xref: /freebsd/share/man/man9/vm_page_dontneed.9 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
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
1221642577SAlfred Perlstein.\"    notice(s), this list of conditions and the following disclaimer in the
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1421642577SAlfred Perlstein.\"
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2621642577SAlfred Perlstein.\"
2721642577SAlfred Perlstein.Dd July 30, 2001
2821642577SAlfred Perlstein.Dt VM_PAGE_DONTNEED 9
2921642577SAlfred Perlstein.Os
3021642577SAlfred Perlstein.Sh NAME
3121642577SAlfred Perlstein.Nm vm_page_dontneed
3221642577SAlfred Perlstein.Nd "indicate that a page is not needed anymore"
3321642577SAlfred Perlstein.Sh SYNOPSIS
3421642577SAlfred Perlstein.In sys/param.h
3521642577SAlfred Perlstein.In vm/vm.h
3621642577SAlfred Perlstein.In vm/vm_page.h
3721642577SAlfred Perlstein.Ft void
3821642577SAlfred Perlstein.Fn vm_page_dontneed "vm_page_t m"
3921642577SAlfred Perlstein.Sh DESCRIPTION
4021642577SAlfred PerlsteinThe
4121642577SAlfred Perlstein.Fn vm_page_dontneed
4221642577SAlfred Perlsteinfunction advises the VM system that the given page is no longer
4321642577SAlfred Perlsteinrequired.
441f620c2eSRuslan ErmilovIf the page is already in the inactive queue or in the cache queue, this
4521642577SAlfred Perlsteinfunction does nothing; otherwise the page is deactivated.
4621642577SAlfred Perlstein.Pp
4721642577SAlfred PerlsteinNote that
4821642577SAlfred Perlstein.Fn vm_page_dontneed
4921642577SAlfred Perlsteindoes not necessarily deactivate a page, but instead implements an
5021642577SAlfred Perlsteinalgorithm that attempts to prevent small objects from having their
5121642577SAlfred Perlsteinpages reused too quickly, and large objects from flushing smaller
5221642577SAlfred Perlsteinones from the queues as their pages are released.
5321642577SAlfred Perlstein.Sh SEE ALSO
5421642577SAlfred Perlstein.Xr vm_page_deactivate 9
5521642577SAlfred Perlstein.Sh AUTHORS
5621642577SAlfred PerlsteinThis manual page was written by
57*8a7314fcSBaptiste Daroussin.An Chad David Aq Mt davidc@acns.ab.ca .
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