Proposals

Globally fair group CPU scheduling

Session information has not yet been published for this event.

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Presentation
Scheduled: Friday, September 9, 2011 from 3:10 – 4:00pm in Alexander Valley Ball Room

One Line Summary

A look at the fairness and wake-up latency improvements that can be achieved by extending vruntime beyond the per-cpu level.

Abstract

The approximations used for the scheduling of group entities in the CPU scheduler are currently managed on a per-cpu basis. While each entities’ weight is globally approximated, the virtual timeline used for scheduling decisions is still completely localized.

This results in both a lack of fairness and unpredictable wake-up latencies, for group entities.

In this presentation we’ll first cover exactly what problems arise as a result of this, as well as their latency impact. We’ll follow with some approaches for global approximation, their drawbacks, and where appropriate the realized gains.

Tags

cpu, scheduler, cfs

Presentation Materials

slides

Speaker

  • Paul Turner

    Google

    Biography

    Paul is an engineer and technical lead with Google’s production kernel team. His interests lie primarily in the cpu scheduling and memory management sub-systems, with a focus on improving latency under high-frequency operations and scalability.