Re: [PATCH 00/16] dyn_array and nr_irqs support v2

[ebiederm@xmission.com (Eric W. Biederman)]

Yinghai Lu <yhlu.kernel@gmail.com> writes:

> Please check dyn_array support for x86

YH you have not addressed any of my core concerns and this exceeds my review limit.
Unfortunately I don't feel like this is a productive process.

My core concerns are:
- You have not separated out and separately pushed the regression patch.  So that we can
  fix the current rc release.  Simply tuning NR_IRQS is all I feel comfortable with for
  fixing things in the post merge window period.

- The generic code has no business with dealing with NR_IRQS sized arrays.
  Since we don't have a generic problem I don't see why we should have a generic dyn_array solution.

- The dyn_array infrastructure does not provide for per numa node allocation of
  irq_desc structures, limiting NUMA scalability.

- You appear to be papering over problems instead of digging in and actually fixing them.

YH  Here is what I was suggesting when the topic of killing NR_IRQs came up a week or so
ago.
http://lkml.org/lkml/2008/7/10/439
http://lkml.org/lkml/2008/7/10/532

Which essentially boils down to:
- Removing NR_IRQS from the non-irq infrastructure code.
- Add a config option for architectures that are not going to use an array
- In the genirq code have a lookup function that goes from irq number to irq_desc *.

The rest we should be able to handle in a arch dependent fashion.

When we are done we should be able to create a stable irq number for msi interrupts
that is something like:  bus:dev:fun:vector_no which is 8+5+3+12=28 bits long.

Eric