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Fairly major cleanup of the text.

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PR: docs/32241
This commit is contained in:
Chad David 2002-01-09 08:42:43 +00:00
parent 2bbe1e9d6c
commit 2e693d1919
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=89122
1 changed files with 18 additions and 15 deletions
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33
share/man/man9/vm_page_alloc.9
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@ -31,7 +31,7 @@
.Os
.Sh NAME
.Nm vm_page_alloc
.Nd "allocates a page for the object and index"
.Nd "allocate a page for a vm_object"
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
@ -41,34 +41,37 @@
.Sh DESCRIPTION
The
.Fn vm_page_alloc
function allocates a page for
function allocates a page at
.Fa pindex
in the VM object
.Fa object .
It is assumed that a page has not already been allocated for
.Fa pindex
and
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.
.Pp
The
.Fn vm_page_alloc
function will not block.
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 of the page that should be allocated.
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_SYSTEM
The page can be allocated even if the buffer cache queue is empty
and the free count is above the interrupt reserved water mark.
This should be used only when the system really needs the page.
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
@ -82,9 +85,9 @@ except the page returned is zeroed.
.El
.El
.Sh RETURN VALUES
A
The
.Vt vm_page_t
is returned if successful; otherwise,
that was allocated is returned if successful; otherwise,
.Dv NULL
is returned.
.Sh NOTES