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freebsd-skq/sys/vm/vm_page.h
dillon b7a0b99c31 Rip out PQ_ZERO queue. PQ_ZERO functionality is now combined in with 
PQ_FREE.  There is little operational difference other then the kernel
    being a few kilobytes smaller and the code being more readable.

    * vm_page_select_free() has been *greatly* simplified.
    * The PQ_ZERO page queue and supporting structures have been removed
    * vm_page_zero_idle() revamped (see below)

    PG_ZERO setting and clearing has been migrated from vm_page_alloc()
    to vm_page_free[_zero]() and will eventually be guarenteed to remain
    tracked throughout a page's life ( if it isn't already ).

    When a page is freed, PG_ZERO pages are appended to the appropriate
    tailq in the PQ_FREE queue while non-PG_ZERO pages are prepended.
    When locating a new free page, PG_ZERO selection operates from within
    vm_page_list_find() ( get page from end of queue instead of beginning
    of queue ) and then only occurs in the nominal critical path case.  If
    the nominal case misses, both normal and zero-page allocation devolves
    into the same _vm_page_list_find() select code without any specific
    zero-page optimizations.

    Additionally, vm_page_zero_idle() has been revamped.  Hysteresis has been
    added and zero-page tracking adjusted to conform with the other changes.
    Currently hysteresis is set at 1/3 (lo) and 1/2 (hi) the number of free
    pages.  We may wish to increase both parameters as time permits.  The
    hysteresis is designed to avoid silly zeroing in borderline allocation/free
    situations.
1999-02-08 00:37:36 +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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* $Id: vm_page.h,v 1.54 1999/02/07 20:45:15 dillon Exp $
*/
/*
* Resident memory system definitions.
*/
#ifndef _VM_PAGE_
#define _VM_PAGE_
#include "opt_vmpage.h"
#include <vm/pmap.h>
#include <machine/atomic.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).
*/
TAILQ_HEAD(pglist, vm_page);
struct vm_page {
TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */
struct vm_page *hnext; /* hash table link (O,P) */
TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
vm_object_t object; /* which object am I in (O,P)*/
vm_pindex_t pindex; /* offset into object (O,P) */
vm_offset_t phys_addr; /* physical address of page */
u_short queue; /* page queue index */
u_short flags, /* see below */
pc; /* page color */
u_short wire_count; /* wired down maps refs (P) */
short hold_count; /* page hold count */
u_char act_count; /* page usage count */
u_char busy; /* page busy count */
/* 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 */
u_char dirty; /* map of dirty DEV_BSIZE chunks */
#elif PAGE_SIZE == 8192
u_short valid; /* map of valid DEV_BSIZE chunks */
u_short dirty; /* map of dirty DEV_BSIZE chunks */
#endif
};
/*
* note SWAPBLK_NONE is a flag, basically the high bit.
*/
#define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */
#define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */
/*
* Page coloring parameters
*/
/* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */
/* Define one of the following */
#if defined(PQ_HUGECACHE)
#define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME3 17 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */
#endif
/* Define one of the following */
#if defined(PQ_LARGECACHE)
#define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME3 17 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */
#endif
/*
* Use 'options PQ_NOOPT' to disable page coloring
*/
#if defined(PQ_NOOPT)
#define PQ_PRIME1 1
#define PQ_PRIME2 1
#define PQ_PRIME3 1
#define PQ_L2_SIZE 1
#endif
#if defined(PQ_NORMALCACHE)
#define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME3 11 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */
#endif
#if defined(PQ_MEDIUMCACHE) || !defined(PQ_L2_SIZE)
#define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_PRIME3 5 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */
#endif
#define PQ_L2_MASK (PQ_L2_SIZE - 1)
#define PQ_NONE 0
#define PQ_FREE 1
/* #define PQ_ZERO (1 + PQ_L2_SIZE) */
#define PQ_INACTIVE (1 + 1*PQ_L2_SIZE)
#define PQ_ACTIVE (2 + 1*PQ_L2_SIZE)
#define PQ_CACHE (3 + 1*PQ_L2_SIZE)
#define PQ_COUNT (3 + 2*PQ_L2_SIZE)
extern struct vpgqueues {
struct pglist *pl;
int *cnt;
int *lcnt;
} vm_page_queues[PQ_COUNT];
/*
* These are the flags defined for vm_page.
*
* Note: PG_FILLED and PG_DIRTY are added for the filesystems.
*/
#define PG_BUSY 0x0001 /* page is in transit (O) */
#define PG_WANTED 0x0002 /* someone is waiting for page (O) */
#define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */
#define PG_WRITEABLE 0x0010 /* page is mapped writeable */
#define PG_MAPPED 0x0020 /* page is mapped */
#define PG_ZERO 0x0040 /* page is zeroed */
#define PG_REFERENCED 0x0080 /* page has been referenced */
#define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */
#define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */
/*
* Misc constants.
