Merge branch 'sf/erts_de_busy_limit' into dev

* sf/erts_de_busy_limit:
  Add flag-based setting for the distribution buffer busy limit

2 files changed, 26 insertions, 0 deletions

diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index e36d0adb0d..09c9cf6812 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -906,6 +906,25 @@
           <seealso marker="kernel:error_logger#warning_map/0">error_logger(3)</seealso>
           for further information.</p>
       </item>
+      <tag><c><![CDATA[+zFlag Value]]></c></tag>
+      <item>
+        <p>Miscellaneous flags.</p>
+        <taglist>
+          <tag><marker id="+zdbbl"><c>+zdbbl size</c></marker></tag>
+          <item>
+            <p>Set the distribution buffer busy limit
+	    (<seealso marker="erlang#system_info_dist_buf_busy_limit">dist_buf_busy_limit</seealso>)
+	    in kilobytes. Valid range is 1-2097151. Default is 128.</p>
+            <p>A larger buffer limit will allow processes to buffer
+            more outgoing messages over the distribution. When the
+            buffer limit has been reached, sending processes will be
+            suspended until the buffer size has shrunk. The buffer
+            limit is per distribution channel. A higher limit will
+            give lower latency and higher throughput at the expense
+            of higher memory usage.</p>
+          </item>
+        </taglist>
+      </item>
     </taglist>
   </section>
 
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 59ac3dc66c..25c92bdbb7 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -5624,6 +5624,13 @@ true</pre>
 	      The return value will always be <c>false</c> since
 	      the elib_malloc allocator has been removed.</p>
           </item>
+          <tag><marker id="system_info_dist_buf_busy_limit"><c>dist_buf_busy_limit</c></marker></tag>
+          <item>
+            <p>Returns the value of the distribution buffer busy limit
+	    in bytes. This limit can be set on startup by passing the
+	    <seealso marker="erl#+zdbbl">+zdbbl</seealso> command line
+	    flag to <c>erl</c>.</p>
+          </item>
           <tag><c>fullsweep_after</c></tag>
           <item>
             <p>Returns <c>{fullsweep_after, int()}</c> which is the