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.\"
.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
.\"
.\" 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(s), this list of conditions and the following disclaimer as
.\" the first lines of this file unmodified other than the possible
.\" addition of one or more copyright notices.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice(s), this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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.
.\"
.\" $FreeBSD$
.\"
.Dd July 30, 2001
.Dt VM_PAGE_DONTNEED 9
.Os
.Sh NAME
.Nm vm_page_dontneed
.Nd "indicate that a page is not needed anymore"
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/vm_page.h
.Ft void
.Fn vm_page_dontneed "vm_page_t m"
.Sh DESCRIPTION
The
.Fn vm_page_dontneed
function advises the VM system that the given page is no longer
required.
If the page is already in the inactive queue or in the cache queue, this
function does nothing; otherwise the page is deactivated.
.Pp
Note that
.Fn vm_page_dontneed
does not necessarily deactivate a page, but instead implements an
algorithm that attempts to prevent small objects from having their
pages reused too quickly, and large objects from flushing smaller
ones from the queues as their pages are released.
.Sh SEE ALSO
.Xr vm_page_deactivate 9
.Sh AUTHORS
This manual page was written by
.An Chad David Aq Mt davidc@acns.ab.ca .
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