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 (1 << 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 wait = (pflags & VM_ALLOC_WAITOK) != 0;
185 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
186 pflags |= VM_ALLOC_NOWAIT;
187 for (tries = wait ? 3 : 1;; tries--) {
188 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags,
189 npages, low, high, alignment, boundary, memattr);
190 if (m != NULL || tries == 0)
193 VM_OBJECT_WUNLOCK(object);
194 if (!vm_page_reclaim_contig_domain(domain, pflags, npages,
195 low, high, alignment, boundary) && wait)
196 vm_wait_domain(domain);
197 VM_OBJECT_WLOCK(object);
203 * Allocates a region from the kernel address map and physical pages
204 * within the specified address range to the kernel object. Creates a
205 * wired mapping from this region to these pages, and returns the
206 * region's starting virtual address. The allocated pages are not
207 * necessarily physically contiguous. If M_ZERO is specified through the
208 * given flags, then the pages are zeroed before they are mapped.
211 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
212 vm_paddr_t high, vm_memattr_t memattr)
216 vm_offset_t addr, i, offset;
221 object = kernel_object;
222 size = round_page(size);
223 vmem = vm_dom[domain].vmd_kernel_arena;
224 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
226 offset = addr - VM_MIN_KERNEL_ADDRESS;
227 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
228 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
229 VM_OBJECT_WLOCK(object);
230 for (i = 0; i < size; i += PAGE_SIZE) {
231 m = kmem_alloc_contig_pages(object, atop(offset + i),
232 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
234 VM_OBJECT_WUNLOCK(object);
235 kmem_unback(object, addr, i);
236 vmem_free(vmem, addr, size);
239 KASSERT(vm_page_domain(m) == domain,
240 ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
241 vm_page_domain(m), domain));
242 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
245 pmap_enter(kernel_pmap, addr + i, m, prot,
246 prot | PMAP_ENTER_WIRED, 0);
248 VM_OBJECT_WUNLOCK(object);
253 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
254 vm_memattr_t memattr)
257 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
262 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
263 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
265 struct vm_domainset_iter di;
270 * Do not allow the domainset iterator to override wait flags. The
271 * contiguous memory allocator defines special semantics for M_WAITOK
272 * that do not match the iterator's implementation.
274 iflags = (flags & ~M_WAITOK) | M_NOWAIT;
275 vm_domainset_iter_policy_init(&di, ds, &domain, &iflags);
277 addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
281 } while (vm_domainset_iter_policy(&di, &domain) == 0);
287 * Allocates a region from the kernel address map and physically
288 * contiguous pages within the specified address range to the kernel
289 * object. Creates a wired mapping from this region to these pages, and
290 * returns the region's starting virtual address. If M_ZERO is specified
291 * through the given flags, then the pages are zeroed before they are
295 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
296 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
297 vm_memattr_t memattr)
301 vm_offset_t addr, offset, tmp;
306 object = kernel_object;
307 size = round_page(size);
308 vmem = vm_dom[domain].vmd_kernel_arena;
309 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
311 offset = addr - VM_MIN_KERNEL_ADDRESS;
312 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
314 VM_OBJECT_WLOCK(object);
315 m = kmem_alloc_contig_pages(object, atop(offset), domain,
316 pflags, npages, low, high, alignment, boundary, memattr);
318 VM_OBJECT_WUNLOCK(object);
319 vmem_free(vmem, addr, size);
322 KASSERT(vm_page_domain(m) == domain,
323 ("kmem_alloc_contig_domain: Domain mismatch %d != %d",
324 vm_page_domain(m), domain));
327 for (; m < end_m; m++) {
328 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
331 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW,
332 VM_PROT_RW | PMAP_ENTER_WIRED, 0);
335 VM_OBJECT_WUNLOCK(object);
340 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
341 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
344 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low,
345 high, alignment, boundary, memattr));
349 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags,
350 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
351 vm_memattr_t memattr)
353 struct vm_domainset_iter di;
358 * Do not allow the domainset iterator to override wait flags. The
359 * contiguous memory allocator defines special semantics for M_WAITOK
360 * that do not match the iterator's implementation.
