freebsd-dev/sys/vm/vm_page.h
Konstantin Belousov 2042bb377a Fix grammar.
Submitted by:	bf
MFC after:	2 weeks
2011-09-28 16:12:15 +00:00

457 lines
16 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
/*
* Resident memory system definitions.
*/
#ifndef _VM_PAGE_
#define _VM_PAGE_
#include <vm/pmap.h>
/*
* Management of resident (logical) pages.
*
* A small structure is kept for each resident
* page, indexed by page number. Each structure
* is an element of several lists:
*
* A hash table bucket used to quickly
* perform object/offset lookups
*
* A list of all pages for a given object,
* so they can be quickly deactivated at
* time of deallocation.
*
* An ordered list of pages due for pageout.
*
* In addition, the structure contains the object
* and offset to which this page belongs (for pageout),
* and sundry status bits.
*
* In general, operations on this structure's mutable fields are
* synchronized using either one of or a combination of the lock on the
* object that the page belongs to (O), the pool lock for the page (P),
* or the lock for either the free or paging queues (Q). If a field is
* annotated below with two of these locks, then holding either lock is
* sufficient for read access, but both locks are required for write
* access.
*
* In contrast, the synchronization of accesses to the page's
* dirty field is machine dependent (M). In the
* machine-independent layer, the lock on the object that the
* page belongs to must be held in order to operate on the field.
* However, the pmap layer is permitted to set all bits within
* the field without holding that lock. If the underlying
* architecture does not support atomic read-modify-write
* operations on the field's type, then the machine-independent
* layer uses a 32-bit atomic on the aligned 32-bit word that
* contains the dirty field. In the machine-independent layer,
* the implementation of read-modify-write operations on the
* field is encapsulated in vm_page_clear_dirty_mask().
*/
TAILQ_HEAD(pglist, vm_page);
struct vm_page {
TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (Q) */
TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
struct vm_page *left; /* splay tree link (O) */
struct vm_page *right; /* splay tree link (O) */
vm_object_t object; /* which object am I in (O,P)*/
vm_pindex_t pindex; /* offset into object (O,P) */
vm_paddr_t phys_addr; /* physical address of page */
struct md_page md; /* machine dependant stuff */
uint8_t queue; /* page queue index (P,Q) */
int8_t segind;
short hold_count; /* page hold count (P) */
uint8_t order; /* index of the buddy queue */
uint8_t pool;
u_short cow; /* page cow mapping count (P) */
u_int wire_count; /* wired down maps refs (P) */
uint8_t aflags; /* access is atomic */
uint8_t flags; /* see below, often immutable after alloc */
u_short oflags; /* page flags (O) */
u_char act_count; /* page usage count (O) */
u_char busy; /* page busy count (O) */
/* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
/* so, on normal X86 kernels, they must be at least 8 bits wide */
/* In reality, support for 32KB pages is not fully implemented. */
#if PAGE_SIZE == 4096
uint8_t valid; /* map of valid DEV_BSIZE chunks (O) */
uint8_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
#elif PAGE_SIZE == 8192
uint16_t valid; /* map of valid DEV_BSIZE chunks (O) */
uint16_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
#elif PAGE_SIZE == 16384
uint32_t valid; /* map of valid DEV_BSIZE chunks (O) */
uint32_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
#elif PAGE_SIZE == 32768
uint64_t valid; /* map of valid DEV_BSIZE chunks (O) */
uint64_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
#endif
};
/*
* Page flags stored in oflags:
*
* Access to these page flags is synchronized by the lock on the object
* containing the page (O).
*
* Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
* indicates that the page is not under PV management but
* otherwise should be treated as a normal page. Pages not
* under PV management cannot be paged out via the
* object/vm_page_t because there is no knowledge of their pte
* mappings, and such pages are also not on any PQ queue.