*/
#define ACT_DECLINE 1
#define ACT_ADVANCE 3
#define ACT_INIT 5
#define ACT_MAX 64
#define PFCLUSTER_BEHIND 3
#define PFCLUSTER_AHEAD 3
#ifdef KERNEL
/*
* 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 struct pglist vm_page_queue_free[PQ_L2_SIZE];/* memory free queue */
extern struct pglist vm_page_queue_active; /* active memory queue */
extern struct pglist vm_page_queue_inactive; /* inactive memory queue */
extern struct pglist vm_page_queue_cache[PQ_L2_SIZE];/* cache memory queue */
extern int vm_page_zero_count;
extern vm_page_t vm_page_array; /* First resident page in table */
extern long first_page; /* first physical page number */
/* ... represented in vm_page_array */
extern long last_page; /* last physical page number */
/* ... represented in vm_page_array */
/* [INCLUSIVE] */
extern vm_offset_t first_phys_addr; /* physical address for first_page */
extern vm_offset_t last_phys_addr; /* physical address for last_page */
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
#define IS_VM_PHYSADDR(pa) \
((pa) >= first_phys_addr && (pa) <= last_phys_addr)
#define PHYS_TO_VM_PAGE(pa) \
(&vm_page_array[atop(pa) - first_page ])
/*
* Functions implemented as macros
*/
static __inline void
vm_page_flag_set(vm_page_t m, unsigned int bits)
{
atomic_set_short(&(m)->flags, bits);
}
static __inline void
vm_page_flag_clear(vm_page_t m, unsigned int bits)
{
atomic_clear_short(&(m)->flags, bits);
}
#if 0
static __inline void
vm_page_assert_wait(vm_page_t m, int interruptible)
{
vm_page_flag_set(m, PG_WANTED);
assert_wait((int) m, interruptible);
}
#endif
static __inline void
vm_page_busy(vm_page_t m)
{
KASSERT((m->flags & PG_BUSY) == 0, ("vm_page_busy: page already busy!!!"));
vm_page_flag_set(m, PG_BUSY);
}
/*
* vm_page_flash:
*
* wakeup anyone waiting for the page.
*/
static __inline void
vm_page_flash(vm_page_t m)
{
if (m->flags & PG_WANTED) {
vm_page_flag_clear(m, PG_WANTED);
wakeup(m);
}
}
/*
* vm_page_wakeup:
*
* clear the PG_BUSY flag and wakeup anyone waiting for the
* page.
*
*/
static __inline void
vm_page_wakeup(vm_page_t m)
{
KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!"));
vm_page_flag_clear(m, PG_BUSY);
vm_page_flash(m);
}
/*
*
*
*/
static __inline void
vm_page_io_start(vm_page_t m)
{
atomic_add_char(&(m)->busy, 1);
}
static __inline void
vm_page_io_finish(vm_page_t m)
{
atomic_subtract_char(&m->busy, 1);
if (m->busy == 0)
vm_page_flash(m);
}
#if PAGE_SIZE == 4096
#define VM_PAGE_BITS_ALL 0xff
#endif
#if PAGE_SIZE == 8192
#define VM_PAGE_BITS_ALL 0xffff
#endif
#define VM_ALLOC_NORMAL 0
#define VM_ALLOC_INTERRUPT 1
#define VM_ALLOC_SYSTEM 2
#define VM_ALLOC_ZERO 3
#define VM_ALLOC_RETRY 0x80
void vm_page_activate __P((vm_page_t));
vm_page_t vm_page_alloc __P((vm_object_t, vm_pindex_t, int));
vm_page_t vm_page_grab __P((vm_object_t, vm_pindex_t, int));
void vm_page_cache __P((register vm_page_t));
static __inline void vm_page_copy __P((vm_page_t, vm_page_t));
static __inline void vm_page_free __P((vm_page_t));
static __inline void vm_page_free_zero __P((vm_page_t));
void vm_page_destroy __P((vm_page_t));
void vm_page_deactivate __P((vm_page_t));
void vm_page_insert __P((vm_page_t, vm_object_t, vm_pindex_t));
vm_page_t vm_page_lookup __P((vm_object_t, vm_pindex_t));
vm_object_t vm_page_remove __P((vm_page_t));
void vm_page_rename __P((vm_page_t, vm_object_t, vm_pindex_t));
vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t));
void vm_page_unwire __P((vm_page_t, int));
void vm_page_wire __P((vm_page_t));
void vm_page_unqueue __P((vm_page_t));
void vm_page_unqueue_nowakeup __P((vm_page_t));
void vm_page_set_validclean __P((vm_page_t, int, int));
void vm_page_set_invalid __P((vm_page_t, int, int));
static __inline boolean_t vm_page_zero_fill __P((vm_page_t));
int vm_page_is_valid __P((vm_page_t, int, int));
void vm_page_test_dirty __P((vm_page_t));
int vm_page_bits __P((int, int));
vm_page_t _vm_page_list_find __P((int, int));
int vm_page_queue_index __P((vm_offset_t, int));
#if 0
int vm_page_sleep(vm_page_t m, char *msg, char *busy);
int vm_page_asleep(vm_page_t m, char *msg, char *busy);
#endif
void vm_page_free_toq(vm_page_t m);
/*
* Keep page from being freed by the page daemon
* much of the same effect as wiring, except much lower
* overhead and should be used only for *very* temporary
* holding ("wiring").
