On one side a thermal sensor is associated with one thermal zone. On the other side a governor manages one thermal zone. The governor acts on a cooling device.
Some configurations have multiple sensors for the same performance domain. For instance, one sensor per core and a DVFS per group of cores.
When the energy model is used along with the power allocator, having a shared cooling...
This is a continuation of the similarly titled talk from last year and will focus on the remaining open items.
https://lpc.events/event/16/contributions/1195/
Running a workload on VM results in very disparate CPUfreq/sched behavior compared to running the same workload on the host. This difference in CPUfreq/sched behavior can cause significant power/performance regression (on top of...
Packet processing workloads and software applications that are polling in nature bypass the typical kernel power governors. As these workloads are polling they appear 100% utilized and results in zero power savings. This solution implements a user space power governor that has visibility of the "real" workload utilization and triggers power savings. The presentation will review key components...
Utilisation clamping enables user-space to set performance/efficiency preference per-task and task group. It is used on Android systems today but alignment with upstream Linux is lacking behind.
This a discussion topic with the aim aligning on the expectations, use-cases, and possible implementation of uclamp.
Hardware vendors increasingly employ hybrid-CPU processors. Hybrid-CPU processors mix multiple CPU types within the same processor, to satisfy previously conflicting tradeoffs in power, performance, and cost.
Some hybrid-CPU processors benefit from a “low-power mode”, a non-linear power savings resulting from all work being restricted to a “low-power CPUs”, while no work runs on the...
In Android systems, there is a potential for significant power consumption due to entire DDR segments being enabled even during periods of lite usage of system when only a fraction of it is actively used, thereby consuming power unnecessarily.
We can optimize DDR power consumption by selectively disabling certain segments during lite system usage and enabling them when additional memory is...
ChromeOS is the second most-popular Linux distribution, designed to be long-lasting on battery and snappy, even for low-cost devices. This is achieved by leveraging various power-saving policies on multiple different platforms, including x86 (Intel, AMD), and ARM. Starting at the point of device development, we monitor and verify cpu idle, module (package/device) idle and system deep sleep...