bridge: Allow users to configure statistics update to OVSDB.
This commit adds a new configuration "stats-update-interval" in
"other_config" of Open_Vswitch table. So users can control the
statistics update frequency. A possible use case is that, users
can lower the update frequency to reduce the cpu consumption of
the ovs-vswitchd thread.
The configured value should always be greater than or equal to
5000 ms. And more frequent statistics update should be achieved
via OpenFlow.
Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Joe Stringer <joestringer@nicira.com>