Re: [PATCH net 0/4] net: add rx_unhandled stat counter

From: Eric Dumazet
Date: Thu Jan 28 2016 - 08:00:13 EST


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