"Nest" Is An Interesting New Take On Linux Kernel Scheduling For Better CPU Performance

[birdie]

I've been thinking about that for years, it's strange no one has raised the issue earlier. The Linux kernel is notorious for its penchant for juggling tasks between CPU cores for no reasons and that results in emptying whatever you had in L1/L2 caches prior and non-zero delays considering new CPU cores could be at their absolute lowest power settings when they are given a task to execute.

You could simply run:

7z b -mmt1

And see in top or any graphical process manager how the task is thrown between CPU cores.

[bezirg]

Volta but is it coming to upstream?

[Volta]

I was hopping for 6.1/6.2 to be the 'ultimate' kernel with features like RT, MGLRU and IO_uring_spawn, but now this.. Another great feature worth waiting for.

[phoronix]

Phoronix: "Nest" Is An Interesting New Take On Linux Kernel Scheduling For Better CPU Performance

There has been a number of different efforts in recent time to further enhance the Linux kernel's scheduler to better adapt to modern hardware architectures whether it be for Intel hybrid CPU designs, adapting to new CPU cache configurations, or just better scaling with today's ever-increasing core counts. Another scheduler effort detailed this week is "Nest" that aims to keep tasks on "warm cores" with hopes of lower latency due to being already at higher clock/performance states and ideally operating at an optimal turbo/boost frequency. The Nest developers find that their scheduler "improves performance 10%-2x and can reduce energy usage" with modern hardware...

https://www.phoronix.com/news/Nest-Linux-Scheduling-Warm-Core