swish/commit

Include ping

diff --git a/applications/swish.pl b/applications/swish.pl
index efeaaae..04bbb6d 100644
--- a/applications/swish.pl
+++ b/applications/swish.pl
@@ -92,12 +92,16 @@ user:file_search_path(render, library(swish/render)).
 %        only running queries and saving files is restricted. Note
 %        that this flag has no effect if no authentication module is
 %        loaded.
+%        - ping
+%        Ping pengine status every N seconds.  Updates sparkline
+%        chart with stack usage.
 
 swish_config:config(show_beware,    false).
 swish_config:config(tabled_results, true).
 swish_config:config(application,    swish).
 swish_config:config(csv_formats,    [rdf, prolog]).
 swish_config:config(public_access,  true).
+swish_config:config(ping,           10).
 
 %%     swish_config:source_alias(Alias, Options) is nondet.
 %