/*- * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) * * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * Kernel memory management. */ #include __FBSDID("$FreeBSD$"); #include "opt_vm.h" #include #include #include /* for ticks and hz */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include vm_map_t kernel_map; vm_map_t exec_map; vm_map_t pipe_map; const void *zero_region; CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); /* NB: Used by kernel debuggers. */ const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; u_int exec_map_entry_size; u_int exec_map_entries; SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, #if defined(__arm__) || defined(__sparc64__) &vm_max_kernel_address, 0, #else SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, #endif "Max kernel address"); #if VM_NRESERVLEVEL > 0 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) #else /* On non-superpage architectures want large import sizes. */ #define KVA_QUANTUM_SHIFT (10 + PAGE_SHIFT) #endif #define KVA_QUANTUM (1 << KVA_QUANTUM_SHIFT) /* * kva_alloc: * * Allocate a virtual address range with no underlying object and * no initial mapping to physical memory. Any mapping from this * range to physical memory must be explicitly created prior to * its use, typically with pmap_qenter(). Any attempt to create * a mapping on demand through vm_fault() will result in a panic. */ vm_offset_t kva_alloc(vm_size_t size) { vm_offset_t addr; size = round_page(size); if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) return (0); return (addr); } /* * kva_free: * * Release a region of kernel virtual memory allocated * with kva_alloc, and return the physical pages * associated with that region. * * This routine may not block on kernel maps. */ void kva_free(vm_offset_t addr, vm_size_t size) { size = round_page(size); vmem_free(kernel_arena, addr, size); } /* * Allocates a region from the kernel address map and physical pages * within the specified address range to the kernel object. Creates a * wired mapping from this region to these pages, and returns the * region's starting virtual address. The allocated pages are not * necessarily physically contiguous. If M_ZERO is specified through the * given flags, then the pages are zeroed before they are mapped. */ vm_offset_t kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) { vmem_t *vmem; vm_object_t object = kernel_object; vm_offset_t addr, i, offset; vm_page_t m; int pflags, tries; size = round_page(size); vmem = vm_dom[domain].vmd_kernel_arena; if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr)) return (0); offset = addr - VM_MIN_KERNEL_ADDRESS; pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); pflags |= VM_ALLOC_NOWAIT; VM_OBJECT_WLOCK(object); for (i = 0; i < size; i += PAGE_SIZE) { tries = 0; retry: m = vm_page_alloc_contig_domain(object, atop(offset + i), domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); if (m == NULL) { VM_OBJECT_WUNLOCK(object); if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { if (!vm_page_reclaim_contig_domain(domain, pflags, 1, low, high, PAGE_SIZE, 0) && (flags & M_WAITOK) != 0) vm_wait_domain(domain); VM_OBJECT_WLOCK(object); tries++; goto retry; } kmem_unback(object, addr, i); vmem_free(vmem, addr, size); return (0); } KASSERT(vm_phys_domain(m) == domain, ("kmem_alloc_attr_domain: Domain mismatch %d != %d", vm_phys_domain(m), domain)); if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) pmap_zero_page(m); m->valid = VM_PAGE_BITS_ALL; pmap_enter(kernel_pmap, addr + i, m, VM_PROT_RW, VM_PROT_RW | PMAP_ENTER_WIRED, 0); } VM_OBJECT_WUNLOCK(object); return (addr); } vm_offset_t kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) { struct vm_domainset_iter di; vm_offset_t addr; int domain; vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); do { addr = kmem_alloc_attr_domain(domain, size, flags, low, high, memattr); if (addr != 0) break; } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); return (addr); } /* * Allocates a region from the kernel address map and physically * contiguous pages within the specified address range to the kernel * object. Creates a wired mapping from this region to these pages, and * returns the region's starting virtual address. If M_ZERO is specified * through the given flags, then the pages are zeroed before they are * mapped. */ vm_offset_t kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) { vmem_t *vmem; vm_object_t object = kernel_object; vm_offset_t addr, offset, tmp; vm_page_t end_m, m; u_long npages; int pflags, tries; size = round_page(size); vmem = vm_dom[domain].vmd_kernel_arena; if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr)) return (0); offset = addr - VM_MIN_KERNEL_ADDRESS; pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); pflags |= VM_ALLOC_NOWAIT; npages = atop(size); VM_OBJECT_WLOCK(object); tries = 0; retry: m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags, npages, low, high, alignment, boundary, memattr); if (m == NULL) { VM_OBJECT_WUNLOCK(object); if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { if (!vm_page_reclaim_contig_domain(domain, pflags, npages, low, high, alignment, boundary) && (flags & M_WAITOK) != 0) vm_wait_domain(domain); VM_OBJECT_WLOCK(object); tries++; goto retry; } vmem_free(vmem, addr, size); return (0); } KASSERT(vm_phys_domain(m) == domain, ("kmem_alloc_contig_domain: Domain mismatch %d != %d", vm_phys_domain(m), domain)); end_m = m + npages; tmp = addr; for (; m < end_m; m++) { if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) pmap_zero_page(m); m->valid = VM_PAGE_BITS_ALL; pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, VM_PROT_RW | PMAP_ENTER_WIRED, 0); tmp += PAGE_SIZE; } VM_OBJECT_WUNLOCK(object); return (addr); } vm_offset_t kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) { struct vm_domainset_iter di; vm_offset_t addr; int domain; vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); do { addr = kmem_alloc_contig_domain(domain, size, flags, low, high, alignment, boundary, memattr); if (addr != 0) break; } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); return (addr); } /* * kmem_suballoc: * * Allocates a map to manage a subrange * of the kernel virtual address space. * * Arguments are as follows: * * parent Map to take range from * min, max Returned endpoints of map * size Size of range to find * superpage_align Request that min is superpage aligned */ vm_map_t kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max, vm_size_t size, boolean_t superpage_align) { int ret; vm_map_t result; size = round_page(size); *min = vm_map_min(parent); ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_ACC_NO_CHARGE); if (ret != KERN_SUCCESS) panic("kmem_suballoc: bad status return of %d", ret); *max = *min + size; result = vm_map_create(vm_map_pmap(parent), *min, *max); if (result == NULL) panic("kmem_suballoc: cannot create submap"); if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS) panic("kmem_suballoc: unable to change range to submap"); return (result); } /* * kmem_malloc: * * Allocate wired-down pages in the kernel's address space. */ vm_offset_t kmem_malloc_domain(int domain, vm_size_t size, int flags) { vmem_t *arena; vm_offset_t addr; int rv; #if VM_NRESERVLEVEL > 0 if (__predict_true((flags & M_EXEC) == 0)) arena = vm_dom[domain].vmd_kernel_arena; else arena = vm_dom[domain].vmd_kernel_rwx_arena; #else arena = vm_dom[domain].vmd_kernel_arena; #endif size = round_page(size); if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr)) return (0); rv = kmem_back_domain(domain, kernel_object, addr, size, flags); if (rv != KERN_SUCCESS) { vmem_free(arena, addr, size); return (0); } return (addr); } vm_offset_t kmem_malloc(vm_size_t size, int flags) { struct vm_domainset_iter di; vm_offset_t addr; int domain; vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); do { addr = kmem_malloc_domain(domain, size, flags); if (addr != 0) break; } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); return (addr); } /* * kmem_back_domain: * * Allocate physical pages from the specified domain for the specified * virtual address range. */ int kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) { vm_offset_t offset, i; vm_page_t m, mpred; vm_prot_t prot; int pflags; KASSERT(object == kernel_object, ("kmem_back_domain: only supports kernel object.")); offset = addr - VM_MIN_KERNEL_ADDRESS; pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); if (flags & M_WAITOK) pflags |= VM_ALLOC_WAITFAIL; prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; i = 0; VM_OBJECT_WLOCK(object); retry: mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); for (; i < size; i += PAGE_SIZE, mpred = m) { m = vm_page_alloc_domain_after(object, atop(offset + i), domain, pflags, mpred); /* * Ran out of space, free everything up and return. Don't need * to lock page queues