Documentation rebuild

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1748952 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/mod/mpm_common.html.en b/docs/manual/mod/mpm_common.html.en
index 0085cd421eee68afbab344fc3300eddb1237e5e8..a92386d608bce5a9bf81d58624577697a9e5b3bf 100644 (file)
--- a/docs/manual/mod/mpm_common.html.en
+++ b/docs/manual/mod/mpm_common.html.en
@@ -279,6 +279,13 @@ in *BSDs.</td></tr>
     then make each child handle a single bucket (with round-robin distribution
     of the buckets at children creation time).</p>
 
+    <div class="note"><h3>Meaning of "online" CPU core</h3>
+    <p>On Linux (and also BSD) a CPU core can be turned on/off if 
+    <a href="https://www.kernel.org/doc/Documentation/cpu-hotplug.txt">Hotplug</a> 
+    is configured, therefore <code class="directive">ListenCoresBucketsRatio</code> needs to
+    take this parameter into account while calculating the number of buckets to create.</p>
+    </div>
+
     <p><code class="directive">ListenCoresBucketsRatio</code> can improve the
     scalability when accepting new connections is/becomes the bottleneck.
     On systems with a large number of CPU cores, enabling this feature has
@@ -288,7 +295,10 @@ in *BSDs.</td></tr>
     <p>There must be at least twice the number of CPU cores than the
     configured <var>ratio</var> for this to be active. The recommended
     <var>ratio</var> is <code>8</code>, hence at least <code>16</code>
-    cores should be available at runtime when this value is used.</p>
+    cores should be available at runtime when this value is used.
+    The right <var>ratio</var> to obtain maximum performance needs to be calculated
+    for each target system, testing multiple values and observing the variations in your 
+    key performance metrics.</p>
 
 </div>
 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>