&vm_pageout_deficit, 1);
dc1fd4b3
MD
2168 pagedaemon_wakeup();
2169 return (NULL);
984263bc
MD
2170 } else {
2171 /*
dc1fd4b3 2172 * No pages available, wakeup the pageout daemon and give up.
984263bc 2173 */
534ee349 2174 atomic_add_int(&vm_pageout_deficit, 1);
984263bc
MD
2175 pagedaemon_wakeup();
2176 return (NULL);
2177 }
2178
2179 /*
b12defdc
MD
2180 * v_free_count can race so loop if we don't find the expected
2181 * page.
984263bc 2182 */
75979118
MD
2183 if (m == NULL) {
2184 vmstats_rollup();
b12defdc 2185 goto loop;
75979118 2186 }
984263bc
MD
2187
2188 /*
d2d8515b
MD
2189 * Good page found. The page has already been busied for us and
2190 * removed from its queues.
984263bc 2191 */
d2d8515b
MD
2192 KASSERT(m->dirty == 0,
2193 ("vm_page_alloc: free/cache page %p was dirty", m));
b12defdc 2194 KKASSERT(m->queue == PQ_NONE);
984263bc 2195
54341a3b
MD
2196#if 0
2197done:
2198#endif
984263bc 2199 /*
d2d8515b
MD
2200 * Initialize the structure, inheriting some flags but clearing
2201 * all the rest. The page has already been busied for us.
984263bc 2202 */
e4b2227a
MD
2203 vm_page_flag_clear(m, ~PG_KEEP_NEWPAGE_MASK);
2204
b12defdc 2205 KKASSERT(m->wire_count == 0);
bc0aa189 2206 KKASSERT((m->busy_count & PBUSY_MASK) == 0);
984263bc 2207 m->act_count = 0;
984263bc 2208 m->valid = 0;
984263bc
MD
2209
2210 /*
b12defdc
MD
2211 * Caller must be holding the object lock (asserted by
2212 * vm_page_insert()).
2213 *
2214 * NOTE: Inserting a page here does not insert it into any pmaps
2215 * (which could cause us to block allocating memory).
85946b6c
MD
2216 *
2217 * NOTE: If no object an unassociated page is allocated, m->pindex
2218 * can be used by the caller for any purpose.
984263bc 2219 */
d2d8515b
MD
2220 if (object) {
2221 if (vm_page_insert(m, object, pindex) == FALSE) {
d2d8515b 2222 vm_page_free(m);
d2d8515b 2223 if ((page_req & VM_ALLOC_NULL_OK) == 0)
f7de9d7f
MD
2224 panic("PAGE RACE %p[%ld]/%p",
2225 object, (long)pindex, m);
2226 m = NULL;
d2d8515b
MD
2227 }
2228 } else {
85946b6c 2229 m->pindex = pindex;
d2d8515b 2230 }
984263bc
MD
2231
2232 /*
2233 * Don't wakeup too often - wakeup the pageout daemon when
2234 * we would be nearly out of memory.
2235 */
20479584 2236 pagedaemon_wakeup();
984263bc 2237
9765affa 2238 /*
bc0aa189 2239 * A BUSY page is returned.
9765affa 2240 */
984263bc
MD
2241 return (m);
2242}
2243
888a40a7
MD
2244/*
2245 * Returns number of pages available in our DMA memory reserve
2246 * (adjusted with vm.dma_reserved=<value>m in /boot/loader.conf)
2247 */
2248vm_size_t
2249vm_contig_avail_pages(void)
2250{
2251 alist_blk_t blk;
2252 alist_blk_t count;
2253 alist_blk_t bfree;
2254 spin_lock(&vm_contig_spin);
2255 bfree = alist_free_info(&vm_contig_alist, &blk, &count);
2256 spin_unlock(&vm_contig_spin);
2257
2258 return bfree;
2259}
2260
79d182b0
MD
2261/*
2262 * Attempt to allocate contiguous physical memory with the specified
2263 * requirements.
2264 */
2265vm_page_t
2266vm_page_alloc_contig(vm_paddr_t low, vm_paddr_t high,
2267 unsigned long alignment, unsigned long boundary,
8b9ed12e 2268 unsigned long size, vm_memattr_t memattr)
79d182b0
MD
2269{
2270 alist_blk_t blk;
8b9ed12e 2271 vm_page_t m;
b7ea2f3f 2272 vm_pindex_t i;
fe63a898 2273#if 0
df47a6f0 2274 static vm_pindex_t contig_rover;
fe63a898 2275#endif
79d182b0
MD
2276
2277 alignment >>= PAGE_SHIFT;
2278 if (alignment == 0)
2279 alignment = 1;
2280 boundary >>= PAGE_SHIFT;
2281 if (boundary == 0)
2282 boundary = 1;
2283 size = (size + PAGE_MASK) >> PAGE_SHIFT;
2284
fe63a898
MD
2285#if 0
2286 /*
2287 * Disabled temporarily until we find a solution for DRM (a flag
2288 * to always use the free space reserve, for performance).
2289 */
df47a6f0
MD
2290 if (high == BUS_SPACE_MAXADDR && alignment <= PAGE_SIZE &&
2291 boundary <= PAGE_SIZE && size == 1 &&
2292 memattr == VM_MEMATTR_DEFAULT) {
2293 /*
2294 * Any page will work, use vm_page_alloc()
2295 * (e.g. when used from kmem_alloc_attr())
2296 */
2297 m = vm_page_alloc(NULL, (contig_rover++) & 0x7FFFFFFF,
2298 VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM |
2299 VM_ALLOC_INTERRUPT);
2300 m->valid = VM_PAGE_BITS_ALL;
2301 vm_page_wire(m);
2302 vm_page_wakeup(m);
fe63a898
MD
2303 } else
2304#endif
2305 {
df47a6f0
MD
2306 /*
2307 * Use the low-memory dma reserve
2308 */
2309 spin_lock(&vm_contig_spin);
2310 blk = alist_alloc(&vm_contig_alist, 0, size);
2311 if (blk == ALIST_BLOCK_NONE) {
2312 spin_unlock(&vm_contig_spin);
2313 if (bootverbose) {
2314 kprintf("vm_page_alloc_contig: %ldk nospace\n",
2315 (size << PAGE_SHIFT) / 1024);
2316 print_backtrace(5);
2317 }
2318 return(NULL);
79d182b0 2319 }
df47a6f0
MD
2320 if (high && ((vm_paddr_t)(blk + size) << PAGE_SHIFT) > high) {
2321 alist_free(&vm_contig_alist, blk, size);
2322 spin_unlock(&vm_contig_spin);
2323 if (bootverbose) {
2324 kprintf("vm_page_alloc_contig: %ldk high "
2325 "%016jx failed\n",
2326 (size << PAGE_SHIFT) / 1024,
2327 (intmax_t)high);
2328 }
2329 return(NULL);
79d182b0 2330 }
df47a6f0
MD
2331 spin_unlock(&vm_contig_spin);
2332 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT);
79d182b0 2333 }
ef67e7a3 2334 if (vm_contig_verbose) {
df47a6f0
MD
2335 kprintf("vm_page_alloc_contig: %016jx/%ldk "
2336 "(%016jx-%016jx al=%lu bo=%lu pgs=%lu attr=%d\n",
2337 (intmax_t)m->phys_addr,
2338 (size << PAGE_SHIFT) / 1024,
2339 low, high, alignment, boundary, size, memattr);
79d182b0 2340 }
b7ea2f3f
MD
2341 if (memattr != VM_MEMATTR_DEFAULT) {
2342 for (i = 0;i < size; i++)
8b9ed12e 2343 pmap_page_set_memattr(&m[i], memattr);
b7ea2f3f 2344 }
8b9ed12e 2345 return m;
79d182b0
MD
2346}
2347
2348/*
2349 * Free contiguously allocated pages. The pages will be wired but not busy.
