Perf/memleak (#1791)

* perf: disable mlockall to reduce memory usage

mlockall will lock all virtual memory page into physic memory and prevent memory recycle.
With this option rss size reduced from 39M to 7M

* perf: fix memory leak

dist/images/Dockerfile.base

@@ -14,6 +14,8 @@ RUN apt update && apt install build-essential git libnuma-dev autoconf curl \
 RUN cd /usr/src/ && \
     git clone -b ovn-22.03.1 --depth=1 https://github.com/kubeovn/ovs.git && \
     cd ovs && \
+    # fix memleak
+    curl -s https://github.com/kubeovn/ovs/commit/2dc8e7aa202818952b2fa80b47298604530c9de0.patch | git apply && \
     # increase election timer
     curl -s https://github.com/kubeovn/ovs/commit/22ea22c40b46ee5adeae977ff6cfca81b3ff25d7.patch | git apply && \
     # compile without avx512

dist/images/start-ovs.sh

@@ -135,7 +135,7 @@ function exchange_link_names() {
 exchange_link_names
 
 # Start vswitchd. restart will automatically set/unset flow-restore-wait which is not what we want
-/usr/share/openvswitch/scripts/ovs-ctl start --no-ovsdb-server --system-id=random
+/usr/share/openvswitch/scripts/ovs-ctl start --no-ovsdb-server --system-id=random --no-mlockall
 /usr/share/openvswitch/scripts/ovs-ctl --protocol=udp --dport=6081 enable-protocol
 
 sleep 1