On Wed, 2016-05-04 at 12:50 -0400, David Miller wrote:

From: Eric Dumazet <redacted>
Date: Wed, 04 May 2016 07:27:06 -0700

quoted

kernel was fine, and most user land apps were fine as well.

Userland should really not have to deal with garbage like this.

And because it quietly works just fine on x86-64, nothing makes
sure that applications will universally get this right anyways.

Better to align things properly and magically all of these issues
simply disappear.

Sure, but in practice we end up consuming 16 bytes (instead of 12) per
u64 attribute, only on some arches. 33 % space overhead.

So maybe some dumps will abort on those arches, while on x86 the size of
skb might be below some magic limit.

I guess this is fine, we do not break ABI in any way.