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>
75 #include <sys/domainset.h>
76 #include <sys/eventhandler.h>
77 #include <sys/kernel.h>
79 #include <sys/malloc.h>
81 #include <sys/rwlock.h>
82 #include <sys/sysctl.h>
84 #include <sys/vmmeter.h>
87 #include <vm/vm_param.h>
88 #include <vm/vm_domainset.h>
89 #include <vm/vm_kern.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_page.h>
94 #include <vm/vm_pageout.h>
95 #include <vm/vm_pagequeue.h>
96 #include <vm/vm_phys.h>
97 #include <vm/vm_radix.h>
98 #include <vm/vm_extern.h>
101 struct vm_map kernel_map_store;
102 struct vm_map exec_map_store;
103 struct vm_map pipe_map_store;
105 const void *zero_region;
106 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
108 /* NB: Used by kernel debuggers. */
109 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS;
111 u_int exec_map_entry_size;
112 u_int exec_map_entries;
114 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD,
115 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address");
117 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD,
119 &vm_max_kernel_address, 0,
121 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS,
123 "Max kernel address");
125 #if VM_NRESERVLEVEL > 0
126 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
128 /* On non-superpage architectures we want large import sizes. */
129 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT)
131 #define KVA_QUANTUM (1ul << KVA_QUANTUM_SHIFT)
132 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128)
134 extern void uma_startup2(void);
139 * Allocate a virtual address range with no underlying object and
140 * no initial mapping to physical memory. Any mapping from this
141 * range to physical memory must be explicitly created prior to
142 * its use, typically with pmap_qenter(). Any attempt to create
143 * a mapping on demand through vm_fault() will result in a panic.
146 kva_alloc(vm_size_t size)
150 size = round_page(size);
151 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr))
160 * Release a region of kernel virtual memory allocated
161 * with kva_alloc, and return the physical pages
162 * associated with that region.
164 * This routine may not block on kernel maps.
167 kva_free(vm_offset_t addr, vm_size_t size)
170 size = round_page(size);
171 vmem_free(kernel_arena, addr, size);
175 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain,
176 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high,
177 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
183 VM_OBJECT_ASSERT_WLOCKED(object);
185 wait = (pflags & VM_ALLOC_WAITOK) != 0;
186 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0;
187 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
188 pflags |= VM_ALLOC_NOWAIT;
189 for (tries = wait ? 3 : 1;; tries--) {
190 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags,
191 npages, low, high, alignment, boundary, memattr);
192 if (m != NULL || tries == 0 || !reclaim)
195 VM_OBJECT_WUNLOCK(object);
196 if (!vm_page_reclaim_contig_domain(domain, pflags, npages,
197 low, high, alignment, boundary) && wait)
198 vm_wait_domain(domain);
199 VM_OBJECT_WLOCK(object);
205 * Allocates a region from the kernel address map and physical pages
206 * within the specified address range to the kernel object. Creates a
207 * wired mapping from this region to these pages, and returns the
208 * region's starting virtual address. The allocated pages are not
209 * necessarily physically contiguous. If M_ZERO is specified through the
210 * given flags, then the pages are zeroed before they are mapped.
213 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
214 vm_paddr_t high, vm_memattr_t memattr)
218 vm_offset_t addr, i, offset;
224 object = kernel_object;
225 asize = round_page(size);
226 vmem = vm_dom[domain].vmd_kernel_arena;
227 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr))
229 offset = addr - VM_MIN_KERNEL_ADDRESS;
230 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
231 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
232 VM_OBJECT_WLOCK(object);
233 for (i = 0; i < asize; i += PAGE_SIZE) {
234 m = kmem_alloc_contig_pages(object, atop(offset + i),
235 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
237 VM_OBJECT_WUNLOCK(object);
238 kmem_unback(object, addr, i);
239 vmem_free(vmem, addr, asize);
242 KASSERT(vm_page_domain(m) == domain,
243 ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
244 vm_page_domain(m), domain));
245 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
248 pmap_enter(kernel_pmap, addr + i, m, prot,
249 prot | PMAP_ENTER_WIRED, 0);
251 VM_OBJECT_WUNLOCK(object);
252 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE);
257 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
258 vm_memattr_t memattr)
261 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
266 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
267 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
269 struct vm_domainset_iter di;
273 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
275 addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
279 } while (vm_domainset_iter_policy(&di, &domain) == 0);
285 * Allocates a region from the kernel address map and physically
286 * contiguous pages within the specified address range to the kernel
287 * object. Creates a wired mapping from this region to these pages, and
288 * returns the region's starting virtual address. If M_ZERO is specified
289 * through the given flags, then the pages are zeroed before they are
293 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
294 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
295 vm_memattr_t memattr)
299 vm_offset_t addr, offset, tmp;
305 object = kernel_object;
306 asize = round_page(size);
307 vmem = vm_dom[domain].vmd_kernel_arena;
308 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr))
310 offset = addr - VM_MIN_KERNEL_ADDRESS;
311 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
312 npages = atop(asize);
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, asize);
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);
335 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE);
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;
357 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
359 addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
360 alignment, boundary, memattr);
363 } while (vm_domainset_iter_policy(&di, &domain) == 0);
371 * Initializes a map to manage a subrange
372 * of the kernel virtual address space.
