diff options
Diffstat (limited to 'share/man/man9/vm_page_hold.9')
| -rw-r--r-- | share/man/man9/vm_page_hold.9 | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/share/man/man9/vm_page_hold.9 b/share/man/man9/vm_page_hold.9 new file mode 100644 index 0000000..971d6c2 --- /dev/null +++ b/share/man/man9/vm_page_hold.9 @@ -0,0 +1,75 @@ +.\" +.\" 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 13, 2001 +.Dt VM_PAGE_HOLD 9 +.Os +.Sh NAME +.Nm vm_page_hold , +.Nm vm_page_unhold +.Nd "update a page's 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. +.Pp +.Fn vm_page_hold +should only be used for very temporary wiring of a page, +as that page will not be considered for paging or +reallocation for as long as its hold count is greater +than zero. +Also note that while wired pages are removed from whatever +queue they are on, +.Fn vm_page_hold +does not affect the location of the page. +If it is on a queue prior to the call, it will still +be there afterward. +.Pp +If the page needs to be held for a long period of time, +.Xr vm_page_wire 9 +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 that the page will be freed by the +page daemon. +.Sh SEE ALSO +.Xr vm_page_unwire 9 , +.Xr vm_page_wire 9 +.Sh AUTHORS +This manual page was written by +.An Chad David Aq Mt davidc@acns.ab.ca . |
