vm_kern.c revision 212931
1139825Simp/*- 21541Srgrimes * Copyright (c) 1991, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * This code is derived from software contributed to Berkeley by 61541Srgrimes * The Mach Operating System project at Carnegie-Mellon University. 71541Srgrimes * 81541Srgrimes * Redistribution and use in source and binary forms, with or without 91541Srgrimes * modification, are permitted provided that the following conditions 101541Srgrimes * are met: 111541Srgrimes * 1. Redistributions of source code must retain the above copyright 121541Srgrimes * notice, this list of conditions and the following disclaimer. 131541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141541Srgrimes * notice, this list of conditions and the following disclaimer in the 151541Srgrimes * documentation and/or other materials provided with the distribution. 161541Srgrimes * 4. Neither the name of the University nor the names of its contributors 171541Srgrimes * may be used to endorse or promote products derived from this software 181541Srgrimes * without specific prior written permission. 191541Srgrimes * 201541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301541Srgrimes * SUCH DAMAGE. 311541Srgrimes * 321817Sdg * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 331541Srgrimes * 341541Srgrimes * 351541Srgrimes * Copyright (c) 1987, 1990 Carnegie-Mellon University. 361541Srgrimes * All rights reserved. 371541Srgrimes * 381541Srgrimes * Authors: Avadis Tevanian, Jr., Michael Wayne Young 395455Sdg * 401541Srgrimes * Permission to use, copy, modify and distribute this software and 411541Srgrimes * its documentation is hereby granted, provided that both the copyright 421541Srgrimes * notice and this permission notice appear in all copies of the 431541Srgrimes * software, derivative works or modified versions, and any portions 441541Srgrimes * thereof, and that both notices appear in supporting documentation. 455455Sdg * 465455Sdg * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 475455Sdg * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 481541Srgrimes * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 495455Sdg * 501541Srgrimes * Carnegie Mellon requests users of this software to return to 511541Srgrimes * 521541Srgrimes * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 531541Srgrimes * School of Computer Science 541541Srgrimes * Carnegie Mellon University 551541Srgrimes * Pittsburgh PA 15213-3890 561541Srgrimes * 571541Srgrimes * any improvements or extensions that they make and grant Carnegie the 581541Srgrimes * rights to redistribute these changes. 591541Srgrimes */ 601541Srgrimes 611541Srgrimes/* 621541Srgrimes * Kernel memory management. 631541Srgrimes */ 641541Srgrimes 65116226Sobrien#include <sys/cdefs.h> 66116226Sobrien__FBSDID("$FreeBSD: head/sys/vm/vm_kern.c 212931 2010-09-20 20:41:59Z mdf $"); 67116226Sobrien 681541Srgrimes#include <sys/param.h> 691541Srgrimes#include <sys/systm.h> 7087157Sluigi#include <sys/kernel.h> /* for ticks and hz */ 71168395Spjd#include <sys/eventhandler.h> 7276166Smarkm#include <sys/lock.h> 7376166Smarkm#include <sys/mutex.h> 742112Swollman#include <sys/proc.h> 756129Sdg#include <sys/malloc.h> 76188964Srwatson#include <sys/sysctl.h> 771541Srgrimes 781541Srgrimes#include <vm/vm.h> 7912662Sdg#include <vm/vm_param.h> 8012662Sdg#include <vm/pmap.h> 8112662Sdg#include <vm/vm_map.h> 8212662Sdg#include <vm/vm_object.h> 831541Srgrimes#include <vm/vm_page.h> 841541Srgrimes#include <vm/vm_pageout.h> 8512726Sbde#include <vm/vm_extern.h> 86168395Spjd#include <vm/uma.h> 871541Srgrimes 8819830Sdysonvm_map_t kernel_map=0; 8919830Sdysonvm_map_t kmem_map=0; 9019830Sdysonvm_map_t exec_map=0; 91118764Ssilbyvm_map_t pipe_map; 9219830Sdysonvm_map_t buffer_map=0; 932112Swollman 941541Srgrimes/* 9547841Sdt * kmem_alloc_nofault: 9647841Sdt * 97118317Salc * Allocate a virtual address range with no underlying object and 98118317Salc * no initial mapping to physical memory. Any mapping from this 99118317Salc * range to physical memory must be explicitly created prior to 100118317Salc * its use, typically with pmap_qenter(). Any attempt to create 101118317Salc * a mapping on demand through vm_fault() will result in a panic. 