TurboSched Is A New Linux Scheduler Focused On Maximizing Turbo Frequency Usage

TurboSched is a new Linux kernel scheduler that's been in development by IBM for maximizing use of turbo frequencies for the longest possible periods of time. Rather than this scheduler trying to balance the load across all available CPU cores, it tries to keep the priority tasks on a select group of cores while aiming to keep the other cores idle in order to allow for the power allowance to be used by those few turbo-capable cores with the high priority work.

TurboSched aims to keep low utilization tasks to already active cores as opposed to waking up new cores from their idle/power-savings states. This is beneficial for allowing the CPU cores most likely to be kept in their turbo state for longer while saving power in terms of not waking up extra cores for brief periods of time when handling various background/jitter tasks.

With TurboSched being developed by IBM, it's written with their latest POWER9 processors in mind but would be interesting to see it applied to AMD and Intel CPUs moving forward. At least on POWER CPUs, IBM found this TurboSched implementation could help POWER9 workloads up to 13%.

For now TurboSched is living as patches on the kernel mailing list. It will be interesting to see where this leads and how well it could potentially help AMD and Intel CPUs if adapted for those x86_64 processors.