Added some information to ListenCoresBucketsRatio documentation page already in trunk.

    then make each child handle a single bucket (with round-robin distribution

    of the buckets at children creation time).</p>

    <note><title>Meaning of "online" CPU core</title>

    <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 <directive>ListenCoresBucketsRatio</directive> needs to

    take this parameter into account while calculating the number of buckets to create.</p>

    </note>

    <p><directive>ListenCoresBucketsRatio</directive> 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

    <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>

</usage>

</directivesynopsis>