Re: [RFC PATCH v2 1/1] scsi: mpi3mr: Introduce smp_affinity_enable module parameter

[Daniel Wagner]

On Sun, Jun 22, 2025 at 10:17:51PM -0700, Christoph Hellwig wrote:
> On Wed, Jun 18, 2025 at 07:49:16AM +0100, John Garry wrote:
> > BTW, if you use taskset to set the affinity of a process and ensure that
> > /sys/block/xxx/queue/rq_affinity is set so that we complete on same CPU as
> > submitted, then I thought that this would ensure that interrupts are not
> > bothering other CPUs.
> 
> The RT folks want to not even have interrupts on the application CPUs.
> That's perfectly reasonable and a common request.  Why doing driver
> hacks as in this patch and many others is so completely insane.  Instead
> we need common functionality for that.  The core irq layer has added
> them for managed interrupts, and Daniel has been working on the blk-mq side
> for a while.

Indeed, I am in the process to finish the work on my next version for
the isolcpus support in the block layer. I hope to send it out the next
version this week.