From d9e71f5227c1ead88b703e6015ae0f3b9c83b5af Mon Sep 17 00:00:00 2001 From: David Hunt Date: Wed, 31 Jan 2018 12:29:46 +0000 Subject: [PATCH] doc: add hyperthreading note to power library guide Signed-off-by: David Hunt Acked-by: Marko Kovacevic --- doc/guides/prog_guide/power_man.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/doc/guides/prog_guide/power_man.rst b/doc/guides/prog_guide/power_man.rst index c5d62a395c..fdf8f5fddb 100644 --- a/doc/guides/prog_guide/power_man.rst +++ b/doc/guides/prog_guide/power_man.rst @@ -97,6 +97,14 @@ basis. This is achieved by enabling Turbo Boost Technology in the BIOS, then looping through the relevant cores and enabling/disabling Turbo Boost on each core. +Use of Power Library in a Hyper-Threaded Environment +---------------------------------------------------- + +In the case where the power library is in use on a system with Hyper-Threading enabled, +the frequency on the physical core is set to the highest frequency of the Hyper-Thread siblings. +So even though an application may request a scale down, the core frequency will +remain at the highest frequency until all Hyper-Threads on that core request a scale down. + API Overview of the Power Library --------------------------------- -- 2.20.1