2350 * When freeing to the alist we leave them wired and not busy.
2351 */
2352void
2353vm_page_free_contig(vm_page_t m, unsigned long size)
2354{
2355 vm_paddr_t pa = VM_PAGE_TO_PHYS(m);
2356 vm_pindex_t start = pa >> PAGE_SHIFT;
2357 vm_pindex_t pages = (size + PAGE_MASK) >> PAGE_SHIFT;
2358
ef67e7a3 2359 if (vm_contig_verbose) {
79d182b0
MD
2360 kprintf("vm_page_free_contig: %016jx/%ldk\n",
2361 (intmax_t)pa, size / 1024);
2362 }
2363 if (pa < vm_low_phys_reserved) {
2364 KKASSERT(pa + size <= vm_low_phys_reserved);
2365 spin_lock(&vm_contig_spin);
2366 alist_free(&vm_contig_alist, start, pages);
2367 spin_unlock(&vm_contig_spin);
2368 } else {
2369 while (pages) {
2370 vm_page_busy_wait(m, FALSE, "cpgfr");
2371 vm_page_unwire(m, 0);
2372 vm_page_free(m);
2373 --pages;
2374 ++m;
2375 }
2376
2377 }
2378}
2379
2380
163f8d24
MD
2381/*
2382 * Wait for sufficient free memory for nominal heavy memory use kernel
2383 * operations.
55b50bd5
MD
2384 *
2385 * WARNING! Be sure never to call this in any vm_pageout code path, which
2386 * will trivially deadlock the system.
163f8d24
MD
2387 */
2388void
2389vm_wait_nominal(void)
2390{
2391 while (vm_page_count_min(0))
2392 vm_wait(0);
2393}
2394
12052253
MD
2395/*
2396 * Test if vm_wait_nominal() would block.
2397 */
2398int
2399vm_test_nominal(void)
2400{
2401 if (vm_page_count_min(0))
2402 return(1);
2403 return(0);
2404}
2405
984263bc 2406/*
de71fd3f
MD
2407 * Block until free pages are available for allocation, called in various
2408 * places before memory allocations.
cd3c66bd
MD
2409 *
2410 * The caller may loop if vm_page_count_min() == FALSE so we cannot be
2411 * more generous then that.
984263bc 2412 */
984263bc 2413void
4ecf7cc9 2414vm_wait(int timo)
984263bc 2415{
cd3c66bd
MD
2416 /*
2417 * never wait forever
2418 */
2419 if (timo == 0)
2420 timo = hz;
9ad0147b 2421 lwkt_gettoken(&vm_token);
cd3c66bd 2422
32c821cf
MD
2423 if (curthread == pagethread ||
2424 curthread == emergpager) {
cd3c66bd
MD
2425 /*
2426 * The pageout daemon itself needs pages, this is bad.
2427 */
2428 if (vm_page_count_min(0)) {
2429 vm_pageout_pages_needed = 1;
2430 tsleep(&vm_pageout_pages_needed, 0, "VMWait", timo);
2431 }
984263bc 2432 } else {
cd3c66bd
MD
2433 /*
2434 * Wakeup the pageout daemon if necessary and wait.
77d1fb91
MD
2435 *
2436 * Do not wait indefinitely for the target to be reached,
2437 * as load might prevent it from being reached any time soon.
2438 * But wait a little to try to slow down page allocations
2439 * and to give more important threads (the pagedaemon)
2440 * allocation priority.
cd3c66bd
MD
2441 */
2442 if (vm_page_count_target()) {
2443 if (vm_pages_needed == 0) {
2444 vm_pages_needed = 1;
2445 wakeup(&vm_pages_needed);
2446 }
2447 ++vm_pages_waiting; /* SMP race ok */
2448 tsleep(&vmstats.v_free_count, 0, "vmwait", timo);
984263bc 2449 }
984263bc 2450 }
9ad0147b 2451 lwkt_reltoken(&vm_token);
984263bc
MD
2452}
2453
2454/*
de71fd3f
MD
2455 * Block until free pages are available for allocation
2456 *
cd3c66bd 2457 * Called only from vm_fault so that processes page faulting can be
de71fd3f 2458 * easily tracked.
984263bc 2459 */
984263bc 2460void
3b47bfc4 2461vm_wait_pfault(void)
984263bc 2462{
cd3c66bd
MD
2463 /*
2464 * Wakeup the pageout daemon if necessary and wait.
77d1fb91
MD
2465 *
2466 * Do not wait indefinitely for the target to be reached,
2467 * as load might prevent it from being reached any time soon.
2468 * But wait a little to try to slow down page allocations
2469 * and to give more important threads (the pagedaemon)
2470 * allocation priority.
cd3c66bd 2471 */
3b47bfc4 2472 if (vm_page_count_min(0)) {
cd3c66bd 2473 lwkt_gettoken(&vm_token);
3b47bfc4
MD
2474 while (vm_page_count_severe()) {
2475 if (vm_page_count_target()) {
2c9e2984
MD
2476 thread_t td;
2477
3b47bfc4
MD
2478 if (vm_pages_needed == 0) {
2479 vm_pages_needed = 1;
2480 wakeup(&vm_pages_needed);
2481 }
2482 ++vm_pages_waiting; /* SMP race ok */
2483 tsleep(&vmstats.v_free_count, 0, "pfault", hz);
2c9e2984
MD
2484
2485 /*
2486 * Do not stay stuck in the loop if the system is trying
2487 * to kill the process.
2488 */
2489 td = curthread;
2490 if (td->td_proc && (td->td_proc->p_flags & P_LOWMEMKILL))
2491 break;
cd3c66bd 2492 }
cd3c66bd
MD
2493 }
2494 lwkt_reltoken(&vm_token);
984263bc 2495 }
984263bc
MD
2496}
2497
984263bc 2498/*
de71fd3f
MD
2499 * Put the specified page on the active list (if appropriate). Ensure
2500 * that act_count is at least ACT_INIT but do not otherwise mess with it.
984263bc 2501 *
b12defdc 2502 * The caller should be holding the page busied ? XXX
de71fd3f 2503 * This routine may not block.
