freebsd-dev/sys/vm/vm_pager.h
dg 117fc1d2b0 These changes embody the support of the fully coherent merged VM buffer cache,
much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.

The majority of the merged VM/cache work is by John Dyson.

The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.

vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme.  The scheme is almost fully compatible with the old filesystem
interface.  Significant improvement in the number of opportunities for write
clustering.

vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache.  Fixup of vfs_cluster to eliminate the bogus pagemove stuff.

vm_object.c:
Yet more improvements in the collapse code.  Elimination of some windows that
can cause list corruption.

vm_pageout.c:
Fixed it, it really works better now.  Somehow in 2.0, some "enhancements"
broke the code.  This code has been reworked from the ground-up.

vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.

pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.

vm_glue.c
Much simpler and more effective swapping code.  No more gratuitous swapping.

proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.

swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency.  Now the
code doesn't need it anymore.

machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.

machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.

ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache.  Add "bypass" support for sneaking in on
busy buffers.

Submitted by:	John Dyson and David Greenman
1995-01-09 16:06:02 +00:00

144 lines
5.4 KiB
C

/*
* Copyright (c) 1990 University of Utah.
* 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 Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
*
* @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
* $Id: vm_pager.h,v 1.4 1994/10/09 01:52:17 phk Exp $
*/
/*
* Pager routine interface definition.
* For BSD we use a cleaner version of the internal pager interface.
*/
#ifndef _VM_PAGER_
#define _VM_PAGER_
TAILQ_HEAD(pagerlst, pager_struct);
struct pager_struct {
TAILQ_ENTRY(pager_struct) pg_list; /* links for list management */
caddr_t pg_handle; /* ext. handle (vp, dev, fp) */
int pg_type; /* type of pager */
struct pagerops *pg_ops; /* pager operations */
void *pg_data; /* private pager data */
};
/* pager types */
#define PG_DFLT -1
#define PG_SWAP 0
#define PG_VNODE 1
#define PG_DEVICE 2
/* flags */
#define PG_CLUSTERGET 1
#define PG_CLUSTERPUT 2
struct pagerops {
void (*pgo_init) __P((void)); /* Initialize pager. */
vm_pager_t(*pgo_alloc) __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t)); /* Allocate pager. */
void (*pgo_dealloc) __P((vm_pager_t)); /* Disassociate. */
int (*pgo_getpage) __P((vm_pager_t, vm_page_t, boolean_t));
int (*pgo_getpages) __P((vm_pager_t, vm_page_t *, int, int, boolean_t)); /* Get (read) page. */
int (*pgo_putpage) __P((vm_pager_t, vm_page_t, boolean_t));
int (*pgo_putpages) __P((vm_pager_t, vm_page_t *, int, boolean_t, int *)); /* Put (write) page. */
boolean_t(*pgo_haspage) __P((vm_pager_t, vm_offset_t)); /* Does pager have page? */
};
#define VM_PAGER_ALLOC(h, s, p, o) (*(pg)->pg_ops->pgo_alloc)(h, s, p, o)
#define VM_PAGER_DEALLOC(pg) (*(pg)->pg_ops->pgo_dealloc)(pg)
#define VM_PAGER_GET(pg, m, s) (*(pg)->pg_ops->pgo_getpage)(pg, m, s)
#define VM_PAGER_GET_MULTI(pg, m, c, r, s) (*(pg)->pg_ops->pgo_getpages)(pg, m, c, r, s)
#define VM_PAGER_PUT(pg, m, s) (*(pg)->pg_ops->pgo_putpage)(pg, m, s)
#define VM_PAGER_PUT_MULTI(pg, m, c, s, rtval) (*(pg)->pg_ops->pgo_putpages)(pg, m, c, s, rtval)
#define VM_PAGER_HASPAGE(pg, o) (*(pg)->pg_ops->pgo_haspage)(pg, o)
/*
* get/put return values
* OK operation was successful
* BAD specified data was out of the accepted range
* FAIL specified data was in range, but doesn't exist
* PEND operations was initiated but not completed
* ERROR error while accessing data that is in range and exists
* AGAIN temporary resource shortage prevented operation from happening
*/
#define VM_PAGER_OK 0
#define VM_PAGER_BAD 1
#define VM_PAGER_FAIL 2
#define VM_PAGER_PEND 3
#define VM_PAGER_ERROR 4
#define VM_PAGER_AGAIN 5
#ifdef KERNEL
extern struct pagerops *dfltpagerops;
vm_pager_t vm_pager_allocate __P((int, caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
vm_page_t vm_pager_atop __P((vm_offset_t));
void vm_pager_deallocate __P((vm_pager_t));
int vm_pager_get_pages __P((vm_pager_t, vm_page_t *, int, int, boolean_t));
boolean_t vm_pager_has_page __P((vm_pager_t, vm_offset_t));
void vm_pager_init __P((void));
vm_pager_t vm_pager_lookup __P((struct pagerlst *, caddr_t));
vm_offset_t vm_pager_map_pages __P((vm_page_t *, int, boolean_t));
vm_offset_t vm_pager_map_page __P((vm_page_t));
int vm_pager_put_pages __P((vm_pager_t, vm_page_t *, int, boolean_t, int *));
void vm_pager_sync __P((void));
void vm_pager_unmap_pages __P((vm_offset_t, int));
void vm_pager_unmap_page __P((vm_offset_t));
/*
* XXX compat with old interface
*/
#define vm_pager_get(p, m, s) \
({ \
vm_page_t ml[1]; \
ml[0] = (m); \
vm_pager_get_pages(p, ml, 1, 0, s); \
})
#define vm_pager_put(p, m, s) \
({ \
int rtval; \
vm_page_t ml[1]; \
ml[0] = (m); \
vm_pager_put_pages(p, ml, 1, s, &rtval); \
rtval; \
})
#endif
#endif /* _VM_PAGER_ */