LUDOC-229 debugging: Add console message rate limiting section

Added a section under section 29.2 "Lustre Debugging Procedures" which
covers the libcfs module parameters which can be used to control
Lustre console message rate limiting.  The new section covers
disabling the rate limiting entirely as well as modifying the minimum
and maximum message delays.

Signed-off-by: Ryan Haasken <haasken@cray.com>
Change-Id: If9bcb7fa7bdfd40fce37aa3c36358ed21bcaf138
Reviewed-on: http://review.whamcloud.com/9566
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Reviewed-by: Richard Henwood <richard.henwood@intel.com>

diff --git a/LustreDebugging.xml b/LustreDebugging.xml
index eb5b1a2..32fd72b 100644 (file)
--- a/LustreDebugging.xml
+++ b/LustreDebugging.xml
@@ -717,6 +717,13 @@ Filesystem volume name:   myth-OST0004
 lctl> show dlmtrace 
 lctl&gt; debug_kernel [<replaceable>filename</replaceable>] </screen>
     </section>
+    <section remap="h3">
+      <title>Controlling Console Message Rate Limiting</title>
+      <para>Some console messages which are printed by Lustre are rate limited.  When such messages are printed, they may be followed by a message saying "Skipped N previous similar message(s)," where N is the number of messages skipped.  This rate limiting can be completely disabled by a libcfs module parameter called <literal>libcfs_console_ratelimit</literal>.  To disable console message rate limiting, add this line to <literal>/etc/modprobe.d/lustre.conf</literal> and then reload Lustre modules.</para>
+      <screen>options libcfs libcfs_console_ratelimit=0</screen>
+      <para>It is also possible to set the minimum and maximum delays between rate-limited console messages using the module parameters <literal>libcfs_console_max_delay</literal> and <literal>libcfs_console_min_delay</literal>.  Set these in <literal>/etc/modprobe.d/lustre.conf</literal> and then reload Lustre modules.  Additional information on libcfs module parameters is available via <literal>modinfo</literal>:</para>
+      <screen>modinfo libcfs</screen>
+    </section>
   </section>
   <section xml:id="dbdoclet.50438274_80443">
     <title><indexterm><primary>debugging</primary><secondary>developers tools</secondary></indexterm>Lustre Debugging for Developers</title>