here as we know that the pages we got * aren't on any queues. */ if (m == NULL) { if ((flags & M_NOWAIT) == 0) goto retry; VM_OBJECT_WUNLOCK(object); kmem_unback(object, addr, i); return (KERN_NO_SPACE); } KASSERT(vm_phys_domain(m) == domain, ("kmem_back_domain: Domain mismatch %d != %d", vm_phys_domain(m), domain)); if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) pmap_zero_page(m); KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("kmem_malloc: page %p is managed", m)); m->valid = VM_PAGE_BITS_ALL; pmap_enter(kernel_pmap, addr + i, m, prot, prot | PMAP_ENTER_WIRED, 0); #if VM_NRESERVLEVEL > 0 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) m->oflags |= VPO_KMEM_EXEC; #endif } VM_OBJECT_WUNLOCK(object); return (KERN_SUCCESS); } /* * kmem_back: * * Allocate physical pages for the specified virtual address range. */ int kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) { vm_offset_t end, next, start; int domain, rv; KASSERT(object == kernel_object, ("kmem_back: only supports kernel object.")); for (start = addr, end = addr + size; addr < end; addr = next) { /* * We must ensure that pages backing a given large virtual page * all come from the same physical domain. */ if (vm_ndomains > 1) { domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; next = roundup2(addr + 1, KVA_QUANTUM); if (next > end || next < start) next = end; } else next = end; rv = kmem_back_domain(domain, object, addr, next - addr, flags); if (rv != KERN_SUCCESS) { kmem_unback(object, start, addr - start); break; } } return (rv); } /* * kmem_unback: * * Unmap and free the physical pages underlying the specified virtual * address range. * * A physical page must exist within the specified object at each index * that is being unmapped. */ static struct vmem * _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) { struct vmem *arena; vm_page_t m, next; vm_offset_t end, offset; int domain; KASSERT(object == kernel_object, ("kmem_unback: only supports kernel object.")); if (size == 0) return (NULL); pmap_remove(kernel_pmap, addr, addr + size); offset = addr - VM_MIN_KERNEL_ADDRESS; end = offset + size; VM_OBJECT_WLOCK(object); m = vm_page_lookup(object, atop(offset)); domain = vm_phys_domain(m); #if VM_NRESERVLEVEL > 0 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) arena = vm_dom[domain].vmd_kernel_arena; else arena = vm_dom[domain].vmd_kernel_rwx_arena; #else arena = vm_dom[domain].vmd_kernel_arena; #endif for (; offset < end; offset += PAGE_SIZE, m = next) { next = vm_page_next(m); vm_page_unwire(m, PQ_NONE); vm_page_free(m); } VM_OBJECT_WUNLOCK(object); return (arena); } void kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) { (void)_kmem_unback(object, addr, size); } /* * kmem_free: * * Free memory allocated with kmem_malloc. The size must match the * original allocation. */ void kmem_free(vm_offset_t addr, vm_size_t size) { struct vmem *arena; size = round_page(size); arena = _kmem_unback(kernel_object, addr, size); if (arena != NULL) vmem_free(arena, addr, size); } /* * kmap_alloc_wait: * * Allocates pageable memory from a sub-map of the kernel. If the submap * has no room, the caller sleeps waiting for more memory in the submap. * * This routine may block. */ vm_offset_t kmap_alloc_wait(vm_map_t map, vm_size_t size) { vm_offset_t addr; size = round_page(size); if (!swap_reserve(size)) return (0); for (;;) { /* * To make this work for more than one map, use the map's lock * to lock out sleepers/wakers. */ vm_map_lock(map); if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0) break; /* no space now; see if we can ever get space */ if (vm_map_max(map) - vm_map_min(map) < size) { vm_map_unlock(map); swap_release(size); return (0); } map->needs_wakeup = TRUE; vm_map_unlock_and_wait(map, 0); } vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, MAP_ACC_CHARGED); vm_map_unlock(map); return (addr); } /* * kmap_free_wakeup: * * Returns memory to a submap of the kernel, and wakes up any processes * waiting for memory in that map. */ void kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) { vm_map_lock(map); (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); if (map->needs_wakeup) { map->needs_wakeup = FALSE; vm_map_wakeup(map); } vm_map_unlock(map); } void kmem_init_zero_region(void) { vm_offset_t addr, i; vm_page_t m; /* * Map a single physical page of zeros to a larger virtual range. * This requires less looping in places that want large