Issue Report

Bug

Container Linux Version

NAME="Container Linux by CoreOS"
ID=coreos
VERSION=2191.5.0
VERSION_ID=2191.5.0
BUILD_ID=2019-09-04-0357
PRETTY_NAME="Container Linux by CoreOS 2191.5.0 (Rhyolite)"
ANSI_COLOR="38;5;75"
HOME_URL="https://coreos.com/"
BUG_REPORT_URL="https://issues.coreos.com"
COREOS_BOARD="amd64-usr"

Environment

Azure, AWS, and VMware

Expected Behavior

Highly threaded, I/O blocked containers running on Kubernetes on CoreOS should be able to use their full configured CPU request.

Actual Behavior

Highly threaded, I/O blocked containers running on Kubernetes on CoreOS are heavily throttled well before they approach their CPU request. We are seeing CPU performance impact of 50% in production for some Java web applications- i.e. if we request 6 cores, we are throttled at 3.

See https://lkml.org/lkml/2019/5/17/581 for the kernel patch to fix this, which is landing in 5.4.

Because this bug heavily impacts the main intended use case of CoreOS Container Linux, would it be possible to prioritize this patch for backport?