xnu-1228.9.59.tar.gz

[apple/xnu.git] / osfmk / vm / vm_resident.c

/*
 * 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,
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 * 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 <debug.h>
#include <libkern/OSAtomic.h>

#include <mach/clock_types.h>
#include <mach/vm_prot.h>
#include <mach/vm_statistics.h>
#include <mach/sdt.h>
#include <kern/counters.h>
#include <kern/sched_prim.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/zalloc.h>
#include <kern/xpr.h>
#include <vm/pmap.h>
#include <vm/vm_init.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>			/* kernel_memory_allocate() */
#include <kern/misc_protos.h>
#include <zone_debug.h>
#include <vm/cpm.h>
#include <ppc/mappings.h>		/* (BRINGUP) */
#include <pexpert/pexpert.h>	/* (BRINGUP) */

#include <vm/vm_protos.h>
#include <vm/memory_object.h>
#include <vm/vm_purgeable_internal.h>

#if CONFIG_EMBEDDED
#include <sys/kern_memorystatus.h>
#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 <pager,paging_offset> 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 <mach_vm_debug.h>
#if	MACH_VM_DEBUG

#include <mach_debug/hash_info.h>
#include <vm/vm_debug.h>

/*
 *	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 <mach_kdb.h>
#if	MACH_KDB

#include <ddb/db_output.h>
#include <vm/vm_print.h>
#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 */