From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8F98386566 for ; Mon, 13 Apr 2026 05:03:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776056605; cv=none; b=Fawx2Mh9dK9by5Z4nY8dQcVNLST04E8EkEfc5xVU3GFv4gLV3NnCc+dxb4+lMcPsUAUC9e7GqIyJQT8veWkVNPCKvjgZo150z0hP75R+c+svVl24OOo7XhjKJoFMBS4V6x0uyraQ7s0aMQvJHBCHz7QK8siqp/bTxZ808/8GAPs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776056605; c=relaxed/simple; bh=2L7O0U0ExmYqZ1og3MD3W3RnaeewohUnJ9nb1qeHewM=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=HhDt2+nCLMXEfqHL+QBh5cxu8sGwlfwIZS/Y5zVe5jJS64MUUQQJzyM65EzYOgkD9HvelFeak9UarQ7qirb6HsZAHTHWDr/JdMyO1eJ2Ii+20kTiISStI+LEb9aFjEXtpUiJdM8/CvRTi5b2flC0RE6NDskucC4c9tqo4ry2E8A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=K6OiJLeK; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=UaigkrmO; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="K6OiJLeK"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="UaigkrmO" Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 63CNJ4Kj2745122 for ; Mon, 13 Apr 2026 05:03:19 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= X1meCnpTLq4hEXz2VH+vYcBDlyL0wD7MXjHoWxKiirs=; b=K6OiJLeKKJMkU3Lz EQp1yrm2WA9rbMJ1OS/JgWfwB3ItqZrDwsitd5m8a0uEqHvsuoG8Hdh29qAiNPEE R0l7O0JpZIR2WNaD1wlfJ9gX050hHnUQqsK7XSqpEajxb/o22Adn465HoSpbNnfL WIlw8asA/4RuqzwJFkDSwe7Q2BrcXPLpE5LHSAdjElvdMCTHeMJh9eJmom4JjOuE NNHfwyctJJy1oVncB3lbMFdoZj7dv1lHe606MPoOQ0i4Z0cv3ex/O0DWZdTIZCEd taAqq6bXpb8ZNcbUrqw9hAr2nSCyGmxwhg6ulx2u4Je/M2nyGWJ8Ji7pP6HvrBHc C0eUeQ== Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4dffk6kt6w-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Mon, 13 Apr 2026 05:03:18 +0000 (GMT) Received: by mail-pf1-f197.google.com with SMTP id d2e1a72fcca58-82f07078eaaso1970495b3a.0 for ; Sun, 12 Apr 2026 22:03:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1776056598; x=1776661398; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:from:user-agent:mime-version:date:message-id:from:to :cc:subject:date:message-id:reply-to; bh=X1meCnpTLq4hEXz2VH+vYcBDlyL0wD7MXjHoWxKiirs=; b=UaigkrmOj7vv4z6N0inHjrRPoqs8WVikYslpIxUflxvlYVpSZe8ma0mAWhS4h/TOjy Gw8BAwuK+hif/tyWM2T1qr/3MrCDXdVx7zRFxlOxDnmxpejod7luvr/rZKruD5XR9IuE FL0MbPdzXL3NTl05+/R6b3MR4KlAs8qrEsry+KJOeJWkR9CVE8BF2KhNKvAiGMmI1mes Qm+0qtrzAPJabboo6Jd0yxZrwmQ4B5E17HAOee93qr9dx8UnAYx/qxMdH1RXQ4w+WnIH B5IJFGv7fMuO4dT845ujWRI+fUidnU4iVDqX4/9KvgTN+BWaxsKsplQg70u6+6k7yoOF IPKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776056598; x=1776661398; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:from:user-agent:mime-version:date:message-id:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=X1meCnpTLq4hEXz2VH+vYcBDlyL0wD7MXjHoWxKiirs=; b=LhJneYzM/dVTSSjNs8UYw59TPGZymNHjcDHra8bht0U2jm8BfX9L0uYZpXJU5h/oSb TM8b9vktGjninGM/Lf2G9ZupyGKXr/GUKNqLTT0pOMmerX4eoXu7qvEUtSku6TVELgwI GBgQM+98Knec1gOw3T8HWKVgI5ceD7sjp3o7MvpPBSc5nDdO1Y7wrRgP86VfBbg5ZMyY Qh46GcIKe31MEkb3Jt7W+7ga2wkuUP9vnDG6phynFjxEpYMK/GtSR0GmCJiuOZNFKFN6 