984263bc
MD
2504 */
2505void
2506vm_page_activate(vm_page_t m)
2507{
b12defdc 2508 u_short oqueue;
984263bc 2509
b12defdc 2510 vm_page_spin_lock(m);
0ca81fbe 2511 if (m->queue - m->pc != PQ_ACTIVE && !(m->flags & PG_FICTITIOUS)) {
b12defdc
MD
2512 _vm_page_queue_spin_lock(m);
2513 oqueue = _vm_page_rem_queue_spinlocked(m);
2514 /* page is left spinlocked, queue is unlocked */
984263bc 2515
b12defdc
MD
2516 if (oqueue == PQ_CACHE)
2517 mycpu->gd_cnt.v_reactivated++;
e05899ce 2518 if ((m->flags & PG_UNMANAGED) == 0) {
984263bc
MD
2519 if (m->act_count < ACT_INIT)
2520 m->act_count = ACT_INIT;
027193eb 2521 _vm_page_add_queue_spinlocked(m, PQ_ACTIVE + m->pc, 0);
984263bc 2522 }
b12defdc
MD
2523 _vm_page_and_queue_spin_unlock(m);
2524 if (oqueue == PQ_CACHE || oqueue == PQ_FREE)
2525 pagedaemon_wakeup();
984263bc
MD
2526 } else {
2527 if (m->act_count < ACT_INIT)
2528 m->act_count = ACT_INIT;
b12defdc 2529 vm_page_spin_unlock(m);
984263bc 2530 }
984263bc
MD
2531}
2532
2533/*
de71fd3f
MD
2534 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
2535 * routine is called when a page has been added to the cache or free
2536 * queues.
984263bc 2537 *
de71fd3f 2538 * This routine may not block.
984263bc
MD
2539 */
2540static __inline void
2541vm_page_free_wakeup(void)
2542{
75979118
MD
2543 globaldata_t gd = mycpu;
2544
984263bc 2545 /*
cd3c66bd
MD
2546 * If the pageout daemon itself needs pages, then tell it that
2547 * there are some free.
984263bc
MD
2548 */
2549 if (vm_pageout_pages_needed &&
75979118
MD
2550 gd->gd_vmstats.v_cache_count + gd->gd_vmstats.v_free_count >=
2551 gd->gd_vmstats.v_pageout_free_min
de71fd3f 2552 ) {
984263bc 2553 vm_pageout_pages_needed = 0;
77d1fb91 2554 wakeup(&vm_pageout_pages_needed);
984263bc 2555 }
de71fd3f 2556
984263bc 2557 /*
cd3c66bd
MD
2558 * Wakeup processes that are waiting on memory.
2559 *
77d1fb91
MD
2560 * Generally speaking we want to wakeup stuck processes as soon as
2561 * possible. !vm_page_count_min(0) is the absolute minimum point
2562 * where we can do this. Wait a bit longer to reduce degenerate
2563 * re-blocking (vm_page_free_hysteresis). The target check is just
2564 * to make sure the min-check w/hysteresis does not exceed the
2565 * normal target.
984263bc 2566 */
cd3c66bd 2567 if (vm_pages_waiting) {
77d1fb91
MD
2568 if (!vm_page_count_min(vm_page_free_hysteresis) ||
2569 !vm_page_count_target()) {
2570 vm_pages_waiting = 0;
2571 wakeup(&vmstats.v_free_count);
2572 ++mycpu->gd_cnt.v_ppwakeups;
2573 }
2574#if 0
cd3c66bd
MD
2575 if (!vm_page_count_target()) {
2576 /*
2577 * Plenty of pages are free, wakeup everyone.
2578 */
2579 vm_pages_waiting = 0;
2580 wakeup(&vmstats.v_free_count);
2581 ++mycpu->gd_cnt.v_ppwakeups;
2582 } else if (!vm_page_count_min(0)) {
2583 /*
2584 * Some pages are free, wakeup someone.
2585 */
2586 int wcount = vm_pages_waiting;
2587 if (wcount > 0)
2588 --wcount;
2589 vm_pages_waiting = wcount;
2590 wakeup_one(&vmstats.v_free_count);
2591 ++mycpu->gd_cnt.v_ppwakeups;
2592 }
77d1fb91 2593#endif
984263bc
MD
2594 }
2595}
2596
2597/*
b12defdc
MD
2598 * Returns the given page to the PQ_FREE or PQ_HOLD list and disassociates
2599 * it from its VM object.
984263bc 2600 *
bc0aa189 2601 * The vm_page must be BUSY on entry. BUSY will be released on
b12defdc 2602 * return (the page will have been freed).
984263bc 2603 */
984263bc
MD
2604void
2605vm_page_free_toq(vm_page_t m)
2606{
12e4aaff 2607 mycpu->gd_cnt.v_tfree++;
17cde63e 2608 KKASSERT((m->flags & PG_MAPPED) == 0);
bc0aa189 2609 KKASSERT(m->busy_count & PBUSY_LOCKED);
17cde63e 2610
bc0aa189
MD
2611 if ((m->busy_count & PBUSY_MASK) || ((m->queue - m->pc) == PQ_FREE)) {
2612 kprintf("vm_page_free: pindex(%lu), busy %08x, "
2613 "hold(%d)\n",
2614 (u_long)m->pindex, m->busy_count, m->hold_count);
984263bc
MD
2615 if ((m->queue - m->pc) == PQ_FREE)
2616 panic("vm_page_free: freeing free page");
2617 else
2618 panic("vm_page_free: freeing busy page");
2619 }
2620
2621 /*
b12defdc
MD
2622 * Remove from object, spinlock the page and its queues and
2623 * remove from any queue. No queue spinlock will be held
2624 * after this section (because the page was removed from any
2625 * queue).
984263bc 2626 */
984263bc
MD
2627 vm_page_remove(m);
2628
2629 /*
f2d22ebf
MD
2630 * No further management of fictitious pages occurs beyond object
2631 * and queue removal.
984263bc 2632 */
984263bc 2633 if ((m->flags & PG_FICTITIOUS) != 0) {
0ca81fbe 2634 KKASSERT(m->queue == PQ_NONE);
9765affa 2635 vm_page_wakeup(m);
984263bc
MD
2636 return;
2637 }
0ca81fbe
MD
2638 vm_page_and_queue_spin_lock(m);
2639 _vm_page_rem_queue_spinlocked(m);
984263bc
MD
2640
2641 m->valid = 0;
2642 vm_page_undirty(m);
2643
2644 if (m->wire_count != 0) {
2645 if (m->wire_count > 1) {
de71fd3f
MD
2646 panic(
2647 "vm_page_free: invalid wire count (%d), pindex: 0x%lx",
2648 m->wire_count, (long)m->pindex);
984263bc 2649 }
73c351d1 2650 panic("vm_page_free: freeing wired page");
984263bc
MD
2651 }
2652
984263bc
MD
2653 /*
2654 * Clear the UNMANAGED flag when freeing an unmanaged page.
9bf025db 2655 * Clear the NEED_COMMIT flag
984263bc 2656 */
9bf025db 2657 if (m->flags & PG_UNMANAGED)
b12defdc 2658 vm_page_flag_clear(m, PG_UNMANAGED);
9bf025db
MD
2659 if (m->flags & PG_NEED_COMMIT)
2660 vm_page_flag_clear(m, PG_NEED_COMMIT);
984263bc
MD
2661
2662 if (m->hold_count != 0) {
027193eb 2663 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0);
de71fd3f 2664 } else {
635c9c15 2665 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1);
de71fd3f 2666 }
984263bc
MD
2667
2668 /*
bc0aa189 2669 * This sequence allows us to clear BUSY while still holding
b12defdc
MD
2670 * its spin lock, which reduces contention vs allocators. We
2671 * must not leave the queue locked or _vm_page_wakeup() may
2672 * deadlock.
