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 D8CD137267E for ; Fri, 21 Aug 2026 05:03:19 +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=1787288601; cv=none; b=n9H5OP+mOu4AxUNlZjxFTOCuulszFE0D2LnvsQHgJcrt72VIF6mv89I/coRX7RrWYJ7LhYTWzIMVDPXF0wNCINU7G7cE5X4tzIWphXLd/7uK6SUsWCyY3OFKg105VXgwSGjjoon60vRlaeXJbLA1DyC72ZtY33dxxdSwFpm32hs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787288601; c=relaxed/simple; bh=XnuZsf0nMjLkzfEZKDluhvBN6Lpj8IpIlLwi4mU/wRQ=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=I4LsmhvkecvycBnogOrV3op/vYcIPBk+HU/HCrCLPXtc6n7kD5OYddiw5rPg1htC2oTNxpkeqMTX2cx5NvygSMt5oL2kRleXV8LztGcklqWWsjOeeiYrVJcBgcHo9NvhfQRx1NyXm3UMCNLKkTSeTWGVfZ7SKFP+JZnpNckCfRk= 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=MRrL8w81; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=D+0L/28r; 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="MRrL8w81"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="D+0L/28r" Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67L4djEs1907622 for ; Fri, 21 Aug 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= is/gf7jTRlgqU5YwXx1zH35HMFgTgN6XMPeMmbQXJZQ=; b=MRrL8w81tcXwTFKa iLHncOSbpHRgA21ZcG+X+IUWI7vwiUZ3HeBnH+tiGBtb3MpoqI73OZNE8GrvNZsW YUd4z/n/etynVsLIscR8siN/JjeERVxk4KHbya/itzZ5TPRmYzqI3nTas6KRKjp0 4seMooGYjdpnAOMnGwIvYsbrJTkNYiFJ6vPLUfKSSilAmKwbiRvvTGcH4mwRI6he bp8YUhRt3C7SnZE56dH5g40bovNfYRbcXP0B7s2zs7eAGf0nazSV6ak+CsgLvLUw 9ogqD6LaZGMAscP20qabArQnXUQrCBRq6YlybD44WRvkq/0141Y8e0iMtO79styl F9ufdQ== Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4g6fuhg20q-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Fri, 21 Aug 2026 05:03:19 +0000 (GMT) Received: by mail-pl1-f200.google.com with SMTP id d9443c01a7336-2cc6dd43737so12142325ad.2 for ; Thu, 20 Aug 2026 22:03:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1787288598; x=1787893398; darn=vger.kernel.org; h=content-transfer-encoding:content-type: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:content-type; bh=is/gf7jTRlgqU5YwXx1zH35HMFgTgN6XMPeMmbQXJZQ=; b=D+0L/28rFewFvNuNtMbiwEZZA+57XojfkaGAskSsgWCwXmBuYUodvD5ya6LUieqj4Z bx/o3A3wRQTPOUhbRQkrSvtX8/RG3g31IGebvv5DBt7g1b0szaiJTptAmXZ2f3U7KtJW kfCPIR+9xP5hSSd0M96/aA4GxT9fsdO/agFMKcX6AG6379494CvmovON8nnSNk2LIGUS Ifr00Q4VEXtFDl4SWquvNd17uuE2UbrOxTN4H/ivha7+tktwJJRtGblGsdB2KKzrui4i Sdb6WhTdxbZmUCz+YRfN/oiAHQrcbOY/nFAisYCqM8a7dHQpR7G4NaRTz5ErJ4HgkQT1 dEOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787288598; x=1787893398; h=content-transfer-encoding:content-type: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:content-type; bh=is/gf7jTRlgqU5YwXx1zH35HMFgTgN6XMPeMmbQXJZQ=; b=tZd9sdBJIR5ee2oP1YQOZc+2ABl7i7mThFxuBLrgICPzMhtAKDTrelQkGriQoWrVOz vvTcQ+nvzCDYO3QielADAAulwwvhgpph4NsXXkO/NjEuSzYp3ARc6GEsunGN1NcP5Vva o84U4MmUYDnVgzYs6GUJiBWEJqkYPAJ2/28loy+bwOr4H341h7L1NnPDQHxLqCh+IKTR +jQJzyXFvRhQtdcsj0msvci1Roa1BVghQV1665E8VDMVdG9XXtHoKwE8XAuUW+/6hx80 xOxkf91xES51cZ3VowPDWu5OKRNCnQPrEr6Eis4/8hVJSLpMmplggT1HYhojDQgYA2jz yUhA== X-Forwarded-Encrypted: i=1; AHgh+Rqdz3veO9K8GATigD7c9ORYkRCuNY2f0VHIySie9dQsUdyStRQw6jfBmkdxTdd5WSvuW0xENImAnSx469k=@vger.kernel.org X-Gm-Message-State: AFuF++kNfU9Lc0Wb4N57w48/qBYUhOfMPxNUykI/xUB7v6R4rhAMFX91 BSi/TaRQr4kf24bGwV5cdDkznJdTQ4xFieK37PIIiBHKY0mwbEKO0zF0T/h37n5L3ImyQylEfzv