374 * Arguments are as follows:
376 * parent Map to take range from
377 * min, max Returned endpoints of map
378 * size Size of range to find
379 * superpage_align Request that min is superpage aligned
382 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
383 vm_size_t size, bool superpage_align)
387 size = round_page(size);
389 *min = vm_map_min(parent);
390 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
391 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
393 if (ret != KERN_SUCCESS)
394 panic("kmem_subinit: bad status return of %d", ret);
396 vm_map_init(map, vm_map_pmap(parent), *min, *max);
397 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS)
398 panic("kmem_subinit: unable to change range to submap");
402 * kmem_malloc_domain:
404 * Allocate wired-down pages in the kernel's address space.
407 kmem_malloc_domain(int domain, vm_size_t size, int flags)
414 if (__predict_true((flags & M_EXEC) == 0))
415 arena = vm_dom[domain].vmd_kernel_arena;
417 arena = vm_dom[domain].vmd_kernel_rwx_arena;
418 asize = round_page(size);
419 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr))
422 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags);
423 if (rv != KERN_SUCCESS) {
424 vmem_free(arena, addr, asize);
427 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE);
432 kmem_malloc(vm_size_t size, int flags)
435 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags));
439 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
441 struct vm_domainset_iter di;
445 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
447 addr = kmem_malloc_domain(domain, size, flags);
450 } while (vm_domainset_iter_policy(&di, &domain) == 0);
458 * Allocate physical pages from the specified domain for the specified
459 * virtual address range.
462 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
463 vm_size_t size, int flags)
465 vm_offset_t offset, i;
470 KASSERT(object == kernel_object,
471 ("kmem_back_domain: only supports kernel object."));
473 offset = addr - VM_MIN_KERNEL_ADDRESS;
474 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
475 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
476 if (flags & M_WAITOK)
477 pflags |= VM_ALLOC_WAITFAIL;
478 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
481 VM_OBJECT_WLOCK(object);
483 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
484 for (; i < size; i += PAGE_SIZE, mpred = m) {
485 m = vm_page_alloc_domain_after(object, atop(offset + i),
486 domain, pflags, mpred);
489 * Ran out of space, free everything up and return. Don't need
490 * to lock page queues here as we know that the pages we got
491 * aren't on any queues.
494 if ((flags & M_NOWAIT) == 0)
496 VM_OBJECT_WUNLOCK(object);
497 kmem_unback(object, addr, i);
498 return (KERN_NO_SPACE);
500 KASSERT(vm_page_domain(m) == domain,
501 ("kmem_back_domain: Domain mismatch %d != %d",
502 vm_page_domain(m), domain));
503 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
505 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
506 ("kmem_malloc: page %p is managed", m));
508 pmap_enter(kernel_pmap, addr + i, m, prot,
509 prot | PMAP_ENTER_WIRED, 0);
510 if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
511 m->oflags |= VPO_KMEM_EXEC;
513 VM_OBJECT_WUNLOCK(object);
515 return (KERN_SUCCESS);
521 * Allocate physical pages for the specified virtual address range.
524 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
526 vm_offset_t end, next, start;
529 KASSERT(object == kernel_object,
530 ("kmem_back: only supports kernel object."));
532 for (start = addr, end = addr + size; addr < end; addr = next) {
534 * We must ensure that pages backing a given large virtual page
535 * all come from the same physical domain.
