Rafael J. Wysocki
9d0ef7af1f
All systems with a defined ACPI preferred profile that are not "servers" have been using the load-based P-state selection algorithm in intel_pstate since 4.12-rc1 (mobile systems and laptops have been using it since 4.10-rc1) and no problems with it have been reported to date. In particular, no regressions with respect to the PID-based P-state selection have been reported. Also testing indicates that the P-state selection algorithm based on CPU load is generally on par with the PID-based algorithm performance-wise, and for some workloads it turns out to be better than the other one, while being more straightforward and easier to understand at the same time. Moreover, the PID-based P-state selection algorithm in intel_pstate is known to be unstable in some situation and generally problematic, the issues with it are hard to address and it has become a significant maintenance burden. For these reasons, make intel_pstate use the "powersave" P-state selection algorithm based on CPU load in the active mode on all systems and drop the PID-based P-state selection code along with all things related to it from the driver. Also update the documentation accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.