hfa82Snz/I845z3VO0obfCKbiXkjPVSOrkS2RguFKxVDJUTZRpqQq+ppiVCbnOuPYolD 1hvA== X-Forwarded-Encrypted: i=1; AFNElJ8w6NplTOpHmM8mfJI5wCsLf9MsPApK8YJn0VXhthHgTbcDjgf09DLv8tB2tVShL66WQDi316CGww==@vger.kernel.org X-Gm-Message-State: AOJu0YzMBvEbytFOzW5WUTy/mwNlRwAKu5J2pBwxnh8GxQzZG93cH9uB jTvRrHFfswKiyxCFoxQvX9rN5EUZfAPt4MrhcLgqsDFaTex0cmgz9EQKWvt/EL/yHpFY6al1BHo wUrVZnIKy5PKvA7JmDlRM3CYk1voEFDf6SRKlWXQ3qtSGSXylfjQX+dvtCJ75PnpApY9sOw== X-Gm-Gg: AeBDietrD9OnEyxZn47KNkPtJNHciirUSahyT3CYK2DaSNWDrt8OnLLlJs1jHPpRe+P C1/b2aVYBHYdhyIoOM8/OJlOX1TDi7pCgW7goLrhnKlUhv8avlAxbCvvx3UNJfpG5v9R0D/HLsA xOsTchOBFaXhU7jW2POsOx0aKWprDLCu8mqY6sfwvXi3KDmSDu8jVmk3mLXxlbqEvcqn3z8Amsq FfHrPX7i5CJPOFnoC2U5JXv5qwF+rpQZdqXLhjbsANAJU8sIdI2WrLbP1OGlntAodSpEvPmW4l0 dKxq+AxF2v2rWZcuyiEM0jDi3TRZK1KtBCdoiY3g2rsgEO5b7NqQecfGPmfv/ELmPJc6mc5Hqp/ NK4TFUid0XCSCpoRBwrvepeTi8Kf4YlzqBK9+RmTi8LtrTvfxTAc= X-Received: by 2002:a05:6a00:6c8b:b0:82c:6b23:6d10 with SMTP id d2e1a72fcca58-82f0c1ce9d0mr11933298b3a.3.1776056597526; Sun, 12 Apr 2026 22:03:17 -0700 (PDT) X-Received: by 2002:a05:6a00:6c8b:b0:82c:6b23:6d10 with SMTP id d2e1a72fcca58-82f0c1ce9d0mr11933258b3a.3.1776056596865; Sun, 12 Apr 2026 22:03:16 -0700 (PDT) Received: from [10.217.198.242] ([202.46.22.19]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f0c4e3d41sm12205132b3a.48.2026.04.12.22.03.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 12 Apr 2026 22:03:16 -0700 (PDT) Message-ID: <5cfd774e-8797-4765-a36a-c3dc2d6ac004@oss.qualcomm.com> Date: Mon, 13 Apr 2026 10:33:10 +0530 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: "Maulik Shah (mkshah)" Subject: Re: [PATCH v2] cpuidle: Deny idle entry when CPU already have IPI interrupt pending To: "Rafael J. Wysocki" Cc: Daniel Lezcano , Christian Loehle , Ulf Hansson , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <20260403-cpuidle_ipi-v2-1-b3e44b032e2c@oss.qualcomm.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDEzMDA0NSBTYWx0ZWRfX8GKfloIqOg7G 3DBfylC8eq4tqaVPegvnUVa0Ovf/3PPQNOCoTOcJC53OqgVfxnXaK6LFvzg5Hv143GynNpwSR+y D+qxcDo9aQdZXFbqkfPRliju92drECk3kMErUEYss9UgMPji6g5ts6JRtF+5gTeb01u/gq1uMoI xvCk4tclE3GtsGzS0elNyzDoeu1PF/9cIJsogZ4bQS+l+pnldkhYOc1I2mLTBNJt6WE5ELsgs2v qOzkpBCmb/rmubt7DAbKs4TWP2IQYx9aGTRb8Wu03r0vGsHFVb08xHhU286II2QmrSvpDW+IAT5 92uQlAQWYlqeoRpBZrCqnyiJzIz+NJ7+rwWCJdNnEF+NDTinNEAqhVAlvAynL3sVM5iQy5lfnC5 yqrbckhkq6UJkN9BSLd6tJBLZvgTXY8jntayFrUZ+qlqKtRaGQiSKhMofSLKimLPZmi7ZzeVUEx xZFL/0a1aGRZMmrV2sQ== X-Authority-Analysis: v=2.4 cv=YM2vDxGx c=1 sm=1 tr=0 ts=69dc7916 cx=c_pps a=rEQLjTOiSrHUhVqRoksmgQ==:117 a=fChuTYTh2wq5r3m49p7fHw==:17 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=YMgV9FUhrdKAYTUUvYB2:22 a=NEAV23lmAAAA:8 a=VwQbUJbxAAAA:8 a=EUspDBNiAAAA:8 a=lggpn7pwzXPsZ0vCzx8A:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=2VI0MkxyNR6bbpdq8BZq:22 X-Proofpoint-GUID: zoanPhFXIAzYh2lO-sN5sqwa76POQkjm X-Proofpoint-ORIG-GUID: zoanPhFXIAzYh2lO-sN5sqwa76POQkjm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-13_01,2026-04-09_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 