10247841Sdt */ 10347841Sdtvm_offset_t 10447841Sdtkmem_alloc_nofault(map, size) 10547841Sdt vm_map_t map; 10670480Salfred vm_size_t size; 10747841Sdt{ 10847841Sdt vm_offset_t addr; 10970480Salfred int result; 11047841Sdt 11147841Sdt size = round_page(size); 11247841Sdt addr = vm_map_min(map); 113178933Salc result = vm_map_find(map, NULL, 0, &addr, size, VMFS_ANY_SPACE, 114178933Salc VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 11547841Sdt if (result != KERN_SUCCESS) { 11647841Sdt return (0); 11747841Sdt } 11847841Sdt return (addr); 11947841Sdt} 12047841Sdt 12147841Sdt/* 122206819Sjmallett * kmem_alloc_nofault_space: 123206819Sjmallett * 124206819Sjmallett * Allocate a virtual address range with no underlying object and 125206819Sjmallett * no initial mapping to physical memory within the specified 126206819Sjmallett * address space. Any mapping from this range to physical memory 127206819Sjmallett * must be explicitly created prior to its use, typically with 128206819Sjmallett * pmap_qenter(). Any attempt to create a mapping on demand 129206819Sjmallett * through vm_fault() will result in a panic. 130206819Sjmallett */ 131206819Sjmallettvm_offset_t 132206819Sjmallettkmem_alloc_nofault_space(map, size, find_space) 133206819Sjmallett vm_map_t map; 134206819Sjmallett vm_size_t size; 135206819Sjmallett int find_space; 136206819Sjmallett{ 137206819Sjmallett vm_offset_t addr; 138206819Sjmallett int result; 139206819Sjmallett 140206819Sjmallett size = round_page(size); 141206819Sjmallett addr = vm_map_min(map); 142206819Sjmallett result = vm_map_find(map, NULL, 0, &addr, size, find_space, 143206819Sjmallett VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 144206819Sjmallett if (result != KERN_SUCCESS) { 145206819Sjmallett return (0); 146206819Sjmallett } 147206819Sjmallett return (addr); 148206819Sjmallett} 149206819Sjmallett 150206819Sjmallett/* 1511541Srgrimes * Allocate wired-down memory in the kernel's address map 1521541Srgrimes * or a submap. 1531541Srgrimes */ 1548876Srgrimesvm_offset_t 1555455Sdgkmem_alloc(map, size) 15670480Salfred vm_map_t map; 15770480Salfred vm_size_t size; 1581541Srgrimes{ 1595455Sdg vm_offset_t addr; 16070480Salfred vm_offset_t offset; 1615455Sdg vm_offset_t i; 1621541Srgrimes 1631541Srgrimes size = round_page(size); 1641541Srgrimes 1651541Srgrimes /* 1665455Sdg * Use the kernel object for wired-down kernel pages. Assume that no 1675455Sdg * region of the kernel object is referenced more than once. 1681541Srgrimes */ 1691541Srgrimes 1701541Srgrimes /* 1715455Sdg * Locate sufficient space in the map. This will give us the final 1725455Sdg * virtual address for the new memory, and thus will tell us the 1735455Sdg * offset within the kernel map. 1741541Srgrimes */ 1751541Srgrimes vm_map_lock(map); 17633758Sdyson if (vm_map_findspace(map, vm_map_min(map), size, &addr)) { 1771541Srgrimes vm_map_unlock(map); 1781541Srgrimes return (0); 1791541Srgrimes } 1801541Srgrimes offset = addr - VM_MIN_KERNEL_ADDRESS; 1811541Srgrimes vm_object_reference(kernel_object); 18213490Sdyson vm_map_insert(map, kernel_object, offset, addr, addr + size, 18313490Sdyson VM_PROT_ALL, VM_PROT_ALL, 0); 1841541Srgrimes vm_map_unlock(map); 1851541Srgrimes 1861541Srgrimes /* 1875455Sdg * Guarantee that there are pages already in this object before 188122383Smini * calling vm_map_wire. This is to prevent the following 1895455Sdg * scenario: 1908876Srgrimes * 1915455Sdg * 1) Threads have swapped out, so that there is a pager for the 1925455Sdg * kernel_object. 