Re: [dpdk-dev] [dpdk-stable] [PATCH] net/bonding: stop and deactivate slaves when bonding port is stopped

[Chas Williams <3chas3@gmail.com>]

On Fri, Aug 24, 2018 at 6:39 AM Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> On 8/23/2018 4:21 PM, Chas Williams wrote:
> >
> >
> > On Thu, Aug 23, 2018 at 9:15 AM Ferruh Yigit <ferruh.yigit@intel.com
> > <mailto:ferruh.yigit@intel.com>> wrote:
> >
> >     On 8/6/2018 4:50 PM, Chas Williams wrote:
> >     > On Sun, Aug 5, 2018 at 5:55 PM Thomas Monjalon <
> thomas@monjalon.net
> >     <mailto:thomas@monjalon.net>> wrote:
> >     >
> >     >> 02/08/2018 15:38, Doherty, Declan:
> >     >>> On 01/08/2018 2:18 PM, Radu Nicolau wrote:
> >     >>>> When a bonding port is stopped also stop and deactivate all
> slaves.
> >     >>>> Otherwise slaves will be still listed as active.
> >     >>>>
> >     >>>> Fixes: 69bce062132b ("net/bonding: do not clear active slave
> count")
> >     >>>> Cc: stable@dpdk.org <mailto:stable@dpdk.org>
> >     >>>>
> >     >>>> Signed-off-by: Radu Nicolau <radu.nicolau@intel.com
> >     <mailto:radu.nicolau@intel.com>>
> >     >>>
> >     >>> Acked-by: Declan Doherty <declan.doherty@intel.com
> >     <mailto:declan.doherty@intel.com>>
> >     >>
> >     >> Waiting for opinion from the other bonding maintainer (Chas)
> >     >> who started to review and has some doubts.
> >     >>
> >     >
> >     > The slaves being listed as active is not a bug.  If the slaves are
> not
> >     > deactivated, then they should be considered activated.  Previously,
> >     > stopping the bonding PMD just reset the active slave count.  That's
> >     > not the right way to deactivate slaves.  This was fixed by
> 69bce062132b.
> >     >
> >     > This patch is new behavior of explicitly deactivating the slaves
> when
> >     > the bonding PMD is stopped.
> >     >
> >     > As I mentioned, I think this makes life difficult for those of us
> using
> >     > an external state machine.  However, that should probably be fixed
> >     > differently then.
> >     >
> >     >
> >     >>
> >     >> Chas, please do you agree with Declan's ack?
> >     >>
> >     >>
> >     >>
> >     > Change the Fixes line.
> >
> >     Hi Chas,
> >
> >     Are you OK with the rest of the patch if Fixes line fixed?
> >     If already have a proposed fixes line I can fix it while merging.
> >
> >
> > Yes, the rest of the patch is fine as long as the Fixes is correct.
> > Try this:
> >
> >     Fixes: 2efb58cbab6e ("bond: new link bonding library")
> >
> > And it's really new behavior.  Perhaps Fixes: isn't quite right.
> > The current code works fine with activated slaves existing outside
> > of the stop/star.
>
> From your description dropping Fixes line seems OK, but it will effect if
> the
> patch backported or not.
>

Then dont' drop the Fixes line.  See below.


> Isn't it clear from bonding requirement what should slave ports' status be
> when
> bonding port it stopped?
>

I am guessing the author's original intent was to deactivate all the
slaves because he reset the activate slave count to 0.  However, that
didn't actually deactivate a slave and later activating an already
active slave after another start would result in some odd failures.

In a more existential sense, what does active mean?  In the case of
802.3ad, a slave is potentially active until the protocol says otherwise
which means a timeout.  So the stopped/started aspect of the port
isn't necessarily a concern.  If you are just briefly stopping a
port to reconfigure, perhaps you don't want to renegotiate the
802.3ad state.  Of course, if you reconfigure a port, there is a
good chance you want to renegotiate with the other end anyway.

TL;DR -- fine with this patch.  Add new Fixes line so backported.