# Linux Randomly Picking Idle CPU Cores Shows Modest Win On High Core Count Systems

DevFeed: [Linux Randomly Picking Idle CPU Cores Shows Modest Win On High Core Count Systems](<https://devfeed.tech/articles/linux-randomly-picking-idle-cpu-cores-shows-modest-win-on-high-core-count-systems-31409.md>)

Original publisher: [Read original article](<https://www.phoronix.com/news/Linux-Random-Equal-Idle-CPUs>)

Author: Michael Larabel

Published: 2026-09-16T13:30:04Z

Content type: news

Language: en

Sources: [Phoronix](<https://devfeed.tech/sources/phoronix.md>)

Topics: [Linux](<https://devfeed.tech/topics/linux.md>), [Linux Kernel](<https://devfeed.tech/topics/linux-kernel.md>), [cpu](<https://devfeed.tech/topics/cpu.md>), [benchmarking](<https://devfeed.tech/topics/benchmarking.md>), [systems](<https://devfeed.tech/topics/systems.md>)

Tags: [benchmarking](<https://devfeed.tech/tags/benchmarking.md>), [cpu](<https://devfeed.tech/tags/cpu.md>), [desktop-linux](<https://devfeed.tech/tags/desktop-linux.md>), [linux](<https://devfeed.tech/tags/linux.md>), [linux-benchmarking](<https://devfeed.tech/tags/linux-benchmarking.md>), [linux-hardware-benchmarks](<https://devfeed.tech/tags/linux-hardware-benchmarks.md>), [linux-hardware-reviews](<https://devfeed.tech/tags/linux-hardware-reviews.md>), [linux-how-to](<https://devfeed.tech/tags/linux-how-to.md>), [linux-kernel](<https://devfeed.tech/tags/linux-kernel.md>), [linux-performance](<https://devfeed.tech/tags/linux-performance.md>), [linux-server-benchmarks](<https://devfeed.tech/tags/linux-server-benchmarks.md>), [open-source-graphics](<https://devfeed.tech/tags/open-source-graphics.md>), [patches](<https://devfeed.tech/tags/patches.md>), [phoronix](<https://devfeed.tech/tags/phoronix.md>), [phoronix-test-suite](<https://devfeed.tech/tags/phoronix-test-suite.md>), [scheduler](<https://devfeed.tech/tags/scheduler.md>), [ubuntu-benchmarks](<https://devfeed.tech/tags/ubuntu-benchmarks.md>), [ubuntu-hardware](<https://devfeed.tech/tags/ubuntu-hardware.md>)

## AI overview

A Linux kernel patch series proposes randomizing the selection among equally shallow idle CPU cores to reduce scan-order bias and prevent concurrent tasks from converging on the same core. Testing on a 160-core Ampere Altra system showed throughput improvements of up to a few percent in Stress-NG benchmarking, while the benefits on smaller systems remain uncertain.

## Source excerpt

Arm engineer Christian Loehle sent out a patch series today proposing that the Linux scheduler code randomize its picking of equally shallow idle CPU cores. This randomization is showing to deliver a win at least for high CPU core counts for better distributing workloads...