Re: [PATCH net-next v6 06/15] ethtool: netlink bitset handling

Johannes Berg
2019-07-04T12:22:01Z

On Thu, 2019-07-04 at 14:17 +0200, Michal Kubecek wrote:
> On Thu, Jul 04, 2019 at 02:03:02PM +0200, Johannes Berg wrote:
> > On Thu, 2019-07-04 at 13:52 +0200, Michal Kubecek wrote:
> > >
> > > There is still the question if it it should be implemented as a nested
> > > attribute which could look like the current compact form without the
> > > "list" flag (if there is no mask, it's a list). Or an unstructured data
> > > block consisting of u32 bit length
> >
> > You wouldn't really need the length, since the attribute has a length
> > already :-)
>
> It has byte length, not bit length. The bitmaps we are dealing with
> can have any bit length, not necessarily multiples of 8 (or even 32).

Not sure why that matters? You have the mask, so you don't really need
to additionally say that you're only going up to a certain bit?

I mean, say you want to set some bits <=17, why would you need to say
that they're <=17 if you have a
value: 0b00000000'000000xx'xxxxxxxx'xxxxxxxx
mask: 0b00000000'00000011'11111111'11111111

johannes