From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id A95441B75C for ; Wed, 31 Jan 2018 13:29:59 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jan 2018 04:29:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,440,1511856000"; d="scan'208";a="200227685" Received: from silpixa00397898.ir.intel.com ([10.237.223.116]) by fmsmga006.fm.intel.com with ESMTP; 31 Jan 2018 04:29:57 -0800 From: David Hunt To: dev@dpdk.org Cc: david.hunt@intel.com Date: Wed, 31 Jan 2018 12:29:46 +0000 Message-Id: <1517401786-118971-1-git-send-email-david.hunt@intel.com> X-Mailer: git-send-email 2.7.4 Subject: [dpdk-dev] [PATCH] doc: add info on hyperthreading to power library X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 31 Jan 2018 12:30:00 -0000 Signed-off-by: David Hunt --- 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 c5d62a3..fdf8f5f 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 --------------------------------- -- 2.7.4