Lines Matching full:cpufreq
17 :doc:`CPU performance scaling subsystem <cpufreq>` in the Linux kernel
18 (``CPUFreq``). It is a scaling driver for the Sandy Bridge and later
21 how ``CPUFreq`` works in general, so this is the time to read
22 Documentation/admin-guide/pm/cpufreq.rst if you have not done that yet.]
29 refer to Intel Software Developer’s Manual [2]_). However, the ``CPUFreq`` core
34 practical for ``intel_pstate`` to supply the ``CPUFreq`` core with a table of
40 CPUs. Consequently, if ``intel_pstate`` is in use, every ``CPUFreq`` policy
41 object corresponds to one logical CPU and ``CPUFreq`` policies are effectively
50 ``sysfs`` which allows another ``CPUFreq`` scaling driver to be loaded and
61 mode it responds to requests made by a generic ``CPUFreq`` governor implementing
73 ``scaling_driver`` policy attribute in ``sysfs`` for all ``CPUFreq`` policies
76 In this mode the driver bypasses the scaling governors layer of ``CPUFreq`` and
78 can be applied to ``CPUFreq`` policies in the same way as generic scaling
216 ``sysfs`` for all ``CPUFreq`` policies contains the string "intel_cpufreq".
217 Then, the driver behaves like a regular ``CPUFreq`` scaling driver. That is,
226 corresponding to CPUs and provides the ``CPUFreq`` core (and the scaling
231 ``CPUFreq`` core. However, in this mode the driver does not register
233 information comes from the ``CPUFreq`` core (and is the last frequency selected
297 ``CPUFreq`` core and (in the passive mode) to generic scaling governors. This
300 :ref:`below <acpi-cpufreq>` for more information).
402 registered itself with the ``CPUFreq`` core and it has figured out that it is
412 ``schedutil`` is used as the ``CPUFreq`` governor which requires ``intel_pstate``
505 supplied to the ``CPUFreq`` core and exposed via the policy interface,
535 driver with the ``CPUFreq`` core).
564 The interpretation of some ``CPUFreq`` policy attributes described in
565 Documentation/admin-guide/pm/cpufreq.rst is special with ``intel_pstate``
628 ``CPUFreq`` policy attributes. The coordination between those limits is based
669 ``CPUFreq`` policy directory in ``sysfs``. They are :
700 .. _acpi-cpufreq:
702 ``intel_pstate`` vs ``acpi-cpufreq``
712 ``acpi-cpufreq`` scaling driver. On systems supported by ``intel_pstate``
713 the ``acpi-cpufreq`` driver uses the same hardware CPU performance scaling
728 available frequencies supplied by ``acpi-cpufreq`` to the ``CPUFreq`` core and
732 frequency reported by ``acpi-cpufreq`` is higher by 1 MHz than the frequency
740 the turbo threshold if ``acpi-cpufreq`` is used as the scaling driver, because
753 turbo P-states overall, ``acpi-cpufreq`` simply avoids using the topmost state
757 Apart from the above, ``acpi-cpufreq`` works like ``intel_pstate`` in the
783 ``acpi-cpufreq`` even if the latter is preferred on the given system.
791 ``intel_pstate`` and on platforms where the ``pcc-cpufreq`` scaling
792 driver is used instead of ``acpi-cpufreq``.
826 by ``CPUFreq``, and the other one is the ``pstate_sample`` trace event specific
842 scaling governor (for the policies it is attached to), or by the ``CPUFreq``