Re: [next-queue 1/3] i40e: Store the irq number in i40e_q_vector

[Maciej Fijalkowski <maciej.fijalkowski@intel.com>]

On Wed, Oct 05, 2022 at 12:37:19PM -0700, Jesse Brandeburg wrote:
> On 10/5/2022 11:40 AM, Joe Damato wrote:
> 
> > > If you're really wanting to reorganize these structs I'd prefer a bit more
> > > diligent effort to prove no inadvertent side effects (like maybe by turning
> > > up the interrupt rate and looking at perf data while receiving 512 byte
> > > packets. The rate should remain the same (or better) and the number of cache
> > > misses on these structs should remain roughly the same. Maybe a seperate
> > > patch series?
> > 
> > I honestly did think that reorganizing the struct was probably out of scope
> > of this change, so if you agree so I'll drop this change from the v2 and
> > keep the original which adds irq_num to the end of the struct.
> 
> I agree, especially in these routines, doing simple, explainable/observable
> changes is best.

Jesse, I recall now that this weird qvector struct layout is also the case
on ice driver. Maybe we should document it somewhere/somehow (or even
explain) to avoid touching it? I believe that not only me would have such
a knee-jerk reaction to try to pack it.