2) The kmsg zone is empty, and so we are 193122383Smini * kmem_allocing a new page for it. 3) vm_map_wire calls vm_fault; 1945455Sdg * there is no page, but there is a pager, so we call 1955455Sdg * pager_data_request. But the kmsg zone is empty, so we must 1965455Sdg * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when 1975455Sdg * we get the data back from the pager, it will be (very stale) 1985455Sdg * non-zero data. kmem_alloc is defined to return zero-filled memory. 1998876Srgrimes * 2005455Sdg * We're intentionally not activating the pages we allocate to prevent a 201122383Smini * race with page-out. vm_map_wire will wire the pages. 2021541Srgrimes */ 203120761Salc VM_OBJECT_LOCK(kernel_object); 2045455Sdg for (i = 0; i < size; i += PAGE_SIZE) { 2055455Sdg vm_page_t mem; 2061541Srgrimes 20733109Sdyson mem = vm_page_grab(kernel_object, OFF_TO_IDX(offset + i), 208136923Salc VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_RETRY); 209120761Salc mem->valid = VM_PAGE_BITS_ALL; 210166964Salc KASSERT((mem->flags & PG_UNMANAGED) != 0, 211166964Salc ("kmem_alloc: page %p is managed", mem)); 2121541Srgrimes } 213120761Salc VM_OBJECT_UNLOCK(kernel_object); 2145455Sdg 2151541Srgrimes /* 2165455Sdg * And finally, mark the data as non-pageable. 2171541Srgrimes */ 218118771Sbms (void) vm_map_wire(map, addr, addr + size, 219118771Sbms VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 2201541Srgrimes 2215455Sdg return (addr); 2221541Srgrimes} 2231541Srgrimes 2241541Srgrimes/* 2251541Srgrimes * kmem_free: 2261541Srgrimes * 2271541Srgrimes * Release a region of kernel virtual memory allocated 2281541Srgrimes * with kmem_alloc, and return the physical pages 2291541Srgrimes * associated with that region. 23042957Sdillon * 23142957Sdillon * This routine may not block on kernel maps. 2321541Srgrimes */ 2338876Srgrimesvoid 2345455Sdgkmem_free(map, addr, size) 2355455Sdg vm_map_t map; 23670480Salfred vm_offset_t addr; 2375455Sdg vm_size_t size; 2381541Srgrimes{ 23971571Sjhb 2401541Srgrimes (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size)); 2411541Srgrimes} 2421541Srgrimes 2431541Srgrimes/* 2441541Srgrimes * kmem_suballoc: 2451541Srgrimes * 2461541Srgrimes * Allocates a map to manage a subrange 2471541Srgrimes * of the kernel virtual address space. 2481541Srgrimes * 2491541Srgrimes * Arguments are as follows: 2501541Srgrimes * 2511541Srgrimes * parent Map to take range from 25270480Salfred * min, max Returned endpoints of map 2531541Srgrimes * size Size of range to find 254178933Salc * superpage_align Request that min is superpage aligned 2551541Srgrimes */ 2568876Srgrimesvm_map_t 257178933Salckmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 258178933Salc vm_size_t size, boolean_t superpage_align) 2591541Srgrimes{ 26070478Salfred int ret; 2615455Sdg vm_map_t result; 2621541Srgrimes 2631541Srgrimes size = round_page(size); 2641541Srgrimes 265178637Salc *min = vm_map_min(parent); 266178933Salc ret = vm_map_find(parent, NULL, 0, min, size, superpage_align ? 