Linux systems normally send all interrupts (IRQs) to one CPU, unless they are explicitly farmed out to other CPUs. A program has been written, irqbalance, that takes care of distributing the interrupt load among all available processors.
We use a fork of v0.56, because newer versions rely on x86-specific bits that are not present on ARM. Furthermore, we use a fork of that maintained by SolidRun that has been packaged for Debian.
Running irqbalance will improve performance. Notably, audio stutters much less when running irqbalance.
As with all of the other packages, use git-buildpackage to build the Debian package from git:
git clone https://github.com/xobs/irqbalanced cd irqbalance git-buildpackage -us -uc --git-upstream-tag=v0.56-r1
The package includes a systemd service file that will get automatically enabled upon installation.