Re: [Drbd-dev] [PATCH net-next v2] block/drbd: use nla_put_u64_64bit()

From: Lars Ellenberg
Date: Wed May 04 2016 - 08:53:05 EST

On Wed, May 04, 2016 at 02:49:00PM +0200, Nicolas Dichtel wrote:
> Le 04/05/2016 11:05, Lars Ellenberg a écrit :
> [snip]
> > We don't have an "alignment problem" there, btw.
> > Last time I checked, we did work fine without this alignment magic,
> > we already take care of that, yes, even on affected architectures.
> The code adds several consecutive u64 attributes. The nl attribute header is 4
> bytes, thus the full attribute length is 12 bytes. If the first u64 is aligned
> on 8 (nla_data()), the next one is not aligned on 8: it starts 12 bytes (8 (u64)
> + 4 (nl attr hdr)) after the previous u64.

Yes. Which in our case is not a problem.
But I don't object to the padding per se,
if that is how things "should be".

I try to understand why you so much object to using 0 as pad.