*
*/
#define VPO_BUSY 0x0001 /* page is in transit */
#define VPO_WANTED 0x0002 /* someone is waiting for page */
#define VPO_UNMANAGED 0x0004 /* No PV management for page */
#define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */
#define VPO_NOSYNC 0x0400 /* do not collect for syncer */
#define PQ_NONE 255
#define PQ_INACTIVE 0
#define PQ_ACTIVE 1
#define PQ_HOLD 2
#define PQ_COUNT 3
struct vpgqueues {
struct pglist pl;
int *cnt;
};
extern struct vpgqueues vm_page_queues[PQ_COUNT];
struct vpglocks {
struct mtx data;
char pad[CACHE_LINE_SIZE - sizeof(struct mtx)];
} __aligned(CACHE_LINE_SIZE);
extern struct vpglocks vm_page_queue_free_lock;
extern struct vpglocks pa_lock[];
#if defined(__arm__)
#define PDRSHIFT PDR_SHIFT
#elif !defined(PDRSHIFT)
#define PDRSHIFT 21
#endif
#define pa_index(pa) ((pa) >> PDRSHIFT)
#define PA_LOCKPTR(pa) &pa_lock[pa_index((pa)) % PA_LOCK_COUNT].data
#define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
#define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
#define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
#define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
#define PA_UNLOCK_COND(pa) \
do { \
if ((pa) != 0) { \
PA_UNLOCK((pa)); \
(pa) = 0; \
} \
} while (0)
#define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
#define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
#define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
#define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
#define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
#define vm_page_lock_assert(m, a) mtx_assert(vm_page_lockptr((m)), (a))
#define vm_page_queue_free_mtx vm_page_queue_free_lock.data
/*
* These are the flags defined for vm_page.
*
* aflags are updated by atomic accesses. Use the vm_page_aflag_set()
* and vm_page_aflag_clear() functions to set and clear the flags.
*
* PGA_REFERENCED may be cleared only if the object containing the page is
* locked.
*
* PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it
* does so, the page must be VPO_BUSY.
*/
#define PGA_WRITEABLE 0x01 /* page may be mapped writeable */
#define PGA_REFERENCED 0x02 /* page has been referenced */
/*
* Page flags. If changed at any other time than page allocation or
* freeing, the modification must be protected by the vm_page lock.
*/
#define PG_CACHED 0x01 /* page is cached */
#define PG_FREE 0x02 /* page is free */
#define PG_FICTITIOUS 0x04 /* physical page doesn't exist (O) */
#define PG_ZERO 0x08 /* page is zeroed */
#define PG_MARKER 0x10 /* special queue marker page */
#define PG_SLAB 0x20 /* object pointer is actually a slab */
#define PG_WINATCFLS 0x40 /* flush dirty page on inactive q */
/*
* Misc constants.
*/
#define ACT_DECLINE 1
#define ACT_ADVANCE 3
#define ACT_INIT 5
#define ACT_MAX 64
#ifdef _KERNEL
#include <vm/vm_param.h>
/*
* Each pageable resident page falls into one of five lists:
*
* free
* Available for allocation now.
*
* cache
* Almost available for allocation. Still associated with
* an object, but clean and immediately freeable.
*
* hold
* Will become free after a pending I/O operation
* completes.
*
* The following lists are LRU sorted:
*
* inactive
* Low activity, candidates for reclamation.
* This is the list of pages that should be
* paged out next.
*
* active
* Pages that are "active" i.e. they have been
* recently referenced.
