From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH net-next v3] net: ipv4: add support for ECMP hash policy
 choice
Date: Wed, 15 Mar 2017 08:20:23 -0700
Message-ID: <20170315082023.2a976f0b@xeon-e3>
References: <1489505775-2913-1-git-send-email-nikolay@cumulusnetworks.com>
        <20170314085502.47d48a4e@xeon-e3>
        <8088fe5f-0c0b-bdba-4fba-e9e28bbed02e@cumulusnetworks.com>
        <20170314.114837.619141079617104809.davem@davemloft.net>
        <20170314132506.6233b1e7@xeon-e3>
        <CAJieiUjeYH=u6W5p18JA=RwKuFpX6HSrifD0fRE1rR2e0fsvhw@mail.gmail.com>
        <20170314144204.20d5c3a5@xeon-e3>
        <CAJieiUgQpOidyE-OH73QQpMcQnzEgd+9bGPOKA-yAaFtb3fcwQ@mail.gmail.com>
        <20170314162715.141f1d4b@xeon-e3>
        <0c0473f7-beab-ea87-6dde-77aa345258ff@cumulusnetworks.com>
        <5b5cf0ac-d152-3c8e-d54b-1059f561efee@6wind.com>
        <5c0b73c5-ee6b-d67f-b01e-0d749c8ced6d@cumulusnetworks.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: nicolas.dichtel@6wind.com,
        Roopa Prabhu <roopa@cumulusnetworks.com>,
        David Miller <davem@davemloft.net>,
        Nikolay Aleksandrov <nikolay@cumulusnetworks.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>, jkbs@redhat.com,
        Eric Dumazet <edumazet@google.com>,
        Peter Christensen <pch@ordbogen.com>
To: David Ahern <dsa@cumulusnetworks.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mail-pf0-f169.google.com ([209.85.192.169]:36181 "EHLO
        mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751416AbdCOPUc (ORCPT
        <rfc822;netdev@vger.kernel.org>); Wed, 15 Mar 2017 11:20:32 -0400
Received: by mail-pf0-f169.google.com with SMTP id o126so10305973pfb.3
        for <netdev@vger.kernel.org>; Wed, 15 Mar 2017 08:20:31 -0700 (PDT)
In-Reply-To: <5c0b73c5-ee6b-d67f-b01e-0d749c8ced6d@cumulusnetworks.com>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

On Wed, 15 Mar 2017 09:01:16 -0600
David Ahern <dsa@cumulusnetworks.com> wrote:

> On 3/15/17 3:17 AM, Nicolas Dichtel wrote:
> >>> Is there another patch to add the NETCONFA_ECMP support?
> >>>  
> >>
> >> does userspace care?  
> > Yes, I think it is needed so that userspace can correctly monitor this behavior.
> > It also enables to check this parameter through netlink.
> >   
> 
> I don't understand why userspace cares. What can userspace do with that
> information?

There are cases such as routing or switch control from userspace where the desire
is to track kernel behavior in an external program. I know of at least 3 cases where
this is done.