From patchwork Mon Mar 8 14:31:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Bityutskiy X-Patchwork-Id: 12122489 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9264AC433E0 for ; Mon, 8 Mar 2021 14:32:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B4F46519C for ; Mon, 8 Mar 2021 14:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229474AbhCHOcP (ORCPT ); Mon, 8 Mar 2021 09:32:15 -0500 Received: from mga14.intel.com ([192.55.52.115]:9466 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbhCHObs (ORCPT ); Mon, 8 Mar 2021 09:31:48 -0500 IronPort-SDR: lS4p2Iltii6z8kmxu6C8b7BoUIrmUD3ltpnwOceVmQHC9v/SKTplxumpK2QutJH/lwXdq3hhIl C6BAd7nLGzpQ== X-IronPort-AV: E=McAfee;i="6000,8403,9916"; a="187401919" X-IronPort-AV: E=Sophos;i="5.81,232,1610438400"; d="scan'208";a="187401919" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2021 06:31:48 -0800 IronPort-SDR: MVB9OIH4LOPqwh3KPAnw36OKRvtq5h4JC1sqIUfGGuSQUSSLix245eeTgq8usd9mENgYbnjguD Xw3Wx3mhS0SQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,232,1610438400"; d="scan'208";a="385866301" Received: from powerlab.fi.intel.com (HELO powerlab.backendnet) ([10.237.71.25]) by orsmga002.jf.intel.com with ESMTP; 08 Mar 2021 06:31:46 -0800 From: Artem Bityutskiy To: "Rafael J. Wysocki" Cc: Linux PM Mailing List Subject: [PATCH] intel_idle: update ICX C6 data Date: Mon, 8 Mar 2021 16:31:46 +0200 Message-Id: <20210308143146.3443166-1-dedekind1@gmail.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Artem Bityutskiy This patch changes IceLake Xeon C6 latency from 128 us to 170 us. The latency was measured with the "wult" tool and corresponds to the 99.99th percentile when measuring with the "nic" method. Note, the 128 us figure correspond to the median latency, but in intel_idle we use the "worst case" latency figure instead. C6 target residency was increased from 384 us to 600 us, which may result in less C6 residency in some workloads. This value was tested and compared to values 384, and 1000. Value 600 is a reasonable tradeoff between power and performance. Signed-off-by: Artem Bityutskiy Acked-by: Zhang Rui --- drivers/idle/intel_idle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Changelog: v2->v3: Change target_residency from 1000us to 600us, based on Rui's feedback. v1->v2: Re-measured ICX with newer BIOS 21D02, which has C1 demotion bug fixed. diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 3273360f30f7..6cac0b748efa 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -744,8 +744,8 @@ static struct cpuidle_state icx_cstates[] __initdata = { .name = "C6", .desc = "MWAIT 0x20", .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, - .exit_latency = 128, - .target_residency = 384, + .exit_latency = 170, + .target_residency = 600, .enter = &intel_idle, .enter_s2idle = intel_idle_s2idle, }, {