freebsd-skq/sys/vm/vm_pageout.h
kib 3851a62f83 vm_pageout_flush() might cache the pages that finished write to the
backing storage. Such pages might be then reused, racing with the
assert in vm_object_page_collect_flush() that verified that dirty
pages from the run (most likely, pages with VM_PAGER_AGAIN status) are
write-protected still. In fact, the page indexes for the pages that
were removed from the object page list should be ignored by
vm_object_page_clean().

Return the length of successfully written run from vm_pageout_flush(),
that is, the count of pages between requested page and first page
after requested with status VM_PAGER_AGAIN. Supply the requested page
index in the array to vm_pageout_flush(). Use the returned run length
to forward the index of next page to clean in vm_object_page_clean().

Reported by:	avg
Reviewed by:	alc
MFC after:	1 week
2010-11-18 21:09:02 +00:00

111 lines
3.8 KiB
C

/*-
* 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_pageout.h 8.2 (Berkeley) 1/12/94
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Avadis Tevanian, Jr.
*
* 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.
*
* $FreeBSD$
*/
#ifndef _VM_VM_PAGEOUT_H_
#define _VM_VM_PAGEOUT_H_
/*
* Header file for pageout daemon.
*/
/*
* Exported data structures.
*/
extern int vm_page_max_wired;
extern int vm_pages_needed; /* should be some "event" structure */
extern int vm_pageout_pages_needed;
extern int vm_pageout_deficit;
extern int vm_pageout_page_count;
/*
* Swap out requests
*/
#define VM_SWAP_NORMAL 1
#define VM_SWAP_IDLE 2
#define VM_OOM_MEM 1
#define VM_OOM_SWAPZ 2
/*
* Exported routines.
*/
/*
* Signal pageout-daemon and wait for it.
*/
extern void pagedaemon_wakeup(void);
#define VM_WAIT vm_wait()
#define VM_WAITPFAULT vm_waitpfault()
extern void vm_wait(void);
extern void vm_waitpfault(void);
#ifdef _KERNEL
boolean_t vm_pageout_fallback_object_lock(vm_page_t, vm_page_t *);
int vm_pageout_flush(vm_page_t *, int, int, int, int *);
void vm_pageout_oom(int shortage);
boolean_t vm_pageout_page_lock(vm_page_t, vm_page_t *);
void vm_contig_grow_cache(int, vm_paddr_t, vm_paddr_t);
#endif
#endif /* _VM_VM_PAGEOUT_H_ */