xref: /freebsd/share/man/man9/vm_page_dontneed.9 (revision 8a7314fcb5347f8296a072e0c4f67a9f64303186)
121642577SAlfred Perlstein.\"
221642577SAlfred Perlstein.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
321642577SAlfred Perlstein.\"
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821642577SAlfred Perlstein.\"    notice(s), this list of conditions and the following disclaimer as
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1021642577SAlfred Perlstein.\"    addition of one or more copyright notices.
1121642577SAlfred Perlstein.\" 2. Redistributions in binary form must reproduce the above copyright
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1421642577SAlfred Perlstein.\"
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2721642577SAlfred Perlstein.\" $FreeBSD$
2821642577SAlfred Perlstein.\"
2921642577SAlfred Perlstein.Dd July 30, 2001
3021642577SAlfred Perlstein.Dt VM_PAGE_DONTNEED 9
3121642577SAlfred Perlstein.Os
3221642577SAlfred Perlstein.Sh NAME
3321642577SAlfred Perlstein.Nm vm_page_dontneed
3421642577SAlfred Perlstein.Nd "indicate that a page is not needed anymore"
3521642577SAlfred Perlstein.Sh SYNOPSIS
3621642577SAlfred Perlstein.In sys/param.h
3721642577SAlfred Perlstein.In vm/vm.h
3821642577SAlfred Perlstein.In vm/vm_page.h
3921642577SAlfred Perlstein.Ft void
4021642577SAlfred Perlstein.Fn vm_page_dontneed "vm_page_t m"
4121642577SAlfred Perlstein.Sh DESCRIPTION
4221642577SAlfred PerlsteinThe
4321642577SAlfred Perlstein.Fn vm_page_dontneed
4421642577SAlfred Perlsteinfunction advises the VM system that the given page is no longer
4521642577SAlfred Perlsteinrequired.
461f620c2eSRuslan ErmilovIf the page is already in the inactive queue or in the cache queue, this
4721642577SAlfred Perlsteinfunction does nothing; otherwise the page is deactivated.
4821642577SAlfred Perlstein.Pp
4921642577SAlfred PerlsteinNote that
5021642577SAlfred Perlstein.Fn vm_page_dontneed
5121642577SAlfred Perlsteindoes not necessarily deactivate a page, but instead implements an
5221642577SAlfred Perlsteinalgorithm that attempts to prevent small objects from having their
5321642577SAlfred Perlsteinpages reused too quickly, and large objects from flushing smaller
5421642577SAlfred Perlsteinones from the queues as their pages are released.
5521642577SAlfred Perlstein.Sh SEE ALSO
5621642577SAlfred Perlstein.Xr vm_page_deactivate 9
5721642577SAlfred Perlstein.Sh AUTHORS
5821642577SAlfred PerlsteinThis manual page was written by
59*8a7314fcSBaptiste Daroussin.An Chad David Aq Mt davidc@acns.ab.ca .
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