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freebsd-skq/sys/vm/vm_page.h
dillon a179ee09ab This patch implements O_DIRECT about 80% of the way. It takes a patchset 
Tor created a while ago, removes the raw I/O piece (that has cache coherency
problems), and adds a buffer cache / VM freeing piece.

Essentially this patch causes O_DIRECT I/O to not be left in the cache, but
does not prevent it from going through the cache, hence the 80%.  For
the last 20% we need a method by which the I/O can be issued directly to
buffer supplied by the user process and bypass the buffer cache entirely,
but still maintain cache coherency.

I also have the code working under -stable but the changes made to sys/file.h
may not be MFCable, so an MFC is not on the table yet.

Submitted by:	tegge, dillon
2001-05-24 07:22:27 +00:00

653 lines
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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 ])
/*
* For now, a global vm lock
*/
#define VM_PAGE_MTX(m) (&vm_mtx)
/*
* Functions implemented as macros
*/
static __inline void
vm_page_flag_set(vm_page_t m, unsigned short bits)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
m->flags |= bits;
}
static __inline void
vm_page_flag_clear(vm_page_t m, unsigned short bits)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
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)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
m->busy++;
}
static __inline void
vm_page_io_finish(vm_page_t m)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
m->busy--;
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));
int vm_page_try_to_free __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)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
mem->hold_count++;
}
static __inline void
vm_page_unhold(vm_page_t mem)
{
mtx_assert(VM_PAGE_MTX(m), MA_OWNED);
--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);
msleep(m, VM_PAGE_MTX(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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