From: Rafael J. Wysocki Date: Tue, 26 Jun 2018 15:20:43 +0000 (+0200) Subject: Documentation: intel_pstate: Describe hwp_dynamic_boost sysfs knob X-Git-Tag: v5.15~8517^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=649f53a3e4cf6873741673b9271275e484c56194;p=platform%2Fkernel%2Flinux-starfive.git 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 --- diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst index d74fb57..8f1d3de4 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``