On Fri, Jan 24, 2014 at 2:58 PM, Jarno Rajahalme <jrajaha...@nicira.com> wrote: > Userspace already sets NLM_F_ECHO when it wants a reply, make use of > it. > > For set and del, OVS userspace only sets the NLM_F_ECHO if stats are > needed back. So, we minimize the data sent back by only responding > with key and stats for ovs_flow_cmd_new, ovs_flow_cmd_set, and > ovs_flow_cmd_del. > > When not returning actions, we can allocate the reply (if requested) > before finding the flow, i.e., before locking anything. We make use > of this in following patches. > > Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
I think this is too tailored to what userspace is currently expecting today. Currently, we send notifications of flow changes to a multicast group and any other subscribers should get notifications even if NLM_F_ECHO is not set. In addition, dropping certain fields depending on what we currently need is definitely API breakage and seems error prone in the future. If the primary benefit here is not holding a lock while doing memory allocation then it seems like we could still make a change along these lines by doing optimistic allocation where we do a lookup with a read lock, allocate the response, and then take the write lock to check the result and perform the action. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
