From nobody Fri Dec 26 21:40:07 2025 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 2AC118F68 for ; Mon, 1 Jan 2024 15:47:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.vnet.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="JGdFAaCs" Received: from pps.filterd (m0353726.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 401BPLfa015354; Mon, 1 Jan 2024 15:46:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=SEi5QyF57QQotla5oo7Z73kTzQqNtaL/QU2bLCXWa3I=; b=JGdFAaCs26f/VLdE36CHeu3zNl5gYNOb1J+UxE9kO1n5csL7y6qnpqvaXZS7pl4cr9KB QnKpzjBBIji6/zzz9x+LlQihYgP6AHTvKbUFxRm5q23EKecsLNwcfQZkFOHc1bKCZDTk W7lIKrSaOsu0qef7hMzJDnYXPhonhJmt5LtNbj0LjVAEB7yvHLBwsYIimp64+Zqeq1BX RFUMFrQ1F2eoedofN8eII0dfwAjSq6s9/keFWC3SJGxz81R+Da+y0BTOdibAxjsTqLUW uu9UVZoUqAkfqEic223KIxtbo2e7ENkwWZtLEqTC+/WoLX/L3J3ptDmSxBP9jPjHuail JQ== Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3vb63fxfns-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 01 Jan 2024 15:46:57 +0000 Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 401DcplE027284; Mon, 1 Jan 2024 15:46:56 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 3vawht0e23-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 01 Jan 2024 15:46:56 +0000 Received: from smtpav07.fra02v.mail.ibm.com (smtpav07.fra02v.mail.ibm.com [10.20.54.106]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 401FktLO5898766 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 1 Jan 2024 15:46:55 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EA8B92004D; Mon, 1 Jan 2024 15:46:54 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ACEA520040; Mon, 1 Jan 2024 15:46:52 +0000 (GMT) Received: from li-c1fdab4c-355a-11b2-a85c-ef242fe9efb4.ibm.com.com (unknown [9.171.34.133]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 1 Jan 2024 15:46:52 +0000 (GMT) From: Shrikanth Hegde To: mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org Cc: sshegde@linux.vnet.ibm.com, dietmar.eggemann@arm.com, linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, yu.c.chen@intel.com, tim.c.chen@linux.intel.com Subject: [PATCH v2 2/2] sched: add READ_ONCE and use existing helper function to access ->avg_irq Date: Mon, 1 Jan 2024 21:16:24 +0530 Message-Id: <20240101154624.100981-3-sshegde@linux.vnet.ibm.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240101154624.100981-1-sshegde@linux.vnet.ibm.com> References: <20240101154624.100981-1-sshegde@linux.vnet.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: vN-6IJ68DUztn9UTzgfwZ0OgwTcitjLC X-Proofpoint-ORIG-GUID: vN-6IJ68DUztn9UTzgfwZ0OgwTcitjLC X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-01-01_08,2024-01-01_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 phishscore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 suspectscore=0 spamscore=0 mlxlogscore=645 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2401010128 Content-Type: text/plain; charset="utf-8" Use existing helper function cpu_util_irq instead of referencing it directly. It was noted that avg_irq could be updated by different CPU than the one which is trying to access it. avg_irq is updated with WRITE_ONCE. Use READ_ONCE to access it in order to avoid any compiler optimizations. Signed-off-by: Shrikanth Hegde Reviewed-by: Vincent Guittot --- kernel/sched/fair.c | 4 +--- kernel/sched/sched.h | 2 +- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1aeca3f943a8..02631060ca7e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9221,10 +9221,8 @@ static inline bool others_have_blocked(struct rq *rq) if (thermal_load_avg(rq)) return true; -#ifdef CONFIG_HAVE_SCHED_AVG_IRQ - if (READ_ONCE(rq->avg_irq.util_avg)) + if (cpu_util_irq(rq)) return true; -#endif return false; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e58a54bda77d..edc20c5cc7ce 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3125,7 +3125,7 @@ static inline bool uclamp_rq_is_idle(struct rq *rq) #ifdef CONFIG_HAVE_SCHED_AVG_IRQ static inline unsigned long cpu_util_irq(struct rq *rq) { - return rq->avg_irq.util_avg; + return READ_ONCE(rq->avg_irq.util_avg); } static inline -- 2.39.3