362 iflags = (flags & ~M_WAITOK) | M_NOWAIT;
363 vm_domainset_iter_policy_init(&di, ds, &domain, &iflags);
365 addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
366 alignment, boundary, memattr);
369 } while (vm_domainset_iter_policy(&di, &domain) == 0);
377 * Initializes a map to manage a subrange
378 * of the kernel virtual address space.
380 * Arguments are as follows:
382 * parent Map to take range from
383 * min, max Returned endpoints of map
384 * size Size of range to find
385 * superpage_align Request that min is superpage aligned
388 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
389 vm_size_t size, bool superpage_align)
393 size = round_page(size);
395 *min = vm_map_min(parent);
396 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
397 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
399 if (ret != KERN_SUCCESS)
400 panic("kmem_subinit: bad status return of %d", ret);
402 vm_map_init(map, vm_map_pmap(parent), *min, *max);
403 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS)
404 panic("kmem_subinit: unable to change range to submap");
408 * kmem_malloc_domain:
410 * Allocate wired-down pages in the kernel's address space.
413 kmem_malloc_domain(int domain, vm_size_t size, int flags)
419 if (__predict_true((flags & M_EXEC) == 0))
420 arena = vm_dom[domain].vmd_kernel_arena;
422 arena = vm_dom[domain].vmd_kernel_rwx_arena;
423 size = round_page(size);
424 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr))
427 rv = kmem_back_domain(domain, kernel_object, addr, size, flags);
428 if (rv != KERN_SUCCESS) {
429 vmem_free(arena, addr, size);
436 kmem_malloc(vm_size_t size, int flags)
439 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags));
443 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
445 struct vm_domainset_iter di;
449 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
451 addr = kmem_malloc_domain(domain, size, flags);
454 } while (vm_domainset_iter_policy(&di, &domain) == 0);
462 * Allocate physical pages from the specified domain for the specified
463 * virtual address range.
466 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
467 vm_size_t size, int flags)
469 vm_offset_t offset, i;
474 KASSERT(object == kernel_object,
475 ("kmem_back_domain: only supports kernel object."));
477 offset = addr - VM_MIN_KERNEL_ADDRESS;
478 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
479 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
480 if (flags & M_WAITOK)
481 pflags |= VM_ALLOC_WAITFAIL;
482 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
485 VM_OBJECT_WLOCK(object);
487 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
488 for (; i < size; i += PAGE_SIZE, mpred = m) {
489 m = vm_page_alloc_domain_after(object, atop(offset + i),
490 domain, pflags, mpred);
493 * Ran out of space, free everything up and return. Don't need
494 * to lock page queues here as we know that the pages we got
495 * aren't on any queues.
498 if ((flags & M_NOWAIT) == 0)
500 VM_OBJECT_WUNLOCK(object);
501 kmem_unback(object, addr, i);
502 return (KERN_NO_SPACE);
504 KASSERT(vm_page_domain(m) == domain,
505 ("kmem_back_domain: Domain mismatch %d != %d",
506 vm_page_domain(m), domain));
507 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
509 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
510 ("kmem_malloc: page %p is managed", m));
512 pmap_enter(kernel_pmap, addr + i, m, prot,
513 prot | PMAP_ENTER_WIRED, 0);
514 if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
515 m->oflags |= VPO_KMEM_EXEC;
517 VM_OBJECT_WUNLOCK(object);
519 return (KERN_SUCCESS);
525 * Allocate physical pages for the specified virtual address range.
528 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
530 vm_offset_t end, next, start;
533 KASSERT(object == kernel_object,
534 ("kmem_back: only supports kernel object."));
536 for (start = addr, end = addr + size; addr < end; addr = next) {
538 * We must ensure that pages backing a given large virtual page
539 * all come from the same physical domain.
