Documentation: intel_pstate: Describe hwp_dynamic_boost sysfs knob

Document the recently introduced hwp_dynamic_boost sysfs knob
allowing user space to tell intel_pstate to use iowait boosting
in the active mode with HWP enabled (to improve performance).

Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Srinivas Pandruvada <[email protected]>
This commit is contained in:
Rafael J. Wysocki 2018-06-26 17:20:43 +02:00
commit 649f53a3e4

View file

@ -378,6 +378,17 @@ argument is passed to the kernel in the command line.
but it affects the maximum possible value of per-policy P-state limits
(see `Interpretation of Policy Attributes`_ below for details).
``hwp_dynamic_boost``
This attribute is only present if ``intel_pstate`` works in the
`active mode with the HWP feature enabled <Active Mode With HWP_>`_ in
the processor. If set (equal to 1), it causes the minimum P-state limit
to be increased dynamically for a short time whenever a task previously
waiting on I/O is selected to run on a given logical CPU (the purpose
of this mechanism is to improve performance).
This setting has no effect on logical CPUs whose minimum P-state limit
is directly set to the highest non-turbo P-state or above it.
.. _status_attr:
``status``