xref: /freebsd/share/man/man9/vm_page_grab.9 (revision 8a7314fcb5347f8296a072e0c4f67a9f64303186)
121642577SAlfred Perlstein.\"
221642577SAlfred Perlstein.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
300cf6892SKonstantin Belousov.\" Copyright (c) 2013 The FreeBSD Foundation
400cf6892SKonstantin Belousov.\"
500cf6892SKonstantin Belousov.\" Portions of this documentation were written by Konstantin Belousov
600cf6892SKonstantin Belousov.\" under sponsorship from the FreeBSD Foundation.
721642577SAlfred Perlstein.\"
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1221642577SAlfred Perlstein.\"    notice(s), this list of conditions and the following disclaimer as
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3121642577SAlfred Perlstein.\" $FreeBSD$
3221642577SAlfred Perlstein.\"
3300cf6892SKonstantin Belousov.Dd August 23, 2013
3421642577SAlfred Perlstein.Dt VM_PAGE_GRAB 9
3521642577SAlfred Perlstein.Os
3621642577SAlfred Perlstein.Sh NAME
3721642577SAlfred Perlstein.Nm vm_page_grab
3821642577SAlfred Perlstein.Nd "returns a page from an object"
3921642577SAlfred Perlstein.Sh SYNOPSIS
4021642577SAlfred Perlstein.In sys/param.h
4121642577SAlfred Perlstein.In vm/vm.h
4221642577SAlfred Perlstein.In vm/vm_page.h
4321642577SAlfred Perlstein.Ft vm_page_t
4421642577SAlfred Perlstein.Fn vm_page_grab "vm_object_t object" "vm_pindex_t pindex" "int allocflags"
4521642577SAlfred Perlstein.Sh DESCRIPTION
4621642577SAlfred PerlsteinThe
4721642577SAlfred Perlstein.Fn vm_page_grab
4821642577SAlfred Perlsteinfunction returns the page at
4921642577SAlfred Perlstein.Fa pindex
5021642577SAlfred Perlsteinfrom the given object.
511f620c2eSRuslan ErmilovIf the page exists and is busy,
5221642577SAlfred Perlstein.Fn vm_page_grab
5321642577SAlfred Perlsteinwill sleep while waiting for it.
541f620c2eSRuslan ErmilovIf the page does not exist, it is allocated.
5500cf6892SKonstantin BelousovThe function sleeps until the allocation request can be satisfied.
5621642577SAlfred Perlstein.Pp
5700cf6892SKonstantin BelousovThe function requires the
5800cf6892SKonstantin Belousov.Fa object
5900cf6892SKonstantin Belousovto be locked on entry, and returns with the object locked.
6000cf6892SKonstantin BelousovIf the
6121642577SAlfred Perlstein.Fn vm_page_grab
6200cf6892SKonstantin Belousovfunction sleeps for any reason, the object lock is temporary dropped.
6300cf6892SKonstantin Belousov.Pp
6400cf6892SKonstantin BelousovThe
6500cf6892SKonstantin Belousov.Fn vm_page_grab
6600cf6892SKonstantin Belousovsupports all of the flags supported by
672a6b4327SJohn-Mark Gurney.Xr vm_page_alloc 9 .
6800cf6892SKonstantin BelousovIn addition,
6900cf6892SKonstantin Belousov.Fn vm_page_grab
7000cf6892SKonstantin Belousovsupports the following flags:
7100cf6892SKonstantin Belousov.Bl -tag -width ".Dv VM_ALLOC_IGN_SBUSY"
7200cf6892SKonstantin Belousov.It Dv VM_ALLOC_IGN_SBUSY
7300cf6892SKonstantin BelousovWhen waiting for the busy state of the existing page to drain,
7400cf6892SKonstantin Belousovonly test for exclusive busy; ignore the shared busy counter.
7500cf6892SKonstantin Belousov.El
7600cf6892SKonstantin Belousov.Sh RETURN VALUES
7700cf6892SKonstantin BelousovThe
7800cf6892SKonstantin Belousov.Fn vm_page_grab
7900cf6892SKonstantin Belousovalways returns the page.
8021642577SAlfred Perlstein.Sh SEE ALSO
8121642577SAlfred Perlstein.Xr vm_page_alloc 9
8221642577SAlfred Perlstein.Sh AUTHORS
83571dba6eSHiten PandyaThis manual page was written by
84*8a7314fcSBaptiste Daroussin.An Chad David Aq Mt davidc@acns.ab.ca .
85