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 6BE85C00140 for ; Mon, 15 Aug 2022 15:06:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232667AbiHOPGA (ORCPT ); Mon, 15 Aug 2022 11:06:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242623AbiHOPFv (ORCPT ); Mon, 15 Aug 2022 11:05:51 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3D046463 for ; Mon, 15 Aug 2022 08:05:50 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id k6-20020a05600c1c8600b003a54ecc62f6so4034254wms.5 for ; Mon, 15 Aug 2022 08:05:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:from:to:cc; bh=a9389HMELxJaALXWoZVA9uSSCnD92DID1O+kWIz5Q7Y=; b=l9idI3EXeXwoiHGPTiYG510sBtkNxnGlSmTuGO9OHaOzaotpxkME6sArmmJ3bEzq4l n8JQhllUV8VfzTLYKXX0uvgpq7br5CW3lfHPJOZgPv3eWnfbH1HkmMtk2t0mn6MQ+TQL ARUERBgY2SC8dKEijOhJ7izRiAd5zMJH3oH40ApIeIrvNWT5LiPf44IfjPTPeqUwJSHO bVvYWyvtu+tm3e41Ac5aa2WLLb2XAh4It6xlNKQLa12pGgBNfIF54Ef5iTuvMxGXtl9l 3qMry9ey+PVw6Ir18jJAwDpP6yEkvQw9segjDYXfrQwVmkcCf1z4J+zxP2Ij2KBNe+8J 5G0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:x-gm-message-state:from:to:cc; bh=a9389HMELxJaALXWoZVA9uSSCnD92DID1O+kWIz5Q7Y=; b=jZl/EpFho/jBpYNzhu0sThSneWR1tcatF4lgSJWBtgRrtYhx5PzWMY9KIPSbPDlDK0 0bANGTOJXZZ+IlLUg2TxoKzUsAFdb7gmYxY6X5OEVoRR7XMX0qOLxpYgC8hiITWXklEo iIKUEvJylQNeV2mbJNGoIpzExIzqttKP9uKCgqLO/DqbDAwPhvcJBjl/U25CfVGutK09 55W7VDMX7ixDJ9DfPG7KVO5W9uI4sHwmvn09Z4ZGnpGv5eYiRuk7w+5RRhUQjheeWRxO jVVrFM6ip994K2WwlVDj0myra9k8O/1m9vyytYbvzRADVtegsG+SKHeS/AxCbi2GcNIQ U20g== X-Gm-Message-State: ACgBeo2XtpumrmIXiSgDqQsriiM6TppQi4ManWsqqqc4OTi+oxvvCesd D/Q9+GiPON53z113Gy8Gs3M2Vg== X-Google-Smtp-Source: AA6agR67ROI7beQv+IqveURxbMA5xPmG6QPx4r0Z2Q9VyaAMdMfXjtq1yAvi/Sb4/KdUH0SgX3To6Q== X-Received: by 2002:a05:600c:5102:b0:3a5:a46d:5d4b with SMTP id o2-20020a05600c510200b003a5a46d5d4bmr11081106wms.68.1660575948565; Mon, 15 Aug 2022 08:05:48 -0700 (PDT) Received: from localhost ([109.180.234.208]) by smtp.gmail.com with ESMTPSA id j15-20020a05600c190f00b003a5f54e3bbbsm4550660wmq.38.2022.08.15.08.05.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Aug 2022 08:05:48 -0700 (PDT) From: Punit Agrawal To: Perry Yuan Cc: , , , , , , , , , , , , Subject: Re: [PATCH v5 6/7] cpufreq: amd-pstate: update pstate frequency transition delay time References: <20220814163548.326686-1-Perry.Yuan@amd.com> <20220814163548.326686-7-Perry.Yuan@amd.com> Date: Mon, 15 Aug 2022 16:05:47 +0100 In-Reply-To: <20220814163548.326686-7-Perry.Yuan@amd.com> (Perry Yuan's message of "Mon, 15 Aug 2022 00:35:47 +0800") Message-ID: <87bkslim2c.fsf@stealth> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Perry Yuan writes: > Change the default transition latency to be 20ms that is more > reasonable transition delay for AMD processors in non-EPP driver mode. > > Update transition delay time to 1ms, in the AMD CPU autonomous mode and > non-autonomous mode, CPPC firmware will decide frequency at 1ms timescale > based on the workload utilization. > > Acked-by: Viresh Kumar > Signed-off-by: Perry Yuan > --- > drivers/cpufreq/amd-pstate.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index e40177d14310..9cb051d61422 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -41,8 +41,8 @@ > #include > #include "amd-pstate-trace.h" > > -#define AMD_PSTATE_TRANSITION_LATENCY 0x20000 > -#define AMD_PSTATE_TRANSITION_DELAY 500 > +#define AMD_PSTATE_TRANSITION_LATENCY 20000 > +#define AMD_PSTATE_TRANSITION_DELAY 1000 How were these values derived? If from documentation, it'll be good to add a link to the relevant documentation. And if they were derived from testing, please mention this in the commit log (along with some details of the tests used to determine the value). > > /* > * TODO: We need more time to fine tune processors with shared memory solution