267194766Skib VMFS_ALIGNED_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 268194766Skib MAP_ACC_NO_CHARGE); 269177762Salc if (ret != KERN_SUCCESS) 270177762Salc panic("kmem_suballoc: bad status return of %d", ret); 2711541Srgrimes *max = *min + size; 27232702Sdyson result = vm_map_create(vm_map_pmap(parent), *min, *max); 2731541Srgrimes if (result == NULL) 2741541Srgrimes panic("kmem_suballoc: cannot create submap"); 27570478Salfred if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS) 2761541Srgrimes panic("kmem_suballoc: unable to change range to submap"); 2775455Sdg return (result); 2781541Srgrimes} 2791541Srgrimes 2801541Srgrimes/* 28142957Sdillon * kmem_malloc: 2821541Srgrimes * 28342957Sdillon * Allocate wired-down memory in the kernel's address map for the higher 28442957Sdillon * level kernel memory allocator (kern/kern_malloc.c). We cannot use 28542957Sdillon * kmem_alloc() because we may need to allocate memory at interrupt 28642957Sdillon * level where we cannot block (canwait == FALSE). 2871541Srgrimes * 28842957Sdillon * This routine has its own private kernel submap (kmem_map) and object 28942957Sdillon * (kmem_object). This, combined with the fact that only malloc uses 29042957Sdillon * this routine, ensures that we will never block in map or object waits. 2911541Srgrimes * 29242957Sdillon * We don't worry about expanding the map (adding entries) since entries 29342957Sdillon * for wired maps are statically allocated. 29442957Sdillon * 29578592Sbmilekic * `map' is ONLY allowed to be kmem_map or one of the mbuf submaps to 29678592Sbmilekic * which we never free. 2971541Srgrimes */ 2981541Srgrimesvm_offset_t 29942957Sdillonkmem_malloc(map, size, flags) 30070480Salfred vm_map_t map; 30170480Salfred vm_size_t size; 30242957Sdillon int flags; 3031541Srgrimes{ 3045455Sdg vm_offset_t addr; 305211194Smdf int i, rv; 3061541Srgrimes 3071541Srgrimes size = round_page(size); 3081541Srgrimes addr = vm_map_min(map); 3091541Srgrimes 3101541Srgrimes /* 3115455Sdg * Locate sufficient space in the map. This will give us the final 3125455Sdg * virtual address for the new memory, and thus will tell us the 3135455Sdg * offset within the kernel map. 3141541Srgrimes */ 3151541Srgrimes vm_map_lock(map); 31633758Sdyson if (vm_map_findspace(map, vm_map_min(map), size, &addr)) { 3171541Srgrimes vm_map_unlock(map); 318175210Spjd if ((flags & M_NOWAIT) == 0) { 319175210Spjd for (i = 0; i < 8; i++) { 320175210Spjd EVENTHANDLER_INVOKE(vm_lowmem, 0); 321175210Spjd uma_reclaim(); 322175210Spjd vm_map_lock(map); 323175210Spjd if (vm_map_findspace(map, vm_map_min(map), 324175210Spjd size, &addr) == 0) { 325175210Spjd break; 326175210Spjd } 327168395Spjd vm_map_unlock(map); 328175210Spjd tsleep(&i, 0, "nokva", (hz / 4) * (i + 1)); 329175210Spjd } 330175210Spjd if (i == 8) { 331168395Spjd panic("kmem_malloc(%ld): kmem_map too small: %ld total allocated", 332175210Spjd (long)size, (long)map->size); 333168395Spjd } 334168395Spjd } else { 335168395Spjd return (0); 336168395Spjd } 3371541Srgrimes } 338211194Smdf 339211194Smdf rv = kmem_back(map, addr, size, flags); 340211194Smdf vm_map_unlock(map); 341211194Smdf return (rv == KERN_SUCCESS ? addr : 0); 342211194Smdf} 343211194Smdf 344211194Smdf/* 345211194Smdf * kmem_back: 346211194Smdf * 347211194Smdf * Allocate physical pages for the specified virtual address range. 348211194Smdf */ 349211194Smdfint 350211194Smdfkmem_back(vm_map_t map, vm_offset_t addr, vm_size_t size, int flags) 351211194Smdf{ 352211194Smdf vm_offset_t offset, i; 353211194Smdf vm_map_entry_t entry; 354211194Smdf vm_page_t m; 355211194Smdf int pflags; 356211194Smdf 357212931Smdf KASSERT(vm_map_locked(map), ("kmem_back: map %p is not locked", map)); 35815367Sdyson offset = addr - VM_MIN_KERNEL_ADDRESS; 3591541Srgrimes vm_object_reference(kmem_object); 36013490Sdyson vm_map_insert(map, kmem_object, offset, addr, addr + size, 36113490Sdyson VM_PROT_ALL, VM_PROT_ALL, 0); 3621541Srgrimes 36398455Sjeff if ((flags & (M_NOWAIT|M_USE_RESERVE)) == M_NOWAIT) 364108351Salc pflags = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED; 36598455Sjeff else 366108351Salc pflags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED; 36798455Sjeff 36898455Sjeff if (flags & M_ZERO) 36998455Sjeff pflags |= VM_ALLOC_ZERO; 37098455Sjeff 371113489Salc VM_OBJECT_LOCK(kmem_object); 3721541Srgrimes for (i = 0; i < size; i += PAGE_SIZE) { 37315809Sdysonretry: 37498450Sjeff m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), pflags); 37598450Sjeff 3761541Srgrimes /* 3775455Sdg * Ran out of space, free everything up and return. Don't need 3785455Sdg * to lock page queues here as we know that the pages we got 3795455Sdg * aren't on any queues. 