> > Hardware C-state auto-demotion is a mechanism where the HW overrides > > the OS C-state request, instead demoting to a shallower state, > > which is less expensive, but saves less power. > I'm interrested, for pytimechart, to have trace information of what > actual c-state got reached after each idle request. > Do you have any info on how to get that? the actual c-state residency can be seen in the residency counters that are exported by turbostat. However, at the time of the request/return the OS doesn't know that it's request got demoted demoted (or un-demoted). No, checking the counters is not something we want to add to the idle entry/exit path -- they are not optimized for speed. thanks, Len Brown, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