wh89qD8bZkjGLBb3Z0aLQnmwBdw1mHbGQIExz81DDoX3vEotG61jC6nZN6Bq+rqsnoPSOjRQbbV U= X-Gm-Gg: AR+sD13IdSMWKErunI+z+o+s9CDaYzSTjazUVQbnuBV0UYsBHW29gDAiP1A/TKgb7W6 JoIAI52GvaYb37jsaTa9Rcz4veWTQaF8W9CQCtyWlTZB2cL9T9cPKE+ynSCiAadnbwy1xYUfwqn iIGxXrGX+d1NAk0Pv1+8oNaxL6H6Xondxt/qcYtRPpn4CNJM70XnRAqvCDq/CHY1UCUdAQJFX+Z oY1yqVA4MLF5g3VPXfZbn4Eco7kkKFgkjXG96Kc5N53xlVh+X+jCgxZygUZbRG+bLNry3Ct7C/L Zw7qIOTzibLXYfXyWsjobWrEvIfMSmdbDXhjA8S/mdt90oER2sPOSAv9/eRkWoq2YjaK1pL9gqd RULBUwmhaRovER1H2NDL04YzE7GuEOA== X-Received: by 2002:a17:902:e943:b0:2d6:3c2f:69b with SMTP id d9443c01a7336-2d64af6f8cemr72646665ad.8.1787288598408; Thu, 20 Aug 2026 22:03:18 -0700 (PDT) X-Received: by 2002:a17:902:e943:b0:2d6:3c2f:69b with SMTP id d9443c01a7336-2d64af6f8cemr72645935ad.8.1787288597955; Thu, 20 Aug 2026 22:03:17 -0700 (PDT) Received: from [10.217.198.242] ([202.46.22.19]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2d62d555f2esm13819795ad.5.2026.08.20.22.03.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 20 Aug 2026 22:03:17 -0700 (PDT) Message-ID: <8b728c1a-f783-4660-8ed0-eb131875f2d2@oss.qualcomm.com> Date: Fri, 21 Aug 2026 10:33:13 +0530 Precedence: bulk X-Mailing-List: linux-kernel@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: Christian Loehle , "Rafael J. Wysocki" Cc: Daniel Lezcano , 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> <5cfd774e-8797-4765-a36a-c3dc2d6ac004@oss.qualcomm.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-ORIG-GUID: 15jgVI7TmoXmV0hOIDz1SLxlujakQemY X-Proofpoint-Spam-Info: AW1haW4tMjYwODIxMDAzMiBTYWx0ZWRfX0dKCXVXemWJC NogXvlTfSF/CVvwj2+TtQolMuzEyvaceVFXrOmc/STaLkFoyzlgwUwwEVwPDedk2zKxpRyY3024 0K/Ic9ST54BrGVkwBcv57EIelBn3SJU= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODIxMDAzMiBTYWx0ZWRfX9/4nb6WrJN8c 3PTQ5MNhG1qAtXT0afYtP32Nhru1J9DK/JT0uRILVE2lQvy7pO2EvGqddRpeJVgP8HXYF7+K6dT UFTl2up08BDqqfuj/9XQkfVpmDleKt4rCWL58rxa1sAbFac7ctuu4IUTXcXGhOFD3Cv2r4al+Ud rWM0/XnoqNeb5ozkNY8iq8A6oYUpZ5cezqCrQYw9M0Kq4QIqYn8soCjhdqLhOXF/NeHhhXenI79 kIl4ySq0XKoIZaU73vyUvesqlenOVn1z9ZY++YqpsGrfPUbjcMcTvUZ+S3Cf3DuCl+GFl2NVJEz R3lmU4YFCu3be4ckv/+P49UkJzOfAXeIvBCW0ia0z7UMew4j5/Ni1rWl9TmuFOmhy3hOVw8vumk cYOWmObmzd+m0mbC1X3Wx+E5CjZhyM0ziPAUdRc2Y2mcwu2XTSqbzIgtsXr0QPwdBdYgHvkAH0l pGQ2VkNWbeLYwfPIXeA== X-Proofpoint-GUID: 15jgVI7TmoXmV0hOIDz1SLxlujakQemY X-Authority-Analysis: v=2.4 cv=UtFT8ewB c=1 sm=1 tr=0 ts=6a87dc17 cx=c_pps a=IZJwPbhc+fLeJZngyXXI0A==:117 a=fChuTYTh2wq5r3m49p7fHw==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=Um2Pa8k9VHT-vaBCBUpS:22 a=NEAV23lmAAAA:8 a=VwQbUJbxAAAA:8 a=EUspDBNiAAAA:8 a=6lJ8GlR-gWZHLfuqW2AA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=uG9DUKGECoFWVXl0Dc02:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-21_01,2026-08-20_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 suspectscore=0 bulkscore=0 adultscore=0 clxscore=1015 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608210032 On 8/18/2026 9:40 PM, Christian Loehle wrote: > On 4/13/26 06:03, Maulik Shah (mkshah) wrote: >> >> >> 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. >> > What do we do about the cpuidle stats in that case? > I'm thinking primiarly about last_residency_ns and rejected here. As the idle entry will not happen (call_cpuidle() is not invoked) the stats would also not required to be updated. Thanks, Maulik