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Change Kernel HZ to 1000
Closed, ResolvedPublic

Description

As part of looking at the current kernel build, I noticed that we're using a 250hz kernel.

This appears to be a holdover from basing the kernel on Debian builds, which still use 250hz (almost every other distro uses 1000hz).

Switching to 1000hz gives us much better latency (50-66%), at the expense of slightly more CPU load in a VM.

The other advantage for VyOS is that it will force waiting threads (eg, waiting for RDMA from a NIC) to relinquish much faster, allowing significantly more PPS, and also let XPD/eBPF scripts have more cpu cycles when they're needed, rather than having to block.

Details

Difficulty level
Unknown (require assessment)
Version
current
Why the issue appeared?
Will be filled on close
Is it a breaking change?
Perfectly compatible