AMD Continues Working On SmartShift Support For Linux

Announced last year by AMD was SmartShift Technology for laptops with both AMD CPUs and GPUs to allow dynamically shifting the power budget between the CPU/GPU depending upon the current workload. AMD promoted SmartShift as delivering up to 14% extra performance and now this technology is being worked on for their Linux driver.

AMD describes SmartShift as "AMD SmartShift enabled notebooks feature a hardware boosting interface between the Processor and Graphics with machine learning algorithms to automatically boost performance where workloads demand it. This interface links the common Infinity Control Fabric blocks together so that the CPU and GPU react quickly to different workloads."

SmartShift appeared in select all-AMD notebooks last year before saying the roll-out was paused until 2021. At Computex Taipei 2021 they talked again about SmartShift briefly and we are also seeing the latest Linux kernel patches posted for enabling SmartShift on Linux.

AMD this week for Computex Taipei began re-talking about SmartShift after announcing it last year. (Coincidentally?) new Linux patches have also been appearing.

Published on Sunday was the fifth time a patch for AMDGPU was submitted for enabling SmartShift with the discrete Radeon notebook GPU when part of a supported system.

Today was also another patch sent out again for exposing the SmartShift power-share information to user-space via sysfs. This exposes the APU and dGPU power sharing information to user-space for monitoring the behavior and verify that it is in fact working on a given system. The sysfs information will indicate how much of the APU power headroom is being used by the discrete GPU.

A follow-up patch adds a writable sysfs attribute for controlling the SmartShift bias level. From -100 to 100 is the interface for setting -100 to prefer maximum APU performance while 100 is for preferring maximum GPU performance with the default 0 level being balanced performance.

So it seems the SmartShift support for Linux is getting squared away in time for the next round of AMD Ryzen + Radeon laptops coming to market. Presumably this time around there will be more prevalent SmartShift support given their newly-announced AMD Advantage program and more time to bake the SmartShift functionality since last year's initial debut.

These SmartShift Linux patches haven't yet been queued into any development trees but if deemed ready soon enough could still make it for the 5.14 kernel otherwise postponed to later in the year.