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

From: Aaron Tomlin
Date: Wed Jun 25 2025 - 09:04:51 EST


On Tue, Jun 24, 2025 at 04:29:58PM +0200, Daniel Wagner wrote:
> 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.

Hi Christoph, Daniel,

Understood. I agree, common functionality is indeed preferred.
Daniel, I look forward to your submission.

Kind regards,

--
Aaron Tomlin