xref: /xnu-10002.61.3/osfmk/man/default_pager_add_segment.html (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1*0f4c859eSApple OSS Distributions<h2>default_pager_add_segment</h2>
2*0f4c859eSApple OSS Distributions<hr>
3*0f4c859eSApple OSS Distributions<p>
4*0f4c859eSApple OSS Distributions<strong>Server Interface</strong> - Add additional backing storage for a default pager.
5*0f4c859eSApple OSS Distributions<h3>SYNOPSIS</h3>
6*0f4c859eSApple OSS Distributions<pre>
7*0f4c859eSApple OSS Distributions<strong>#include&lt mach/default_pager_object.h&gt</strong>
8*0f4c859eSApple OSS Distributions
9*0f4c859eSApple OSS Distributions<strong>kern_return_t   default_pager_add_segment</strong>
10*0f4c859eSApple OSS Distributions                <strong>(mach_port_t</strong>                      <var>backing_store</var>,
11*0f4c859eSApple OSS Distributions                 <strong>mach_port_t</strong>                             <var>device</var>,
12*0f4c859eSApple OSS Distributions                 <strong>recnum_t</strong>                                <var>offset</var>,
13*0f4c859eSApple OSS Distributions                 <strong>recnum_t</strong>                                 <var>count</var>,
14*0f4c859eSApple OSS Distributions                 <strong>int</strong>                                <var>record_size</var><strong>);</strong>
15*0f4c859eSApple OSS Distributions</pre>
16*0f4c859eSApple OSS Distributions<h3>PARAMETERS</h3>
17*0f4c859eSApple OSS Distributions<dl>
18*0f4c859eSApple OSS Distributions<p>
19*0f4c859eSApple OSS Distributions<dt> <var>backing_store</var>
20*0f4c859eSApple OSS Distributions<dd>
21*0f4c859eSApple OSS Distributions[in backing store (receive) right] The backing store port.
22*0f4c859eSApple OSS Distributions<p>
23*0f4c859eSApple OSS Distributions<dt> <var>device</var>
24*0f4c859eSApple OSS Distributions<dd>
25*0f4c859eSApple OSS Distributions[in device port] The port for the device containing the backing storage
26*0f4c859eSApple OSS Distributionspartition.
27*0f4c859eSApple OSS Distributions<p>
28*0f4c859eSApple OSS Distributions<dt> <var>offset</var>
29*0f4c859eSApple OSS Distributions<dd>
30*0f4c859eSApple OSS Distributions[in scalar] The offset, in <var>record_size units</var>, to the beginning of the
31*0f4c859eSApple OSS Distributionsbacking storage on the device.
32*0f4c859eSApple OSS Distributions<p>
33*0f4c859eSApple OSS Distributions<dt> <var>count</var>
34*0f4c859eSApple OSS Distributions<dd>
35*0f4c859eSApple OSS Distributions[in scalar] The number of <var>record_size</var> units
36*0f4c859eSApple OSS Distributionsin the partition/segment.
37*0f4c859eSApple OSS Distributions<p>
38*0f4c859eSApple OSS Distributions<dt> <var>record_size</var>
39*0f4c859eSApple OSS Distributions<dd>
40*0f4c859eSApple OSS Distributions[in scalar] The size, in bytes, of the storage device record.
41*0f4c859eSApple OSS Distributions</dl>
42*0f4c859eSApple OSS Distributions<h3>DESCRIPTION</h3>
43*0f4c859eSApple OSS Distributions<p>
44*0f4c859eSApple OSS DistributionsThe <strong>default_pager_add_segment</strong> function is called to add a partition to
45*0f4c859eSApple OSS Distributionsa default pager's backing storage (i.e. expand the amount of backing
46*0f4c859eSApple OSS Distributionsstorage available to a memory manager). The kernel does not make
47*0f4c859eSApple OSS Distributionsthis call itself (which is why it can be a synchronous call); this
48*0f4c859eSApple OSS Distributionsrequest is only issued by tasks holding the backing store port,
49*0f4c859eSApple OSS Distributionscreated with <strong>default_pager_backing_store_create</strong>, for a default memory
50*0f4c859eSApple OSS Distributionsmanager.
51*0f4c859eSApple OSS DistributionsThe result is that the pager may use count records on device starting
52*0f4c859eSApple OSS Distributionsat offset for paging, and each record is record_size bytes in length
53*0f4c859eSApple OSS Distributions(note that the device_* calls are, or can be, record oriented).
54*0f4c859eSApple OSS Distributions<h3>RETURN VALUES</h3>
55*0f4c859eSApple OSS Distributions<dl>
56*0f4c859eSApple OSS Distributions<p>
57*0f4c859eSApple OSS Distributions<dt> <strong>KERN_FAILURE</strong>
58*0f4c859eSApple OSS Distributions<dd>
59*0f4c859eSApple OSS DistributionsThe default pager does not support this operation.
60*0f4c859eSApple OSS Distributions<p>
61*0f4c859eSApple OSS Distributions<dt> <strong>KERN_INVALID_ARGUMENT</strong>
62*0f4c859eSApple OSS Distributions<dd>
63*0f4c859eSApple OSS DistributionsThe <var>backing_store</var> port does not represent a valid backing store or the
64*0f4c859eSApple OSS Distributionsspecified segment overlaps an existing partition.
65*0f4c859eSApple OSS Distributions<p>
66*0f4c859eSApple OSS Distributions<dt> <strong>KERN_RESOURCE_SHORTAGE</strong>
67*0f4c859eSApple OSS Distributions<dd>
68*0f4c859eSApple OSS DistributionsThe default pager is unable to allocate internal resources
69*0f4c859eSApple OSS Distributions     to manage the new backing storage.
70*0f4c859eSApple OSS Distributions<p>
71*0f4c859eSApple OSS Distributions<dt> <strong>KERN_SUCCESS</strong>
72*0f4c859eSApple OSS Distributions<dd>
73*0f4c859eSApple OSS DistributionsThe operation was successful.
74*0f4c859eSApple OSS Distributions</dl>
75*0f4c859eSApple OSS Distributions<h3>RELATED INFORMATION</h3>
76*0f4c859eSApple OSS Distributions<p>
77*0f4c859eSApple OSS DistributionsFunctions:
78*0f4c859eSApple OSS Distributions<a href="DP_backing_store_create.html"><strong>default_pager_backing_store_create</strong></a>,
79*0f4c859eSApple OSS Distributions<a href="DP_backing_store_delete.html"><strong>default_pager_backing_store_delete</strong></a>,
80*0f4c859eSApple OSS Distributions<a href="DP_backing_store_info.html"><strong>default_pager_backing_store_info</strong></a>.
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