537 if (vm_ndomains > 1) {
538 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
539 while (VM_DOMAIN_EMPTY(domain))
541 next = roundup2(addr + 1, KVA_QUANTUM);
542 if (next > end || next < start)
548 rv = kmem_back_domain(domain, object, addr, next - addr, flags);
549 if (rv != KERN_SUCCESS) {
550 kmem_unback(object, start, addr - start);
560 * Unmap and free the physical pages underlying the specified virtual
563 * A physical page must exist within the specified object at each index
564 * that is being unmapped.
567 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
571 vm_offset_t end, offset;
574 KASSERT(object == kernel_object,
575 ("kmem_unback: only supports kernel object."));
579 pmap_remove(kernel_pmap, addr, addr + size);
580 offset = addr - VM_MIN_KERNEL_ADDRESS;
582 VM_OBJECT_WLOCK(object);
583 m = vm_page_lookup(object, atop(offset));
584 domain = vm_page_domain(m);
585 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
586 arena = vm_dom[domain].vmd_kernel_arena;
588 arena = vm_dom[domain].vmd_kernel_rwx_arena;
589 for (; offset < end; offset += PAGE_SIZE, m = next) {
590 next = vm_page_next(m);
591 vm_page_xbusy_claim(m);
592 vm_page_unwire_noq(m);
595 VM_OBJECT_WUNLOCK(object);
601 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
604 (void)_kmem_unback(object, addr, size);
610 * Free memory allocated with kmem_malloc. The size must match the
611 * original allocation.
614 kmem_free(vm_offset_t addr, vm_size_t size)
618 size = round_page(size);
619 kasan_mark((void *)addr, size, size, 0);
620 arena = _kmem_unback(kernel_object, addr, size);
622 vmem_free(arena, addr, size);
628 * Allocates pageable memory from a sub-map of the kernel. If the submap
629 * has no room, the caller sleeps waiting for more memory in the submap.
631 * This routine may block.
634 kmap_alloc_wait(vm_map_t map, vm_size_t size)
638 size = round_page(size);
639 if (!swap_reserve(size))
644 * To make this work for more than one map, use the map's lock
645 * to lock out sleepers/wakers.
648 addr = vm_map_findspace(map, vm_map_min(map), size);
649 if (addr + size <= vm_map_max(map))
651 /* no space now; see if we can ever get space */
652 if (vm_map_max(map) - vm_map_min(map) < size) {
657 map->needs_wakeup = TRUE;
658 vm_map_unlock_and_wait(map, 0);
660 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
669 * Returns memory to a submap of the kernel, and wakes up any processes
670 * waiting for memory in that map.
673 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
677 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
678 if (map->needs_wakeup) {
679 map->needs_wakeup = FALSE;
686 kmem_init_zero_region(void)
692 * Map a single physical page of zeros to a larger virtual range.
693 * This requires less looping in places that want large amounts of
694 * zeros, while not using much more physical resources.
696 addr = kva_alloc(ZERO_REGION_SIZE);
697 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO);
698 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
699 pmap_qenter(addr + i, &m, 1);
700 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
702 zero_region = (const void *)addr;
706 * Import KVA from the kernel map into the kernel arena.
709 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
714 KASSERT((size % KVA_QUANTUM) == 0,
715 ("kva_import: Size %jd is not a multiple of %d",
716 (intmax_t)size, (int)KVA_QUANTUM));
717 addr = vm_map_min(kernel_map);
718 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
719 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
720 if (result != KERN_SUCCESS)
729 * Import KVA from a parent arena into a per-domain arena. Imports must be
730 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
733 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
736 KASSERT((size % KVA_QUANTUM) == 0,
737 ("kva_import_domain: Size %jd is not a multiple of %d",
738 (intmax_t)size, (int)KVA_QUANTUM));
739 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
740 VMEM_ADDR_MAX, flags, addrp));
746 * Create the kernel map; insert a mapping covering kernel text,
747 * data, bss, and all space allocated thus far (`boostrap' data). The
748 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
749 * `start' as allocated, and the range between `start' and `end' as free.
750 * Create the kernel vmem arena and its per-domain children.
