Details
Major Description
The cgroups isolator currently lacks support for binding (also called pinning) containers to a set of cores. The GNU/Linux kernel is known to make sub-optimal core assignments for processes and threads. Poor assignments impact program performance, specifically in terms of cache locality. Applications requiring GPU resources can benefit from this feature by getting access to cores closest to the GPU hardware, which reduces cpu-gpu copy latency.
Most cluster management systems from the HPC community (SLURM) provide both cgroup isolation and cpu binding. This feature would provide similar capabilities. The current interest in supporting Intel's Cache Allocation Technology, and the advent of Intel's Knights-series processors, will require making choices about where container's are going to run on the mesos-agent's processor(s) cores - this feature is a step toward developing a robust solution.
The improvement in this JIRA ticket will handle hardware topology detection, track container-to-core utilization in a histogram, and use a mathematical optimization technique to select cores for container assignment based on latency and the container-to-core utilization histogram.
For GPU tasks, the improvement will prioritize selection of cores based on latency between the GPU and cores in an effort to minimize copy latency.