2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
64 * Kernel memory management.
67 #include <sys/cdefs.h>
68 __FBSDID("$FreeBSD$");
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/kernel.h> /* for ticks and hz */
75 #include <sys/domainset.h>
76 #include <sys/eventhandler.h>
79 #include <sys/malloc.h>
80 #include <sys/rwlock.h>
81 #include <sys/sysctl.h>
83 #include <sys/vmmeter.h>
86 #include <vm/vm_param.h>
87 #include <vm/vm_domainset.h>
88 #include <vm/vm_kern.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_object.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_pageout.h>
94 #include <vm/vm_pagequeue.h>
95 #include <vm/vm_phys.h>
96 #include <vm/vm_radix.h>
97 #include <vm/vm_extern.h>
100 struct vm_map kernel_map_store;
101 struct vm_map exec_map_store;
102 struct vm_map pipe_map_store;
104 const void *zero_region;
105 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
107 /* NB: Used by kernel debuggers. */
108 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS;
110 u_int exec_map_entry_size;
111 u_int exec_map_entries;
113 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD,
114 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address");
116 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD,
118 &vm_max_kernel_address, 0,
120 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS,
122 "Max kernel address");
124 #if VM_NRESERVLEVEL > 0
125 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
127 /* On non-superpage architectures we want large import sizes. */
128 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT)
130 #define KVA_QUANTUM (1ul << KVA_QUANTUM_SHIFT)
131 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128)
133 extern void uma_startup2(void);
138 * Allocate a virtual address range with no underlying object and
139 * no initial mapping to physical memory. Any mapping from this
140 * range to physical memory must be explicitly created prior to
141 * its use, typically with pmap_qenter(). Any attempt to create
142 * a mapping on demand through vm_fault() will result in a panic.
145 kva_alloc(vm_size_t size)
149 size = round_page(size);
150 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr))
159 * Release a region of kernel virtual memory allocated
160 * with kva_alloc, and return the physical pages
161 * associated with that region.
163 * This routine may not block on kernel maps.
166 kva_free(vm_offset_t addr, vm_size_t size)
169 size = round_page(size);
170 vmem_free(kernel_arena, addr, size);
174 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain,
175 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high,
176 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
182 VM_OBJECT_ASSERT_WLOCKED(object);
184 /* Disallow an invalid combination of flags. */
185 MPASS((pflags & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) !=
186 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM));
188 wait = (pflags & VM_ALLOC_WAITOK) != 0;
189 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0;
190 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
191 pflags |= VM_ALLOC_NOWAIT;
192 for (tries = wait ? 3 : 1;; tries--) {
193 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags,
194 npages, low, high, alignment, boundary, memattr);
195 if (m != NULL || tries == 0 || !reclaim)
198 VM_OBJECT_WUNLOCK(object);
199 if (!vm_page_reclaim_contig_domain(domain, pflags, npages,
200 low, high, alignment, boundary) && wait)
201 vm_wait_domain(domain);
202 VM_OBJECT_WLOCK(object);
208 * Allocates a region from the kernel address map and physical pages
209 * within the specified address range to the kernel object. Creates a
210 * wired mapping from this region to these pages, and returns the
211 * region's starting virtual address. The allocated pages are not
212 * necessarily physically contiguous. If M_ZERO is specified through the
213 * given flags, then the pages are zeroed before they are mapped.
