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freebsd/sys/vm/vm_page.h
Alan Cox 2446e4f02c Enable the new physical memory allocator. 
This allocator uses a binary buddy system with a twist.  First and
foremost, this allocator is required to support the implementation of
superpages.  As a side effect, it enables a more robust implementation
of contigmalloc(9).  Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).

The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages.  Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space.  The performance benefits vary.  In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.

This allocator does not implement page coloring.  The reason is that
superpages have much the same effect.  The contiguous physical memory
allocation necessary for a superpage is inherently colored.

Finally, the one caveat is that this allocator does not effectively
support prezeroed pages.  I hope this is temporary.  On i386, this is
a slight pessimization.  However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects.  I speculate
that this is true in general of machines with a direct map.

Approved by:	re
2007-06-16 04:57:06 +00:00

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/*-
* 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.
*
* Fields in this structure are locked either by the lock on the
* object that the page belongs to (O) or by the lock on the page
* queues (P).
*
* The 'valid' and 'dirty' fields are distinct. A page may have dirty
* bits set without having associated valid bits set. This is used by
* NFS to implement piecemeal writes.
*/
TAILQ_HEAD(pglist, vm_page);
struct vm_page {
TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */
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 */
int8_t segind;
u_short flags; /* see below */
uint8_t order; /* index of the buddy queue */
uint8_t pool;
u_short wire_count; /* wired down maps refs (P) */
u_int cow; /* page cow mapping count */
short hold_count; /* page hold count */
u_short oflags; /* page flags (O) */
u_char act_count; /* page usage count */
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 */
#if PAGE_SIZE == 4096
u_char valid; /* map of valid DEV_BSIZE chunks (O) */
u_char dirty; /* map of dirty DEV_BSIZE chunks */
#elif PAGE_SIZE == 8192
u_short valid; /* map of valid DEV_BSIZE chunks (O) */
u_short dirty; /* map of dirty DEV_BSIZE chunks */
#elif PAGE_SIZE == 16384
u_int valid; /* map of valid DEV_BSIZE chunks (O) */
u_int dirty; /* map of dirty DEV_BSIZE chunks */
#elif PAGE_SIZE == 32768
u_long valid; /* map of valid DEV_BSIZE chunks (O) */
u_long dirty; /* map of dirty DEV_BSIZE chunks */
#endif
};
/*
* Page flags stored in oflags:
*
* Access to these page flags is synchronized by the lock on the object
* containing the page (O).
*/
#define VPO_BUSY 0x0001 /* page is in transit */
#define VPO_WANTED 0x0002 /* someone is waiting for page */
#define VPO_CLEANCHK 0x0100 /* page will be checked for cleaning */
#define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */
#define VPO_NOSYNC 0x0400 /* do not collect for syncer */
/* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
#if PAGE_SIZE == 32768
#ifdef CTASSERT
CTASSERT(sizeof(u_long) >= 8);
#endif
#endif
#define PQ_NONE 0
#define PQ_INACTIVE 1
#define PQ_ACTIVE 2
#define PQ_CACHE 3
#define PQ_HOLD 4
#define PQ_COUNT 5
#define PQ_MAXCOUNT 5
/* Returns the real queue a page is on. */
#define VM_PAGE_GETQUEUE(m) ((m)->queue)
/* Returns the well known queue a page is on. */
#define VM_PAGE_GETKNOWNQUEUE1(m) VM_PAGE_GETQUEUE(m)
#define VM_PAGE_GETKNOWNQUEUE2(m) VM_PAGE_GETQUEUE(m)
/* Given the real queue number and a page color return the well know queue. */
#define VM_PAGE_RESOLVEQUEUE(m, q) (q)
/* Returns true if the page is in the named well known queue. */
#define VM_PAGE_INQUEUE1(m, q) (VM_PAGE_GETKNOWNQUEUE1(m) == (q))
#define VM_PAGE_INQUEUE2(m, q) (VM_PAGE_GETKNOWNQUEUE2(m) == (q))
/* Sets the queue a page is on. */
#define VM_PAGE_SETQUEUE1(m, q) (VM_PAGE_GETQUEUE(m) = (q))
#define VM_PAGE_SETQUEUE2(m, q) (VM_PAGE_GETQUEUE(m) = (q))
struct vpgqueues {
struct pglist pl;
int *cnt;
};
extern struct vpgqueues vm_page_queues[PQ_MAXCOUNT];
extern struct mtx vm_page_queue_free_mtx;
/*
* These are the flags defined for vm_page.
*
* Note: PG_UNMANAGED (used by OBJT_PHYS) 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, nor can they be removed from their objects via
* the object, and such pages are also not on any PQ queue.
*/
#define PG_FREE 0x0002 /* page is free */
#define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */
#define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */
#define PG_WRITEABLE 0x0010 /* page is mapped writeable */
#define PG_ZERO 0x0040 /* page is zeroed */
#define PG_REFERENCED 0x0080 /* page has been referenced */
#define PG_UNMANAGED 0x0800 /* No PV management for page */
#define PG_MARKER 0x1000 /* special queue marker page */
#define PG_SLAB 0x2000 /* object pointer is actually a slab */
/*
* 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 four lists:
*
* free
* Available for allocation now.
*
* The following are all LRU sorted:
*
* cache
* Almost available for allocation. Still in an
* object, but clean and immediately freeable at
* non-interrupt times.
*
* 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.
*
* zero
* Pages that are really free and have been pre-zeroed
*
*/
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 mtx vm_page_queue_mtx;
#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 /* vm_page_grab() only */
#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
void vm_page_flag_set(vm_page_t m, unsigned short bits);
void vm_page_flag_clear(vm_page_t m, unsigned short 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_init(void);
void vm_pageq_enqueue(int queue, vm_page_t m);
void vm_pageq_remove_nowakeup(vm_page_t m);
void vm_pageq_remove(vm_page_t m);
void vm_pageq_requeue(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_grab (vm_object_t, vm_pindex_t, int);
void vm_page_cache (register vm_page_t);
int vm_page_try_to_cache (vm_page_t);
int vm_page_try_to_free (vm_page_t);
void vm_page_dontneed (register vm_page_t);
void vm_page_deactivate (vm_page_t);
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);
void vm_page_remove (vm_page_t);
void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
vm_page_t vm_page_select_cache(void);
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_unwire (vm_page_t, int);
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);
void vm_page_cowsetup (vm_page_t);
void vm_page_cowclear (vm_page_t);
/*
* 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)
{
m->dirty = 0;
}
#endif /* _KERNEL */
#endif /* !_VM_PAGE_ */
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