*/
static __inline void
vm_page_hold(vm_page_t mem)
{
mem->hold_count++;
}
static __inline void
vm_page_unhold(vm_page_t mem)
{
--mem->hold_count;
KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
}
/*
* vm_page_protect:
*
* Reduce the protection of a page. This routine never
* raises the protection and therefore can be safely
* called if the page is already at VM_PROT_NONE ( it
* will be a NOP effectively ).
*/
static __inline void
vm_page_protect(vm_page_t mem, int prot)
{
if (prot == VM_PROT_NONE) {
if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) {
pmap_page_protect(VM_PAGE_TO_PHYS(mem), VM_PROT_NONE);
vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED);
}
} else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) {
pmap_page_protect(VM_PAGE_TO_PHYS(mem), VM_PROT_READ);
vm_page_flag_clear(mem, PG_WRITEABLE);
}
}
/*
* vm_page_zero_fill:
*
* Zero-fill the specified page.
* Written as a standard pagein routine, to
* be used by the zero-fill object.
*/
static __inline boolean_t
vm_page_zero_fill(m)
vm_page_t m;
{
pmap_zero_page(VM_PAGE_TO_PHYS(m));
return (TRUE);
}
/*
* vm_page_copy:
*
* Copy one page to another
*/
static __inline void
vm_page_copy(src_m, dest_m)
vm_page_t src_m;
vm_page_t dest_m;
{
pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m));
dest_m->valid = VM_PAGE_BITS_ALL;
}
/*
* vm_page_free:
*
* Free a page
*
* The clearing of PG_ZERO is a temporary safety until the code can be
* reviewed to determine that PG_ZERO is being properly cleared on
* write faults or maps. PG_ZERO was previously cleared in
* vm_page_alloc().
*/
static __inline void
vm_page_free(m)
vm_page_t m;
{
vm_page_flag_clear(m, PG_ZERO);
vm_page_free_toq(m);
}
/*
* vm_page_free_zero:
*
* Free a page to the zerod-pages queue
*/
static __inline void
vm_page_free_zero(m)
vm_page_t m;
{
vm_page_flag_set(m, PG_ZERO);
vm_page_free_toq(m);
}
/*
* vm_page_sleep_busy:
*
* Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE)
* m->busy is zero. Returns TRUE if it had to sleep ( including if
* it almost had to sleep and made temporary spl*() mods), FALSE
* otherwise.
*
* This routine assumes that interrupts can only remove the busy
* status from a page, not set the busy status or change it from
* PG_BUSY to m->busy or vise versa (which would create a timing
* window).
*
* Note that being an inline, this code will be well optimized.
*/
static __inline int
vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg)
{
if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) {
int s = splvm();
if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) {
/*
* Page is busy. Wait and retry.
*/
vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
tsleep(m, PVM, msg, 0);
}
splx(s);
return(TRUE);
/* not reached */
}
return(FALSE);
}
/*
* vm_page_dirty:
*
* make page all dirty
*/
static __inline void
vm_page_dirty(vm_page_t m)
{
KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!"));
m->dirty = VM_PAGE_BITS_ALL;
}
static __inline vm_page_t
vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
{
vm_page_t m;
#if PQ_L2_SIZE > 1
if (prefer_zero) {
m = TAILQ_LAST(vm_page_queues[basequeue+index].pl, pglist);
} else {
m = TAILQ_FIRST(vm_page_queues[basequeue+index].pl);
}
if (m == NULL)
m = _vm_page_list_find(basequeue, index);
#else
if (prefer_zero) {
m = TAILQ_LAST(vm_page_queues[basequeue].pl, pglist);
} else {
m = TAILQ_FIRST(vm_page_queues[basequeue].pl);
}
#endif
return(m);
}
#endif /* KERNEL */
#endif /* !_VM_PAGE_ */
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