753 kmem_init(vm_offset_t start, vm_offset_t end)
758 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
759 kernel_map->system_map = 1;
760 vm_map_lock(kernel_map);
761 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
762 (void)vm_map_insert(kernel_map, NULL, 0,
766 VM_MIN_KERNEL_ADDRESS,
768 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
769 /* ... and ending with the completion of the above `insert' */
773 * Mark KVA used for the page array as allocated. Other platforms
774 * that handle vm_page_array allocation can simply adjust virtual_avail
777 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array,
778 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
779 sizeof(struct vm_page)),
780 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
782 vm_map_unlock(kernel_map);
785 * Use a large import quantum on NUMA systems. This helps minimize
786 * interleaving of superpages, reducing internal fragmentation within
787 * the per-domain arenas.
789 if (vm_ndomains > 1 && PMAP_HAS_DMAP)
790 quantum = KVA_NUMA_IMPORT_QUANTUM;
792 quantum = KVA_QUANTUM;
795 * Initialize the kernel_arena. This can grow on demand.
797 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
798 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum);
800 for (domain = 0; domain < vm_ndomains; domain++) {
802 * Initialize the per-domain arenas. These are used to color
803 * the KVA space in a way that ensures that virtual large pages
804 * are backed by memory from the same physical domain,
805 * maximizing the potential for superpage promotion.
807 vm_dom[domain].vmd_kernel_arena = vmem_create(
808 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
809 vmem_set_import(vm_dom[domain].vmd_kernel_arena,
810 kva_import_domain, NULL, kernel_arena, quantum);
813 * In architectures with superpages, maintain separate arenas
814 * for allocations with permissions that differ from the
815 * "standard" read/write permissions used for kernel memory,
816 * so as not to inhibit superpage promotion.
818 * Use the base import quantum since this arena is rarely used.
820 #if VM_NRESERVLEVEL > 0
821 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
822 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
823 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
824 kva_import_domain, (vmem_release_t *)vmem_xfree,
825 kernel_arena, KVA_QUANTUM);
827 vm_dom[domain].vmd_kernel_rwx_arena =
828 vm_dom[domain].vmd_kernel_arena;
833 * This must be the very first call so that the virtual address
834 * space used for early allocations is properly marked used in
841 * kmem_bootstrap_free:
843 * Free pages backing preloaded data (e.g., kernel modules) to the
844 * system. Currently only supported on platforms that create a
845 * vm_phys segment for preloaded data.
848 kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
850 #if defined(__i386__) || defined(__amd64__)
851 struct vm_domain *vmd;
856 end = trunc_page(start + size);
857 start = round_page(start);
861 * Preloaded files do not have execute permissions by default on amd64.
862 * Restore the default permissions to ensure that the direct map alias
865 pmap_change_prot(start, end - start, VM_PROT_RW);
867 for (va = start; va < end; va += PAGE_SIZE) {
868 pa = pmap_kextract(va);
869 m = PHYS_TO_VM_PAGE(pa);
871 vmd = vm_pagequeue_domain(m);
872 vm_domain_free_lock(vmd);
873 vm_phys_free_pages(m, 0);
874 vm_domain_free_unlock(vmd);
876 vm_domain_freecnt_inc(vmd, 1);
877 vm_cnt.v_page_count++;
879 pmap_remove(kernel_pmap, start, end);
880 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
885 * Allow userspace to directly trigger the VM drain routine for testing
889 debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
894 error = sysctl_handle_int(oidp, &i, 0, req);
897 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
900 EVENTHANDLER_INVOKE(vm_lowmem, i);
903 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem,
904 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I",
905 "set to trigger vm_lowmem event with given flags");
908 debug_uma_reclaim(SYSCTL_HANDLER_ARGS)
913 error = sysctl_handle_int(oidp, &i, 0, req);
914 if (error != 0 || req->newptr == NULL)
916 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN &&
917 i != UMA_RECLAIM_DRAIN_CPU)
922 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim,
923 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I",
924 "set to generate request to reclaim uma caches");
927 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS)
929 int domain, error, request;
932 error = sysctl_handle_int(oidp, &request, 0, req);
933 if (error != 0 || req->newptr == NULL)
936 domain = request >> 4;
938 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN &&
939 request != UMA_RECLAIM_DRAIN_CPU)
941 if (domain < 0 || domain >= vm_ndomains)
943 uma_reclaim_domain(request, domain);
946 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain,
947 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
948 debug_uma_reclaim_domain, "I",