984263bc 2673 */
b12defdc
MD
2674 _vm_page_queue_spin_unlock(m);
2675 if (_vm_page_wakeup(m)) {
2676 vm_page_spin_unlock(m);
2677 wakeup(m);
984263bc 2678 } else {
b12defdc 2679 vm_page_spin_unlock(m);
984263bc 2680 }
984263bc 2681 vm_page_free_wakeup();
984263bc
MD
2682}
2683
2684/*
de71fd3f
MD
2685 * vm_page_unmanage()
2686 *
2687 * Prevent PV management from being done on the page. The page is
e05899ce
MD
2688 * also removed from the paging queues, and as a consequence of no longer
2689 * being managed the pageout daemon will not touch it (since there is no
2690 * way to locate the pte mappings for the page). madvise() calls that
2691 * mess with the pmap will also no longer operate on the page.
de71fd3f
MD
2692 *
2693 * Beyond that the page is still reasonably 'normal'. Freeing the page
2694 * will clear the flag.
2695 *
2696 * This routine is used by OBJT_PHYS objects - objects using unswappable
2697 * physical memory as backing store rather then swap-backed memory and
2698 * will eventually be extended to support 4MB unmanaged physical
2699 * mappings.
654a39f0 2700 *
b12defdc 2701 * Caller must be holding the page busy.
984263bc 2702 */
984263bc
MD
2703void
2704vm_page_unmanage(vm_page_t m)
2705{
bc0aa189 2706 KKASSERT(m->busy_count & PBUSY_LOCKED);
984263bc 2707 if ((m->flags & PG_UNMANAGED) == 0) {
e05899ce 2708 vm_page_unqueue(m);
984263bc
MD
2709 }
2710 vm_page_flag_set(m, PG_UNMANAGED);
984263bc
MD
2711}
2712
2713/*
e05899ce
MD
2714 * Mark this page as wired down by yet another map. We do not adjust the
2715 * queue the page is on, it will be checked for wiring as-needed.
984263bc 2716 *
b12defdc 2717 * Caller must be holding the page busy.
984263bc
MD
2718 */
2719void
2720vm_page_wire(vm_page_t m)
2721{
984263bc
MD
2722 /*
2723 * Only bump the wire statistics if the page is not already wired,
2724 * and only unqueue the page if it is on some queue (if it is unmanaged
f2d22ebf
MD
2725 * it is already off the queues). Don't do anything with fictitious
2726 * pages because they are always wired.
984263bc 2727 */
bc0aa189 2728 KKASSERT(m->busy_count & PBUSY_LOCKED);
f2d22ebf 2729 if ((m->flags & PG_FICTITIOUS) == 0) {
b12defdc 2730 if (atomic_fetchadd_int(&m->wire_count, 1) == 0) {
b7ea2f3f 2731 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count, 1);
f2d22ebf 2732 }
f2d22ebf 2733 KASSERT(m->wire_count != 0,
17cde63e 2734 ("vm_page_wire: wire_count overflow m=%p", m));
984263bc 2735 }
984263bc
MD
2736}
2737
2738/*
de71fd3f
MD
2739 * Release one wiring of this page, potentially enabling it to be paged again.
2740 *
e05899ce
MD
2741 * Note that wired pages are no longer unconditionally removed from the
2742 * paging queues, so the page may already be on a queue. Move the page
2743 * to the desired queue if necessary.
2744 *
de71fd3f
MD
2745 * Many pages placed on the inactive queue should actually go
2746 * into the cache, but it is difficult to figure out which. What
2747 * we do instead, if the inactive target is well met, is to put
2748 * clean pages at the head of the inactive queue instead of the tail.
2749 * This will cause them to be moved to the cache more quickly and
2750 * if not actively re-referenced, freed more quickly. If we just
2751 * stick these pages at the end of the inactive queue, heavy filesystem
2752 * meta-data accesses can cause an unnecessary paging load on memory bound
2753 * processes. This optimization causes one-time-use metadata to be
2754 * reused more quickly.
2755 *
f84f7e81
MD
2756 * Pages marked PG_NEED_COMMIT are always activated and never placed on
2757 * the inactive queue. This helps the pageout daemon determine memory
2758 * pressure and act on out-of-memory situations more quickly.
2759 *
de71fd3f
MD
2760 * BUT, if we are in a low-memory situation we have no choice but to
2761 * put clean pages on the cache queue.
2762 *
2763 * A number of routines use vm_page_unwire() to guarantee that the page
2764 * will go into either the inactive or active queues, and will NEVER
2765 * be placed in the cache - for example, just after dirtying a page.
2766 * dirty pages in the cache are not allowed.
2767 *
de71fd3f 2768 * This routine may not block.
984263bc
MD
2769 */
2770void
2771vm_page_unwire(vm_page_t m, int activate)
2772{
bc0aa189 2773 KKASSERT(m->busy_count & PBUSY_LOCKED);
f2d22ebf
MD
2774 if (m->flags & PG_FICTITIOUS) {
2775 /* do nothing */
e05899ce 2776 } else if ((int)m->wire_count <= 0) {
f2d22ebf
MD
2777 panic("vm_page_unwire: invalid wire count: %d", m->wire_count);
2778 } else {
b12defdc 2779 if (atomic_fetchadd_int(&m->wire_count, -1) == 1) {
b7ea2f3f 2780 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count,-1);
984263bc
MD
2781 if (m->flags & PG_UNMANAGED) {
2782 ;
f84f7e81 2783 } else if (activate || (m->flags & PG_NEED_COMMIT)) {
e05899ce
MD
2784 vm_page_activate(m);
2785#if 0
b12defdc 2786 vm_page_spin_lock(m);
027193eb
MD
2787 _vm_page_add_queue_spinlocked(m,
2788 PQ_ACTIVE + m->pc, 0);
b12defdc 2789 _vm_page_and_queue_spin_unlock(m);
e05899ce 2790#endif
984263bc 2791 } else {
e05899ce
MD
2792 vm_page_deactivate(m);
2793#if 0
b12defdc 2794 vm_page_spin_lock(m);
984263bc 2795 vm_page_flag_clear(m, PG_WINATCFLS);
027193eb
MD
2796 _vm_page_add_queue_spinlocked(m,
2797 PQ_INACTIVE + m->pc, 0);
b12defdc 2798 _vm_page_and_queue_spin_unlock(m);
e05899ce 2799#endif
984263bc
MD
2800 }
2801 }
984263bc 2802 }
984263bc
MD
2803}
2804
984263bc 2805/*
e05899ce 2806 * Move the specified page to the inactive queue.
984263bc
MD
2807 *
2808 * Normally athead is 0 resulting in LRU operation. athead is set
2809 * to 1 if we want this page to be 'as if it were placed in the cache',
2810 * except without unmapping it from the process address space.
