Re: Affinity managed interrupts vs non-managed interrupts

[Christoph Hellwig]

On Sat, Sep 01, 2018 at 12:48:46AM +0200, Thomas Gleixner wrote:
> > We want some changes in current API which can allow us to  pass flags
> > (like *local numa affinity*) and cpu-msix mapping are from local numa node
> > + effective cpu are spread across local numa node.
> 
> What you really want is to split the vector space for your device into two
> blocks. One for the regular per cpu queues and the other (16 or how many
> ever) which are managed separately, i.e. spread out evenly. That needs some
> extensions to the core allocation/management code, but that shouldn't be a
> huge problem.

Note that there are some other uses cases for multiple sets of affinity
managed irqs.  Various network devices insist on having separate TX vs
RX interrupts for example.