The next event with the io latency tracking

This proposal has been accepted as a session.


One Line Summary

The IO latency tracking allows to track per task the expected sleep time when blocked on an IO. Coupled with the next timer event, it gives an accurate information about the next event supposed to wake up a cpu


The increasing part of the embedded systems in the linux ecosystem forces the kernel developers to take into account an energy efficient approach when bringing a new platform. The different energy frameworks are standalone sub-systems acting independently and in a opportunistic way when there is nothing to do on the system. The energy efficient scheduler wants to integrate all these energy components in order to act proactively by having a better knowledge of the potential energy saving for each scheduling decision it will take. This presentation describes a new paradigm where the events occurring in a acceptable interval are considered predictable and can be tracked per task. It will describe the IO latency tracking fully integrated in the scheduler and, thanks to better predictions, allows to get ride of the cpuidle’s governor by directly choosing an idle state from the scheduler

Presentation Materials