Quick Fair Queueing Plus (QFQ+)

Quick Fair Queueing Plus (QFQ+) is a new scheduler obtained by applying the modification scheme described in this technical report to the QFQ packet scheduler.

QFQ+ replaced QFQ in mainline Linux from 3.8.

According to my tests, performed using this ad-hoc test-environment, and exactly in the scenarios where fair-queueing schedulers provide better service guarantees than round-robin ones, the execution time of QFQ+ may be even lower than that of DRR. A short description of QFQ+ is here, whereas a detailed description and more information on the tests can be found in the same technical report.

I have also recorded a video, showing the performance of QFQ+, compared to that of DRR. Here are the scripts used in the demo: