Question: How to set the `smp_affinity` of a specific interrupt?

[teodorkostov]

I would like to set the smp_affinity of the network card (eth0) interrupts on a specifi core (let's say 0). Further more I would like to specify the affinity of a few network related services (e.g. sshd) to the same core.

How can I configure with tuned the affinity of a single interrupt? Does tuned have a way to manage the affinity of other services?

PS: The kernel command line irqaffinity narrows down the cores where the interrupts happen. However, I would like to have more detailed control for specific interrupts.

[yarda]

AFAIK there is currently no support for this in the TuneD engine, but we would definitely accept related PRs. It sounds like useful feature.

As a workaround if you want to control this via TuneD profiles, you could create bash script that is executed by the [script] TuneD plugin and control it manually there via echo > /proc/irq/.../smp_affinity.

[adriaan42]

Just stumbled across this issue... Tuning of individual interrupts is actually possible now (https://github.com/redhat-performance/tuned/commit/1aeb223b74a3683da6ca36bfc8ba23fcd7a73572).

And for services, I would recommend doing this via SystemD, by setting their AllowedCPUs.