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.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
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.\" $FreeBSD: src/share/man/man9/vm_map_findspace.9,v 1.5.22.1.4.1 2010/06/14 02:09:06 kensmith Exp $
.\"
.Dd December 8, 2010
.Dt VM_MAP_FINDSPACE 9
.Os
.Sh NAME
.Nm vm_map_findspace
.Nd find a free region within a map
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/vm_map.h
.Ft int
.Fo vm_map_findspace
.Fa "vm_map_t map" "vm_offset_t start" "vm_size_t length" "vm_size_t align" "int flags" "vm_offset_t *addr"
.Fc
.Sh DESCRIPTION
The
.Fn vm_map_findspace
function attempts to find a region with sufficient space in the
.Fa map
for an object of size
.Fa length
at the address
.Fa addr
with the alignment
.Fa align .
The flags parameter can be:
.Bl -tag -width ".Fa flags"
.It Dv MAP_STACK
The space returned is for stack regions and can intersect the stack address
space.
.El
.Sh IMPLEMENTATION NOTES
It is the caller's responsibility to obtain a lock on the
.Fa map
before calling this function.
.Pp
This routine may call
.Fn pmap_growkernel
to grow the kernel's address space, if and only if the mapping is being
made within the kernel address space, and if insufficient space remains
in the
.Va kernel_map .
.Sh RETURN VALUES
The
.Fn vm_map_findspace
function returns the value 0 if successful, and
.Fa *addr
will contain the first virtual address in the found region;
otherwise, the value 1 is returned.
.Sh AUTHORS
This manual page was written by
.An Bruce M Simpson Aq Mt bms@spc.org .