From: Venkatesh Srinivas Date: Wed, 22 Dec 2010 02:53:49 +0000 (-0800) Subject: Import vm_page_alloc manpage from FreeBSD and add DFly-specifics. X-Git-Tag: v2.11.0~420 X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/bd5e5d2d28768174e7ee90289593da4acc65bc8f Import vm_page_alloc manpage from FreeBSD and add DFly-specifics. --- diff --git a/share/man/man9/vm_page_alloc.9 b/share/man/man9/vm_page_alloc.9 new file mode 100644 index 0000000000..7d28543dd2 --- /dev/null +++ b/share/man/man9/vm_page_alloc.9 @@ -0,0 +1,98 @@ +.\" +.\" Copyright (C) 2001 Chad David . 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: src/share/man/man9/vm_page_alloc.9,v 1.6 2005/06/28 20:15:18 hmp Exp $ +.\" +.Dd December 19, 2010 +.Dt VM_PAGE_ALLOC 9 +.Os +.Sh NAME +.Nm vm_page_alloc +.Nd "allocate a page for a" +.Vt vm_object +.Sh SYNOPSIS +.In sys/param.h +.In vm/vm.h +.In vm/vm_page.h +.Ft vm_page_t +.Fn vm_page_alloc "vm_object_t object" "vm_pindex_t pindex" "int page_req" +.Sh DESCRIPTION +The +.Fn vm_page_alloc +function allocates a page at +.Fa pindex +within +.Fa object . +It is assumed that a page has not already been allocated at +.Fa pindex . +The page returned is inserted into the object, but is not inserted +into the pmap. The vm_object must be locked on entry. +.Pp +.Fn vm_page_alloc +will not block. +.Pp +Its arguments are: +.Bl -tag -width ".Fa page_req" +.It Fa object +The VM object to allocate the page for. +.It Fa pindex +The index into the object at which the page should be inserted. +.It Fa page_req +A flag indicating how the page should be allocated. +.Bl -tag -width ".Dv VM_ALLOC_INTERRUPT" +.It Dv VM_ALLOC_NORMAL +The page should be allocated with no special treatment. +.It Dv VM_ALLOC_QUICK +The page should only be allocated from the free queue. +.It Dv VM_ALLOC_SYSTEM +The page can be allocated if the cache queue is empty and the free +page count is above the interrupt reserved water mark. +If +.Dv VM_ALLOC_INTERRUPT +is set, the page can be allocated as long as the free page count is +greater than zero. +This flag should be used only when the system really needs the page. +.It Dv VM_ALLOC_INTERRUPT +.Fn vm_page_alloc +is being called during an interrupt and therefore the cache cannot +be accessed. +The page will only be returned successfully if the free count is greater +than zero. +.It Dv VM_ALLOC_ZERO +Indicate a preference for a pre-zeroed page. +There is no guarantee that the page thus returned will be zeroed, but +it will be marked as such. +.El +.El +.Sh RETURN VALUES +The +.Vt vm_page_t +that was allocated is returned if successful; otherwise, +.Dv NULL +is returned. The returned page will be marked PG_BUSY. +.Sh AUTHORS +This manual page was written by +.An Chad David Aq davidc@acns.ab.ca .