1<h2>default_pager_add_segment</h2>
2<hr>
3<p>
4<strong>Server Interface</strong> - Add additional backing storage for a default pager.
5<h3>SYNOPSIS</h3>
6<pre>
7<strong>#include&lt mach/default_pager_object.h&gt</strong>
8
9<strong>kern_return_t   default_pager_add_segment</strong>
10                <strong>(mach_port_t</strong>                      <var>backing_store</var>,
11                 <strong>mach_port_t</strong>                             <var>device</var>,
12                 <strong>recnum_t</strong>                                <var>offset</var>,
13                 <strong>recnum_t</strong>                                 <var>count</var>,
14                 <strong>int</strong>                                <var>record_size</var><strong>);</strong>
15</pre>
16<h3>PARAMETERS</h3>
17<dl>
18<p>
19<dt> <var>backing_store</var>
20<dd>
21[in backing store (receive) right] The backing store port.
22<p>
23<dt> <var>device</var>
24<dd>
25[in device port] The port for the device containing the backing storage 
26partition.
27<p>
28<dt> <var>offset</var>
29<dd>
30[in scalar] The offset, in <var>record_size units</var>, to the beginning of the
31backing storage on the device.
32<p>
33<dt> <var>count</var>
34<dd>
35[in scalar] The number of <var>record_size</var> units
36in the partition/segment.
37<p>
38<dt> <var>record_size</var>
39<dd>
40[in scalar] The size, in bytes, of the storage device record.
41</dl>
42<h3>DESCRIPTION</h3>
43<p>
44The <strong>default_pager_add_segment</strong> function is called to add a partition to
45a default pager's backing storage (i.e. expand the amount of backing
46storage available to a memory manager). The kernel does not make
47this call itself (which is why it can be a synchronous call); this
48request is only issued by tasks holding the backing store port,
49created with <strong>default_pager_backing_store_create</strong>, for a default memory
50manager.
51The result is that the pager may use count records on device starting
52at offset for paging, and each record is record_size bytes in length
53(note that the device_* calls are, or can be, record oriented).
54<h3>RETURN VALUES</h3>
55<dl>
56<p>
57<dt> <strong>KERN_FAILURE</strong>
58<dd>
59The default pager does not support this operation.
60<p>
61<dt> <strong>KERN_INVALID_ARGUMENT</strong>
62<dd>
63The <var>backing_store</var> port does not represent a valid backing store or the 
64specified segment overlaps an existing partition.
65<p>
66<dt> <strong>KERN_RESOURCE_SHORTAGE</strong>
67<dd>
68The default pager is unable to allocate internal resources
69     to manage the new backing storage.
70<p>
71<dt> <strong>KERN_SUCCESS</strong>
72<dd>
73The operation was successful.
74</dl>
75<h3>RELATED INFORMATION</h3>
76<p>
77Functions:
78<a href="DP_backing_store_create.html"><strong>default_pager_backing_store_create</strong></a>,
79<a href="DP_backing_store_delete.html"><strong>default_pager_backing_store_delete</strong></a>,
80<a href="DP_backing_store_info.html"><strong>default_pager_backing_store_info</strong></a>.
81