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From: Thomas Graf <tgraf-H+wXaHxf7aLQT0dZR+AlfA@public•gmane.org>
To: Jesse Gross <jesse-l0M0P4e3n4LQT0dZR+AlfA@public•gmane.org>
Cc: "dev-yBygre7rU0TnMu66kgdUjQ@public•gmane.org"
	<dev-yBygre7rU0TnMu66kgdUjQ@public•gmane.org>,
	netdev <netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>
Subject: Re: [PATCH v2] linux: Signal datapath that unaligned Netlink message can be received
Date: Tue, 17 Dec 2013 19:08:59 +0100	[thread overview]
Message-ID: <52B0933B.4030107@redhat.com> (raw)
In-Reply-To: <CAEP_g=8MtthzO=P-JpTE0jH23_EaU+rp4qiwv_Y721vxyZuFTw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.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.

  parent reply	other threads:[~2013-12-17 18:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-30 12:25 [PATCH v2] linux: Signal datapath that unaligned Netlink message can be received Thomas Graf
     [not found] ` <a960865f3ad68da1016f35085c1d84126e92f0a5.1385814128.git.tgraf-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-12-17  1:23   ` Jesse Gross
2013-12-17  9:52     ` Thomas Graf
     [not found]       ` <52B01EE5.4000704-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-12-17 17:49         ` Jesse Gross
     [not found]           ` <CAEP_g=8MtthzO=P-JpTE0jH23_EaU+rp4qiwv_Y721vxyZuFTw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-12-17 18:08             ` Thomas Graf [this message]
2013-12-17 19:21               ` Jesse Gross

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