CPU bandwidth control for CFS
Venue
Proceedings of the Linux Symposium, Linux Symposium (2010), pp. 245-254
Publication Year
2010
Authors
Paul Turner, Bharata B Rao, Nikhil Rao
BibTeX
Abstract
Over the past few years there has been an increasing focus on the development of
features which deliver resource management within the Linux kernel. The addition of
the fair group scheduler has enabled the provisioning of proportional CPU time
through the specification of group weights. As the scheduler is inherently
work-conserving in nature, a task or a group may consume excess CPU share in an
otherwise idle system. There are many scenarios where this unbounded CPU share may
lead to unacceptable utilization or latency variation. CPU bandwidth control
approaches this problem by allowing an explicit upper bound for allowable CPU
bandwidth to be defined in addition to the lower bound already provided by shares.
There are many enterprise scenarios where this functionality is useful. In
particular are the cases of pay-per-use environments, and user facing services
where provisioning is latency bounded. In this paper we detail the motivations
behind this feature, the challenges involved in incorporating into CFS (Completely
Fair Scheduler), and the future development road map.