2811 *
b12defdc 2812 * vm_page's spinlock must be held on entry and will remain held on return.
e05899ce
MD
2813 * This routine may not block. The caller does not have to hold the page
2814 * busied but should have some sort of interlock on its validity.
984263bc 2815 */
b12defdc
MD
2816static void
2817_vm_page_deactivate_locked(vm_page_t m, int athead)
984263bc 2818{
b12defdc
MD
2819 u_short oqueue;
2820
984263bc
MD
2821 /*
2822 * Ignore if already inactive.
2823 */
0ca81fbe 2824 if (m->queue - m->pc == PQ_INACTIVE || (m->flags & PG_FICTITIOUS))
984263bc 2825 return;
b12defdc
MD
2826 _vm_page_queue_spin_lock(m);
2827 oqueue = _vm_page_rem_queue_spinlocked(m);
984263bc 2828
e05899ce 2829 if ((m->flags & PG_UNMANAGED) == 0) {
b12defdc 2830 if (oqueue == PQ_CACHE)
12e4aaff 2831 mycpu->gd_cnt.v_reactivated++;
984263bc 2832 vm_page_flag_clear(m, PG_WINATCFLS);
027193eb 2833 _vm_page_add_queue_spinlocked(m, PQ_INACTIVE + m->pc, athead);
b396bb03
MD
2834 if (athead == 0) {
2835 atomic_add_long(
2836 &vm_page_queues[PQ_INACTIVE + m->pc].adds, 1);
2837 }
984263bc 2838 }
bb0d6093 2839 /* NOTE: PQ_NONE if condition not taken */
b12defdc
MD
2840 _vm_page_queue_spin_unlock(m);
2841 /* leaves vm_page spinlocked */
984263bc
MD
2842}
2843
573fb415
MD
2844/*
2845 * Attempt to deactivate a page.
2846 *
2847 * No requirements.
2848 */
984263bc
MD
2849void
2850vm_page_deactivate(vm_page_t m)
2851{
b12defdc
MD
2852 vm_page_spin_lock(m);
2853 _vm_page_deactivate_locked(m, 0);
2854 vm_page_spin_unlock(m);
2855}
2856
2857void
2858vm_page_deactivate_locked(vm_page_t m)
2859{
2860 _vm_page_deactivate_locked(m, 0);
984263bc
MD
2861}
2862
2863/*
da2da420 2864 * Attempt to move a busied page to PQ_CACHE, then unconditionally unbusy it.
b12defdc 2865 *
da2da420
MD
2866 * This function returns non-zero if it successfully moved the page to
2867 * PQ_CACHE.
573fb415 2868 *
da2da420 2869 * This function unconditionally unbusies the page on return.
984263bc
MD
2870 */
2871int
2872vm_page_try_to_cache(vm_page_t m)
2873{
16b1cc2d
MD
2874 /*
2875 * Shortcut if we obviously cannot move the page, or if the
0ca81fbe 2876 * page is already on the cache queue, or it is ficitious.
16b1cc2d 2877 */
b12defdc 2878 if (m->dirty || m->hold_count || m->wire_count ||
16b1cc2d 2879 m->queue - m->pc == PQ_CACHE ||
0ca81fbe 2880 (m->flags & (PG_UNMANAGED | PG_NEED_COMMIT | PG_FICTITIOUS))) {
16b1cc2d 2881 vm_page_wakeup(m);
984263bc
MD
2882 return(0);
2883 }
b12defdc
MD
2884
2885 /*
2886 * Page busied by us and no longer spinlocked. Dirty pages cannot
2887 * be moved to the cache.
2888 */
984263bc 2889 vm_page_test_dirty(m);
d86d27a8 2890 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
50e32333 2891 vm_page_wakeup(m);
984263bc 2892 return(0);
654a39f0 2893 }
984263bc
MD
2894 vm_page_cache(m);
2895 return(1);
2896}
2897
2898/*
de71fd3f
MD
2899 * Attempt to free the page. If we cannot free it, we do nothing.
2900 * 1 is returned on success, 0 on failure.
573fb415 2901 *
16b1cc2d 2902 * Caller provides an unlocked/non-busied page.
573fb415 2903 * No requirements.
984263bc 2904 */
984263bc
MD
2905int
2906vm_page_try_to_free(vm_page_t m)
2907{
16b1cc2d 2908 if (vm_page_busy_try(m, TRUE))
b12defdc 2909 return(0);
82034c53
MD
2910
2911 /*
2912 * The page can be in any state, including already being on the free
2913 * queue. Check to see if it really can be freed.
2914 */
2915 if (m->dirty || /* can't free if it is dirty */
2916 m->hold_count || /* or held (XXX may be wrong) */
2917 m->wire_count || /* or wired */
9bf025db 2918 (m->flags & (PG_UNMANAGED | /* or unmanaged */
0ca81fbe
MD
2919 PG_NEED_COMMIT | /* or needs a commit */
2920 PG_FICTITIOUS)) || /* or is fictitious */
82034c53
MD
2921 m->queue - m->pc == PQ_FREE || /* already on PQ_FREE */
2922 m->queue - m->pc == PQ_HOLD) { /* already on PQ_HOLD */
16b1cc2d 2923 vm_page_wakeup(m);
984263bc
MD
2924 return(0);
2925 }
b12defdc
MD
2926
2927 /*
82034c53
MD
2928 * We can probably free the page.
2929 *
b12defdc
MD
2930 * Page busied by us and no longer spinlocked. Dirty pages will
2931 * not be freed by this function. We have to re-test the
2932 * dirty bit after cleaning out the pmaps.
2933 */
984263bc 2934 vm_page_test_dirty(m);
d86d27a8 2935 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
b12defdc 2936 vm_page_wakeup(m);
984263bc 2937 return(0);
654a39f0 2938 }
984263bc 2939 vm_page_protect(m, VM_PROT_NONE);
d86d27a8 2940 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
b12defdc
MD
2941 vm_page_wakeup(m);
2942 return(0);
2943 }
984263bc
MD
2944 vm_page_free(m);
2945 return(1);
2946}
2947
984263bc
MD
2948/*
2949 * vm_page_cache
2950 *
2951 * Put the specified page onto the page cache queue (if appropriate).
2952 *
a491077e
MD
2953 * The page must be busy, and this routine will release the busy and
2954 * possibly even free the page.
984263bc
MD
2955 */
2956void
2957vm_page_cache(vm_page_t m)
2958{
fde6be6a
MD
2959 /*
2960 * Not suitable for the cache
2961 */
0ca81fbe 2962 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT | PG_FICTITIOUS)) ||
bc0aa189
MD
2963 (m->busy_count & PBUSY_MASK) ||
2964 m->wire_count || m->hold_count) {
a491077e 2965 vm_page_wakeup(m);
984263bc
MD
2966 return;
2967 }
c9ec86b3
MD
2968
2969 /*
2970 * Already in the cache (and thus not mapped)
2971 */
17cde63e
MD
2972 if ((m->queue - m->pc) == PQ_CACHE) {
2973 KKASSERT((m->flags & PG_MAPPED) == 0);
a491077e 2974 vm_page_wakeup(m);
984263bc 2975 return;
17cde63e 2976 }
984263bc
MD
2977
2978 /*
c9ec86b3
MD
2979 * Caller is required to test m->dirty, but note that the act of
2980 * removing the page from its maps can cause it to become dirty
2981 * on an SMP system due to another cpu running in usermode.
