/* * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ /* * Mach Operating System * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University * All Rights Reserved. * * 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 Mellon * the rights to redistribute these changes. */ /* */ /* * File: vm/vm_page.c * Author: Avadis Tevanian, Jr., Michael Wayne Young * * Resident memory management module. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* kernel_memory_allocate() */ #include #include #include #include /* (BRINGUP) */ #include /* (BRINGUP) */ #include #include #include #if CONFIG_EMBEDDED #include #endif int speculative_age_index = 0; int speculative_steal_index = 0; struct vm_speculative_age_q vm_page_queue_speculative[VM_PAGE_MAX_SPECULATIVE_AGE_Q + 1]; /* * Associated with page of user-allocatable memory is a * page structure. */ /* * These variables record the values returned by vm_page_bootstrap, * for debugging purposes. The implementation of pmap_steal_memory * and pmap_startup here also uses them internally. */ vm_offset_t virtual_space_start; vm_offset_t virtual_space_end; int vm_page_pages; /* * The vm_page_lookup() routine, which provides for fast * (virtual memory object, offset) to page lookup, employs * the following hash table. The vm_page_{insert,remove} * routines install and remove associations in the table. * [This table is often called the virtual-to-physical, * or VP, table.] */ typedef struct { vm_page_t pages; #if MACH_PAGE_HASH_STATS int cur_count; /* current count */ int hi_count; /* high water mark */ #endif /* MACH_PAGE_HASH_STATS */ } vm_page_bucket_t; vm_page_bucket_t *vm_page_buckets; /* Array of buckets */ unsigned int vm_page_bucket_count = 0; /* How big is array? */ unsigned int vm_page_hash_mask; /* Mask for hash function */ unsigned int vm_page_hash_shift; /* Shift for hash function */ uint32_t vm_page_bucket_hash; /* Basic bucket hash */ decl_simple_lock_data(,vm_page_bucket_lock) #if MACH_PAGE_HASH_STATS /* This routine is only for debug. It is intended to be called by * hand by a developer using a kernel debugger. This routine prints * out vm_page_hash table statistics to the kernel debug console. */ void hash_debug(void) { int i; int numbuckets = 0; int highsum = 0; int maxdepth = 0; for (i = 0; i < vm_page_bucket_count; i++) { if (vm_page_buckets[i].hi_count) { numbuckets++; highsum += vm_page_buckets[i].hi_count; if (vm_page_buckets[i].hi_count > maxdepth) maxdepth = vm_page_buckets[i].hi_count; } } printf("Total number of buckets: %d\n", vm_page_bucket_count); printf("Number used buckets: %d = %d%%\n", numbuckets, 100*numbuckets/vm_page_bucket_count); printf("Number unused buckets: %d = %d%%\n", vm_page_bucket_count - numbuckets, 100*(vm_page_bucket_count-numbuckets)/vm_page_bucket_count); printf("Sum of bucket max depth: %d\n", highsum); printf("Average bucket depth: %d.%2d\n", highsum/vm_page_bucket_count, highsum%vm_page_bucket_count); printf("Maximum bucket depth: %d\n", maxdepth); } #endif /* MACH_PAGE_HASH_STATS */ /* * The virtual page size is currently implemented as a runtime * variable, but is constant once initialized using vm_set_page_size. * This initialization must be done in the machine-dependent * bootstrap sequence, before calling other machine-independent * initializations. * * All references to the virtual page size outside this * module must use the PAGE_SIZE, PAGE_MASK and PAGE_SHIFT * constants. */ vm_size_t page_size = PAGE_SIZE; vm_size_t page_mask = PAGE_MASK; int page_shift = PAGE_SHIFT; /* * Resident page structures are initialized from * a template (see vm_page_alloc). * * When adding a new field to the virtual memory * object structure, be sure to add initialization * (see vm_page_bootstrap). */ struct vm_page vm_page_template; vm_page_t vm_pages = VM_PAGE_NULL; unsigned int vm_pages_count = 0; /* * Resident pages that represent real memory * are allocated from a set of free lists, * one per color. */ unsigned int vm_colors; unsigned int vm_color_mask; /* mask is == (vm_colors-1) */ unsigned int vm_cache_geometry_colors = 0; /* set by hw dependent code during startup */ queue_head_t vm_page_queue_free[MAX_COLORS]; vm_page_t vm_page_queue_fictitious; unsigned int vm_page_free_wanted; unsigned int vm_page_free_wanted_privileged; unsigned int vm_page_free_count; unsigned int vm_page_fictitious_count; unsigned int vm_page_free_count_minimum; /* debugging */ /* * Occasionally, the virtual memory system uses * resident page structures that do not refer to * real pages, for example to leave a page with * important state information in the VP table. * * These page structures are allocated the way * most other kernel structures are. */ zone_t vm_page_zone; decl_mutex_data(,vm_page_alloc_lock) unsigned int io_throttle_zero_fill; /* * Fictitious pages don't have a physical address, * but we must initialize phys_page to something. * For debugging, this should be a strange value * that the pmap module can recognize in assertions. */ vm_offset_t vm_page_fictitious_addr = (vm_offset_t) -1; /* * Guard pages are not accessible so they don't * need a physical address, but we need to enter * one in the pmap. * Let's make it recognizable and make sure that * we don't use a real physical page with that * physical address. */ vm_offset_t vm_page_guard_addr = (vm_offset_t) -2; /* * Resident page structures are also chained on * queues that are used by the page replacement * system (pageout daemon). These queues are * defined here, but are shared by the pageout * module. The inactive queue is broken into * inactive and zf for convenience as the * pageout daemon often assignes a higher * affinity to zf pages */ queue_head_t vm_page_queue_active; queue_head_t vm_page_queue_inactive; queue_head_t vm_page_queue_zf; /* inactive memory queue for zero fill */ unsigned int vm_page_active_count; unsigned int vm_page_inactive_count; unsigned int vm_page_throttled_count; unsigned int vm_page_speculative_count; unsigned int vm_page_wire_count; unsigned int vm_page_gobble_count = 0; unsigned int vm_page_wire_count_warning = 0; unsigned int vm_page_gobble_count_warning = 0; unsigned int vm_page_purgeable_count = 0; /* # of pages purgeable now */ uint64_t vm_page_purged_count = 0; /* total count of purged pages */ unsigned int vm_page_speculative_recreated = 0; unsigned int vm_page_speculative_created = 0; unsigned int vm_page_speculative_used = 0; ppnum_t vm_lopage_poolstart = 0; ppnum_t vm_lopage_poolend = 0; int vm_lopage_poolsize = 0; uint64_t max_valid_dma_address = 0xffffffffffffffffULL; /* * Several page replacement parameters are also * shared with this module, so that page allocation * (done here in vm_page_alloc) can trigger the * pageout daemon. */ unsigned int vm_page_free_target = 0; unsigned int vm_page_free_min = 0; unsigned int vm_page_inactive_target = 0; unsigned int vm_page_inactive_min = 0; unsigned int vm_page_free_reserved = 0; unsigned int vm_page_zfill_throttle_count = 0; /* * The VM system has a couple of heuristics for deciding * that pages are "uninteresting" and should be placed * on the inactive queue as likely candidates for replacement. * These variables let the heuristics be controlled at run-time * to make experimentation easier. */ boolean_t vm_page_deactivate_hint = TRUE; /* * vm_set_page_size: * * Sets the page size, perhaps based upon the memory * size. Must be called before any use of page-size * dependent functions. * * Sets page_shift and page_mask from page_size. */ void vm_set_page_size(void) { page_mask = page_size - 1; if ((page_mask & page_size) != 0) panic("vm_set_page_size: page size not a power of two"); for (page_shift = 0; ; page_shift++) if ((1U << page_shift) == page_size) break; } /* Called once during statup, once the cache geometry is known. */ static void vm_page_set_colors( void ) { unsigned int n, override; if ( PE_parse_boot_argn("colors", &override, sizeof (override)) ) /* colors specified as a boot-arg? */ n = override; else if ( vm_cache_geometry_colors ) /* do we know what the cache geometry is? */ n = vm_cache_geometry_colors; else n = DEFAULT_COLORS; /* use default if all else fails */ if ( n == 0 ) n = 1; if ( n > MAX_COLORS ) n = MAX_COLORS; /* the count must be a power of 2 */ if ( ( n & (n - 1)) !=0 ) panic("vm_page_set_colors"); vm_colors = n; vm_color_mask = n - 1; } /* * vm_page_bootstrap: * * Initializes the resident memory module. * * Allocates memory for the page cells, and * for the object/offset-to-page hash table headers. * Each page cell is initialized and placed on the free list. * Returns the range of available kernel virtual memory. */ void vm_page_bootstrap( vm_offset_t *startp, vm_offset_t *endp) { register vm_page_t m; unsigned int i; unsigned int log1; unsigned int log2; unsigned int size; /* * Initialize the vm_page template. */ m = &vm_page_template; m->object = VM_OBJECT_NULL; /* reset later */ m->offset = (vm_object_offset_t) -1; /* reset later */ m->wire_count = 0; m->pageq.next = NULL; m->pageq.prev = NULL; m->listq.next = NULL; m->listq.prev = NULL; m->speculative = FALSE; m->throttled = FALSE; m->inactive = FALSE; m->active = FALSE; m->no_cache = FALSE; m->laundry = FALSE; m->free = FALSE; m->pmapped = FALSE; m->wpmapped = FALSE; m->reference = FALSE; m->pageout = FALSE; m->dump_cleaning = FALSE; m->list_req_pending = FALSE; m->busy = TRUE; m->wanted = FALSE; m->tabled = FALSE; m->fictitious = FALSE; m->private = FALSE; m->absent = FALSE; m->error = FALSE; m->dirty = FALSE; m->cleaning = FALSE; m->precious = FALSE; m->clustered = FALSE; m->unusual = FALSE; m->restart = FALSE; m->zero_fill = FALSE; m->encrypted = FALSE; m->encrypted_cleaning = FALSE; m->deactivated = FALSE; m->phys_page = 0; /* reset later */ /* * Initialize the page queues. */ mutex_init(&vm_page_queue_free_lock, 0); mutex_init(&vm_page_queue_lock, 0); mutex_init(&vm_purgeable_queue_lock, 0); for (i = 0; i < PURGEABLE_Q_TYPE_MAX; i++) { int group; purgeable_queues[i].token_q_head = 0; purgeable_queues[i].token_q_tail = 0; for (group = 0; group < NUM_VOLATILE_GROUPS; group++) queue_init(&purgeable_queues[i].objq[group]); purgeable_queues[i].type = i; purgeable_queues[i].new_pages = 0; #if MACH_ASSERT purgeable_queues[i].debug_count_tokens = 0; purgeable_queues[i].debug_count_objects = 0; #endif }; for (i = 0; i < MAX_COLORS; i++ ) queue_init(&vm_page_queue_free[i]); queue_init(&vm_lopage_queue_free); vm_page_queue_fictitious = VM_PAGE_NULL; queue_init(&vm_page_queue_active); queue_init(&vm_page_queue_inactive); queue_init(&vm_page_queue_throttled); queue_init(&vm_page_queue_zf); for ( i = 0; i <= VM_PAGE_MAX_SPECULATIVE_AGE_Q; i++ ) { queue_init(&vm_page_queue_speculative[i].age_q); vm_page_queue_speculative[i].age_ts.tv_sec = 0; vm_page_queue_speculative[i].age_ts.tv_nsec = 0; } vm_page_free_wanted = 0; vm_page_free_wanted_privileged = 0; vm_page_set_colors(); /* * Steal memory for the map and zone subsystems. */ vm_map_steal_memory(); zone_steal_memory(); /* * Allocate (and initialize) the virtual-to-physical * table hash buckets. * * The number of buckets should be a power of two to * get a good hash function. The following computation * chooses the first power of two that is greater * than the number of physical pages in the system. */ simple_lock_init(&vm_page_bucket_lock, 0); if (vm_page_bucket_count == 0) { unsigned int npages = pmap_free_pages(); vm_page_bucket_count = 1; while (vm_page_bucket_count < npages) vm_page_bucket_count <<= 1; } vm_page_hash_mask = vm_page_bucket_count - 1; /* * Calculate object shift value for hashing algorithm: * O = log2(sizeof(struct vm_object)) * B = log2(vm_page_bucket_count) * hash shifts the object left by * B/2 - O */ size = vm_page_bucket_count; for (log1 = 0; size > 1; log1++) size /= 2; size = sizeof(struct vm_object); for (log2 = 0; size > 1; log2++) size /= 2; vm_page_hash_shift = log1/2 - log2 + 1; vm_page_bucket_hash = 1 << ((log1 + 1) >> 1); /* Get (ceiling of sqrt of table size) */ vm_page_bucket_hash |= 1 << ((log1 + 1) >> 2); /* Get (ceiling of quadroot of table size) */ vm_page_bucket_hash |= 1; /* Set bit and add 1 - always must be 1 to insure unique series */ if (vm_page_hash_mask & vm_page_bucket_count) printf("vm_page_bootstrap: WARNING -- strange page hash\n"); vm_page_buckets = (vm_page_bucket_t *) pmap_steal_memory(vm_page_bucket_count * sizeof(vm_page_bucket_t)); for (i = 0; i < vm_page_bucket_count; i++) { register vm_page_bucket_t *bucket = &vm_page_buckets[i]; bucket->pages = VM_PAGE_NULL; #if MACH_PAGE_HASH_STATS bucket->cur_count = 0; bucket->hi_count = 0; #endif /* MACH_PAGE_HASH_STATS */ } /* * Machine-dependent code allocates the resident page table. * It uses vm_page_init to initialize the page frames. * The code also returns to us the virtual space available * to the kernel. We don't trust the pmap module * to get the alignment right. */ pmap_startup(&virtual_space_start, &virtual_space_end); virtual_space_start = round_page(virtual_space_start); virtual_space_end = trunc_page(virtual_space_end); *startp = virtual_space_start; *endp = virtual_space_end; /* * Compute the initial "wire" count. * Up until now, the pages which have been set aside are not under * the VM system's control, so although they aren't explicitly * wired, they nonetheless can't be moved. At this moment, * all VM managed pages are "free", courtesy of pmap_startup. */ vm_page_wire_count = atop_64(max_mem) - vm_page_free_count; /* initial value */ vm_page_free_count_minimum = vm_page_free_count; printf("vm_page_bootstrap: %d free pages and %d wired pages\n", vm_page_free_count, vm_page_wire_count); simple_lock_init(&vm_paging_lock, 0); } #ifndef MACHINE_PAGES /* * We implement pmap_steal_memory and pmap_startup with the help * of two simpler functions, pmap_virtual_space and pmap_next_page. */ void * pmap_steal_memory( vm_size_t size) { vm_offset_t addr, vaddr; ppnum_t phys_page; /* * We round the size to a round multiple. */ size = (size + sizeof (void *) - 1) &~ (sizeof (void *) - 1); /* * If this is the first call to pmap_steal_memory, * we have to initialize ourself. */ if (virtual_space_start == virtual_space_end) { pmap_virtual_space(&virtual_space_start, &virtual_space_end); /* * The initial values must be aligned properly, and * we don't trust the pmap module to do it right. */ virtual_space_start = round_page(virtual_space_start); virtual_space_end = trunc_page(virtual_space_end); } /* * Allocate virtual memory for this request. */ addr = virtual_space_start; virtual_space_start += size; kprintf("pmap_steal_memory: %08X - %08X; size=%08X\n", addr, virtual_space_start, size); /* (TEST/DEBUG) */ /* * Allocate and map physical pages to back new virtual pages. */ for (vaddr = round_page(addr); vaddr < addr + size; vaddr += PAGE_SIZE) { if (!pmap_next_page(&phys_page)) panic("pmap_steal_memory"); /* * XXX Logically, these mappings should be wired, * but some pmap modules barf if they are. */ pmap_enter(kernel_pmap, vaddr, phys_page, VM_PROT_READ|VM_PROT_WRITE, VM_WIMG_USE_DEFAULT, FALSE); /* * Account for newly stolen memory */ vm_page_wire_count++; } return (void *) addr; } void pmap_startup( vm_offset_t *startp, vm_offset_t *endp) { unsigned int i, npages, pages_initialized, fill, fillval; ppnum_t phys_page; addr64_t tmpaddr; unsigned int num_of_lopages = 0; unsigned int last_index; /* * We calculate how many page frames we will have * and then allocate the page structures in one chunk. */ tmpaddr = (addr64_t)pmap_free_pages() * (addr64_t)PAGE_SIZE; /* Get the amount of memory left */ tmpaddr = tmpaddr + (addr64_t)(round_page_32(virtual_space_start) - virtual_space_start); /* Account for any slop */ npages = (unsigned int)(tmpaddr / (addr64_t)(PAGE_SIZE + sizeof(*vm_pages))); /* Figure size of all vm_page_ts, including enough to hold the vm_page_ts */ vm_pages = (vm_page_t) pmap_steal_memory(npages * sizeof *vm_pages); /* * Initialize the page frames. */ for (i = 0, pages_initialized = 0; i < npages; i++) { if (!pmap_next_page(&phys_page)) break; vm_page_init(&vm_pages[i], phys_page); vm_page_pages++; pages_initialized++; } vm_pages_count = pages_initialized; /* * Check if we want to initialize pages to a known value */ fill = 0; /* Assume no fill */ if (PE_parse_boot_argn("fill", &fillval, sizeof (fillval))) fill = 1; /* Set fill */ /* * if vm_lopage_poolsize is non-zero, than we need to reserve * a pool of pages whose addresess are less than 4G... this pool * is used by drivers whose hardware can't DMA beyond 32 bits... * * note that I'm assuming that the page list is ascending and * ordered w/r to the physical address */ for (i = 0, num_of_lopages = vm_lopage_poolsize; num_of_lopages && i < pages_initialized; num_of_lopages--, i++) { vm_page_t m; m = &vm_pages[i]; if (m->phys_page >= (1 << (32 - PAGE_SHIFT))) panic("couldn't reserve the lopage pool: not enough lo pages\n"); if (m->phys_page < vm_lopage_poolend) panic("couldn't reserve the lopage pool: page list out of order\n"); vm_lopage_poolend = m->phys_page; if (vm_lopage_poolstart == 0) vm_lopage_poolstart = m->phys_page; else { if (m->phys_page < vm_lopage_poolstart) panic("couldn't reserve the lopage pool: page list out of order\n"); } if (fill) fillPage(m->phys_page, fillval); /* Fill the page with a know value if requested at boot */ vm_page_release(m); } last_index = i; // -debug code remove if (2 == vm_himemory_mode) { // free low -> high so high is preferred for (i = last_index + 1; i <= pages_initialized; i++) { if(fill) fillPage(vm_pages[i - 1].phys_page, fillval); /* Fill the page with a know value if requested at boot */ vm_page_release(&vm_pages[i - 1]); } } else // debug code remove- /* * Release pages in reverse order so that physical pages * initially get allocated in ascending addresses. This keeps * the devices (which must address physical memory) happy if * they require several consecutive pages. */ for (i = pages_initialized; i > last_index; i--) { if(fill) fillPage(vm_pages[i - 1].phys_page, fillval); /* Fill the page with a know value if requested at boot */ vm_page_release(&vm_pages[i - 1]); } #if 0 { vm_page_t xx, xxo, xxl; int i, j, k, l; j = 0; /* (BRINGUP) */ xxl = 0; for( i = 0; i < vm_colors; i++ ) { queue_iterate(&vm_page_queue_free[i], xx, vm_page_t, pageq) { /* BRINGUP */ j++; /* (BRINGUP) */ if(j > vm_page_free_count) { /* (BRINGUP) */ panic("pmap_startup: too many pages, xx = %08X, xxl = %08X\n", xx, xxl); } l = vm_page_free_count - j; /* (BRINGUP) */ k = 0; /* (BRINGUP) */ if(((j - 1) & 0xFFFF) == 0) kprintf("checking number %d of %d\n", j, vm_page_free_count); for(xxo = xx->pageq.next; xxo != &vm_page_queue_free[i]; xxo = xxo->pageq.next) { /* (BRINGUP) */ k++; if(k > l) panic("pmap_startup: too many in secondary check %d %d\n", k, l); if((xx->phys_page & 0xFFFFFFFF) == (xxo->phys_page & 0xFFFFFFFF)) { /* (BRINGUP) */ panic("pmap_startup: duplicate physaddr, xx = %08X, xxo = %08X\n", xx, xxo); } } xxl = xx; } } if(j != vm_page_free_count) { /* (BRINGUP) */ panic("pmap_startup: vm_page_free_count does not match, calc = %d, vm_page_free_count = %08X\n", j, vm_page_free_count); } } #endif /* * We have to re-align virtual_space_start, * because pmap_steal_memory has been using it. */ virtual_space_start = round_page_32(virtual_space_start); *startp = virtual_space_start; *endp = virtual_space_end; } #endif /* MACHINE_PAGES */ /* * Routine: vm_page_module_init * Purpose: * Second initialization pass, to be done after * the basic VM system is ready. */ void vm_page_module_init(void) { vm_page_zone = zinit((vm_size_t) sizeof(struct vm_page), 0, PAGE_SIZE, "vm pages"); #if ZONE_DEBUG zone_debug_disable(vm_page_zone); #endif /* ZONE_DEBUG */ zone_change(vm_page_zone, Z_EXPAND, FALSE); zone_change(vm_page_zone, Z_EXHAUST, TRUE); zone_change(vm_page_zone, Z_FOREIGN, TRUE); /* * Adjust zone statistics to account for the real pages allocated * in vm_page_create(). [Q: is this really what we want?] */ vm_page_zone->count += vm_page_pages; vm_page_zone->cur_size += vm_page_pages * vm_page_zone->elem_size; mutex_init(&vm_page_alloc_lock, 0); } /* * Routine: vm_page_create * Purpose: * After the VM system is up, machine-dependent code * may stumble across more physical memory. For example, * memory that it was reserving for a frame buffer. * vm_page_create turns this memory into available pages. */ void vm_page_create( ppnum_t start, ppnum_t end) { ppnum_t phys_page; vm_page_t m; for (phys_page = start; phys_page < end; phys_page++) { while ((m = (vm_page_t) vm_page_grab_fictitious()) == VM_PAGE_NULL) vm_page_more_fictitious(); vm_page_init(m, phys_page); vm_page_pages++; vm_page_release(m); } } /* * vm_page_hash: * * Distributes the object/offset key pair among hash