Progress Report 2015/08/31

Previously Energy Aware Scheduling Kernel Summit 2014 ◦ rt-app: creates workload patterns based on workload description files (current JSON).

rt-app A test application that starts multiple periodic threads in order to simulate a real-time periodic load. Not only the sleep and run pattern can be emulated, but also the dependency between tasks. ◦ accessing same critical resources, creating sequential wake up or syncing the wake up of threads. The use case is described in a json like file

Workloads Main objects ◦ Global objects  Duration, Calibration, default_policy, io_device, … ◦ Tasks/Threads  Instance, priority, cpus, phases, …  run, sleep, mem, iorun, timer, lock, wait, sync, …

Run event Emulate the execution of a load. ◦ The duration is defined in usec, but the run event will effectively run a number of time a loop that waste cpu cycles. ◦ The duration is transformed in a number of loop by the ns per loop value defined in calibration.  Default: CPU[0] ◦ The actual duration will vary with the frequency or the compute capacity of the CPU.

Outputs Log some metrics for each phase that is executed by a thread ◦ perf: number of loop that has been executed by run events ◦ run: time spent by the thread to execute the run events ◦ period: duration to execute the complete phase ◦ start/end : absolute start and end time of a phase. ◦ rel_st: start time of a phase relatively to the begin of the use case.

Example Output – web-BrowserMain-0.log # Policy : SCHED_OTHER priority : 0 #idx perf run period start end rel_st …

Examples [power/rt-app.git] / doc / examples / ◦ browser-long.json ◦ browser-short.json ◦ mp3-long.json ◦ mp3-short.json ◦ spreading-tasks.json ◦ video-long.json ◦ video-short.json

Next cpufreq_governor_efficiency ◦ Measure the efficiency of cpufreq governors using rt-app Cross-compile rt-app and try it on Juno board