From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: [PATCH v2] linux: Signal datapath that unaligned Netlink message can be received Date: Tue, 17 Dec 2013 19:08:59 +0100 Message-ID: <52B0933B.4030107@redhat.com> References: <52B01EE5.4000704@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Cc: "dev-yBygre7rU0TnMu66kgdUjQ@public.gmane.org" , netdev To: Jesse Gross Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dev-bounces-yBygre7rU0TnMu66kgdUjQ@public.gmane.org Errors-To: dev-bounces-yBygre7rU0TnMu66kgdUjQ@public.gmane.org List-Id: netdev.vger.kernel.org On 12/17/2013 06:49 PM, Jesse Gross wrote: > I think there's also a potential downgrade issue if we add a new > feature to the list of capabilities - it won't automatically reset > since userspace is now using v2 of the netlink protocol. Obviously, > this isn't an issue yet but it we should make sure that it is > addressed before there is a release. >> Defining the NLM_F_REPLACE semantics is non trivial if we want to do >> more than just update the settings. I will propose this in a follow up >> patch. > > Couldn't userspace just issue an OVS_DP_CMD_SET on start? Right, that works as well but introduces a small race compared to NLM_F_REPLACE which would be atomic. I think we can live with that. I will send a v3 of this patch with dpif-linux changed to issue OVS_DP_CMD_SET first and fall back to OVS_DP_CMD_NEW if no DP exists.