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

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 8/24/2018 3:05 PM, Chas Williams wrote:
> 
> 
> On Fri, Aug 24, 2018 at 6:39 AM Ferruh Yigit <ferruh.yigit@intel.com
> <mailto: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>
>     > <mailto: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>
>     >     <mailto: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>
>     <mailto:stable@dpdk.org <mailto:stable@dpdk.org>>
>     >     >>>>
>     >     >>>> Signed-off-by: Radu Nicolau <radu.nicolau@intel.com
>     <mailto:radu.nicolau@intel.com>
>     >     <mailto:radu.nicolau@intel.com <mailto:radu.nicolau@intel.com>>>
>     >     >>>
>     >     >>> Acked-by: Declan Doherty <declan.doherty@intel.com
>     <mailto:declan.doherty@intel.com>
>     >     <mailto: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.

Yes, intention seems as you said, there is an unit test that expects active
slave count to be 0 after bond port stopped.
Your change to remove setting active slave count to zero on bond stop causes
that test fail.
To fix the unit test, all slaves stopped and deactivated.

I think it is still clear if that expectation from unit test coming from bonding
requirement and development assumption. But will get the patch, with updated
fixes line, to fix the unit test.

> 
> 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.
> 
> 
> 
>