Re: [PATCH V2] nvme-pci: assign separate irq vectors for adminq and ioq0

From: Christoph Hellwig
Date: Thu Mar 08 2018 - 02:42:27 EST


On Thu, Mar 01, 2018 at 09:10:42AM -0700, Keith Busch wrote:
> On Thu, Mar 01, 2018 at 11:03:30PM +0800, Ming Lei wrote:
> > If all CPUs for the 1st IRQ vector of admin queue are offline, then I
> > guess NVMe can't work any more.
>
> Yikes, with respect to admin commands, it appears you're right if your
> system allows offlining CPU0.
>
> > So looks it is a good idea to make admin queue's IRQ vector assigned as
> > non-managed IRQs.
>
> It'd still be considered managed even if it's a 'pre_vector', though
> it would get the default mask with all possible CPUs.

Which basically does the right thing. So I suspect we'll need to
go with a patch like this, just with a way better changelog.