984263bc 2982 */
c9ec86b3 2983 if (m->dirty) {
984263bc
MD
2984 panic("vm_page_cache: caching a dirty page, pindex: %ld",
2985 (long)m->pindex);
2986 }
c9ec86b3
MD
2987
2988 /*
2989 * Remove all pmaps and indicate that the page is not
17cde63e
MD
2990 * writeable or mapped. Our vm_page_protect() call may
2991 * have blocked (especially w/ VM_PROT_NONE), so recheck
2992 * everything.
c9ec86b3
MD
2993 */
2994 vm_page_protect(m, VM_PROT_NONE);
9bf025db 2995 if ((m->flags & (PG_UNMANAGED | PG_MAPPED)) ||
bc0aa189
MD
2996 (m->busy_count & PBUSY_MASK) ||
2997 m->wire_count || m->hold_count) {
a491077e 2998 vm_page_wakeup(m);
9bf025db 2999 } else if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
c9ec86b3 3000 vm_page_deactivate(m);
a491077e 3001 vm_page_wakeup(m);
c9ec86b3 3002 } else {
b12defdc
MD
3003 _vm_page_and_queue_spin_lock(m);
3004 _vm_page_rem_queue_spinlocked(m);
3005 _vm_page_add_queue_spinlocked(m, PQ_CACHE + m->pc, 0);
16b1cc2d
MD
3006 _vm_page_and_queue_spin_unlock(m);
3007 vm_page_wakeup(m);
c9ec86b3
MD
3008 vm_page_free_wakeup();
3009 }
984263bc
MD
3010}
3011
3012/*
de71fd3f
MD
3013 * vm_page_dontneed()
3014 *
3015 * Cache, deactivate, or do nothing as appropriate. This routine
3016 * is typically used by madvise() MADV_DONTNEED.
3017 *
3018 * Generally speaking we want to move the page into the cache so
3019 * it gets reused quickly. However, this can result in a silly syndrome
3020 * due to the page recycling too quickly. Small objects will not be
3021 * fully cached. On the otherhand, if we move the page to the inactive
3022 * queue we wind up with a problem whereby very large objects
3023 * unnecessarily blow away our inactive and cache queues.
3024 *
3025 * The solution is to move the pages based on a fixed weighting. We
3026 * either leave them alone, deactivate them, or move them to the cache,
3027 * where moving them to the cache has the highest weighting.
3028 * By forcing some pages into other queues we eventually force the
3029 * system to balance the queues, potentially recovering other unrelated
3030 * space from active. The idea is to not force this to happen too
3031 * often.
573fb415 3032 *
b12defdc 3033 * The page must be busied.
984263bc 3034 */
984263bc
MD
3035void
3036vm_page_dontneed(vm_page_t m)
3037{
3038 static int dnweight;
3039 int dnw;
3040 int head;
3041
3042 dnw = ++dnweight;
3043
3044 /*
3045 * occassionally leave the page alone
3046 */
984263bc 3047 if ((dnw & 0x01F0) == 0 ||
027193eb 3048 m->queue - m->pc == PQ_INACTIVE ||
984263bc
MD
3049 m->queue - m->pc == PQ_CACHE
3050 ) {
3051 if (m->act_count >= ACT_INIT)
3052 --m->act_count;
3053 return;
3054 }
3055
31da5e4d
VS
3056 /*
3057 * If vm_page_dontneed() is inactivating a page, it must clear
3058 * the referenced flag; otherwise the pagedaemon will see references
3059 * on the page in the inactive queue and reactivate it. Until the
3060 * page can move to the cache queue, madvise's job is not done.
3061 */
3062 vm_page_flag_clear(m, PG_REFERENCED);
3063 pmap_clear_reference(m);
3064
984263bc
MD
3065 if (m->dirty == 0)
3066 vm_page_test_dirty(m);
3067
3068 if (m->dirty || (dnw & 0x0070) == 0) {
3069 /*
3070 * Deactivate the page 3 times out of 32.
3071 */
3072 head = 0;
3073 } else {
3074 /*
3075 * Cache the page 28 times out of every 32. Note that
3076 * the page is deactivated instead of cached, but placed
3077 * at the head of the queue instead of the tail.
3078 */
3079 head = 1;
3080 }
b12defdc
MD
3081 vm_page_spin_lock(m);
3082 _vm_page_deactivate_locked(m, head);
3083 vm_page_spin_unlock(m);
3084}
3085
3086/*
3087 * These routines manipulate the 'soft busy' count for a page. A soft busy
bc0aa189
MD
3088 * is almost like a hard BUSY except that it allows certain compatible
3089 * operations to occur on the page while it is busy. For example, a page
3090 * undergoing a write can still be mapped read-only.
3091 *
3092 * We also use soft-busy to quickly pmap_enter shared read-only pages
3093 * without having to hold the page locked.
b12defdc 3094 *
bc0aa189
MD
3095 * The soft-busy count can be > 1 in situations where multiple threads
3096 * are pmap_enter()ing the same page simultaneously, or when two buffer
3097 * cache buffers overlap the same page.
95270b7e
MD
3098 *
3099 * The caller must hold the page BUSY when making these two calls.
b12defdc
MD
3100 */
3101void
3102vm_page_io_start(vm_page_t m)
3103{
bc0aa189
MD
3104 uint32_t ocount;
3105
3106 ocount = atomic_fetchadd_int(&m->busy_count, 1);
3107 KKASSERT(ocount & PBUSY_LOCKED);
b12defdc
MD
3108}
3109
3110void
3111vm_page_io_finish(vm_page_t m)
3112{
bc0aa189
MD
3113 uint32_t ocount;
3114
3115 ocount = atomic_fetchadd_int(&m->busy_count, -1);
3116 KKASSERT(ocount & PBUSY_MASK);
3117#if 0
3118 if (((ocount - 1) & (PBUSY_LOCKED | PBUSY_MASK)) == 0)
3119 wakeup(m);
3120#endif
3121}
3122
3123/*
3124 * Attempt to soft-busy a page. The page must not be PBUSY_LOCKED.
3125 *
793bf44f
MD
3126 * We can't use fetchadd here because we might race a hard-busy and the
3127 * page freeing code asserts on a non-zero soft-busy count (even if only
3128 * temporary).
3129 *
bc0aa189
MD
3130 * Returns 0 on success, non-zero on failure.
3131 */
3132int
3133vm_page_sbusy_try(vm_page_t m)
3134{
3135 uint32_t ocount;
3136
793bf44f
MD
3137 for (;;) {
3138 ocount = m->busy_count;
3139 cpu_ccfence();
3140 if (ocount & PBUSY_LOCKED)
3141 return 1;
3142 if (atomic_cmpset_int(&m->busy_count, ocount, ocount + 1))
3143 break;
3144 }
3145 return 0;
3146#if 0
bc0aa189
MD
3147 if (m->busy_count & PBUSY_LOCKED)
3148 return 1;
3149 ocount = atomic_fetchadd_int(&m->busy_count, 1);
3150 if (ocount & PBUSY_LOCKED) {
3151 vm_page_sbusy_drop(m);
3152 return 1;
3153 }
3154 return 0;
793bf44f 3155#endif
984263bc
MD
3156}
3157
9bf025db
MD
3158/*
3159 * Indicate that a clean VM page requires a filesystem commit and cannot
3160 * be reused. Used by tmpfs.
