Re: [PATCH net-next v8 1/2] net/sched: cls_flower: remove unions from fl_flow_key

[Simon Horman]

On Mon, Mar 16, 2026 at 04:19:17PM -0700, Jakub Kicinski wrote:
> On Mon, 16 Mar 2026 08:34:47 +0000 Simon Horman wrote:
> > On Sat, Mar 14, 2026 at 10:00:02AM -0700, Jakub Kicinski wrote:
> > > On Fri, 13 Mar 2026 13:26:51 +0000 Simon Horman wrote:  
> > > > It seems to me that the use of a union is intentional here, as either IPv4
> > > > or IPv6 addresses can be present in each case - never both.  And that
> > > > control.addr_type and enc_control.addr_type are intended to allow
> > > > differentiation of the address type in use for each of these unions.  
> > > 
> > > My reading was that the initial author simply wanted to save space in
> > > the struct.
> > > 
> > > As the commit message explains this leads to complications in the logic
> > > which sets the keys. The alternative is to complicate
> > > FL_KEY_SET_IF_MASKED - doable, but given that the union feels like a
> > > micro-optimization in the first place the simpler approach of separating
> > > fields seems okay too? (TBH my mind also initially went down the
> > > FL_KEY_SET_IF_MASKED rabbit hole but once I saw the simplicity of
> > > Cedric's patch I changed my mind)  
> > 
> > Sure, now this has been put to me more than once I agree.
> > 
> > But if we go this way, then can we also simplify some of the existing logic?
> > As a follow-up?
> 
> Which logic do you have in mind? Sorry if I'm being slow.

Sorry for being vague.
Let me do my homework and come back if I have a concrete suggestion.