freebsd-nq/share/man/man9/vm_page_hold.9
Alfred Perlstein 6484c361f7 Document some of the kernel vm_page API as well as the pbuf API.
Submitted by: Chad David <davidc@acns.ab.ca>
2001-07-18 06:09:13 +00:00

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.Dd July 13, 2001
.Dt VM_PAGE_HOLD 9
.Os
.Sh NAME
.Nm vm_page_hold ,
.Nm vm_page_unhold
.Nd "updates a pages hold count"
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/vm_page.h
.Ft void
.Fn vm_page_hold "vm_page_t m"
.Ft void
.Fn vm_page_unhold "vm_page_t m"
.Sh DESCRIPTION
The
.Fn vm_page_hold
function increases the hold count on a page.
This prevents the page daemon from freeing the page.
.Fn vm_page_hold
should only be used for very temporary wiring of a page.
If the page needs to be held for a longer period
.Fn vm_page_write
should be used.
.Pp
.Fn vm_page_unhold
function reduces the hold count on a page.
If the hold count is zero it is possible the page will be freed by the
page daemon.
.Sh SEE ALSO
.Xr vm_page_wire 9
.Xr wm_page_unwire 9
.Sh AUTHORS
This man page was written by
.An Chad David Aq davidc@acns.ab.ca .