541 if (vm_ndomains > 1) {
542 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
543 while (VM_DOMAIN_EMPTY(domain))
545 next = roundup2(addr + 1, KVA_QUANTUM);
546 if (next > end || next < start)
552 rv = kmem_back_domain(domain, object, addr, next - addr, flags);
553 if (rv != KERN_SUCCESS) {
554 kmem_unback(object, start, addr - start);
564 * Unmap and free the physical pages underlying the specified virtual
567 * A physical page must exist within the specified object at each index
568 * that is being unmapped.
571 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
575 vm_offset_t end, offset;
578 KASSERT(object == kernel_object,
579 ("kmem_unback: only supports kernel object."));
583 pmap_remove(kernel_pmap, addr, addr + size);
584 offset = addr - VM_MIN_KERNEL_ADDRESS;
586 VM_OBJECT_WLOCK(object);
587 m = vm_page_lookup(object, atop(offset));
588 domain = vm_page_domain(m);
589 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
590 arena = vm_dom[domain].vmd_kernel_arena;
592 arena = vm_dom[domain].vmd_kernel_rwx_arena;
593 for (; offset < end; offset += PAGE_SIZE, m = next) {
594 next = vm_page_next(m);
595 vm_page_xbusy_claim(m);
596 vm_page_unwire_noq(m);
599 VM_OBJECT_WUNLOCK(object);
605 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
608 (void)_kmem_unback(object, addr, size);
614 * Free memory allocated with kmem_malloc. The size must match the
615 * original allocation.
618 kmem_free(vm_offset_t addr, vm_size_t size)
622 size = round_page(size);
623 arena = _kmem_unback(kernel_object, addr, size);
625 vmem_free(arena, addr, size);
631 * Allocates pageable memory from a sub-map of the kernel. If the submap
632 * has no room, the caller sleeps waiting for more memory in the submap.
634 * This routine may block.
637 kmap_alloc_wait(vm_map_t map, vm_size_t size)
641 size = round_page(size);
642 if (!swap_reserve(size))
647 * To make this work for more than one map, use the map's lock
648 * to lock out sleepers/wakers.
651 addr = vm_map_findspace(map, vm_map_min(map), size);
652 if (addr + size <= vm_map_max(map))
654 /* no space now; see if we can ever get space */
655 if (vm_map_max(map) - vm_map_min(map) < size) {
660 map->needs_wakeup = TRUE;
661 vm_map_unlock_and_wait(map, 0);
663 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
672 * Returns memory to a submap of the kernel, and wakes up any processes
673 * waiting for memory in that map.
676 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
680 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
681 if (map->needs_wakeup) {
682 map->needs_wakeup = FALSE;
689 kmem_init_zero_region(void)
695 * Map a single physical page of zeros to a larger virtual range.
696 * This requires less looping in places that want large amounts of
697 * zeros, while not using much more physical resources.
699 addr = kva_alloc(ZERO_REGION_SIZE);
700 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
701 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
702 if ((m->flags & PG_ZERO) == 0)
704 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
705 pmap_qenter(addr + i, &m, 1);
706 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
708 zero_region = (const void *)addr;
712 * Import KVA from the kernel map into the kernel arena.
715 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
720 KASSERT((size % KVA_QUANTUM) == 0,
721 ("kva_import: Size %jd is not a multiple of %d",
722 (intmax_t)size, (int)KVA_QUANTUM));
723 addr = vm_map_min(kernel_map);
724 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
725 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
726 if (result != KERN_SUCCESS)
735 * Import KVA from a parent arena into a per-domain arena. Imports must be
736 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
739 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
742 KASSERT((size % KVA_QUANTUM) == 0,
743 ("kva_import_domain: Size %jd is not a multiple of %d",
744 (intmax_t)size, (int)KVA_QUANTUM));
745 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
746 VMEM_ADDR_MAX, flags, addrp));
752 * Create the kernel map; insert a mapping covering kernel text,
753 * data, bss, and all space allocated thus far (`boostrap' data). The
754 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
755 * `start' as allocated, and the range between `start' and `end' as free.
