From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 96176221FA4 for ; Fri, 27 Jun 2025 07:49:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751010547; cv=none; b=hPak5npslkfpZ094B5ifJY2WDM6Qa3IYS47xKl5Ch4ZP3j+s2pkN+YLah4z1lWD+i4US6veo5D7oShJy2FbHTc85fNEMDJODE7NetcSSSK8CuOGaOsm8T5lPM/VKGzZN/hS79mu3RrNf+lgh3lPliDZaEVnkJd4YUnX5FmApwvw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751010547; c=relaxed/simple; bh=dytr4BQPZi/bIx47Ud3AAQOO8a8GLVowIKGQT4bFWnQ=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=u2JoyJWl+xIIjjPs+sGxWxPzNwOBtlobcKMWmxahLAtgUiqkGnUt0gvGUGVpMi0GOAX8vDcmjlFqkvg9wY3S+1YT+Kc/detmpUG0jUXcYF9yrfDoH3cpFeEoscnGjjLdiVlke8agUeFy+ow5xI5IpPYLrDhENiJrAsLob+tNnyM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5CD961A00; Fri, 27 Jun 2025 00:48:47 -0700 (PDT) Received: from [192.168.0.16] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6CB253F762; Fri, 27 Jun 2025 00:49:03 -0700 (PDT) Message-ID: <7d43a796-d831-430b-92d9-53b3d8351fb6@arm.com> Date: Fri, 27 Jun 2025 08:49:01 +0100 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: question about behaviour of cpuidle on 6.6...seeing *many* missed estimates To: Chris Friesen , daniel.lezcano@linaro.org, kgene@kernel.org, krzysztof.kozlowski@linaro.org, linux-pm@vger.kernel.org References: <0dd1f3be-3bdf-44c9-a6d5-623077714149@windriver.com> Content-Language: en-US From: Christian Loehle In-Reply-To: <0dd1f3be-3bdf-44c9-a6d5-623077714149@windriver.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/26/25 19:26, Chris Friesen wrote: > Hi, > > I've got an Ice Lake server running 6.6 PREEMPT_RT, currently using the acpi_idle cpuidle driver and the "menu" governor.  I'm seeing some weird behaviour with cpuidle and C-states and was hoping someone might be able to shed some light on what's happening. Does your kernel include 3cd2aa93674e cpuidle: menu: Avoid discarding useful information (since v6.6.93)? > [snip]