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From:   Jarod Wilson <jarod@redhat.com>
Date:   Thu, 13 Aug 2020 10:06:56 -0400
Message-ID: <CAKfmpSeRsh4tYaQPg22d8L92i1jEP3J9Y5G8udutGruVURa=Fg@mail.gmail.com>
Subject: Re: [PATCH net] bonding: show saner speed for broadcast mode
To:     Jay Vosburgh <jay.vosburgh@canonical.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Veaceslav Falico <vfalico@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        "David S. Miller" <davem@davemloft.net>,
        Netdev <netdev@vger.kernel.org>
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On Thu, Aug 13, 2020 at 1:30 AM Jay Vosburgh <jay.vosburgh@canonical.com> wrote:
>
> Jarod Wilson <jarod@redhat.com> wrote:
>
> >Broadcast mode bonds transmit a copy of all traffic simultaneously out of
> >all interfaces, so the "speed" of the bond isn't really the aggregate of
> >all interfaces, but rather, the speed of the lowest active interface.
>
>         Did you mean "slowest" here?

I think I was thinking "lowest speed", but the way it's written does
seem a little ambiguous, and slowest would fit better. I'll repost
with slowest.

> >Also, the type of the speed field is u32, not unsigned long, so adjust
> >that accordingly, as required to make min() function here without
> >complaining about mismatching types.
> >
> >Fixes: bb5b052f751b ("bond: add support to read speed and duplex via ethtool")
> >CC: Jay Vosburgh <j.vosburgh@gmail.com>
> >CC: Veaceslav Falico <vfalico@gmail.com>
> >CC: Andy Gospodarek <andy@greyhouse.net>
> >CC: "David S. Miller" <davem@davemloft.net>
> >CC: netdev@vger.kernel.org
> >Signed-off-by: Jarod Wilson <jarod@redhat.com>
>
>         Did you notice this by inspection, or did it come up in use
> somewhere?  I can't recall ever hearing of anyone using broadcast mode,
> so I'm curious if there is a use for it, but this change seems
> reasonable enough regardless.

Someone working on our virt management tools was working on something
displaying bonding speeds in the UI, and reached out, thinking the
reporting for broadcast mode was wrong. My response was similar: I
don't think I've ever actually used broadcast mode or heard of anyone
using it, but for that one person who does, sure, we can probably make
that adjustment. :)

-- 
Jarod Wilson
jarod@redhat.com