Slow response time on OVS causing latency inside guest VM when the active port of a dpdkbond is disabled

Issue

• Slow response time on OVS causing latency inside guest VM when the active port of a dpdkbond is disabled:

[root@overcloud-compute-0 ~]# time ovs-ofctl dump-flows br-int 
[...]
real    0m12.839s
user    0m0.001s
sys 0m0.011s

• The following errors are seen in /var/log/openvswitch/ovs-vswitchd.log:

2020-04-08T13:59:02.392Z|24049|poll_loop|INFO|Dropped 9 log messages in last 10 seconds (most recently, 4 seconds ago) due to excessive rate
2020-04-08T13:59:02.392Z|24050|poll_loop|INFO|wakeup due to [POLLIN] on fd 329 (127.0.0.1:53780<->127.0.0.1:6633) at ../lib/stream-fd.c:157 (72% CPU usage)
2020-04-08T13:59:03.781Z|08044|timeval(revalidator439)|WARN|Unreasonably long 1279ms poll interval (0ms user, 0ms system)
2020-04-08T13:59:03.781Z|08045|timeval(revalidator439)|WARN|context switches: 1 voluntary, 0 involuntary
2020-04-08T13:59:03.781Z|05184|timeval(revalidator430)|WARN|Unreasonably long 1279ms poll interval (0ms user, 0ms system)
2020-04-08T13:59:03.781Z|05185|timeval(revalidator430)|WARN|context switches: 1 voluntary, 0 involuntary
2020-04-08T13:59:03.781Z|05254|timeval(revalidator445)|WARN|Unreasonably long 1279ms poll interval (0ms user, 0ms system)
2020-04-08T13:59:03.781Z|05255|timeval(revalidator445)|WARN|context switches: 3 voluntary, 0 involuntary
2020-04-08T13:59:03.781Z|11315|timeval(revalidator426)|WARN|Unreasonably long 1279ms poll interval (0ms user, 0ms system)
2020-04-08T13:59:03.781Z|11316|timeval(revalidator426)|WARN|context switches: 3 voluntary, 0 involuntary
2020-04-08T13:59:03.783Z|24051|timeval|WARN|Unreasonably long 1391ms poll interval (1368ms user, 3ms system)
2020-04-08T13:59:03.783Z|24052|timeval|WARN|context switches: 2 voluntary, 1638 involuntary
2020-04-08T13:59:05.282Z|07784|ovs_rcu(urcu3)|WARN|blocked 1000 ms waiting for pmd92 to quiesce

• Some packet loss is witnessed.