An Idle Injection Framework Queued For Linux 4.19

Another one of the new frameworks slated for the Linux 4.19 kernel cycle kicking off in August is for idle injection.

Right now drivers like Intel PowerClamp and the AMD CPU cooling code insert idle CPU cycles when needed on their own, in order to keep below an intended power envelope or thermal threshold. Rather than drivers implementing idle injections on their own, the idle injection code within the Linux kernel has moved into a dedicated framework to make it easier for other kernel users to deploy.

The formalization of this idle injection framework was led by the Linaro folks while working on the ARM cpu_cooling code. This framework offers a basic API to force idle periods on specific CPU core(s) for power capping for a specified duration.

More details on this idle injection framework for the Linux kernel can be found via this commit with the code currently being staged in the linux-next branch of the power management subsystem until the Linux 4.19 merge window rolls around in the coming weeks.