From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 239A3C433EF for ; Sun, 30 Jan 2022 10:27:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232545AbiA3K1f (ORCPT ); Sun, 30 Jan 2022 05:27:35 -0500 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:35886 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354584AbiA3K1e (ORCPT ); Sun, 30 Jan 2022 05:27:34 -0500 X-IronPort-AV: E=Sophos;i="5.88,328,1635199200"; d="scan'208";a="4476194" Received: from 173.121.68.85.rev.sfr.net (HELO hadrien) ([85.68.121.173]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jan 2022 11:27:34 +0100 Date: Sun, 30 Jan 2022 11:27:32 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Len Brown cc: linux-pm@vger.kernel.org Subject: DRAM power consumption with turbostat Message-ID: User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hello, I was wondering whether the DRAM power consumption reported by turbostat is reliable on recent Intel machines? In particular, I observed that turbostat reported a high DRAM energy comsumption on a machine (Intel 5128) with persistent memory, but where the persistent memory was not being used. A colleague did an experiemnt on another machine with persistent memory, and reported: ----- I didn't run the test on troll but on another server equipped with PM where I was able to reproduce the bug and by reading directly the msr registers, I see that: CPU Energy units = 0.00006104J DRAM Energy units = 0.00001526J However turbostat assumes that the DRAM Energy units is 0.00006104J when it runs the computation to obtain Joules (hence the too-high value returned by turbostat) ----- I see the code in turbostat that just uses the CPU energy units value (rapl_dram_energy_units_probe), but I don't know what was the MSR used to collect the above information. Overall, I am wondering if the DRAM energy consumption values are reliable in cases with and without persistent memory. thanks, julia