216 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
217 vm_paddr_t high, vm_memattr_t memattr)
221 vm_offset_t addr, i, offset;
226 object = kernel_object;
227 size = round_page(size);
228 vmem = vm_dom[domain].vmd_kernel_arena;
229 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
231 offset = addr - VM_MIN_KERNEL_ADDRESS;
232 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
233 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
234 VM_OBJECT_WLOCK(object);
235 for (i = 0; i < size; i += PAGE_SIZE) {
236 m = kmem_alloc_contig_pages(object, atop(offset + i),
237 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
239 VM_OBJECT_WUNLOCK(object);
240 kmem_unback(object, addr, i);
241 vmem_free(vmem, addr, size);
244 KASSERT(vm_page_domain(m) == domain,
245 ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
246 vm_page_domain(m), domain));
247 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
250 pmap_enter(kernel_pmap, addr + i, m, prot,
251 prot | PMAP_ENTER_WIRED, 0);
253 VM_OBJECT_WUNLOCK(object);
258 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
259 vm_memattr_t memattr)
262 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
267 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
268 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
270 struct vm_domainset_iter di;
274 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
276 addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
280 } while (vm_domainset_iter_policy(&di, &domain) == 0);
286 * Allocates a region from the kernel address map and physically
287 * contiguous pages within the specified address range to the kernel
288 * object. Creates a wired mapping from this region to these pages, and
289 * returns the region's starting virtual address. If M_ZERO is specified
290 * through the given flags, then the pages are zeroed before they are
294 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
295 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
296 vm_memattr_t memattr)
300 vm_offset_t addr, offset, tmp;
305 object = kernel_object;
306 size = round_page(size);
307 vmem = vm_dom[domain].vmd_kernel_arena;
308 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
310 offset = addr - VM_MIN_KERNEL_ADDRESS;
311 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
313 VM_OBJECT_WLOCK(object);
314 m = kmem_alloc_contig_pages(object, atop(offset), domain,
315 pflags, npages, low, high, alignment, boundary, memattr);
317 VM_OBJECT_WUNLOCK(object);
318 vmem_free(vmem, addr, size);
321 KASSERT(vm_page_domain(m) == domain,
322 ("kmem_alloc_contig_domain: Domain mismatch %d != %d",
323 vm_page_domain(m), domain));
326 for (; m < end_m; m++) {
327 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
330 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW,
331 VM_PROT_RW | PMAP_ENTER_WIRED, 0);
334 VM_OBJECT_WUNLOCK(object);
339 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
340 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
343 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low,
344 high, alignment, boundary, memattr));
348 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags,
349 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
350 vm_memattr_t memattr)
352 struct vm_domainset_iter di;
356 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
358 addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
359 alignment, boundary, memattr);
362 } while (vm_domainset_iter_policy(&di, &domain) == 0);
370 * Initializes a map to manage a subrange
371 * of the kernel virtual address space.
373 * Arguments are as follows:
375 * parent Map to take range from
376 * min, max Returned endpoints of map
377 * size Size of range to find
378 * superpage_align Request that min is superpage aligned
381 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
382 vm_size_t size, bool superpage_align)
386 size = round_page(size);
388 *min = vm_map_min(parent);
389 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
390 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
392 if (ret != KERN_SUCCESS)
393 panic("kmem_subinit: bad status return of %d", ret);
395 vm_map_init(map, vm_map_pmap(parent), *min, *max);
396 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS)
397 panic("kmem_subinit: unable to change range to submap");
401 * kmem_malloc_domain:
403 * Allocate wired-down pages in the kernel's address space.
406 kmem_malloc_domain(int domain, vm_size_t size, int flags)
412 if (__predict_true((flags & M_EXEC) == 0))
413 arena = vm_dom[domain].vmd_kernel_arena;
415 arena = vm_dom[domain].vmd_kernel_rwx_arena;
416 size = round_page(size);
417 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr))
420 rv = kmem_back_domain(domain, kernel_object, addr, size, flags);
421 if (rv != KERN_SUCCESS) {
422 vmem_free(arena, addr, size);
429 kmem_malloc(vm_size_t size, int flags)
432 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags));
436 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
438 struct vm_domainset_iter di;
442 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
444 addr = kmem_malloc_domain(domain, size, flags);
447 } while (vm_domainset_iter_policy(&di, &domain) == 0);
455 * Allocate physical pages from the specified domain for the specified
456 * virtual address range.
459 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
460 vm_size_t size, int flags)
462 vm_offset_t offset, i;
467 KASSERT(object == kernel_object,
468 ("kmem_back_domain: only supports kernel object."));
470 offset = addr - VM_MIN_KERNEL_ADDRESS;
471 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
472 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
473 if (flags & M_WAITOK)
474 pflags |= VM_ALLOC_WAITFAIL;
475 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
478 VM_OBJECT_WLOCK(object);
480 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
481 for (; i < size; i += PAGE_SIZE, mpred = m) {
482 m = vm_page_alloc_domain_after(object, atop(offset + i),
483 domain, pflags, mpred);
486 * Ran out of space, free everything up and return. Don't need
487 * to lock page queues here as we know that the pages we got
488 * aren't on any queues.
