Add a man page section on parallel queries.

diff --git a/doc/man1/haeredes.1 b/doc/man1/haeredes.1
index 2c8508ef36afb5a37a7f39b569064a0496f9787a..569897e603c9af9a56bf82bb7ad685f27adc27e9 100644 (file)
--- a/doc/man1/haeredes.1
+++ b/doc/man1/haeredes.1
@@ -59,7 +59,9 @@ b.iana-servers.net.
 a.iana-servers.net.
 .fi
 .P
-However, if you ask a root server, they will return the response in another section, called \(dqauthority\(dq. The \(dqanswer\(dq section is empty:
+However, if you ask a root server, they will return the response in
+another section, called \(dqauthority\(dq. The \(dqanswer\(dq section
+is empty:
 
 .nf
 .I $ dig +short @a.gtld-servers.net example.com NS
@@ -79,6 +81,16 @@ resolver to check the data on the authoritative nameservers.
 .P
 So that's what we do. In NS mode, Haeredes will check both the
 \(dqanswer\(dq and \(dqauthority\(dq sections for results.
+.SH PARALLEL QUERIES
+.P
+Haeredes can use multiple threads to perform its queries. It will use
+a number of threads equal to the number of processors available to the
+GHC runtime. This can be changed with the \fI+RTS \-N\fR flag. For
+example, to use 10 threads,
+
+.nf
+$ haeredes [OPTIONS] [DELEGATES] \fI+RTS -N10\fR
+.fi
 .SH OPTIONS
 
 .IP \fB\-\-no\-append\-root\fR,\ \fB-n\fR