Re: [PATCH 06/13] irq: add a helper spread an affinity mask for MSI/MSI-X vectors

...but now I'll focus on the common/general case! Thanks for the suggestion 
Christoph. I guess would be even better to have a generic function that 
retrieves an optimal mask, something like topology_get_optimal_mask(n, 
*cpumask), in which we get the best distribution of n CPUs among all cores 
and return such a mask - interesting case is when n < num_online_cpus. So, 
this function could be used inside your irq_create_affinity_mask() and 
maybe in other places it is needed.

Yes, we should probably just plug this in where we're using the current
routines.  Block very much optimizes for the cases of either 1 queue
or enough queues for all cpus at the moments.  It would be good to check
what the network drivers currently do.