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freebsd/sys/vm/vm_page.h
Matthew Dillon 2b6b0df712 This implements a better launder limiting solution. There was a solution 
in 4.2-REL which I ripped out in -stable and -current when implementing the
low-memory handling solution.  However, maxlaunder turns out to be the saving
grace in certain very heavily loaded systems (e.g. newsreader box).  The new
algorithm limits the number of pages laundered in the first pageout daemon
pass.  If that is not sufficient then suceessive will be run without any
limit.

Write I/O is now pipelined using two sysctls, vfs.lorunningspace and
vfs.hirunningspace.  This prevents excessive buffered writes in the
disk queues which cause long (multi-second) delays for reads.  It leads
to more stable (less jerky) and generally faster I/O streaming to disk
by allowing required read ops (e.g. for indirect blocks and such) to occur
without interrupting the write stream, amoung other things.

NOTE: eventually, filesystem write I/O pipelining needs to be done on a
per-device basis.  At the moment it is globalized.
2000-12-26 19:41:38 +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.
*
* $FreeBSD$
*/
/*
* Resident memory system definitions.
*/
#ifndef _VM_PAGE_
#define _VM_PAGE_
#if !defined(KLD_MODULE)
#include "opt_vmpage.h"
#endif
#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).
*
* 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) */
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 */
struct md_page md; /* machine dependant stuff */
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: currently use SWAPBLK_NONE as an absolute value rather then
* a flag bit.
*/
#define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */
#define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */
#if !defined(KLD_MODULE)
/*
* Page coloring parameters
*/
/* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */
/* Backward compatibility for existing PQ_*CACHE config options. */
#if !defined(PQ_CACHESIZE)
#if defined(PQ_HUGECACHE)
#define PQ_CACHESIZE 1024
#elif defined(PQ_LARGECACHE)
#define PQ_CACHESIZE 512
#elif defined(PQ_MEDIUMCACHE)
#define PQ_CACHESIZE 256
#elif defined(PQ_NORMALCACHE)
#define PQ_CACHESIZE 64
#elif defined(PQ_NOOPT)
#define PQ_CACHESIZE 0
#else
#define PQ_CACHESIZE 128
#endif
#endif
#if PQ_CACHESIZE >= 1024
#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_L2_SIZE 256 /* A number of colors opt for 1M cache */
#elif PQ_CACHESIZE >= 512
#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_L2_SIZE 128 /* A number of colors opt for 512K cache */
#elif PQ_CACHESIZE >= 256
#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_L2_SIZE 64 /* A number of colors opt for 256K cache */
#elif PQ_CACHESIZE >= 128
#define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */
#define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */
#define PQ_L2_SIZE 32 /* A number of colors opt for 128k cache */
#elif PQ_CACHESIZE >= 64
#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_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */
#else
#define PQ_PRIME1 1 /* Disable page coloring. */
#define PQ_PRIME2 1
#define PQ_L2_SIZE 1
#endif
#define PQ_L2_MASK (PQ_L2_SIZE - 1)
#if 1
#define PQ_NONE 0
#define PQ_FREE 1
#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)
#else
#define PQ_NONE PQ_COUNT
#define PQ_FREE 0
#define PQ_INACTIVE PQ_L2_SIZE
#define PQ_ACTIVE (1 + PQ_L2_SIZE)
#define PQ_CACHE (2 + PQ_L2_SIZE)
#define PQ_COUNT (2 + 2*PQ_L2_SIZE)
#endif
struct vpgqueues {
struct pglist pl;
int *cnt;
int lcnt;
};
extern struct vpgqueues vm_page_queues[PQ_COUNT];
#endif
/*
* These are the flags defined for vm_page.
*
* Note: PG_FILLED and PG_DIRTY are added for the filesystems.
*
* 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_BUSY 0x0001 /* page is in transit (O) */
#define PG_WANTED 0x0002 /* someone is waiting for page (O) */
#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_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 */
#define PG_NOSYNC 0x0400 /* do not collect for syncer */
#define PG_UNMANAGED 0x0800 /* No PV management for page */
#define PG_MARKER 0x1000 /* special queue marker 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 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_TO_PHYS(entry) ((entry)->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 short bits)
{
atomic_set_short(&(m)->flags, bits);
}
static __inline void
vm_page_flag_clear(vm_page_t m, unsigned short 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));
int vm_page_try_to_cache __P((vm_page_t));
void vm_page_dontneed __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_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));
void 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));
vm_page_t vm_add_new_page __P((vm_offset_t pa));
void vm_page_unmanage __P((vm_page_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_dirty __P((vm_page_t, int, int));
void vm_page_clear_dirty __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));
#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_zero_invalid(vm_page_t m, boolean_t setvalid);
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(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(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)
{
#if !defined(KLD_MODULE)
KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!"));
#endif
m->dirty = VM_PAGE_BITS_ALL;
}
/*
* 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;
}
#if !defined(KLD_MODULE)
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
#endif /* _KERNEL */
#endif /* !_VM_PAGE_ */
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