Originally reported here: http://lkml.iu.edu/hypermail/linux/kernel/1712.0/07072.html
We're seeing unexpected CFS throttling. I wrote down detailed
description with an easily reproducible case here:
TL;DR is that even though we don't burn through CFS quota during the
period, throttling kicks in anyways. The larger interval between wakes
up is, the higher chance of throttling we get. We're seeing this on
different kernels (4.4, 4.9, 4.14) and different distros (different
In corner cases well behaved applications that stay within quota get
delayed for two periods in a row, which means 200ms latency with
This issue has been resolved by 512ac999. However 512ac999 caused another separate regression that I've submitted patches for.
My fixes have been accepted as commit de53fd7aed, and a clean-up fix of 763a9ec06c4.
This should be closed as resolved.