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Subject[PATCH] Documentation: intel_pstate: Describe hwp_dynamic_boost sysfs knob
Date
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <rafael.j.wysocki@intel.com>
---
Documentation/admin-guide/pm/intel_pstate.rst | 11 +++++++++++
1 file changed, 11 insertions(+)

Index: linux-pm/Documentation/admin-guide/pm/intel_pstate.rst
===================================================================
--- linux-pm.orig/Documentation/admin-guide/pm/intel_pstate.rst
+++ linux-pm/Documentation/admin-guide/pm/intel_pstate.rst
@@ -378,6 +378,17 @@ argument is passed to the kernel in the
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``
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