756 * Create the kernel vmem arena and its per-domain children.
759 kmem_init(vm_offset_t start, vm_offset_t end)
764 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
765 kernel_map->system_map = 1;
766 vm_map_lock(kernel_map);
767 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
768 (void)vm_map_insert(kernel_map, NULL, 0,
772 VM_MIN_KERNEL_ADDRESS,
774 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
775 /* ... and ending with the completion of the above `insert' */
779 * Mark KVA used for the page array as allocated. Other platforms
780 * that handle vm_page_array allocation can simply adjust virtual_avail
783 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array,
784 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
785 sizeof(struct vm_page)),
786 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
788 vm_map_unlock(kernel_map);
791 * Use a large import quantum on NUMA systems. This helps minimize
792 * interleaving of superpages, reducing internal fragmentation within
793 * the per-domain arenas.
795 if (vm_ndomains > 1 && PMAP_HAS_DMAP)
796 quantum = KVA_NUMA_IMPORT_QUANTUM;
798 quantum = KVA_QUANTUM;
801 * Initialize the kernel_arena. This can grow on demand.
803 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
804 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum);
806 for (domain = 0; domain < vm_ndomains; domain++) {
808 * Initialize the per-domain arenas. These are used to color
809 * the KVA space in a way that ensures that virtual large pages
810 * are backed by memory from the same physical domain,
811 * maximizing the potential for superpage promotion.
813 vm_dom[domain].vmd_kernel_arena = vmem_create(
814 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
815 vmem_set_import(vm_dom[domain].vmd_kernel_arena,
816 kva_import_domain, NULL, kernel_arena, quantum);
819 * In architectures with superpages, maintain separate arenas
820 * for allocations with permissions that differ from the
821 * "standard" read/write permissions used for kernel memory,
822 * so as not to inhibit superpage promotion.
824 * Use the base import quantum since this arena is rarely used.
826 #if VM_NRESERVLEVEL > 0
827 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
828 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
829 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
830 kva_import_domain, (vmem_release_t *)vmem_xfree,
831 kernel_arena, KVA_QUANTUM);
833 vm_dom[domain].vmd_kernel_rwx_arena =
834 vm_dom[domain].vmd_kernel_arena;
839 * This must be the very first call so that the virtual address
840 * space used for early allocations is properly marked used in
847 * kmem_bootstrap_free:
849 * Free pages backing preloaded data (e.g., kernel modules) to the
850 * system. Currently only supported on platforms that create a
851 * vm_phys segment for preloaded data.
854 kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
856 #if defined(__i386__) || defined(__amd64__)
857 struct vm_domain *vmd;
862 end = trunc_page(start + size);
863 start = round_page(start);
867 * Preloaded files do not have execute permissions by default on amd64.
868 * Restore the default permissions to ensure that the direct map alias
871 pmap_change_prot(start, end - start, VM_PROT_RW);
873 for (va = start; va < end; va += PAGE_SIZE) {
874 pa = pmap_kextract(va);
875 m = PHYS_TO_VM_PAGE(pa);
877 vmd = vm_pagequeue_domain(m);
878 vm_domain_free_lock(vmd);
879 vm_phys_free_pages(m, 0);
880 vm_domain_free_unlock(vmd);
882 vm_domain_freecnt_inc(vmd, 1);
883 vm_cnt.v_page_count++;
885 pmap_remove(kernel_pmap, start, end);
886 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
891 * Allow userspace to directly trigger the VM drain routine for testing
895 debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
900 error = sysctl_handle_int(oidp, &i, 0, req);
903 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
906 EVENTHANDLER_INVOKE(vm_lowmem, i);
910 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
911 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags");