Bug#941284: Wishlist/RFC: Use CONFIG_HZ=100 in linux-image-cloud-*

[Flavio Veloso <flaviovs@magnux.com>]

Package: linux-image-cloud-amd64
Version: 4.19+105+deb10u1
Severity: wishlist

Hello,

Since linux-image-cloud-* packages are created for cloud environments -- 
read: servers which do not need desktop-level responsiveness --, 
wouldn't it be beneficial to build the kernels with CONFIG_HZ set to 100?

I guess I do not need to explain the compromise behind timer 
overhead/context switching/RT responsiveness/etc. when choosing 100Hz, 
250Hz (the default), or 1KHz, but here's an except from Kconfig's help: 
"100 Hz is a typical choice for servers, SMP and NUMA systems with lots 
of processors that may show reduced performance if too many timer 
interrupts are occurring."

Beside the reduced timer overhead and potential higher throughput, this 
also would reduce the size of the kernel (https://lwn.net/Articles/56378/).

Regards,
--
FV