amounts of * zeros, while not using much more physical resources. */ addr = kva_alloc(ZERO_REGION_SIZE); m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); if ((m->flags & PG_ZERO) == 0) pmap_zero_page(m); for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) pmap_qenter(addr + i, &m, 1); pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); zero_region = (const void *)addr; } /* * Import KVA from the kernel map into the kernel arena. */ static int kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) { vm_offset_t addr; int result; KASSERT((size % KVA_QUANTUM) == 0, ("kva_import: Size %jd is not a multiple of %d", (intmax_t)size, (int)KVA_QUANTUM)); addr = vm_map_min(kernel_map); result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); if (result != KERN_SUCCESS) return (ENOMEM); *addrp = addr; return (0); } /* * Import KVA from a parent arena into a per-domain arena. Imports must be * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. */ static int kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) { KASSERT((size % KVA_QUANTUM) == 0, ("kva_import_domain: Size %jd is not a multiple of %d", (intmax_t)size, (int)KVA_QUANTUM)); return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags, addrp)); } /* * kmem_init: * * Create the kernel map; insert a mapping covering kernel text, * data, bss, and all space allocated thus far (`boostrap' data). The * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and * `start' as allocated, and the range between `start' and `end' as free. * Create the kernel vmem arena and its per-domain children. */ void kmem_init(vm_offset_t start, vm_offset_t end) { vm_map_t m; int domain; m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); m->system_map = 1; vm_map_lock(m); /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ kernel_map = m; (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0, #ifdef __amd64__ KERNBASE, #else VM_MIN_KERNEL_ADDRESS, #endif start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); /* ... and ending with the completion of the above `insert' */ vm_map_unlock(m); /* * Initialize the kernel_arena. This can grow on demand. */ vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); vmem_set_import(kernel_arena, kva_import, NULL, NULL, KVA_QUANTUM); for (domain = 0; domain < vm_ndomains; domain++) { /* * Initialize the per-domain arenas. These are used to color * the KVA space in a way that ensures that virtual large pages * are backed by memory from the same physical domain, * maximizing the potential for superpage promotion. */ vm_dom[domain].vmd_kernel_arena = vmem_create( "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); vmem_set_import(vm_dom[domain].vmd_kernel_arena, kva_import_domain, NULL, kernel_arena, KVA_QUANTUM); /* * In architectures with superpages, maintain separate arenas * for allocations with permissions that differ from the * "standard" read/write permissions used for kernel memory, * so as not to inhibit superpage promotion. */ #if VM_NRESERVLEVEL > 0 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, kva_import_domain, (vmem_release_t *)vmem_xfree, kernel_arena, KVA_QUANTUM); #endif } } /* * kmem_bootstrap_free: * * Free pages backing preloaded data (e.g., kernel modules) to the * system. Currently only supported on platforms that create a * vm_phys segment for preloaded data. */ void kmem_bootstrap_free(vm_offset_t start, vm_size_t size) { #if defined(__i386__) || defined(__amd64__) struct vm_domain *vmd; vm_offset_t end, va; vm_paddr_t pa; vm_page_t m; end = trunc_page(start + size); start = round_page(start); for (va = start; va < end; va += PAGE_SIZE) { pa = pmap_kextract(va); m = PHYS_TO_VM_PAGE(pa); vmd = vm_pagequeue_domain(m); vm_domain_free_lock(vmd); vm_phys_free_pages(m, 0); vmd->vmd_page_count++; vm_domain_free_unlock(vmd); vm_domain_freecnt_inc(vmd, 1); vm_cnt.v_page_count++; } pmap_remove(kernel_pmap, start, end); (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); #endif } #ifdef DIAGNOSTIC /* * Allow userspace to directly trigger the VM drain routine for testing * purposes. */ static int debug_vm_lowmem(SYSCTL_HANDLER_ARGS) { int error, i; i = 0; error = sysctl_handle_int(oidp, &i, 0, req); if (error) return (error); if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) return (EINVAL); if (i != 0) EVENTHANDLER_INVOKE(vm_lowmem, i); return (0); } SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags"); #endif