From nobody Fri Feb 13 15:07:59 2026 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 7225012C49F for ; Fri, 24 May 2024 15:53:00 +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=1716565982; cv=none; b=Lqd2MwXEHgb6jToS2FRE9em78PN9Ut6TKSM5pZkJ/xhx9/5ek1WpbdDVNutTDcuir4UJAN23zk2LOBwMQVjfgNSqsx66oIST4R7fckCgMWO2btVhb8XmPtO/IoV4DUdnQL2W3yv4MvRmzxPoq8rfdB749AQnZ7Hhs4QMzshozCw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716565982; c=relaxed/simple; bh=890vdz8AVj8lpFtCQhkJD04ptDdcp2OP1uV1uoubhVI=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=PaIskC/StKxp8yMjVVgK4fjiNpkk9lpT+qT+Cou58pojZQdhWsK2UMzbgxbjcsOIwNLWGYh2gxWXrCPZJwRwS3Y7Mcrrgaau2ySuxt6/PAv8dOC70kj3xhzvdLXqZuexDaH0aL3BlsubGweLIjJuxFX4vRBMan1m+E7uBs0SqZQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=SzuzNJ0o; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="SzuzNJ0o" Received: from pps.filterd (m0279864.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 44O9f9Zv007133 for ; Fri, 24 May 2024 15:52:59 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-type:date:from:message-id:mime-version:subject:to; s= qcppdkim1; bh=w27UNgW80NbJvyNK7BSKnoLACrj/aidJmbnMxgB8pE4=; b=Sz uzNJ0oSjl6nN0ws+MHJSBLIMTPmoLbJ9MFQq9bf6ePy82bZWJx6ZG7wE4ttbdyLd 25V41PhCMKoYOwFBAR3Sl/joOQLe4AJlLxSxibe/GG1J6jJsnhm4D4KqIdxDjAMT zmn07vSDCzmGXBmfkdsln3/nEkqH2IYzIr0J2c+qrWYpF5zOdd2ow2cxmh5GIP2q Twm7XaRDdGe8txogaMY9VBjl9QPmYAGu44n9iOkL8Ixv5NlltHyiEozXWD/Hr1wT Aor6dveAWEJWr8O1L80+wlx1GI3qJEa7vwJLTk/9/pcz3/tJa3e7Llrcxw95YnpT 8dC6ZoGquOn7QVAYB/zA== Received: from nasanppmta03.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3yaa8k2v76-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 24 May 2024 15:52:59 +0000 (GMT) Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.45.79.139]) by NASANPPMTA03.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 44OFqwZb022414 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 24 May 2024 15:52:58 GMT Received: from hu-mojha-hyd.qualcomm.com (10.80.80.8) by nasanex01c.na.qualcomm.com (10.45.79.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Fri, 24 May 2024 08:52:57 -0700 From: Mukesh Ojha To: CC: Mukesh Ojha Subject: [PATCH v2] stop_machine: Fix rcu_momentary_dyntick_idle() call in multi_cpu_stop() Date: Fri, 24 May 2024 21:22:41 +0530 Message-ID: <1716565961-18715-1-git-send-email-quic_mojha@quicinc.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01c.na.qualcomm.com (10.45.79.139) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: fnkhmd0ngQmwkrKbIxDDT-o1o7nJg6gu X-Proofpoint-GUID: fnkhmd0ngQmwkrKbIxDDT-o1o7nJg6gu X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.650,FMLib:17.12.28.16 definitions=2024-05-24_04,2024-05-24_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 suspectscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 mlxscore=0 mlxlogscore=699 impostorscore=0 lowpriorityscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2405170001 definitions=main-2405240110 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" rcu_momentary_dyntick_idle() is getting called from all the irq disable path (mention doc section in rcu_momentary_dyntick_idle()) however, in multi_cpu_stop() it is not called from irq disable path. " * Let the RCU core know that this CPU has gone through the scheduler, * which is a quiescent state. This is called when the need for a * quiescent state is urgent, so we burn an atomic operation and full * memory barriers to let the RCU core know about it, regardless of what * this CPU might (or might not) do in the near future. * * We inform the RCU core by emulating a zero-duration dyntick-idle period. * * The caller must have disabled interrupts and must not be idle. " Signed-off-by: Mukesh Ojha Acked-by: Paul E. McKenney --- Change in v2: https://lore.kernel.org/lkml/1712649736-27058-1-git-send-emai= l-quic_mojha@quicinc.com/ - Removed the unnecessary stack trace posted. kernel/stop_machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index cedb17ba158a..f93e6deb8150 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -250,8 +250,8 @@ static int multi_cpu_stop(void *data) * be detected and reported on their side. */ touch_nmi_watchdog(); + rcu_momentary_dyntick_idle(); } - rcu_momentary_dyntick_idle(); } while (curstate !=3D MULTI_STOP_EXIT); =20 local_irq_restore(flags); --=20 2.7.4