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Message-ID: <1453986002.7627.20.camel@edumazet-glaptop2.roam.corp.google.com>
Subject: Re: [PATCH net 0/4] net: add rx_unhandled stat counter
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jarod Wilson <jarod@redhat.com>
Cc: linux-kernel@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>, Jiri Pirko <jiri@mellanox.com>,
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        Veaceslav Falico <vfalico@gmail.com>,
        Andy Gospodarek <gospo@cumulusnetworks.com>, netdev@vger.kernel.org
Date: Thu, 28 Jan 2016 05:00:02 -0800
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On Thu, 2016-01-28 at 01:18 -0500, Jarod Wilson wrote:

> Or not. Now I remember why I added that in the first place:
> 
> In file included from ./arch/x86/include/asm/uaccess.h:7:0,
>                  from net/core/dev.c:75:
> net/core/dev.c: In function 'netdev_stats_to_stats64':
> include/linux/compiler.h:484:20: error: call to '__compiletime_assert_7263' declared with attribute error: BUILD_BUG_ON failed: sizeof(*stats64) != sizeof(*netdev_stats)
>     prefix ## suffix();    \
>                     ^
> 
> Things are actually hard-wired to require that addition at the moment, or
> you get the above build failure. Not sure if it's safe to remove that
> BUILD_BUG_ON() yet, haven't looked closely, it's past my bed time. :)
> 

This was done for the transition from "unsigned long" to "u64", which is
a nop on 64bit arches.

But as we do not need to be compatible, since no linux kernel in the
past had this new field in struct net_device_stats,

and we do not need to add this new field as it is only accessed from
core networking stack [1], you need to adapt this helper.

[1] And maybe some virtual devices like bonding/team