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.
Srinivas Pandruvada
authored
Ev Kontsevoy reported that he can't see the presence of "/proc/sys/kernel/sched_itmt_enabled" on i9-7900x with Asrock x299 Taichi system even if he enabled "Turbo 3.0" in the BIOS. The problem is that even if one core max is 200MHz more than others, the current implementation couldn't enumerate that with the way the system is configured. The system by default configured for legacy mode (no HWP or speed shift technology), in this mode only way we can enumerate via the mail box interface as implemented in this driver. We were planing to only use this driver for Broadwell, but we need to extend this because some Skylake system has same issue as Braodwell systems. On this system BIOS allows to change to HWP mode, where we expect that we can enumerate favored core with ACPI-CPPC. But on this system the core priority is 0xff for all cores in CPPC object. So this is not an option. Hence this change allows Skylake systems to be enumerate favored core similar to Broadwell in legacy mode. Reported-and-tested-by:Ev Kontsevoy <ev@kontsevoy.com> Signed-off-by:
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com>