faq: unload kernel module when non-zero refcnt.
Describe the issue about reference count and how to
drop it and unload the kernel module.
Cc: Greg Rose
@@ -419,3 +419,17 @@ Q: I just upgraded and I see a performance drop. Why?
To get the best possible performance and functionality, it is recommended
to pair the same versions of the kernel module and OVS userspace.
+
+Q: I can't unload the openvswitch kernel module. Why?
+
+ A: The userspace might still hold the reference count. So ``rmmod openvswitch``
+ does not work, for example::
+
+ $ lsmod | grep openvswitch
+ openvswitch 155648 4
+ nf_conncount 24576 1 openvswitch
+
+ Use the command below to drop the refcnt::
+
+ $ ovs-dpctl del-dp system@ovs-system
+ $ rmmod openvswitch
