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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>__init/__exit/__initdata include/linux/init.h</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="Unreliable Guide To Hacking The Linux Kernel" /><link rel="up" href="ch06.html" title="Chapter 6. Common Routines" /><link rel="prev" href="ch06s09.html" title="smp_processor_id() include/asm/smp.h" /><link rel="next" href="ch06s11.html" title="__initcall()/module_init() include/linux/init.h" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="type">__init</span>/<span class="type">__exit</span>/<span class="type">__initdata</span>
<code class="filename">include/linux/init.h</code></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch06s09.html">Prev</a> </td><th width="60%" align="center">Chapter 6. Common Routines</th><td width="20%" align="right"> <a accesskey="n" href="ch06s11.html">Next</a></td></tr></table><hr /></div><div class="sect1" title="__init/__exit/__initdata include/linux/init.h"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="routines-init"></a><span class="type">__init</span>/<span class="type">__exit</span>/<span class="type">__initdata</span>
<code class="filename">include/linux/init.h</code></h2></div></div></div><p>
After boot, the kernel frees up a special section; functions
marked with <span class="type">__init</span> and data structures marked with
<span class="type">__initdata</span> are dropped after boot is complete: similarly
modules discard this memory after initialization. <span class="type">__exit</span>
is used to declare a function which is only required on exit: the
function will be dropped if this file is not compiled as a module.
See the header file for use. Note that it makes no sense for a function
marked with <span class="type">__init</span> to be exported to modules with
<code class="function">EXPORT_SYMBOL()</code> - this will break.
</p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch06s09.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch06.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch06s11.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><code class="function">smp_processor_id</code>()
<code class="filename">include/asm/smp.h</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <code class="function">__initcall()</code>/<code class="function">module_init()</code>
<code class="filename">include/linux/init.h</code></td></tr></table></div></body></html>