3161 */
3162void
3163vm_page_need_commit(vm_page_t m)
3164{
3165 vm_page_flag_set(m, PG_NEED_COMMIT);
d86d27a8 3166 vm_object_set_writeable_dirty(m->object);
9bf025db
MD
3167}
3168
3169void
3170vm_page_clear_commit(vm_page_t m)
3171{
3172 vm_page_flag_clear(m, PG_NEED_COMMIT);
3173}
3174
984263bc 3175/*
06ecca5a 3176 * Grab a page, blocking if it is busy and allocating a page if necessary.
d2d8515b
MD
3177 * A busy page is returned or NULL. The page may or may not be valid and
3178 * might not be on a queue (the caller is responsible for the disposition of
3179 * the page).
984263bc 3180 *
d2d8515b
MD
3181 * If VM_ALLOC_ZERO is specified and the grab must allocate a new page, the
3182 * page will be zero'd and marked valid.
b12defdc 3183 *
d2d8515b
MD
3184 * If VM_ALLOC_FORCE_ZERO is specified the page will be zero'd and marked
3185 * valid even if it already exists.
3186 *
3187 * If VM_ALLOC_RETRY is specified this routine will never return NULL. Also
3188 * note that VM_ALLOC_NORMAL must be specified if VM_ALLOC_RETRY is specified.
d149178e 3189 * VM_ALLOC_NULL_OK is implied when VM_ALLOC_RETRY is specified.
dc1fd4b3 3190 *
06ecca5a
MD
3191 * This routine may block, but if VM_ALLOC_RETRY is not set then NULL is
3192 * always returned if we had blocked.
d2d8515b 3193 *
06ecca5a 3194 * This routine may not be called from an interrupt.
06ecca5a 3195 *
d2d8515b 3196 * No other requirements.
984263bc
MD
3197 */
3198vm_page_t
3199vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3200{
984263bc 3201 vm_page_t m;
b12defdc 3202 int error;
501747bf 3203 int shared = 1;
984263bc 3204
dc1fd4b3
MD
3205 KKASSERT(allocflags &
3206 (VM_ALLOC_NORMAL|VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
501747bf 3207 vm_object_hold_shared(object);
b12defdc
MD
3208 for (;;) {
3209 m = vm_page_lookup_busy_try(object, pindex, TRUE, &error);
3210 if (error) {
3211 vm_page_sleep_busy(m, TRUE, "pgrbwt");
3212 if ((allocflags & VM_ALLOC_RETRY) == 0) {
3213 m = NULL;
3214 break;
984263bc 3215 }
d2d8515b 3216 /* retry */
b12defdc 3217 } else if (m == NULL) {
501747bf
MD
3218 if (shared) {
3219 vm_object_upgrade(object);
3220 shared = 0;
3221 }
d149178e
MD
3222 if (allocflags & VM_ALLOC_RETRY)
3223 allocflags |= VM_ALLOC_NULL_OK;
b12defdc
MD
3224 m = vm_page_alloc(object, pindex,
3225 allocflags & ~VM_ALLOC_RETRY);
3226 if (m)
3227 break;
3228 vm_wait(0);
3229 if ((allocflags & VM_ALLOC_RETRY) == 0)
d2d8515b 3230 goto failed;
984263bc 3231 } else {
b12defdc
MD
3232 /* m found */
3233 break;
984263bc
MD
3234 }
3235 }
d2d8515b
MD
3236
3237 /*
3238 * If VM_ALLOC_ZERO an invalid page will be zero'd and set valid.
3239 *
3240 * If VM_ALLOC_FORCE_ZERO the page is unconditionally zero'd and set
3241 * valid even if already valid.
afd2da4d
MD
3242 *
3243 * NOTE! We have removed all of the PG_ZERO optimizations and also
3244 * removed the idle zeroing code. These optimizations actually
3245 * slow things down on modern cpus because the zerod area is
3246 * likely uncached, placing a memory-access burden on the
3247 * accesors taking the fault.
3248 *
3249 * By always zeroing the page in-line with the fault, no
3250 * dynamic ram reads are needed and the caches are hot, ready
3251 * for userland to access the memory.
d2d8515b
MD
3252 */
3253 if (m->valid == 0) {
3254 if (allocflags & (VM_ALLOC_ZERO | VM_ALLOC_FORCE_ZERO)) {
afd2da4d 3255 pmap_zero_page(VM_PAGE_TO_PHYS(m));
d2d8515b
MD
3256 m->valid = VM_PAGE_BITS_ALL;
3257 }
3258 } else if (allocflags & VM_ALLOC_FORCE_ZERO) {
3259 pmap_zero_page(VM_PAGE_TO_PHYS(m));
3260 m->valid = VM_PAGE_BITS_ALL;
3261 }
d2d8515b 3262failed:
398c240d 3263 vm_object_drop(object);
06ecca5a 3264 return(m);
984263bc
MD
3265}
3266
3267/*
3268 * Mapping function for valid bits or for dirty bits in
3269 * a page. May not block.
3270 *
3271 * Inputs are required to range within a page.
573fb415
MD
3272 *
3273 * No requirements.
3274 * Non blocking.
984263bc 3275 */
573fb415 3276int
984263bc
MD
3277vm_page_bits(int base, int size)
3278{
3279 int first_bit;
3280 int last_bit;
3281
3282 KASSERT(
3283 base + size <= PAGE_SIZE,
3284 ("vm_page_bits: illegal base/size %d/%d", base, size)
3285 );
3286
3287 if (size == 0) /* handle degenerate case */
3288 return(0);
3289
3290 first_bit = base >> DEV_BSHIFT;
3291 last_bit = (base + size - 1) >> DEV_BSHIFT;
3292
3293 return ((2 << last_bit) - (1 << first_bit));
3294}
3295
3296/*
de71fd3f
MD
3297 * Sets portions of a page valid and clean. The arguments are expected
3298 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3299 * of any partial chunks touched by the range. The invalid portion of
3300 * such chunks will be zero'd.
984263bc 3301 *
c7841cbe
MD
3302 * NOTE: When truncating a buffer vnode_pager_setsize() will automatically
3303 * align base to DEV_BSIZE so as not to mark clean a partially
3304 * truncated device block. Otherwise the dirty page status might be
3305 * lost.
3306 *
de71fd3f 3307 * This routine may not block.
984263bc 3308 *
de71fd3f 3309 * (base + size) must be less then or equal to PAGE_SIZE.
984263bc 3310 */
1a54183b
MD
3311static void
3312_vm_page_zero_valid(vm_page_t m, int base, int size)
984263bc 3313{
984263bc
MD
3314 int frag;
3315 int endoff;
3316
3317 if (size == 0) /* handle degenerate case */
3318 return;
3319
3320 /*
3321 * If the base is not DEV_BSIZE aligned and the valid
3322 * bit is clear, we have to zero out a portion of the
3323 * first block.
