From 649f53a3e4cf6873741673b9271275e484c56194 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 26 Jun 2018 17:20:43 +0200 Subject: [PATCH] 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 Acked-by: Srinivas Pandruvada --- Documentation/admin-guide/pm/intel_pstate.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst index d74fb572f6cc..8f1d3de449b5 100644 --- a/Documentation/admin-guide/pm/intel_pstate.rst +++ b/Documentation/admin-guide/pm/intel_pstate.rst @@ -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 `_ 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`` -- 2.30.2