Steven Barrett commented on issue #106 at Alfred Chen / linux-prjc

Steven Barrett
2025-03-31T13:43:16Z

This is interesting, I think there's a few things that are giving you competitive numbers:

A dual core or 4 thread CPU. On the context switch test, I noticed that the CPU usage stays rather low and the score I get is the same on two systems, one 4c 8t, and the other 16c 32t. With EEVDF, the context switch test completely saturates my 5950x, which probably then explains the 15x difference in performance, as that's roughly multiplier for the number of cores.

1000 -> 500hz might make a difference, but I think it probably doesn't make the drastic difference in performance

Full Preemption -> Lazy Preemption: this is probably what's giving you a better score. When I switch to kernel v6.14 I'll retest with lazy preemption and see how things change. It could be that the nature of full preemption is preventing the context switch test from scaling to multiple cores.

Kernel v6.14 itself? General upstream improvements may suddenly make PDS scale here very well.

Anyways, I'll retest this once I'm ported over to v6.14 and compare full vs lazy preemption while I'm there.