491 if ((flags & M_NOWAIT) == 0)
493 VM_OBJECT_WUNLOCK(object);
494 kmem_unback(object, addr, i);
495 return (KERN_NO_SPACE);
497 KASSERT(vm_page_domain(m) == domain,
498 ("kmem_back_domain: Domain mismatch %d != %d",
499 vm_page_domain(m), domain));
500 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
502 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
503 ("kmem_malloc: page %p is managed", m));
505 pmap_enter(kernel_pmap, addr + i, m, prot,
506 prot | PMAP_ENTER_WIRED, 0);
507 if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
508 m->oflags |= VPO_KMEM_EXEC;
510 VM_OBJECT_WUNLOCK(object);
512 return (KERN_SUCCESS);
518 * Allocate physical pages for the specified virtual address range.
521 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
523 vm_offset_t end, next, start;
526 KASSERT(object == kernel_object,
527 ("kmem_back: only supports kernel object."));
529 for (start = addr, end = addr + size; addr < end; addr = next) {
531 * We must ensure that pages backing a given large virtual page
532 * all come from the same physical domain.
534 if (vm_ndomains > 1) {
535 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
536 while (VM_DOMAIN_EMPTY(domain))
538 next = roundup2(addr + 1, KVA_QUANTUM);
539 if (next > end || next < start)
545 rv = kmem_back_domain(domain, object, addr, next - addr, flags);
546 if (rv != KERN_SUCCESS) {
547 kmem_unback(object, start, addr - start);
557 * Unmap and free the physical pages underlying the specified virtual
560 * A physical page must exist within the specified object at each index
561 * that is being unmapped.
564 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
568 vm_offset_t end, offset;
571 KASSERT(object == kernel_object,
572 ("kmem_unback: only supports kernel object."));
576 pmap_remove(kernel_pmap, addr, addr + size);
577 offset = addr - VM_MIN_KERNEL_ADDRESS;
579 VM_OBJECT_WLOCK(object);
580 m = vm_page_lookup(object, atop(offset));
581 domain = vm_page_domain(m);
582 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
583 arena = vm_dom[domain].vmd_kernel_arena;
585 arena = vm_dom[domain].vmd_kernel_rwx_arena;
586 for (; offset < end; offset += PAGE_SIZE, m = next) {
587 next = vm_page_next(m);
588 vm_page_xbusy_claim(m);
589 vm_page_unwire_noq(m);
592 VM_OBJECT_WUNLOCK(object);
598 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
601 (void)_kmem_unback(object, addr, size);
607 * Free memory allocated with kmem_malloc. The size must match the
608 * original allocation.
611 kmem_free(vm_offset_t addr, vm_size_t size)
615 size = round_page(size);
616 arena = _kmem_unback(kernel_object, addr, size);
618 vmem_free(arena, addr, size);
624 * Allocates pageable memory from a sub-map of the kernel. If the submap
625 * has no room, the caller sleeps waiting for more memory in the submap.
627 * This routine may block.
630 kmap_alloc_wait(vm_map_t map, vm_size_t size)
634 size = round_page(size);
635 if (!swap_reserve(size))
640 * To make this work for more than one map, use the map's lock
641 * to lock out sleepers/wakers.
644 addr = vm_map_findspace(map, vm_map_min(map), size);
645 if (addr + size <= vm_map_max(map))
647 /* no space now; see if we can ever get space */
648 if (vm_map_max(map) - vm_map_min(map) < size) {
653 map->needs_wakeup = TRUE;
654 vm_map_unlock_and_wait(map, 0);
656 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
665 * Returns memory to a submap of the kernel, and wakes up any processes
666 * waiting for memory in that map.
669 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
673 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
674 if (map->needs_wakeup) {
675 map->needs_wakeup = FALSE;
682 kmem_init_zero_region(void)
688 * Map a single physical page of zeros to a larger virtual range.
689 * This requires less looping in places that want large amounts of
690 * zeros, while not using much more physical resources.
692 addr = kva_alloc(ZERO_REGION_SIZE);
693 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
694 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
695 if ((m->flags & PG_ZERO) == 0)
697 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
698 pmap_qenter(addr + i, &m, 1);
699 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
701 zero_region = (const void *)addr;
705 * Import KVA from the kernel map into the kernel arena.
