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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>Chapter 7. relay interface support</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="The Linux Kernel API" /><link rel="up" href="index.html" title="The Linux Kernel API" /><link rel="prev" href="re269.html" title="__kfifo_get" /><link rel="next" href="re270.html" title="relay_buf_full" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 7. relay interface support</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re269.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="re270.html">Next</a></td></tr></table><hr /></div><div class="chapter" title="Chapter 7. relay interface support"><div class="titlepage"><div><div><h2 class="title"><a id="relayfs"></a>Chapter 7. relay interface support</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="ch07.html#id2992055">relay interface</a></span></dt></dl></div><p>
Relay interface support
is designed to provide an efficient mechanism for tools and
facilities to relay large amounts of data from kernel space to
user space.
</p><div class="sect1" title="relay interface"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="id2992055"></a>relay interface</h2></div></div></div><div class="toc"><dl><dt><span class="refentrytitle"><a href="re270.html"><span>relay_buf_full</span></a></span><span class="refpurpose"> —
boolean, is the channel buffer full?
</span></dt><dt><span class="refentrytitle"><a href="re271.html"><span>relay_reset</span></a></span><span class="refpurpose"> —
reset the channel
</span></dt><dt><span class="refentrytitle"><a href="re272.html"><span>relay_open</span></a></span><span class="refpurpose"> —
create a new relay channel
</span></dt><dt><span class="refentrytitle"><a href="re273.html"><span>relay_switch_subbuf</span></a></span><span class="refpurpose"> —
switch to a new sub-buffer
</span></dt><dt><span class="refentrytitle"><a href="re274.html"><span>relay_subbufs_consumed</span></a></span><span class="refpurpose"> —
update the buffer's sub-buffers-consumed count
</span></dt><dt><span class="refentrytitle"><a href="re275.html"><span>relay_close</span></a></span><span class="refpurpose"> —
close the channel
</span></dt><dt><span class="refentrytitle"><a href="re276.html"><span>relay_flush</span></a></span><span class="refpurpose"> —
close the channel
</span></dt><dt><span class="refentrytitle"><a href="re277.html"><span>relay_mmap_buf</span></a></span><span class="refpurpose"> —
mmap channel buffer to process address space
</span></dt><dt><span class="refentrytitle"><a href="re278.html"><span>relay_alloc_buf</span></a></span><span class="refpurpose"> —
allocate a channel buffer
</span></dt><dt><span class="refentrytitle"><a href="re279.html"><span>relay_create_buf</span></a></span><span class="refpurpose"> —
allocate and initialize a channel buffer
</span></dt><dt><span class="refentrytitle"><a href="re280.html"><span>relay_destroy_channel</span></a></span><span class="refpurpose"> —
free the channel struct
</span></dt><dt><span class="refentrytitle"><a href="re281.html"><span>relay_destroy_buf</span></a></span><span class="refpurpose"> —
destroy an rchan_buf struct and associated buffer
</span></dt><dt><span class="refentrytitle"><a href="re282.html"><span>relay_remove_buf</span></a></span><span class="refpurpose"> —
remove a channel buffer
</span></dt><dt><span class="refentrytitle"><a href="re283.html"><span>relay_buf_empty</span></a></span><span class="refpurpose"> —
boolean, is the channel buffer empty?
</span></dt><dt><span class="refentrytitle"><a href="re284.html"><span>wakeup_readers</span></a></span><span class="refpurpose"> —
wake up readers waiting on a channel
</span></dt><dt><span class="refentrytitle"><a href="re285.html"><span>__relay_reset</span></a></span><span class="refpurpose"> —
reset a channel buffer
</span></dt><dt><span class="refentrytitle"><a href="re286.html"><span>relay_close_buf</span></a></span><span class="refpurpose"> —
close a channel buffer
</span></dt><dt><span class="refentrytitle"><a href="re287.html"><span>relay_hotcpu_callback</span></a></span><span class="refpurpose"> —
CPU hotplug callback
</span></dt><dt><span class="refentrytitle"><a href="re288.html"><span>relay_late_setup_files</span></a></span><span class="refpurpose"> —
triggers file creation
</span></dt><dt><span class="refentrytitle"><a href="re289.html"><span>relay_file_open</span></a></span><span class="refpurpose"> —
open file op for relay files
</span></dt><dt><span class="refentrytitle"><a href="re290.html"><span>relay_file_mmap</span></a></span><span class="refpurpose"> —
mmap file op for relay files
</span></dt><dt><span class="refentrytitle"><a href="re291.html"><span>relay_file_poll</span></a></span><span class="refpurpose"> —
poll file op for relay files
</span></dt><dt><span class="refentrytitle"><a href="re292.html"><span>relay_file_release</span></a></span><span class="refpurpose"> —
release file op for relay files
</span></dt><dt><span class="refentrytitle"><a href="re293.html"><span>relay_file_read_subbuf_avail</span></a></span><span class="refpurpose"> —
return bytes available in sub-buffer
</span></dt><dt><span class="refentrytitle"><a href="re294.html"><span>relay_file_read_start_pos</span></a></span><span class="refpurpose"> —
find the first available byte to read
</span></dt><dt><span class="refentrytitle"><a href="re295.html"><span>relay_file_read_end_pos</span></a></span><span class="refpurpose"> —
return the new read position
</span></dt></dl></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re269.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="re270.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>__kfifo_get</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>relay_buf_full</span></td></tr></table></div></body></html>