buckets. * * NOTE: The bucket count must be a power of 2 */ #define vm_page_hash(object, offset) (\ ( (natural_t)((uint32_t)object * vm_page_bucket_hash) + ((uint32_t)atop_64(offset) ^ vm_page_bucket_hash))\ & vm_page_hash_mask) /* * vm_page_insert: [ internal use only ] * * Inserts the given mem entry into the object/object-page * table and object list. * * The object must be locked. */ void vm_page_insert( vm_page_t mem, vm_object_t object, vm_object_offset_t offset) { vm_page_insert_internal(mem, object, offset, FALSE); } void vm_page_insert_internal( vm_page_t mem, vm_object_t object, vm_object_offset_t offset, boolean_t queues_lock_held) { register vm_page_bucket_t *bucket; XPR(XPR_VM_PAGE, "vm_page_insert, object 0x%X offset 0x%X page 0x%X\n", (integer_t)object, (integer_t)offset, (integer_t)mem, 0,0); VM_PAGE_CHECK(mem); if (object == vm_submap_object) { /* the vm_submap_object is only a placeholder for submaps */ panic("vm_page_insert(vm_submap_object,0x%llx)\n", offset); } vm_object_lock_assert_exclusive(object); #if DEBUG if (mem->tabled || mem->object != VM_OBJECT_NULL) panic("vm_page_insert: page %p for (obj=%p,off=0x%llx) " "already in (obj=%p,off=0x%llx)", mem, object, offset, mem->object, mem->offset); #endif assert(!object->internal || offset < object->size); /* only insert "pageout" pages into "pageout" objects, * and normal pages into normal objects */ assert(object->pageout == mem->pageout); assert(vm_page_lookup(object, offset) == VM_PAGE_NULL); /* * Record the object/offset pair in this page */ mem->object = object; mem->offset = offset; /* * Insert it into the object_object/offset hash table */ bucket = &vm_page_buckets[vm_page_hash(object, offset)]; simple_lock(&vm_page_bucket_lock); mem->next = bucket->pages; bucket->pages = mem; #if MACH_PAGE_HASH_STATS if (++bucket->cur_count > bucket->hi_count) bucket->hi_count = bucket->cur_count; #endif /* MACH_PAGE_HASH_STATS */ simple_unlock(&vm_page_bucket_lock); /* * Now link into the object's list of backed pages. */ VM_PAGE_INSERT(mem, object); mem->tabled = TRUE; /* * Show that the object has one more resident page. */ object->resident_page_count++; if (object->purgable == VM_PURGABLE_VOLATILE) { if (queues_lock_held == FALSE) vm_page_lockspin_queues(); vm_page_purgeable_count++; if (queues_lock_held == FALSE) vm_page_unlock_queues(); } else if (object->purgable == VM_PURGABLE_EMPTY && mem->throttled) { if (queues_lock_held == FALSE) vm_page_lock_queues(); vm_page_deactivate(mem); if (queues_lock_held == FALSE) vm_page_unlock_queues(); } } /* * vm_page_replace: * * Exactly like vm_page_insert, except that we first * remove any existing page at the given offset in object. * * The object and page queues must be locked. */ void vm_page_replace( register vm_page_t mem, register vm_object_t object, register vm_object_offset_t offset) { vm_page_bucket_t *bucket; vm_page_t found_m = VM_PAGE_NULL; VM_PAGE_CHECK(mem); vm_object_lock_assert_exclusive(object); #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); if (mem->tabled || mem->object != VM_OBJECT_NULL) panic("vm_page_replace: page %p for (obj=%p,off=0x%llx) " "already in (obj=%p,off=0x%llx)", mem, object, offset, mem->object, mem->offset); #endif /* * Record the object/offset pair in this page */ mem->object = object; mem->offset = offset; /* * Insert it into the object_object/offset hash table, * replacing any page that might have been there. */ bucket = &vm_page_buckets[vm_page_hash(object, offset)]; simple_lock(&vm_page_bucket_lock); if (bucket->pages) { vm_page_t *mp = &bucket->pages; register vm_page_t m = *mp; do { if (m->object == object && m->offset == offset) { /* * Remove old page from hash list */ *mp = m->next; found_m = m; break; } mp = &m->next; } while ((m = *mp)); mem->next = bucket->pages; } else { mem->next = VM_PAGE_NULL; } /* * insert new page at head of hash list */ bucket->pages = mem; simple_unlock(&vm_page_bucket_lock); if (found_m) { /* * there was already a page at the specified * offset for this object... remove it from * the object and free it back to the free list */ VM_PAGE_REMOVE(found_m); found_m->tabled = FALSE; found_m->object = VM_OBJECT_NULL; found_m->offset = (vm_object_offset_t) -1; object->resident_page_count--; if (object->purgable == VM_PURGABLE_VOLATILE) { assert(vm_page_purgeable_count > 0); vm_page_purgeable_count--; } /* * Return page to the free list. * Note the page is not tabled now */ vm_page_free(found_m); } /* * Now link into the object's list of backed pages. */ VM_PAGE_INSERT(mem, object); mem->tabled = TRUE; /* * And show that the object has one more resident * page. */ object->resident_page_count++; if (object->purgable == VM_PURGABLE_VOLATILE) { vm_page_purgeable_count++; } else if (object->purgable == VM_PURGABLE_EMPTY) { if (mem->throttled) { vm_page_deactivate(mem); } } } /* * vm_page_remove: [ internal use only ] * * Removes the given mem entry from the object/offset-page * table and the object page list. * * The object and page queues must be locked. */ void vm_page_remove( register vm_page_t mem) { register vm_page_bucket_t *bucket; register vm_page_t this; XPR(XPR_VM_PAGE, "vm_page_remove, object 0x%X offset 0x%X page 0x%X\n", (integer_t)mem->object, (integer_t)mem->offset, (integer_t)mem, 0,0); #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif vm_object_lock_assert_exclusive(mem->object); assert(mem->tabled); assert(!mem->cleaning); VM_PAGE_CHECK(mem); /* * Remove from the object_object/offset hash table */ bucket = &vm_page_buckets[vm_page_hash(mem->object, mem->offset)]; simple_lock(&vm_page_bucket_lock); if ((this = bucket->pages) == mem) { /* optimize for common case */ bucket->pages = mem->next; } else { register vm_page_t *prev; for (prev = &this->next; (this = *prev) != mem; prev = &this->next) continue; *prev = this->next; } #if MACH_PAGE_HASH_STATS bucket->cur_count--; #endif /* MACH_PAGE_HASH_STATS */ simple_unlock(&vm_page_bucket_lock); /* * Now remove from the object's list of backed pages. */ VM_PAGE_REMOVE(mem); /* * And show that the object has one fewer resident * page. */ mem->object->resident_page_count--; if (mem->object->purgable == VM_PURGABLE_VOLATILE) { assert(vm_page_purgeable_count > 0); vm_page_purgeable_count--; } mem->tabled = FALSE; mem->object = VM_OBJECT_NULL; mem->offset = (vm_object_offset_t) -1; } /* * vm_page_lookup: * * Returns the page associated with the object/offset * pair specified; if none is found, VM_PAGE_NULL is returned. * * The object must be locked. No side effects. */ unsigned long vm_page_lookup_hint = 0; unsigned long vm_page_lookup_hint_next = 0; unsigned long vm_page_lookup_hint_prev = 0; unsigned long vm_page_lookup_hint_miss = 0; unsigned long vm_page_lookup_bucket_NULL = 0; unsigned long vm_page_lookup_miss = 0; vm_page_t vm_page_lookup( register vm_object_t object, register vm_object_offset_t offset) { register vm_page_t mem; register vm_page_bucket_t *bucket; queue_entry_t qe; vm_object_lock_assert_held(object); mem = object->memq_hint; if (mem != VM_PAGE_NULL) { assert(mem->object == object); if (mem->offset == offset) { vm_page_lookup_hint++; return mem; } qe = queue_next(&mem->listq); if (! queue_end(&object->memq, qe)) { vm_page_t next_page; next_page = (vm_page_t) qe; assert(next_page->object == object); if (next_page->offset == offset) { vm_page_lookup_hint_next++; object->memq_hint = next_page; /* new hint */ return next_page; } } qe = queue_prev(&mem->listq); if (! queue_end(&object->memq, qe)) { vm_page_t prev_page; prev_page = (vm_page_t) qe; assert(prev_page->object == object); if (prev_page->offset == offset) { vm_page_lookup_hint_prev++; object->memq_hint = prev_page; /* new hint */ return prev_page; } } } /* * Search the hash table for this object/offset pair */ bucket = &vm_page_buckets[vm_page_hash(object, offset)]; /* * since we hold the object lock, we are guaranteed that no * new pages can be inserted into this object... this in turn * guarantess that the page we're looking for can't exist * if the bucket it hashes to is currently NULL even when looked * at outside the scope of the hash bucket lock... this is a * really cheap optimiztion to avoid taking the lock */ if (bucket->pages == VM_PAGE_NULL) { vm_page_lookup_bucket_NULL++; return (VM_PAGE_NULL); } simple_lock(&vm_page_bucket_lock); for (mem = bucket->pages; mem != VM_PAGE_NULL; mem = mem->next) { VM_PAGE_CHECK(mem); if ((mem->object == object) && (mem->offset == offset)) break; } simple_unlock(&vm_page_bucket_lock); if (mem != VM_PAGE_NULL) { if (object->memq_hint != VM_PAGE_NULL) { vm_page_lookup_hint_miss++; } assert(mem->object == object); object->memq_hint = mem; } else vm_page_lookup_miss++; return(mem); } /* * vm_page_rename: * * Move the given memory entry from its * current object to the specified target object/offset. * * The object must be locked. */ void vm_page_rename( register vm_page_t mem, register vm_object_t new_object, vm_object_offset_t new_offset, boolean_t encrypted_ok) { assert(mem->object != new_object); /* * ENCRYPTED SWAP: * The encryption key is based on the page's memory object * (aka "pager") and paging offset. Moving the page to * another VM object changes its "pager" and "paging_offset" * so it has to be decrypted first, or we would lose the key. * * One exception is VM object collapsing, where we transfer pages * from one backing object to its parent object. This operation also * transfers the paging information, so the info * should remain consistent. The caller (vm_object_do_collapse()) * sets "encrypted_ok" in this case. */ if (!encrypted_ok && mem->encrypted) { panic("vm_page_rename: page %p is encrypted\n", mem); } /* * Changes to mem->object require the page lock because * the pageout daemon uses that lock to get the object. */ XPR(XPR_VM_PAGE, "vm_page_rename, new object 0x%X, offset 0x%X page 0x%X\n", (integer_t)new_object, (integer_t)new_offset, (integer_t)mem, 0,0); vm_page_lockspin_queues(); vm_page_remove(mem); vm_page_insert(mem, new_object, new_offset); vm_page_unlock_queues(); } /* * vm_page_init: * * Initialize the fields in a new page. * This takes a structure with random values and initializes it * so that it can be given to vm_page_release or vm_page_insert. */ void vm_page_init( vm_page_t mem, ppnum_t phys_page) { assert(phys_page); *mem = vm_page_template; mem->phys_page = phys_page; } /* * vm_page_grab_fictitious: * * Remove a fictitious page from the free list. * Returns VM_PAGE_NULL if there are no free pages. */ int c_vm_page_grab_fictitious = 0; int c_vm_page_release_fictitious = 0; int c_vm_page_more_fictitious = 0; extern vm_page_t vm_page_grab_fictitious_common(vm_offset_t phys_addr); vm_page_t vm_page_grab_fictitious_common( vm_offset_t phys_addr) { register vm_page_t m; m = (vm_page_t)zget(vm_page_zone); if (m) { vm_page_init(m, phys_addr); m->fictitious = TRUE; } c_vm_page_grab_fictitious++; return m; } vm_page_t vm_page_grab_fictitious(void) { return vm_page_grab_fictitious_common(vm_page_fictitious_addr); } vm_page_t vm_page_grab_guard(void) { return vm_page_grab_fictitious_common(vm_page_guard_addr); } /* * vm_page_release_fictitious: * * Release a fictitious page to the free list. */ void vm_page_release_fictitious( register vm_page_t m) { assert(!m->free); assert(m->busy); assert(m->fictitious); assert(m->phys_page == vm_page_fictitious_addr || m->phys_page == vm_page_guard_addr); c_vm_page_release_fictitious++; #if DEBUG if (m->free) panic("vm_page_release_fictitious"); #endif m->free = TRUE; zfree(vm_page_zone, m); } /* * vm_page_more_fictitious: * * Add more fictitious pages to the free list. * Allowed to block. This routine is way intimate * with the zones code, for several reasons: * 1. we need to carve some page structures out of physical * memory before zones work, so they _cannot_ come from * the zone_map. * 2. the zone needs to be collectable in order to prevent * growth without bound. These structures are used by * the device pager (by the hundreds and thousands), as * private pages for pageout, and as blocking pages for * pagein. Temporary bursts in demand should not result in * permanent allocation of a resource. * 3. To smooth allocation humps, we allocate single pages * with kernel_memory_allocate(), and cram them into the * zone. This also allows us to initialize the vm_page_t's * on the way into the zone, so that zget() always returns * an initialized structure. The zone free element pointer * and the free page pointer are both the first item in the * vm_page_t. * 4. By having the pages in the zone pre-initialized, we need * not keep 2 levels of lists. The garbage collector simply * scans our list, and reduces physical memory usage as it * sees fit. */ void vm_page_more_fictitious(void) { register vm_page_t m; vm_offset_t addr; kern_return_t retval; int i; c_vm_page_more_fictitious++; /* * Allocate a single page from the zone_map. Do not wait if no physical * pages are immediately available, and do not zero the space. We need * our own blocking lock here to prevent having multiple, * simultaneous requests from piling up on the zone_map lock. Exactly * one (of our) threads should be potentially waiting on the map lock. * If winner is not vm-privileged, then the page allocation will fail, * and it will temporarily block here in the vm_page_wait(). */ mutex_lock(&vm_page_alloc_lock); /* * If another thread allocated space, just bail out now. */ if (zone_free_count(vm_page_zone) > 5) { /* * The number "5" is a small number that is larger than the * number of fictitious pages that any single caller will * attempt to allocate. Otherwise, a thread will attempt to * acquire a fictitious page (vm_page_grab_fictitious), fail, * release all of the resources and locks already acquired, * and then call this routine. This routine finds the pages * that the caller released, so fails to allocate new space. * The process repeats infinitely. The largest known number * of fictitious pages required in this manner is 2. 5 is * simply a somewhat larger number. */ mutex_unlock(&vm_page_alloc_lock); return; } retval = kernel_memory_allocate(zone_map, &addr, PAGE_SIZE, VM_PROT_ALL, KMA_KOBJECT|KMA_NOPAGEWAIT); if (retval != KERN_SUCCESS) { /* * No page was available. Tell the pageout daemon, drop the * lock to give another thread a chance at it, and * wait for the pageout daemon to make progress. */ mutex_unlock(&vm_page_alloc_lock); vm_page_wait(THREAD_UNINT); return; } /* * Initialize as many vm_page_t's as will fit on this page. This * depends on the zone code disturbing ONLY the first item of * each zone element. */ m = (vm_page_t)addr; for (i = PAGE_SIZE/sizeof(struct vm_page); i > 0; i--) { vm_page_init(m, vm_page_fictitious_addr); m->fictitious = TRUE; m++; } zcram(vm_page_zone, (void *) addr, PAGE_SIZE); mutex_unlock(&vm_page_alloc_lock); } /* * vm_pool_low(): * * Return true if it is not likely that a non-vm_privileged thread * can get memory without blocking. Advisory only, since the * situation may change under us. */ int vm_pool_low(void) { /* No locking, at worst we will fib. */ return( vm_page_free_count < vm_page_free_reserved ); } /* * this is an interface to support bring-up of drivers * on platforms with physical memory > 4G... */ int vm_himemory_mode = 0; /* * this interface exists to support hardware controllers * incapable of generating DMAs with more than 32 bits * of address on platforms with physical memory > 4G... */ unsigned int vm_lopage_free_count = 0; unsigned int vm_lopage_max_count = 0; queue_head_t vm_lopage_queue_free; vm_page_t vm_page_grablo(void) { register vm_page_t mem; unsigned int vm_lopage_alloc_count; if (vm_lopage_poolsize == 0) return (vm_page_grab()); mutex_lock(&vm_page_queue_free_lock); if (! queue_empty(&vm_lopage_queue_free)) { queue_remove_first(&vm_lopage_queue_free, mem, vm_page_t, pageq); assert(mem->free); assert(mem->busy); assert(!mem->pmapped); assert(!mem->wpmapped); mem->pageq.next = NULL; mem->pageq.prev = NULL; mem->free = FALSE; vm_lopage_free_count--; vm_lopage_alloc_count = (vm_lopage_poolend - vm_lopage_poolstart) - vm_lopage_free_count; if (vm_lopage_alloc_count > vm_lopage_max_count) vm_lopage_max_count = vm_lopage_alloc_count; } else { mem = VM_PAGE_NULL; } mutex_unlock(&vm_page_queue_free_lock); return (mem); } /* * vm_page_grab: * * first try to grab a page from the per-cpu free list... * this must be done while pre-emption is disabled... if * a page is available, we're done... * if no page is available, grab the vm_page_queue_free_lock * and see if current number of free pages would allow us * to grab at least 1... if not, return VM_PAGE_NULL as before... * if there are pages available, disable preemption and * recheck the state of the per-cpu free list... we could * have been preempted and moved to a different cpu, or * some other thread could have re-filled it... if still * empty, figure out how many pages we can steal from the * global free queue and move to the per-cpu queue... * return 1 of these pages when done... only wakeup the * pageout_scan thread if we moved pages from the global * list... no need for the wakeup if we've satisfied the * request from the per-cpu queue. */ #define COLOR_GROUPS_TO_STEAL 4 vm_page_t vm_page_grab( void ) { vm_page_t mem; disable_preemption(); if ((mem = PROCESSOR_DATA(current_processor(), free_pages))) { return_page_from_cpu_list: PROCESSOR_DATA(current_processor(), page_grab_count) += 1; PROCESSOR_DATA(current_processor(), free_pages) = mem->pageq.next; mem->pageq.next = NULL; enable_preemption(); assert(mem->listq.next == NULL && mem->listq.prev == NULL); assert(mem->tabled == FALSE); assert(mem->object == VM_OBJECT_NULL); assert(!mem->laundry); assert(!mem->free); assert(pmap_verify_free(mem->phys_page)); assert(mem->busy); assert(!mem->encrypted); assert(!mem->pmapped); assert(!mem->wpmapped); return mem; } enable_preemption(); mutex_lock(&vm_page_queue_free_lock); /* * Optionally produce warnings if the wire or gobble * counts exceed some threshold. */ if (vm_page_wire_count_warning > 0 && vm_page_wire_count >= vm_page_wire_count_warning) { printf("mk: vm_page_grab(): high wired page count of %d\n", vm_page_wire_count); assert(vm_page_wire_count < vm_page_wire_count_warning); } if (vm_page_gobble_count_warning > 0 && vm_page_gobble_count >= vm_page_gobble_count_warning) { printf("mk: vm_page_grab(): high gobbled page count of %d\n", vm_page_gobble_count); assert(vm_page_gobble_count < vm_page_gobble_count_warning); } /* * Only let privileged threads (involved in pageout) * dip into the reserved pool. */ if ((vm_page_free_count < vm_page_free_reserved) && !(current_thread()->options & TH_OPT_VMPRIV)) { mutex_unlock(&vm_page_queue_free_lock); mem = VM_PAGE_NULL; } else { vm_page_t head; vm_page_t tail; unsigned int pages_to_steal; unsigned int color; while ( vm_page_free_count == 0 ) { mutex_unlock(&vm_page_queue_free_lock); /* * must be a privileged thread to be * in this state since a non-privileged * thread would have bailed if we were * under the vm_page_free_reserved mark */ VM_PAGE_WAIT(); mutex_lock(&vm_page_queue_free_lock); } disable_preemption(); if ((mem = PROCESSOR_DATA(current_processor(), free_pages))) { mutex_unlock(&vm_page_queue_free_lock); /* * we got preempted and moved to another processor * or we got preempted and someone else ran and filled the cache */ goto return_page_from_cpu_list; } if (vm_page_free_count <= vm_page_free_reserved) pages_to_steal = 1; else { pages_to_steal = COLOR_GROUPS_TO_STEAL * vm_colors; if (pages_to_steal > (vm_page_free_count - vm_page_free_reserved)) pages_to_steal = (vm_page_free_count - vm_page_free_reserved); } color = PROCESSOR_DATA(current_processor(), start_color); head = tail = NULL; while (pages_to_steal--) { if (--vm_page_free_count < vm_page_free_count_minimum) vm_page_free_count_minimum = vm_page_free_count; while (queue_empty(&vm_page_queue_free[color])) color = (color + 1) & vm_color_mask; queue_remove_first(&vm_page_queue_free[color], mem, vm_page_t, pageq); mem->pageq.next = NULL; mem->pageq.prev = NULL; color = (color + 1) & vm_color_mask; if (head == NULL) head = mem; else tail->pageq.next = (queue_t)mem; tail = mem; mem->pageq.prev = NULL; assert(mem->listq.next == NULL && mem->listq.prev == NULL); assert(mem->tabled == FALSE); assert(mem->object == VM_OBJECT_NULL); assert(!mem->laundry); assert(mem->free); mem->free = FALSE; assert(pmap_verify_free(mem->phys_page)); assert(mem->busy); assert(!mem->free); assert(!mem->encrypted); assert(!mem->pmapped); assert(!mem->wpmapped); } PROCESSOR_DATA(current_processor(), free_pages) = head->pageq.next; PROCESSOR_DATA(current_processor(), start_color) = color; /* * satisfy this request */ PROCESSOR_DATA(current_processor(), page_grab_count) += 1; mem = head; mem->pageq.next = NULL; mutex_unlock(&vm_page_queue_free_lock); enable_preemption(); } /* * Decide if we should poke the pageout daemon. * We do this if the free count is less than the low * water mark, or if the free count is less than the high * water mark (but above the low water mark) and the inactive * count is less than its target. * * We don't have the counts locked ... if they change a little, * it doesn't really matter. */ if ((vm_page_free_count < vm_page_free_min) || ((vm_page_free_count < vm_page_free_target) && ((vm_page_inactive_count + vm_page_speculative_count) < vm_page_inactive_min))) thread_wakeup((event_t) &vm_page_free_wanted); #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail <= (kern_memorystatus_level - 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif // dbgLog(mem->phys_page, vm_page_free_count, vm_page_wire_count, 4); /* (TEST/DEBUG) */ return mem; } /* * vm_page_release: * * Return a page to the free list. */ void vm_page_release( register vm_page_t mem) { unsigned int color; #if 0 unsigned int pindex; phys_entry *physent; physent = mapping_phys_lookup(mem->phys_page, &pindex); /* (BRINGUP) */ if(physent->ppLink & ppN) { /* (BRINGUP) */ panic("vm_page_release: already released - %08X %08X\n", mem, mem->phys_page); } physent->ppLink = physent->ppLink | ppN; /* (BRINGUP) */ #endif assert(!mem->private && !mem->fictitious); // dbgLog(mem->phys_page, vm_page_free_count, vm_page_wire_count, 5); /* (TEST/DEBUG) */ mutex_lock(&vm_page_queue_free_lock); #if DEBUG if (mem->free) panic("vm_page_release"); #endif mem->free = TRUE; assert(mem->busy); assert(!mem->laundry); assert(mem->object == VM_OBJECT_NULL); assert(mem->pageq.next == NULL && mem->pageq.prev == NULL); assert(mem->listq.next == NULL && mem->listq.prev == NULL); if (mem->phys_page <= vm_lopage_poolend && mem->phys_page >= vm_lopage_poolstart) { /* * this exists to support hardware controllers * incapable of generating DMAs with more than 32 bits * of address on platforms with physical memory > 4G... */ queue_enter_first(&vm_lopage_queue_free, mem, vm_page_t, pageq); vm_lopage_free_count++; } else { color = mem->phys_page & vm_color_mask; queue_enter_first(&vm_page_queue_free[color], mem, vm_page_t, pageq); vm_page_free_count++; /* * Check if we should wake up someone waiting for page. * But don't bother waking them unless they can allocate. * * We wakeup only one thread, to prevent starvation. * Because the scheduling system handles wait queues FIFO, * if we wakeup all waiting threads, one greedy thread * can starve multiple niceguy threads. When the threads * all wakeup, the greedy threads runs first, grabs the page, * and waits for another page. It will be the first to run * when the next page is freed. * * However, there is a slight danger here. * The thread we wake might not use the free page. * Then the other threads could wait indefinitely * while the page goes unused. To forestall this, * the pageout daemon will keep making free pages * as long as vm_page_free_wanted is non-zero. */ if ((vm_page_free_wanted_privileged > 0) && vm_page_free_count) { vm_page_free_wanted_privileged--; thread_wakeup_one((event_t) &vm_page_free_wanted_privileged); } else if ((vm_page_free_wanted > 0) && (vm_page_free_count >= vm_page_free_reserved)) { vm_page_free_wanted--; thread_wakeup_one((event_t) &vm_page_free_count); } } mutex_unlock(&vm_page_queue_free_lock); #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. * Locking is not a big issue, as only a single thread delivers these. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail >= (kern_memorystatus_level + 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif } /* * vm_page_wait: * * Wait for a page to become available. * If there are plenty of free pages, then we don't sleep. * * Returns: * TRUE: There may be another page, try again * FALSE: We were interrupted out of our wait, don't try again */ boolean_t vm_page_wait( int interruptible ) { /* * We can't use vm_page_free_reserved to make this * determination. Consider: some thread might * need to allocate two pages. The first allocation * succeeds, the second fails. After the first page is freed, * a call to vm_page_wait must really block. */ kern_return_t wait_result; int need_wakeup = 0; int is_privileged = current_thread()->options & TH_OPT_VMPRIV; mutex_lock(&vm_page_queue_free_lock); if (is_privileged && vm_page_free_count) { mutex_unlock(&vm_page_queue_free_lock); return TRUE; } if (vm_page_free_count < vm_page_free_target) { if (is_privileged) { if (vm_page_free_wanted_privileged++ == 0) need_wakeup = 1; wait_result = assert_wait((event_t)&vm_page_free_wanted_privileged, interruptible); } else { if (vm_page_free_wanted++ == 0) need_wakeup = 1; wait_result = assert_wait((event_t)&vm_page_free_count, interruptible); } mutex_unlock(&vm_page_queue_free_lock); counter(c_vm_page_wait_block++); if (need_wakeup) thread_wakeup((event_t)&vm_page_free_wanted); if (wait_result == THREAD_WAITING) wait_result = thread_block(THREAD_CONTINUE_NULL); return(wait_result == THREAD_AWAKENED); } else { mutex_unlock(&vm_page_queue_free_lock); return TRUE; } } /* * vm_page_alloc: * * Allocate and return a memory cell associated * with this VM object/offset pair. * * Object must be locked. */ vm_page_t vm_page_alloc( vm_object_t object, vm_object_offset_t offset) { register vm_page_t mem; vm_object_lock_assert_exclusive(object); mem = vm_page_grab(); if (mem == VM_PAGE_NULL) return VM_PAGE_NULL; vm_page_insert(mem, object, offset); return(mem); } vm_page_t vm_page_alloclo( vm_object_t object, vm_object_offset_t offset) { register vm_page_t mem; vm_object_lock_assert_exclusive(object); mem = vm_page_grablo(); if (mem == VM_PAGE_NULL) return VM_PAGE_NULL; vm_page_insert(mem, object, offset); return(mem); } /* * vm_page_alloc_guard: * * Allocate a ficticious page which will be used * as a guard page. The page will be inserted into * the object and returned to the caller. */ vm_page_t vm_page_alloc_guard( vm_object_t object, vm_object_offset_t offset) { register vm_page_t mem; vm_object_lock_assert_exclusive(object); mem = vm_page_grab_guard(); if (mem == VM_PAGE_NULL) return VM_PAGE_NULL; vm_page_insert(mem, object, offset); return(mem); } counter(unsigned int c_laundry_pages_freed = 0;) boolean_t vm_page_free_verify = TRUE; /* * vm_page_free: * * Returns the given page to the free list, * disassociating it with any VM object. * * Object and page queues must be locked prior to entry. */ void vm_page_free_prepare( register vm_page_t mem) { VM_PAGE_CHECK(mem); assert(!mem->free); assert(!mem->cleaning); assert(!mem->pageout); #if DEBUG if (vm_page_free_verify && !mem->fictitious && !mem->private) { assert(pmap_verify_free(mem->phys_page)); } if (mem->object) vm_object_lock_assert_exclusive(mem->object); _mutex_assert(&vm_page_queue_lock, MA_OWNED); if (mem->free) panic("vm_page_free: freeing page on free list\n"); #endif if (mem->laundry) { /* * We may have to free a page while it's being laundered * if we lost its pager (due to a forced unmount, for example). * We need to call vm_pageout_throttle_up() before removing * the page from its VM object, so that we can find out on * which pageout queue the page is. */ vm_pageout_throttle_up(mem); counter(++c_laundry_pages_freed); } if (mem->tabled) vm_page_remove(mem); /* clears tabled, object, offset */ VM_PAGE_QUEUES_REMOVE(mem); /* clears active/inactive/throttled/speculative */ if (mem->wire_count) { if (!mem->private && !mem->fictitious) vm_page_wire_count--; mem->wire_count = 0; assert(!mem->gobbled); } else if (mem->gobbled) { if (!mem->private && !mem->fictitious) vm_page_wire_count--; vm_page_gobble_count--; } mem->gobbled = FALSE; PAGE_WAKEUP(mem); /* clears wanted */ /* Some of these may be unnecessary */ mem->busy = TRUE; mem->absent = FALSE; mem->error = FALSE; mem->dirty = FALSE; mem->precious = FALSE; mem->reference = FALSE; mem->encrypted = FALSE; mem->encrypted_cleaning = FALSE; mem->deactivated = FALSE; mem->pmapped = FALSE; mem->wpmapped = FALSE; if (mem->private) { mem->private = FALSE; mem->fictitious = TRUE; mem->phys_page = vm_page_fictitious_addr; } if (!mem->fictitious) { if (mem->zero_fill == TRUE) { mem->zero_fill = FALSE; OSAddAtomic(-1, (SInt32 *)&vm_zf_count); } vm_page_init(mem, mem->phys_page); } } void vm_page_free( vm_page_t mem) { vm_page_free_prepare(mem); if (mem->fictitious) { vm_page_release_fictitious(mem); } else { vm_page_release(mem); } } /* * Free a list of pages. The list can be up to several hundred pages, * as blocked up by vm_pageout_scan(). * The big win is not having to take the page q and free list locks once * per page. We sort the incoming pages into n lists, one for * each color. * * The page queues must be locked, and are kept locked. */ void vm_page_free_list( vm_page_t mem) { vm_page_t nxt; int pg_count = 0; int color; int inuse_list_head = -1; queue_head_t free_list[MAX_COLORS]; int inuse[MAX_COLORS]; for (color = 0; color < (signed) vm_colors; color++) { queue_init(&free_list[color]); } #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif while (mem) { #if DEBUG if (mem->tabled || mem->object) panic("vm_page_free_list: freeing tabled page\n"); if (mem->inactive || mem->active || mem->throttled || mem->free) panic("vm_page_free_list: freeing page on list\n"); if (vm_page_free_verify && !mem->fictitious && !mem->private) { assert(pmap_verify_free(mem->phys_page)); } #endif assert(mem->pageq.prev == NULL); assert(mem->busy); assert(!mem->free); nxt = (vm_page_t)(mem->pageq.next); if (!mem->fictitious) { if (mem->phys_page <= vm_lopage_poolend && mem->phys_page >= vm_lopage_poolstart) { mem->pageq.next = NULL; vm_page_release(mem); } else { mem->free = TRUE; color = mem->phys_page & vm_color_mask; if (queue_empty(&free_list[color])) { inuse[color] = inuse_list_head; inuse_list_head = color; } queue_enter_first(&free_list[color], mem, vm_page_t, pageq); pg_count++; } } else { assert(mem->phys_page == vm_page_fictitious_addr || mem->phys_page == vm_page_guard_addr); vm_page_release_fictitious(mem); } mem = nxt; } if (pg_count) { unsigned int avail_free_count; mutex_lock(&vm_page_queue_free_lock); color = inuse_list_head; while( color != -1 ) { vm_page_t first, last; vm_page_t first_free; first = (vm_page_t) queue_first(&free_list[color]); last = (vm_page_t) queue_last(&free_list[color]); first_free = (vm_page_t) queue_first(&vm_page_queue_free[color]); if (queue_empty(&vm_page_queue_free[color])) { queue_last(&vm_page_queue_free[color]) = (queue_entry_t) last; } else { queue_prev(&first_free->pageq) = (queue_entry_t) last; } queue_first(&vm_page_queue_free[color]) = (queue_entry_t) first; queue_prev(&first->pageq) = (queue_entry_t) &vm_page_queue_free[color]; queue_next(&last->pageq) = (queue_entry_t) first_free; color = inuse[color]; } vm_page_free_count += pg_count; avail_free_count = vm_page_free_count; while ((vm_page_free_wanted_privileged > 0) && avail_free_count) { vm_page_free_wanted_privileged--; avail_free_count--; thread_wakeup_one((event_t) &vm_page_free_wanted_privileged); } if ((vm_page_free_wanted > 0) && (avail_free_count >= vm_page_free_reserved)) { unsigned int available_pages; if (avail_free_count >= vm_page_free_reserved) { available_pages = (avail_free_count - vm_page_free_reserved); } else { available_pages = 0; } if (available_pages >= vm_page_free_wanted) { vm_page_free_wanted = 0; thread_wakeup((event_t) &vm_page_free_count); } else { while (available_pages--) { vm_page_free_wanted--; thread_wakeup_one((event_t) &vm_page_free_count); } } } mutex_unlock(&vm_page_queue_free_lock); #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail >= (kern_memorystatus_level + 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif } } /* * vm_page_wire: * * Mark this page as wired down by yet * another map, removing it from paging queues * as necessary. * * The page's object and the page queues must be locked. */ void vm_page_wire( register vm_page_t mem) { // dbgLog(current_thread(), mem->offset, mem->object, 1); /* (TEST/DEBUG) */ VM_PAGE_CHECK(mem); #if DEBUG if (mem->object) vm_object_lock_assert_exclusive(mem->object); _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif if (mem->wire_count == 0) { VM_PAGE_QUEUES_REMOVE(mem); if (!mem->private && !mem->fictitious && !mem->gobbled) vm_page_wire_count++; if (mem->gobbled) vm_page_gobble_count--; mem->gobbled = FALSE; if (mem->zero_fill == TRUE) { mem->zero_fill = FALSE; OSAddAtomic(-1, (SInt32 *)&vm_zf_count); } #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail <= (kern_memorystatus_level - 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif /* * ENCRYPTED SWAP: * The page could be encrypted, but * We don't have to decrypt it here * because we don't guarantee that the * data is actually valid at this point. * The page will get decrypted in * vm_fault_wire() if needed. */ } assert(!mem->gobbled); mem->wire_count++; } /* * vm_page_gobble: * * Mark this page as consumed by the vm/ipc/xmm subsystems. * * Called only for freshly vm_page_grab()ed pages - w/ nothing locked. */ void vm_page_gobble( register vm_page_t mem) { vm_page_lockspin_queues(); VM_PAGE_CHECK(mem); assert(!mem->gobbled); assert(mem->wire_count == 0); if (!mem->gobbled && mem->wire_count == 0) { if (!mem->private && !mem->fictitious) vm_page_wire_count++; } vm_page_gobble_count++; mem->gobbled = TRUE; vm_page_unlock_queues(); } /* * vm_page_unwire: * * Release one wiring of this page, potentially * enabling it to be paged again. * * The page's object and the page queues must be locked. */ void vm_page_unwire( register vm_page_t mem) { // dbgLog(current_thread(), mem->offset, mem->object, 0); /* (TEST/DEBUG) */ VM_PAGE_CHECK(mem); assert(mem->wire_count > 0); #if DEBUG if (mem->object) vm_object_lock_assert_exclusive(mem->object); _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif if (--mem->wire_count == 0) { assert(!mem->private && !mem->fictitious); vm_page_wire_count--; assert(!mem->laundry); assert(mem->object != kernel_object); assert(mem->pageq.next == NULL && mem->pageq.prev == NULL); if (mem->object->purgable == VM_PURGABLE_EMPTY) { vm_page_deactivate(mem); } else { vm_page_activate(mem); } #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail >= (kern_memorystatus_level + 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif } } /* * vm_page_deactivate: * * Returns the given page to the inactive list, * indicating that no physical maps have access * to this page. [Used by the physical mapping system.] * * The page queues must be locked. */ void vm_page_deactivate( register vm_page_t m) { boolean_t rapid_age = FALSE; VM_PAGE_CHECK(m); assert(m->object != kernel_object); assert(m->phys_page != vm_page_guard_addr); // dbgLog(m->phys_page, vm_page_free_count, vm_page_wire_count, 6); /* (TEST/DEBUG) */ #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif /* * This page is no longer very interesting. If it was * interesting (active or inactive/referenced), then we * clear the reference bit and (re)enter it in the * inactive queue. Note wired pages should not have * their reference bit cleared. */ if (m->gobbled) { /* can this happen? */ assert(m->wire_count == 0); if (!m->private && !m->fictitious) vm_page_wire_count--; vm_page_gobble_count--; m->gobbled = FALSE; } if (m->private || (m->wire_count != 0)) return; if (m->active && m->deactivated == TRUE) { if (!pmap_is_referenced(m->phys_page)) rapid_age = TRUE; } if (rapid_age == FALSE && !m->fictitious && !m->absent) pmap_clear_reference(m->phys_page); m->reference = FALSE; m->deactivated = FALSE; m->no_cache = FALSE; if (!m->inactive) { VM_PAGE_QUEUES_REMOVE(m); assert(!m->laundry); assert(m->pageq.next == NULL && m->pageq.prev == NULL); if (!IP_VALID(memory_manager_default) && m->dirty && m->object->internal && (m->object->purgable == VM_PURGABLE_DENY || m->object->purgable == VM_PURGABLE_NONVOLATILE || m->object->purgable == VM_PURGABLE_VOLATILE )) { queue_enter(&vm_page_queue_throttled, m, vm_page_t, pageq); m->throttled = TRUE; vm_page_throttled_count++; } else { if (rapid_age == TRUE || (!m->fictitious && m->object->named && m->object->ref_count == 1)) { vm_page_speculate(m, FALSE); vm_page_speculative_recreated++; return; } else { if (m->zero_fill) { queue_enter(&vm_page_queue_zf, m, vm_page_t, pageq); vm_zf_queue_count++; } else { queue_enter(&vm_page_queue_inactive, m, vm_page_t, pageq); } } m->inactive = TRUE; if (!m->fictitious) { vm_page_inactive_count++; token_new_pagecount++; } } } } /* * vm_page_activate: * * Put the specified page on the active list (if appropriate). * * The page queues must be locked. */ void vm_page_activate( register vm_page_t m) { VM_PAGE_CHECK(m); #ifdef FIXME_4778297 assert(m->object != kernel_object); #endif assert(m->phys_page != vm_page_guard_addr); #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif if (m->gobbled) { assert(m->wire_count == 0); if (!m->private && !m->fictitious) vm_page_wire_count--; vm_page_gobble_count--; m->gobbled = FALSE; } if (m->private) return; #if DEBUG if (m->active) panic("vm_page_activate: already active"); #endif if (m->speculative) { DTRACE_VM2(pgrec, int, 1, (uint64_t *), NULL); DTRACE_VM2(pgfrec, int, 1, (uint64_t *), NULL); } VM_PAGE_QUEUES_REMOVE(m); if (m->wire_count == 0) { assert(!m->laundry); assert(m->pageq.next == NULL && m->pageq.prev == NULL); if (!IP_VALID(memory_manager_default) && !m->fictitious && m->dirty && m->object->internal && (m->object->purgable == VM_PURGABLE_DENY || m->object->purgable == VM_PURGABLE_NONVOLATILE || m->object->purgable == VM_PURGABLE_VOLATILE )) { queue_enter(&vm_page_queue_throttled, m, vm_page_t, pageq); m->throttled = TRUE; vm_page_throttled_count++; } else { queue_enter(&vm_page_queue_active, m, vm_page_t, pageq); m->active = TRUE; if (!m->fictitious) vm_page_active_count++; } m->reference = TRUE; m->no_cache = FALSE; } } /* * vm_page_speculate: * * Put the specified page on the speculative list (if appropriate). * * The page queues must be locked. */ void vm_page_speculate( vm_page_t m, boolean_t new) { struct vm_speculative_age_q *aq; VM_PAGE_CHECK(m); assert(m->object != kernel_object); assert(!m->speculative && !m->active && !m->inactive && !m->throttled); assert(m->phys_page != vm_page_guard_addr); assert(m->pageq.next == NULL && m->pageq.prev == NULL); #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif if (m->wire_count == 0) { mach_timespec_t ts; clock_get_system_nanotime(&ts.tv_sec, (unsigned *)&ts.tv_nsec); if (vm_page_speculative_count == 0) { speculative_age_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q; speculative_steal_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q; aq = &vm_page_queue_speculative[speculative_age_index]; /* * set the timer to begin a new group */ aq->age_ts.tv_sec = VM_PAGE_SPECULATIVE_Q_AGE_MS / 1000; aq->age_ts.tv_nsec = (VM_PAGE_SPECULATIVE_Q_AGE_MS % 1000) * 1000 * NSEC_PER_USEC; ADD_MACH_TIMESPEC(&aq->age_ts, &ts); } else { aq = &vm_page_queue_speculative[speculative_age_index]; if (CMP_MACH_TIMESPEC(&ts, &aq->age_ts) >= 0) { speculative_age_index++; if (speculative_age_index > VM_PAGE_MAX_SPECULATIVE_AGE_Q) speculative_age_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q; if (speculative_age_index == speculative_steal_index) { speculative_steal_index = speculative_age_index + 1; if (speculative_steal_index > VM_PAGE_MAX_SPECULATIVE_AGE_Q) speculative_steal_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q; } aq = &vm_page_queue_speculative[speculative_age_index]; if (!queue_empty(&aq->age_q)) vm_page_speculate_ageit(aq); aq->age_ts.tv_sec = VM_PAGE_SPECULATIVE_Q_AGE_MS / 1000; aq->age_ts.tv_nsec = (VM_PAGE_SPECULATIVE_Q_AGE_MS % 1000) * 1000 * NSEC_PER_USEC; ADD_MACH_TIMESPEC(&aq->age_ts, &ts); } } enqueue_tail(&aq->age_q, &m->pageq); m->speculative = TRUE; vm_page_speculative_count++; if (new == TRUE) { m->object->pages_created++; vm_page_speculative_created++; } } } /* * move pages from the specified aging bin to * the speculative bin that pageout_scan claims from * * The page queues must be locked. */ void vm_page_speculate_ageit(struct vm_speculative_age_q *aq) { struct vm_speculative_age_q *sq; vm_page_t t; sq = &vm_page_queue_speculative[VM_PAGE_SPECULATIVE_AGED_Q]; if (queue_empty(&sq->age_q)) { sq->age_q.next = aq->age_q.next; sq->age_q.prev = aq->age_q.prev; t = (vm_page_t)sq->age_q.next; t->pageq.prev = &sq->age_q; t = (vm_page_t)sq->age_q.prev; t->pageq.next = &sq->age_q; } else { t = (vm_page_t)sq->age_q.prev; t->pageq.next = aq->age_q.next; t = (vm_page_t)aq->age_q.next; t->pageq.prev = sq->age_q.prev; t = (vm_page_t)aq->age_q.prev; t->pageq.next = &sq->age_q; sq->age_q.prev = aq->age_q.prev; } queue_init(&aq->age_q); } void vm_page_lru( vm_page_t m) { VM_PAGE_CHECK(m); assert(m->object != kernel_object); assert(m->phys_page != vm_page_guard_addr); #if DEBUG _mutex_assert(&vm_page_queue_lock, MA_OWNED); #endif if (m->active || m->reference) return; if (m->private || (m->wire_count != 0)) return; m->no_cache = FALSE; VM_PAGE_QUEUES_REMOVE(m); assert(!m->laundry); assert(m->pageq.next == NULL && m->pageq.prev == NULL); queue_enter(&vm_page_queue_inactive, m, vm_page_t, pageq); m->inactive = TRUE; vm_page_inactive_count++; token_new_pagecount++; } /* * vm_page_part_zero_fill: * * Zero-fill a part of the page. */ void vm_page_part_zero_fill( vm_page_t m, vm_offset_t m_pa, vm_size_t len) { vm_page_t tmp; VM_PAGE_CHECK(m); #ifdef PMAP_ZERO_PART_PAGE_IMPLEMENTED pmap_zero_part_page(m->phys_page, m_pa, len); #else while (1) { tmp = vm_page_grab(); if (tmp == VM_PAGE_NULL) { vm_page_wait(THREAD_UNINT); continue; } break; } vm_page_zero_fill(tmp); if(m_pa != 0) { vm_page_part_copy(m, 0, tmp, 0, m_pa); } if((m_pa + len) < PAGE_SIZE) { vm_page_part_copy(m, m_pa + len, tmp, m_pa + len, PAGE_SIZE - (m_pa + len)); } vm_page_copy(tmp,m); vm_page_lock_queues(); vm_page_free(tmp); vm_page_unlock_queues(); #endif } /* * vm_page_zero_fill: * * Zero-fill the specified page. */ void vm_page_zero_fill( vm_page_t m) { XPR(XPR_VM_PAGE, "vm_page_zero_fill, object 0x%X offset 0x%X page 0x%X\n", (integer_t)m->object, (integer_t)m->offset, (integer_t)m, 0,0); VM_PAGE_CHECK(m); // dbgTrace(0xAEAEAEAE, m->phys_page, 0); /* (BRINGUP) */ pmap_zero_page(m->phys_page); } /* * vm_page_part_copy: * * copy part of one page to another */ void vm_page_part_copy( vm_page_t src_m, vm_offset_t src_pa, vm_page_t dst_m, vm_offset_t dst_pa, vm_size_t len) { VM_PAGE_CHECK(src_m); VM_PAGE_CHECK(dst_m); pmap_copy_part_page(src_m->phys_page, src_pa, dst_m->phys_page, dst_pa, len); } /* * vm_page_copy: * * Copy one page to another * * ENCRYPTED SWAP: * The source page should not be encrypted. The caller should * make sure the page is decrypted first, if necessary. */ int vm_page_copy_cs_validations = 0; int vm_page_copy_cs_tainted = 0; void vm_page_copy( vm_page_t src_m, vm_page_t dest_m) { XPR(XPR_VM_PAGE, "vm_page_copy, object 0x%X offset 0x%X to object 0x%X offset 0x%X\n", (integer_t)src_m->object, src_m->offset, (integer_t)dest_m->object, dest_m->offset, 0); VM_PAGE_CHECK(src_m); VM_PAGE_CHECK(dest_m); /* * ENCRYPTED SWAP: * The source page should not be encrypted at this point. * The destination page will therefore not contain encrypted * data after the copy. */ if (src_m->encrypted) { panic("vm_page_copy: source page %p is encrypted\n", src_m); } dest_m->encrypted = FALSE; if (src_m->object != VM_OBJECT_NULL && src_m->object->code_signed) { /* * We're copying a page from a code-signed object. * Whoever ends up mapping the copy page might care about * the original page's integrity, so let's validate the * source page now. */ vm_page_copy_cs_validations++; vm_page_validate_cs(src_m); } /* * Propagate the code-signing bits to the copy page. */ dest_m->cs_validated = src_m->cs_validated; dest_m->cs_tainted = src_m->cs_tainted; if (dest_m->cs_tainted) { assert(dest_m->cs_validated); vm_page_copy_cs_tainted++; } pmap_copy_page(src_m->phys_page, dest_m->phys_page); } #if MACH_ASSERT /* * Check that the list of pages is ordered by * ascending physical address and has no holes. */ static int vm_page_verify_contiguous( vm_page_t pages, unsigned int npages) { register vm_page_t m; unsigned int page_count; vm_offset_t prev_addr; prev_addr = pages->phys_page; page_count = 1; for (m = NEXT_PAGE(pages); m != VM_PAGE_NULL; m = NEXT_PAGE(m)) { if (m->phys_page != prev_addr + 1) { printf("m %p prev_addr 0x%x, current addr 0x%x\n", m, prev_addr, m->phys_page); printf("pages %p page_count %d\n", pages, page_count); panic("vm_page_verify_contiguous: not contiguous!"); } prev_addr = m->phys_page; ++page_count; } if (page_count != npages) { printf("pages %p actual count 0x%x but requested 0x%x\n", pages, page_count, npages); panic("vm_page_verify_contiguous: count error"); } return 1; } #endif /* MACH_ASSERT */ #if MACH_ASSERT /* * Check the free lists for proper length etc. */ static void vm_page_verify_free_lists( void ) { unsigned int color, npages; vm_page_t m; vm_page_t prev_m; npages = 0; mutex_lock(&vm_page_queue_free_lock); for( color = 0; color < vm_colors; color++ ) { prev_m = (vm_page_t) &vm_page_queue_free[color]; queue_iterate(&vm_page_queue_free[color], m, vm_page_t, pageq) { if ((vm_page_t) m->pageq.prev != prev_m) panic("vm_page_verify_free_lists: corrupted prev ptr"); if ( ! m->free ) panic("vm_page_verify_free_lists: not free"); if ( ! m->busy ) panic("vm_page_verify_free_lists: not busy"); if ( (m->phys_page & vm_color_mask) != color) panic("vm_page_verify_free_lists: wrong color"); ++npages; prev_m = m; } } if (npages != vm_page_free_count) panic("vm_page_verify_free_lists: npages %u free_count %d", npages, vm_page_free_count); mutex_unlock(&vm_page_queue_free_lock); } #endif /* MACH_ASSERT */ /* * CONTIGUOUS PAGE ALLOCATION * Additional levels of effort: * + consider pages that are currently 'pmapped' * this could be expensive since we'd have * to ask the pmap layer about there state * + consider dirty pages * either clean them or * copy them to other locations... * * Find a region large enough to contain at least n pages * of contiguous physical memory. * * This is done by traversing the vm_page_t array in a linear fashion * we assume that the vm_page_t array has the avaiable physical pages in an * ordered, ascending list... this is currently true of all our implementations * and must remain so... there can be 'holes' in the array... we also can * no longer tolerate the vm_page_t's in the list being 'freed' and reclaimed * which use to happen via 'vm_page_convert'... that function was no longer * being called and was removed... * * The basic flow consists of stabilizing some of the interesting state of * a vm_page_t behind the vm_page_queue and vm_page_free locks... we start our * sweep at the beginning of the array looking for pages that meet our criterea * for a 'stealable' page... currently we are pretty conservative... if the page * meets this criterea and is physically contiguous to the previous page in the 'run' * we keep developing it. If we hit a page that doesn't fit, we reset our state * and start to develop a new run... if at this point we've already considered * at least MAX_CONSIDERED_BEFORE_YIELD pages, we'll drop the 2 locks we hold, * and mutex_pause (which will yield the processor), to keep the latency low w/r * to other threads trying to acquire free pages (or move pages from q to q), * and then continue from the spot we left off... we only make 1 pass through the * array. Once we have a 'run' that is long enough, we'll go into the loop which * which steals the pages from the queues they're currently on... pages on the free * queue can be stolen directly... pages that are on any of the other queues * must be removed from the object they are tabled on... this requires taking the * object lock... we do this as a 'try' to prevent deadlocks... if the 'try' fails * or if the state of the page behind the vm_object lock is no longer viable, we'll * dump the pages we've currently stolen back to the free list, and pick up our * scan from the point where we aborted the 'current' run. * * * Requirements: * - neither vm_page_queue nor vm_free_list lock can be held on entry * * Returns a pointer to a list of gobbled/wired pages or VM_PAGE_NULL. * * Algorithm: */ #define MAX_CONSIDERED_BEFORE_YIELD 1000 #define RESET_STATE_OF_RUN() \ MACRO_BEGIN \ prevcontaddr = -2; \ free_considered = 0; \ substitute_needed = 0; \ npages = 0; \ MACRO_END static vm_page_t vm_page_find_contiguous( unsigned int contig_pages, ppnum_t max_pnum, boolean_t wire) { vm_page_t m = NULL; ppnum_t prevcontaddr; unsigned int npages, considered; unsigned int page_idx, start_idx; int free_considered, free_available; int substitute_needed; #if DEBUG uint32_t tv_start_sec, tv_start_usec, tv_end_sec, tv_end_usec; #endif #if MACH_ASSERT int yielded = 0; int dumped_run = 0; int stolen_pages = 0; #endif if (contig_pages == 0) return VM_PAGE_NULL; #if MACH_ASSERT vm_page_verify_free_lists(); #endif #if DEBUG clock_get_system_microtime(&tv_start_sec, &tv_start_usec); #endif vm_page_lock_queues(); mutex_lock(&vm_page_queue_free_lock); RESET_STATE_OF_RUN(); considered = 0; free_available = vm_page_free_count - vm_page_free_reserved; for (page_idx = 0, start_idx = 0; npages < contig_pages && page_idx < vm_pages_count; page_idx++) { retry: m = &vm_pages[page_idx]; if (max_pnum && m->phys_page > max_pnum) { /* no more low pages... */ break; } if (m->phys_page <= vm_lopage_poolend && m->phys_page >= vm_lopage_poolstart) { /* * don't want to take pages from our * reserved pool of low memory * so don't consider it which * means starting a new run */ RESET_STATE_OF_RUN(); } else if (m->wire_count || m->gobbled || m->encrypted || m->encrypted_cleaning || m->cs_validated || m->cs_tainted || m->error || m->absent || m->pageout_queue || m->laundry || m->wanted || m->precious || m->cleaning || m->overwriting || m->restart || m->unusual || m->list_req_pending) { /* * page is in a transient state * or a state we don't want to deal * with, so don't consider it which * means starting a new run */ RESET_STATE_OF_RUN(); } else if (!m->free && !m->active && !m->inactive && !m->speculative && !m->throttled) { /* * page needs to be on one of our queues * in order for it to be stable behind the * locks we hold at this point... * if not, don't consider it which * means starting a new run */ RESET_STATE_OF_RUN(); } else if (!m->free && (!m->tabled || m->busy)) { /* * pages on the free list are always 'busy' * so we couldn't test for 'busy' in the check * for the transient states... pages that are * 'free' are never 'tabled', so we also couldn't * test for 'tabled'. So we check here to make * sure that a non-free page is not busy and is * tabled on an object... * if not, don't consider it which * means starting a new run */ RESET_STATE_OF_RUN(); } else { if (m->phys_page != prevcontaddr + 1) { npages = 1; start_idx = page_idx; } else { npages++; } prevcontaddr = m->phys_page; if (m->pmapped || m->dirty) substitute_needed++; if (m->free) { free_considered++; } if ((free_considered + substitute_needed) > free_available) { /* * if we let this run continue * we will end up dropping the vm_page_free_count * below the reserve limit... we need to abort * this run, but we can at least re-consider this * page... thus the jump back to 'retry' */ RESET_STATE_OF_RUN(); if (free_available && considered <= MAX_CONSIDERED_BEFORE_YIELD) { considered++; goto retry; } /* * free_available == 0 * so can't consider any free pages... if * we went to retry in this case, we'd * get stuck looking at the same page * w/o making any forward progress * we also want to take this path if we've already * reached our limit that controls the lock latency */ } } if (considered > MAX_CONSIDERED_BEFORE_YIELD && npages <= 1) { mutex_unlock(&vm_page_queue_free_lock); vm_page_unlock_queues(); mutex_pause(0); vm_page_lock_queues(); mutex_lock(&vm_page_queue_free_lock); RESET_STATE_OF_RUN(); /* * reset our free page limit since we * dropped the lock protecting the vm_page_free_queue */ free_available = vm_page_free_count - vm_page_free_reserved; considered = 0; #if MACH_ASSERT yielded++; #endif goto retry; } considered++; } m = VM_PAGE_NULL; if (npages != contig_pages) mutex_unlock(&vm_page_queue_free_lock); else { vm_page_t m1; vm_page_t m2; unsigned int cur_idx; unsigned int tmp_start_idx; vm_object_t locked_object = VM_OBJECT_NULL; boolean_t abort_run = FALSE; tmp_start_idx = start_idx; /* * first pass through to pull the free pages * off of the free queue so that in case we * need substitute pages, we won't grab any * of the free pages in the run... we'll clear * the 'free' bit in the 2nd pass, and even in * an abort_run case, we'll collect all of the * free pages in this run and return them to the free list */ while (start_idx < page_idx) { m1 = &vm_pages[start_idx++]; if (m1->free) { unsigned int color; color = m1->phys_page & vm_color_mask; queue_remove(&vm_page_queue_free[color], m1, vm_page_t, pageq); vm_page_free_count--; } } /* * adjust global freelist counts */ if (vm_page_free_count < vm_page_free_count_minimum) vm_page_free_count_minimum = vm_page_free_count; /* * we can drop the free queue lock at this point since * we've pulled any 'free' candidates off of the list * we need it dropped so that we can do a vm_page_grab * when substituing for pmapped/dirty pages */ mutex_unlock(&vm_page_queue_free_lock); start_idx = tmp_start_idx; cur_idx = page_idx - 1; while (start_idx++ < page_idx) { /* * must go through the list from back to front * so that the page list is created in the * correct order - low -> high phys addresses */ m1 = &vm_pages[cur_idx--]; if (m1->free) { /* * pages have already been removed from * the free list in the 1st pass */ assert(m1->free); assert(m1->busy); assert(!m1->wanted); assert(!m1->laundry); m1->free = FALSE; } else { vm_object_t object; if (abort_run == TRUE) continue; object = m1->object; if (object != locked_object) { if (locked_object) { vm_object_unlock(locked_object); locked_object = VM_OBJECT_NULL; } if (vm_object_lock_try(object)) locked_object = object; } if (locked_object == VM_OBJECT_NULL || (m1->wire_count || m1->gobbled || m1->encrypted || m1->encrypted_cleaning || m1->cs_validated || m1->cs_tainted || m1->error || m1->absent || m1->pageout_queue || m1->laundry || m1->wanted || m1->precious || m1->cleaning || m1->overwriting || m1->restart || m1->unusual || m1->list_req_pending || m1->busy)) { if (locked_object) { vm_object_unlock(locked_object); locked_object = VM_OBJECT_NULL; } tmp_start_idx = cur_idx; abort_run = TRUE; continue; } if (m1->pmapped || m1->dirty) { int refmod; vm_object_offset_t offset; m2 = vm_page_grab(); if (m2 == VM_PAGE_NULL) { if (locked_object) { vm_object_unlock(locked_object); locked_object = VM_OBJECT_NULL; } tmp_start_idx = cur_idx; abort_run = TRUE; continue; } if (m1->pmapped) refmod = pmap_disconnect(m1->phys_page); else refmod = 0; vm_page_copy(m1, m2); m2->reference = m1->reference; m2->dirty = m1->dirty; if (refmod & VM_MEM_REFERENCED) m2->reference = TRUE; if (refmod & VM_MEM_MODIFIED) m2->dirty = TRUE; offset = m1->offset; /* * completely cleans up the state * of the page so that it is ready * to be put onto the free list, or * for this purpose it looks like it * just came off of the free list */ vm_page_free_prepare(m1); /* * make sure we clear the ref/mod state * from the pmap layer... else we risk * inheriting state from the last time * this page was used... */ pmap_clear_refmod(m2->phys_page, VM_MEM_MODIFIED | VM_MEM_REFERENCED); /* * now put the substitute page on the object */ vm_page_insert_internal(m2, locked_object, offset, TRUE); if (m2->reference) vm_page_activate(m2); else vm_page_deactivate(m2); PAGE_WAKEUP_DONE(m2); } else { /* * completely cleans up the state * of the page so that it is ready * to be put onto the free list, or * for this purpose it looks like it * just came off of the free list */ vm_page_free_prepare(m1); } #if MACH_ASSERT stolen_pages++; #endif } m1->pageq.next = (queue_entry_t) m; m1->pageq.prev = NULL; m = m1; } if (locked_object) { vm_object_unlock(locked_object); locked_object = VM_OBJECT_NULL; } if (abort_run == TRUE) { if (m != VM_PAGE_NULL) { vm_page_free_list(m); } #if MACH_ASSERT dumped_run++; #endif /* * want the index of the last * page in this run that was * successfully 'stolen', so back * it up 1 for the auto-decrement on use * and 1 more to bump back over this page */ page_idx = tmp_start_idx + 2; if (page_idx >= vm_pages_count) goto done_scanning; mutex_lock(&vm_page_queue_free_lock); RESET_STATE_OF_RUN(); /* * reset our free page limit since we * dropped the lock protecting the vm_page_free_queue */ free_available = vm_page_free_count - vm_page_free_reserved; goto retry; } for (m1 = m; m1 != VM_PAGE_NULL; m1 = NEXT_PAGE(m1)) { if (wire == TRUE) m1->wire_count++; else m1->gobbled = TRUE; } if (wire == FALSE) vm_page_gobble_count += npages; /* * gobbled pages are also counted as wired pages */ vm_page_wire_count += npages; assert(vm_page_verify_contiguous(m, npages)); } done_scanning: vm_page_unlock_queues(); #if DEBUG clock_get_system_microtime(&tv_end_sec, &tv_end_usec); tv_end_sec -= tv_start_sec; if (tv_end_usec < tv_start_usec) { tv_end_sec--; tv_end_usec += 1000000; } tv_end_usec -= tv_start_usec; if (tv_end_usec >= 1000000) { tv_end_sec++; tv_end_sec -= 1000000; } printf("vm_find_page_contiguous(num=%d,low=%d): found %d pages in %d.%06ds... scanned %d pages... yielded %d times... dumped run %d times... stole %d pages\n", contig_pages, max_pnum, npages, tv_end_sec, tv_end_usec, page_idx, yielded, dumped_run, stolen_pages); #endif #if MACH_ASSERT vm_page_verify_free_lists(); #endif return m; } /* * Allocate a list of contiguous, wired pages. */ kern_return_t cpm_allocate( vm_size_t size, vm_page_t *list, ppnum_t max_pnum, boolean_t wire) { vm_page_t pages; unsigned int npages; if (size % page_size != 0) return KERN_INVALID_ARGUMENT; npages = size / page_size; /* * Obtain a pointer to a subset of the free * list large enough to satisfy the request; * the region will be physically contiguous. */ pages = vm_page_find_contiguous(npages, max_pnum, wire); if (pages == VM_PAGE_NULL) return KERN_NO_SPACE; /* * determine need for wakeups */ if ((vm_page_free_count < vm_page_free_min) || ((vm_page_free_count < vm_page_free_target) && ((vm_page_inactive_count + vm_page_speculative_count) < vm_page_inactive_min))) thread_wakeup((event_t) &vm_page_free_wanted); #if CONFIG_EMBEDDED { int percent_avail; /* * Decide if we need to poke the memorystatus notification thread. */ percent_avail = (vm_page_active_count + vm_page_inactive_count + vm_page_speculative_count + vm_page_free_count + (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 / atop_64(max_mem); if (percent_avail <= (kern_memorystatus_level - 5)) { kern_memorystatus_level = percent_avail; thread_wakeup((event_t)&kern_memorystatus_wakeup); } } #endif /* * The CPM pages should now be available and * ordered by ascending physical address. */ assert(vm_page_verify_contiguous(pages, npages)); *list = pages; return KERN_SUCCESS; } #include #if MACH_VM_DEBUG #include #include /* * Routine: vm_page_info * Purpose: * Return information about the global VP table. * Fills the buffer with as much information as possible * and returns the desired size of the buffer. * Conditions: * Nothing locked. The caller should provide * possibly-pageable memory. */ unsigned int vm_page_info( hash_info_bucket_t *info, unsigned int count) { unsigned int i; if (vm_page_bucket_count < count) count = vm_page_bucket_count; for (i = 0; i < count; i++) { vm_page_bucket_t *bucket = &vm_page_buckets[i]; unsigned int bucket_count = 0; vm_page_t m; simple_lock(&vm_page_bucket_lock); for (m = bucket->pages; m != VM_PAGE_NULL; m = m->next) bucket_count++; simple_unlock(&vm_page_bucket_lock); /* don't touch pageable memory while holding locks */ info[i].hib_count = bucket_count; } return vm_page_bucket_count; } #endif /* MACH_VM_DEBUG */ #include #if MACH_KDB #include #include #define printf kdbprintf /* * Routine: vm_page_print [exported] */ void vm_page_print( db_addr_t db_addr) { vm_page_t p; p = (vm_page_t) (long) db_addr; iprintf("page 0x%x\n", p); db_indent += 2; iprintf("object=0x%x", p->object); printf(", offset=0x%x", p->offset); printf(", wire_count=%d", p->wire_count); iprintf("%sinactive, %sactive, %sthrottled, %sgobbled, %slaundry, %sfree, %sref, %sencrypted\n", (p->inactive ? "" : "!"), (p->active ? "" : "!"), (p->throttled ? "" : "!"), (p->gobbled ? "" : "!"), (p->laundry ? "" : "!"), (p->free ? "" : "!"), (p->reference ? "" : "!"), (p->encrypted ? "" : "!")); iprintf("%sbusy, %swanted, %stabled, %sfictitious, %sprivate, %sprecious\n", (p->busy ? "" : "!"), (p->wanted ? "" : "!"), (p->tabled ? "" : "!"), (p->fictitious ? "" : "!"), (p->private ? "" : "!"), (p->precious ? "" : "!")); iprintf("%sabsent, %serror, %sdirty, %scleaning, %spageout, %sclustered\n", (p->absent ? "" : "!"), (p->error ? "" : "!"), (p->dirty ? "" : "!"), (p->cleaning ? "" : "!"), (p->pageout ? "" : "!"), (p->clustered ? "" : "!")); iprintf("%soverwriting, %srestart, %sunusual\n", (p->overwriting ? "" : "!"), (p->restart ? "" : "!"), (p->unusual ? "" : "!")); iprintf("phys_page=0x%x", p->phys_page); db_indent -= 2; } #endif /* MACH_KDB */