3801541Srgrimes */ 3811541Srgrimes if (m == NULL) { 38242957Sdillon if ((flags & M_NOWAIT) == 0) { 383113489Salc VM_OBJECT_UNLOCK(kmem_object); 38444793Salc vm_map_unlock(map); 38515809Sdyson VM_WAIT; 38644793Salc vm_map_lock(map); 387113489Salc VM_OBJECT_LOCK(kmem_object); 38815809Sdyson goto retry; 38915809Sdyson } 39091946Stegge /* 39191946Stegge * Free the pages before removing the map entry. 39291946Stegge * They are already marked busy. Calling 39391946Stegge * vm_map_delete before the pages has been freed or 39491946Stegge * unbusied will cause a deadlock. 39591946Stegge */ 39691946Stegge while (i != 0) { 39791946Stegge i -= PAGE_SIZE; 39891946Stegge m = vm_page_lookup(kmem_object, 39991946Stegge OFF_TO_IDX(offset + i)); 400108351Salc vm_page_unwire(m, 0); 40191946Stegge vm_page_free(m); 40291946Stegge } 403113489Salc VM_OBJECT_UNLOCK(kmem_object); 404189015Skib vm_map_delete(map, addr, addr + size); 405211194Smdf return (KERN_NO_SPACE); 4061541Srgrimes } 40798455Sjeff if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 408102382Salc pmap_zero_page(m); 409120761Salc m->valid = VM_PAGE_BITS_ALL; 410166964Salc KASSERT((m->flags & PG_UNMANAGED) != 0, 411166964Salc ("kmem_malloc: page %p is managed", m)); 4121541Srgrimes } 413113489Salc VM_OBJECT_UNLOCK(kmem_object); 4141541Srgrimes 4151541Srgrimes /* 4165455Sdg * Mark map entry as non-pageable. Assert: vm_map_insert() will never 4175455Sdg * be able to extend the previous entry so there will be a new entry 4185455Sdg * exactly corresponding to this address range and it will have 4195455Sdg * wired_count == 0. 4201541Srgrimes */ 4211541Srgrimes if (!vm_map_lookup_entry(map, addr, &entry) || 4221541Srgrimes entry->start != addr || entry->end != addr + size || 42344793Salc entry->wired_count != 0) 4241541Srgrimes panic("kmem_malloc: entry not found or misaligned"); 42544793Salc entry->wired_count = 1; 4261541Srgrimes 427124048Salc /* 428124048Salc * At this point, the kmem_object must be unlocked because 429124048Salc * vm_map_simplify_entry() calls vm_object_deallocate(), which 430124048Salc * locks the kmem_object. 431124048Salc */ 43220993Sdyson vm_map_simplify_entry(map, entry); 43320993Sdyson 4341541Srgrimes /* 435164234Salc * Loop thru pages, entering them in the pmap. 4361541Srgrimes */ 437124048Salc VM_OBJECT_LOCK(kmem_object); 4381541Srgrimes for (i = 0; i < size; i += PAGE_SIZE) { 43912767Sdyson m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i)); 44042957Sdillon /* 44142957Sdillon * Because this is kernel_pmap, this call will not block. 44242957Sdillon */ 443175067Salc pmap_enter(kernel_pmap, addr + i, VM_PROT_ALL, m, VM_PROT_ALL, 444175067Salc TRUE); 445108351Salc vm_page_wakeup(m); 4461541Srgrimes } 447124048Salc VM_OBJECT_UNLOCK(kmem_object); 4481541Srgrimes 449211194Smdf return (KERN_SUCCESS); 4501541Srgrimes} 4511541Srgrimes 4521541Srgrimes/* 45342957Sdillon * kmem_alloc_wait: 4541541Srgrimes * 4551541Srgrimes * Allocates pageable memory from a sub-map of the kernel. If the submap 4561541Srgrimes * has no room, the caller sleeps waiting for more memory in the submap. 4571541Srgrimes * 45842957Sdillon * This routine may block. 