708 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
713 KASSERT((size % KVA_QUANTUM) == 0,
714 ("kva_import: Size %jd is not a multiple of %d",
715 (intmax_t)size, (int)KVA_QUANTUM));
716 addr = vm_map_min(kernel_map);
717 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
718 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
719 if (result != KERN_SUCCESS)
728 * Import KVA from a parent arena into a per-domain arena. Imports must be
729 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
732 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
735 KASSERT((size % KVA_QUANTUM) == 0,
736 ("kva_import_domain: Size %jd is not a multiple of %d",
737 (intmax_t)size, (int)KVA_QUANTUM));
738 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
739 VMEM_ADDR_MAX, flags, addrp));
745 * Create the kernel map; insert a mapping covering kernel text,
746 * data, bss, and all space allocated thus far (`boostrap' data). The
747 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
748 * `start' as allocated, and the range between `start' and `end' as free.
749 * Create the kernel vmem arena and its per-domain children.
752 kmem_init(vm_offset_t start, vm_offset_t end)
757 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
758 kernel_map->system_map = 1;
759 vm_map_lock(kernel_map);
760 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
761 (void)vm_map_insert(kernel_map, NULL, 0,
765 VM_MIN_KERNEL_ADDRESS,
767 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
768 /* ... and ending with the completion of the above `insert' */
772 * Mark KVA used for the page array as allocated. Other platforms
773 * that handle vm_page_array allocation can simply adjust virtual_avail
776 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array,
777 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
778 sizeof(struct vm_page)),
779 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
781 vm_map_unlock(kernel_map);
784 * Use a large import quantum on NUMA systems. This helps minimize
785 * interleaving of superpages, reducing internal fragmentation within
786 * the per-domain arenas.
788 if (vm_ndomains > 1 && PMAP_HAS_DMAP)
789 quantum = KVA_NUMA_IMPORT_QUANTUM;
791 quantum = KVA_QUANTUM;
794 * Initialize the kernel_arena. This can grow on demand.
796 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
797 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum);
799 for (domain = 0; domain < vm_ndomains; domain++) {
801 * Initialize the per-domain arenas. These are used to color
802 * the KVA space in a way that ensures that virtual large pages
803 * are backed by memory from the same physical domain,
804 * maximizing the potential for superpage promotion.
806 vm_dom[domain].vmd_kernel_arena = vmem_create(
807 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
808 vmem_set_import(vm_dom[domain].vmd_kernel_arena,
809 kva_import_domain, NULL, kernel_arena, quantum);
812 * In architectures with superpages, maintain separate arenas
813 * for allocations with permissions that differ from the
814 * "standard" read/write permissions used for kernel memory,
815 * so as not to inhibit superpage promotion.
817 * Use the base import quantum since this arena is rarely used.
819 #if VM_NRESERVLEVEL > 0
820 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
821 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
822 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
823 kva_import_domain, (vmem_release_t *)vmem_xfree,
824 kernel_arena, KVA_QUANTUM);
826 vm_dom[domain].vmd_kernel_rwx_arena =
827 vm_dom[domain].vmd_kernel_arena;
832 * This must be the very first call so that the virtual address
833 * space used for early allocations is properly marked used in
840 * kmem_bootstrap_free:
842 * Free pages backing preloaded data (e.g., kernel modules) to the
843 * system. Currently only supported on platforms that create a
844 * vm_phys segment for preloaded data.
847 kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
849 #if defined(__i386__) || defined(__amd64__)
850 struct vm_domain *vmd;
855 end = trunc_page(start + size);
856 start = round_page(start);
860 * Preloaded files do not have execute permissions by default on amd64.
861 * Restore the default permissions to ensure that the direct map alias
864 pmap_change_prot(start, end - start, VM_PROT_RW);
866 for (va = start; va < end; va += PAGE_SIZE) {
867 pa = pmap_kextract(va);
868 m = PHYS_TO_VM_PAGE(pa);
870 vmd = vm_pagequeue_domain(m);
871 vm_domain_free_lock(vmd);
872 vm_phys_free_pages(m, 0);
873 vm_domain_free_unlock(vmd);
875 vm_domain_freecnt_inc(vmd, 1);
876 vm_cnt.v_page_count++;
878 pmap_remove(kernel_pmap, start, end);
879 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
884 * Allow userspace to directly trigger the VM drain routine for testing
888 debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
893 error = sysctl_handle_int(oidp, &i, 0, req);
896 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
899 EVENTHANDLER_INVOKE(vm_lowmem, i);
903 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
904 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags");