rhel/systemd: Set ovs-vswitchd timeout to 5 minutes

During initialization, it's possible that the startup time takes longer
than the systemd default provided.  Set this to be 5 minutes.  If we
take longer than 5 minutes, maybe something is wrong.

As an example of long initialization, enable DPDK, and allocate large
numbers of hugepages before starting ovs-vswitchd.  The vswitchd can
take two or more minutes to start.  During that time, systemd will decide
that the startup time took too long, and kill the parent process, leading
eventually to an error like:
   ovs|00011|daemon_unix|EMER|pipe write failed (Broken pipe)

And a systemd log like:
   ovs-vswitchd.service start operation timed out. Terminating.

The 5 minutes setting has been observed to work on a system where 400G
of hugepages were allocated.

Signed-off-by: Aaron Conole <[email protected]>
Acked-by: Markos Chandras <[email protected]>
Acked-by: Timothy Redaelli <[email protected]>
Signed-off-by: Russell Bryant <[email protected]>

rhel/usr_lib_systemd_system_ovs-vswitchd.service

@@ -18,3 +18,4 @@ ExecStop=/usr/share/openvswitch/scripts/ovs-ctl --no-ovsdb-server stop
 ExecReload=/usr/share/openvswitch/scripts/ovs-ctl --no-ovsdb-server \
           --no-monitor --system-id=random \
           restart $OPTIONS
+TimeoutSec=300