3324 */
3325
3326 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
3327 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0
3328 ) {
3329 pmap_zero_page_area(
3330 VM_PAGE_TO_PHYS(m),
3331 frag,
3332 base - frag
3333 );
3334 }
3335
3336 /*
3337 * If the ending offset is not DEV_BSIZE aligned and the
3338 * valid bit is clear, we have to zero out a portion of
3339 * the last block.
3340 */
3341
3342 endoff = base + size;
3343
3344 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
3345 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0
3346 ) {
3347 pmap_zero_page_area(
3348 VM_PAGE_TO_PHYS(m),
3349 endoff,
3350 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))
3351 );
3352 }
1a54183b 3353}
984263bc 3354
1a54183b
MD
3355/*
3356 * Set valid, clear dirty bits. If validating the entire
3357 * page we can safely clear the pmap modify bit. We also
3358 * use this opportunity to clear the PG_NOSYNC flag. If a process
3359 * takes a write fault on a MAP_NOSYNC memory area the flag will
3360 * be set again.
3361 *
3362 * We set valid bits inclusive of any overlap, but we can only
3363 * clear dirty bits for DEV_BSIZE chunks that are fully within
3364 * the range.
573fb415
MD
3365 *
3366 * Page must be busied?
3367 * No other requirements.
1a54183b
MD
3368 */
3369void
3370vm_page_set_valid(vm_page_t m, int base, int size)
3371{
3372 _vm_page_zero_valid(m, base, size);
3373 m->valid |= vm_page_bits(base, size);
3374}
984263bc 3375
cb1cf930
MD
3376
3377/*
3378 * Set valid bits and clear dirty bits.
3379 *
c183e2fc
MD
3380 * Page must be busied by caller.
3381 *
cb1cf930
MD
3382 * NOTE: This function does not clear the pmap modified bit.
3383 * Also note that e.g. NFS may use a byte-granular base
3384 * and size.
573fb415 3385 *
573fb415 3386 * No other requirements.
cb1cf930 3387 */
1a54183b
MD
3388void
3389vm_page_set_validclean(vm_page_t m, int base, int size)
3390{
3391 int pagebits;
3392
3393 _vm_page_zero_valid(m, base, size);
984263bc
MD
3394 pagebits = vm_page_bits(base, size);
3395 m->valid |= pagebits;
984263bc
MD
3396 m->dirty &= ~pagebits;
3397 if (base == 0 && size == PAGE_SIZE) {
cb1cf930 3398 /*pmap_clear_modify(m);*/
984263bc
MD
3399 vm_page_flag_clear(m, PG_NOSYNC);
3400 }
3401}
3402
0a8aee15
MD
3403/*
3404 * Set valid & dirty. Used by buwrite()
573fb415 3405 *
c183e2fc 3406 * Page must be busied by caller.
0a8aee15
MD
3407 */
3408void
3409vm_page_set_validdirty(vm_page_t m, int base, int size)
3410{
3411 int pagebits;
3412
3413 pagebits = vm_page_bits(base, size);
3414 m->valid |= pagebits;
3415 m->dirty |= pagebits;
d89ce96a 3416 if (m->object)
9bf025db 3417 vm_object_set_writeable_dirty(m->object);
0a8aee15
MD
3418}
3419
cb1cf930
MD
3420/*
3421 * Clear dirty bits.
3422 *
3423 * NOTE: This function does not clear the pmap modified bit.
3424 * Also note that e.g. NFS may use a byte-granular base
3425 * and size.
573fb415
MD
3426 *
3427 * Page must be busied?
3428 * No other requirements.
cb1cf930 3429 */
984263bc
MD
3430void
3431vm_page_clear_dirty(vm_page_t m, int base, int size)
3432{
3433 m->dirty &= ~vm_page_bits(base, size);
1a54183b 3434 if (base == 0 && size == PAGE_SIZE) {
cb1cf930 3435 /*pmap_clear_modify(m);*/
1a54183b
MD
3436 vm_page_flag_clear(m, PG_NOSYNC);
3437 }
984263bc
MD
3438}
3439
17cde63e
MD
3440/*
3441 * Make the page all-dirty.
3442 *
3443 * Also make sure the related object and vnode reflect the fact that the
3444 * object may now contain a dirty page.
573fb415
MD
3445 *
3446 * Page must be busied?
3447 * No other requirements.
17cde63e
MD
3448 */
3449void
3450vm_page_dirty(vm_page_t m)
3451{
3452#ifdef INVARIANTS
3453 int pqtype = m->queue - m->pc;
3454#endif
3455 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE,
3456 ("vm_page_dirty: page in free/cache queue!"));
3457 if (m->dirty != VM_PAGE_BITS_ALL) {
3458 m->dirty = VM_PAGE_BITS_ALL;
3459 if (m->object)
3460 vm_object_set_writeable_dirty(m->object);
3461 }
3462}
3463
984263bc 3464/*
de71fd3f
MD
3465 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3466 * valid and dirty bits for the effected areas are cleared.
984263bc 3467 *
573fb415
MD
3468 * Page must be busied?
3469 * Does not block.
3470 * No other requirements.
984263bc
MD
3471 */
3472void
3473vm_page_set_invalid(vm_page_t m, int base, int size)
3474{
3475 int bits;
3476
3477 bits = vm_page_bits(base, size);
3478 m->valid &= ~bits;
3479 m->dirty &= ~bits;
95270b7e 3480 atomic_add_int(&m->object->generation, 1);
984263bc
MD
3481}
3482
3483/*
de71fd3f
MD
3484 * The kernel assumes that the invalid portions of a page contain
3485 * garbage, but such pages can be mapped into memory by user code.
3486 * When this occurs, we must zero out the non-valid portions of the
3487 * page so user code sees what it expects.
984263bc 3488 *
de71fd3f
MD
3489 * Pages are most often semi-valid when the end of a file is mapped
3490 * into memory and the file's size is not page aligned.
573fb415
MD
3491 *
3492 * Page must be busied?
3493 * No other requirements.
984263bc 3494 */
984263bc
MD
3495void
3496vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3497{
3498 int b;
3499 int i;
3500
3501 /*
3502 * Scan the valid bits looking for invalid sections that
3503 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
3504 * valid bit may be set ) have already been zerod by
3505 * vm_page_set_validclean().
3506 */
984263bc
MD
3507 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3508 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3509 (m->valid & (1 << i))
3510 ) {
3511 if (i > b) {
3512 pmap_zero_page_area(
3513 VM_PAGE_TO_PHYS(m),
3514 b << DEV_BSHIFT,
3515 (i - b) << DEV_BSHIFT
3516 );
3517 }
3518 b = i + 1;
3519 }
3520 }
3521
3522 /*
3523 * setvalid is TRUE when we can safely set the zero'd areas
3524 * as being valid. We can do this if there are no cache consistency
3525 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3526 */
984263bc
MD
3527 if (setvalid)
3528 m->valid = VM_PAGE_BITS_ALL;
3529}
3530