4591541Srgrimes */ 4608876Srgrimesvm_offset_t 4615455Sdgkmem_alloc_wait(map, size) 4625455Sdg vm_map_t map; 4635455Sdg vm_size_t size; 4641541Srgrimes{ 4655455Sdg vm_offset_t addr; 4661541Srgrimes 4671541Srgrimes size = round_page(size); 468194766Skib if (!swap_reserve(size)) 469194766Skib return (0); 4701541Srgrimes 4711541Srgrimes for (;;) { 4721541Srgrimes /* 4735455Sdg * To make this work for more than one map, use the map's lock 4745455Sdg * to lock out sleepers/wakers. 4751541Srgrimes */ 4761541Srgrimes vm_map_lock(map); 47733758Sdyson if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0) 4781541Srgrimes break; 4791541Srgrimes /* no space now; see if we can ever get space */ 4801541Srgrimes if (vm_map_max(map) - vm_map_min(map) < size) { 4811541Srgrimes vm_map_unlock(map); 482194766Skib swap_release(size); 4831541Srgrimes return (0); 4841541Srgrimes } 48599754Salc map->needs_wakeup = TRUE; 486173429Spjd vm_map_unlock_and_wait(map, 0); 4871541Srgrimes } 488194766Skib vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL, 489194766Skib VM_PROT_ALL, MAP_ACC_CHARGED); 4901541Srgrimes vm_map_unlock(map); 4911541Srgrimes return (addr); 4921541Srgrimes} 4931541Srgrimes 4941541Srgrimes/* 49542957Sdillon * kmem_free_wakeup: 4961541Srgrimes * 4979507Sdg * Returns memory to a submap of the kernel, and wakes up any processes 4981541Srgrimes * waiting for memory in that map. 4991541Srgrimes */ 5008876Srgrimesvoid 5015455Sdgkmem_free_wakeup(map, addr, size) 5025455Sdg vm_map_t map; 5035455Sdg vm_offset_t addr; 5045455Sdg vm_size_t size; 5051541Srgrimes{ 50676827Salfred 5071541Srgrimes vm_map_lock(map); 508189015Skib (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 50999754Salc if (map->needs_wakeup) { 51099754Salc map->needs_wakeup = FALSE; 51199754Salc vm_map_wakeup(map); 51299754Salc } 5131541Srgrimes vm_map_unlock(map); 5141541Srgrimes} 5151541Srgrimes 5161541Srgrimes/* 51742957Sdillon * kmem_init: 51842957Sdillon * 51942957Sdillon * Create the kernel map; insert a mapping covering kernel text, 52042957Sdillon * data, bss, and all space allocated thus far (`boostrap' data). The 52142957Sdillon * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 52242957Sdillon * `start' as allocated, and the range between `start' and `end' as free. 5231541Srgrimes */ 5248876Srgrimesvoid 5255455Sdgkmem_init(start, end) 5261541Srgrimes vm_offset_t start, end; 5271541Srgrimes{ 52870480Salfred vm_map_t m; 5291541Srgrimes 53032702Sdyson m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 531108426Salc m->system_map = 1; 5321541Srgrimes vm_map_lock(m); 5331541Srgrimes /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 5341541Srgrimes kernel_map = m; 535108426Salc (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0, 536179923Salc#ifdef __amd64__ 537179923Salc KERNBASE, 538179923Salc#else 539179923Salc VM_MIN_KERNEL_ADDRESS, 540179923Salc#endif 541179923Salc start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 5421541Srgrimes /* ... and ending with the completion of the above `insert' */ 5431541Srgrimes vm_map_unlock(m); 5441541Srgrimes} 545188964Srwatson 546188967Srwatson#ifdef DIAGNOSTIC 547188964Srwatson/* 548188964Srwatson * Allow userspace to directly trigger the VM drain routine for testing 549188964Srwatson * purposes. 550188964Srwatson */ 551188964Srwatsonstatic int 552188964Srwatsondebug_vm_lowmem(SYSCTL_HANDLER_ARGS) 553188964Srwatson{ 554188964Srwatson int error, i; 555188964Srwatson 556188964Srwatson i = 0; 557188964Srwatson error = sysctl_handle_int(oidp, &i, 0, req); 558188964Srwatson if (error) 559188964Srwatson return (error); 560188964Srwatson if (i) 561188964Srwatson EVENTHANDLER_INVOKE(vm_lowmem, 0); 562188964Srwatson return (0); 563188964Srwatson} 564188964Srwatson 565188964SrwatsonSYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0, 566188964Srwatson debug_vm_lowmem, "I", "set to trigger vm_lowmem event"); 567188967Srwatson#endif 568