Add test for cpu affinity

Add a test to check BIND 9 honors CPU affinity mask. This requires
some changes to the start script, to construct the named command.

bin/tests/system/cpu/tests.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+# shellcheck source=conf.sh
+. ../conf.sh
+
+status=0
+n=0
+
+n=$((n+1))
+echo_i "stop server ($n)"
+ret=0
+$PERL ../stop.pl cpu ns1 || ret=1
+test "$ret" -eq 0 || echo_i "failed"
+status=$((status+ret))
+
+n=$((n+1))
+echo_i "start server with taskset ($n)"
+ret=0
+start_server --noclean --taskset fff0 --restart --port "${PORT}" cpu ns1 || ret=1
+test "$ret" -eq 0 || echo_i "failed"
+status=$((status+ret))
+
+n=$((n+1))
+echo_i "check ps output ($n)"
+ret=0
+ps -T -o pid,psr,time,comm -e > ps.out
+pid=$(cat ns1/named.pid)
+echo_i "pid=$pid"
+psr=$(awk -v pid="$pid" '$1 == pid && $4 == "isc-net-0000" {print $2}' < ps.out)
+echo_i "psr=$psr"
+# The next available cpu relative to the existing affinity mask is 4.
+test "$psr" -eq 4 || ret=1
+test "$ret" -eq 0 || echo_i "failed"
+status=$((status+ret))
+
+echo_i "exit status: $status"
+[ $status -eq 0 ] || exit 1