adultscore=0 impostorscore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604010000 definitions=main-2604130045 On 4/6/2026 8:37 PM, Rafael J. Wysocki wrote: > On Fri, Apr 3, 2026 at 6:08 AM Maulik Shah wrote: >> >> CPU can get IPI interrupt from another CPU while it is executing >> cpuidle_select() or about to execute same. The selection do not account >> for pending interrupts and may continue to enter selected idle state only >> to exit immediately. >> >> Example trace collected when there is cross CPU IPI. >> >> [000] 154.892148: sched_waking: comm=sugov:4 pid=491 prio=-1 target_cpu=007 >> [000] 154.892148: ipi_raise: target_mask=00000000,00000080 (Function call interrupts) >> [007] 154.892162: cpu_idle: state=2 cpu_id=7 >> [007] 154.892208: cpu_idle: state=4294967295 cpu_id=7 >> [007] 154.892211: irq_handler_entry: irq=2 name=IPI >> [007] 154.892211: ipi_entry: (Function call interrupts) >> [007] 154.892213: sched_wakeup: comm=sugov:4 pid=491 prio=-1 target_cpu=007 >> [007] 154.892214: ipi_exit: (Function call interrupts) >> >> This impacts performance and the above count increments. >> >> commit ccde6525183c ("smp: Introduce a helper function to check for pending >> IPIs") already introduced a helper function to check the pending IPIs and >> it is used in pmdomain governor to deny the cluster level idle state when >> there is a pending IPI on any of cluster CPUs. >> >> This however does not stop CPU to enter CPU level idle state. Make use of >> same at CPUidle to deny the idle entry when there is already IPI pending. >> >> With change observing glmark2 [1] off screen scores improving in the range >> of 25% to 30% on Qualcomm lemans-evk board which is arm64 based having two >> clusters each with 4 CPUs. >> >> [1] https://github.com/glmark2/glmark2 >> >> Signed-off-by: Maulik Shah >> --- >> Changes in v2: >> - Fix cpumask argument of cpus_peek_for_pending_ipi() to take single cpu >> - Link to v1: https://lore.kernel.org/r/20260316-cpuidle_ipi-v1-1-d0ff6350f4e2@oss.qualcomm.com >> --- >> drivers/cpuidle/cpuidle.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c >> index c7876e9e024f9076663063ad21cfc69343fdbbe7..c01e57df64ca5af8c28da3d971500b3f38306cdf 100644 >> --- a/drivers/cpuidle/cpuidle.c >> +++ b/drivers/cpuidle/cpuidle.c >> @@ -224,6 +224,9 @@ noinstr int cpuidle_enter_state(struct cpuidle_device *dev, >> bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); >> ktime_t time_start, time_end; >> >> + if (cpus_peek_for_pending_ipi(cpumask_of(dev->cpu))) >> + return -EBUSY; >> + > > Why do you want to check it here and not in cpuidle_idle_call(), for example? It can be moved in cpuidle_idle_call(), just before call_cpuidle() too. The intention is to check after cpuidle_select() is done. > > In principle, this check may be useful in the default idle path too. Yes, this check may be useful in default_idle_call() too. Thanks, Maulik > >> instrumentation_begin(); >> >> /* >> >> ---