These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] sys-process/numactl-2.0.19::gentoo  USE="-static-libs" 441 KiB
[ebuild  N     ] sys-apps/irqbalance-1.9.4-r3::gentoo  USE="numa -caps (-selinux) (-systemd) -thermal -tui" 62 KiB

Total: 2 packages (2 new), Size of downloads: 502 KiB