*
*/
struct vnode;
extern int vm_page_zero_count;
extern vm_page_t vm_page_array; /* First resident page in table */
extern int vm_page_array_size; /* number of vm_page_t's */
extern long first_page; /* first physical page number */
#define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0)
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa);
static __inline vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
static __inline vm_page_t
PHYS_TO_VM_PAGE(vm_paddr_t pa)
{
#ifdef VM_PHYSSEG_SPARSE
return (vm_phys_paddr_to_vm_page(pa));
#elif defined(VM_PHYSSEG_DENSE)
return (&vm_page_array[atop(pa) - first_page]);
#else
#error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
#endif
}
extern struct vpglocks vm_page_queue_lock;
#define vm_page_queue_mtx vm_page_queue_lock.data
#define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx)
#define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx)
#if PAGE_SIZE == 4096
#define VM_PAGE_BITS_ALL 0xffu
#elif PAGE_SIZE == 8192
#define VM_PAGE_BITS_ALL 0xffffu
#elif PAGE_SIZE == 16384
#define VM_PAGE_BITS_ALL 0xffffffffu
#elif PAGE_SIZE == 32768
#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
#endif
/* page allocation classes: */
#define VM_ALLOC_NORMAL 0
#define VM_ALLOC_INTERRUPT 1
#define VM_ALLOC_SYSTEM 2
#define VM_ALLOC_CLASS_MASK 3
/* page allocation flags: */
#define VM_ALLOC_WIRED 0x0020 /* non pageable */
#define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
#define VM_ALLOC_RETRY 0x0080 /* Mandatory with vm_page_grab() */
#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
#define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
#define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
#define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */
#define VM_ALLOC_COUNT_SHIFT 16
#define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
void vm_page_aflag_set(vm_page_t m, uint8_t bits);
void vm_page_aflag_clear(vm_page_t m, uint8_t bits);
void vm_page_busy(vm_page_t m);
void vm_page_flash(vm_page_t m);
void vm_page_io_start(vm_page_t m);
void vm_page_io_finish(vm_page_t m);
void vm_page_hold(vm_page_t mem);
void vm_page_unhold(vm_page_t mem);
void vm_page_free(vm_page_t m);
void vm_page_free_zero(vm_page_t m);
void vm_page_dirty(vm_page_t m);
void vm_page_wakeup(vm_page_t m);
void vm_pageq_remove(vm_page_t m);
void vm_page_activate (vm_page_t);
vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
vm_page_t vm_page_alloc_freelist(int, int);
struct vnode *vm_page_alloc_init(vm_page_t);
vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
void vm_page_cache(vm_page_t);
void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
void vm_page_cache_remove(vm_page_t);
void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
int vm_page_try_to_cache (vm_page_t);
int vm_page_try_to_free (vm_page_t);
void vm_page_dontneed(vm_page_t);
void vm_page_deactivate (vm_page_t);
vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
vm_page_t vm_page_next(vm_page_t m);
int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *);
vm_page_t vm_page_prev(vm_page_t m);
void vm_page_putfake(vm_page_t m);
void vm_page_reference(vm_page_t m);
void vm_page_remove (vm_page_t);
void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
void vm_page_requeue(vm_page_t m);
void vm_page_set_valid(vm_page_t m, int base, int size);
void vm_page_sleep(vm_page_t m, const char *msg);
vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
vm_offset_t vm_page_startup(vm_offset_t vaddr);
void vm_page_unhold_pages(vm_page_t *ma, int count);
void vm_page_unwire (vm_page_t, int);
void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_wire (vm_page_t);
void vm_page_set_validclean (vm_page_t, int, int);
void vm_page_clear_dirty (vm_page_t, int, int);
void vm_page_set_invalid (vm_page_t, int, int);
int vm_page_is_valid (vm_page_t, int, int);
void vm_page_test_dirty (vm_page_t);
int vm_page_bits (int, int);
void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
void vm_page_free_toq(vm_page_t m);
void vm_page_zero_idle_wakeup(void);
void vm_page_cowfault (vm_page_t);
int vm_page_cowsetup(vm_page_t);
void vm_page_cowclear (vm_page_t);
#ifdef INVARIANTS
void vm_page_object_lock_assert(vm_page_t m);
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m)
#else
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
#endif
/*
* vm_page_sleep_if_busy:
*
* Sleep and release the page queues lock if VPO_BUSY is set or,
* if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the
* thread slept and the page queues lock was released.
* Otherwise, retains the page queues lock and returns FALSE.
*
* The object containing the given page must be locked.
*/
static __inline int
vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg)
{
if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) {
vm_page_sleep(m, msg);
return (TRUE);
}
return (FALSE);
}
/*
* vm_page_undirty:
*
* Set page to not be dirty. Note: does not clear pmap modify bits
*/
static __inline void
vm_page_undirty(vm_page_t m)
{
VM_PAGE_OBJECT_LOCK_ASSERT(m);
m->dirty = 0;
}
#endif /* _KERNEL */
#endif /* !_VM_PAGE_ */