On Tue, Mar 10, 2015 at 9:51 PM, Nicholas Sielicki <[email protected]> wrote: > I'm curious if there are any planned updates to apmd with regards to exposing > a means for a user to set which c-state a processor should go into. ... > As of 5.4-current, MWAIT is going to C1 when idle in all cases [3], and I > wish to know if that's changed since.
Actually, that was disabled as it caused *increased* power consumption on many boxes. There's work in progress to have the kernel used the C-state information provided by ACPI so that it uses MWAIT properly for the involved system, including the higher C-states. The main hold-up is getting it to work robustly on various systems; sthen@ has one box which hangs as soon as it goes multiuser with the in-progress work. Once I figure out which rule I'm not following (or which rule the _system_ isn't following and how to detect that...) there will be a wider round of testing... Philip Guenther
