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Tue, 10 Mar 2026 15:28:43 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay07.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 62AFSdYS32637270 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Mar 2026 15:28:39 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3EA882004E; Tue, 10 Mar 2026 15:28:39 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4BC032004B; Tue, 10 Mar 2026 15:28:37 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.ibm.com.com (unknown [9.39.21.172]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 10 Mar 2026 15:28:37 +0000 (GMT) From: Shrikanth Hegde To: linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com Cc: sshegde@linux.ibm.com, chleroy@kernel.org, nysal@linux.ibm.com, mkchauras@linux.ibm.com, rafael@kernel.org, daniel.lezcano@kernel.org, christian.loehle@arm.com Subject: [PATCH] cpuidle: powerpc: avoid double clear when breaking snooze Date: Tue, 10 Mar 2026 20:58:11 +0530 Message-ID: <20260310152811.1131119-1-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.51.0 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: xxrWStqe6qlRhXSyzHLhMuvNKGsiNv5p X-Proofpoint-ORIG-GUID: xxrWStqe6qlRhXSyzHLhMuvNKGsiNv5p X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzEwMDEzMSBTYWx0ZWRfXx3JMAEJQJC6s skgMFuHF62v8cujvCbeio3o6VptK5tZXRJ3emFe4PtFOYdtjh6KEtgE9av5JW1pMUvsj0WNAgZ6 C1GJwDMADr+fVd0MzdW01PZve1MKy2Z0uZPB8DFctOtJPSduSeAqhWUPmb+Mvd/NlF3/QqvCAKu 6jk7813h+B6//SZCGzFhPweNcR5aaK9/G9CBOztFt8djhrpQZaskQKF2jPFxY9f1/lfM6x7+R/o sruflTzolJeRoJXn1LH+dYtLX/XvH7gkUgz89BKfg5anF2Sodkqg4FrxslVshG7ipUJg11lIvsf 6UvoJKFRy4af0teOOafV/b6LvJGmwZX325E3gzmFucvUZ0AkfkEJa2CesmyLL5198Da7IzZT2JW 7isnOKDzKVHc2aL0+ixURmqVqaTeXHkM89wmmz1JXA9xmUIbdl8ME/TfBAXCuCMXIEN2FCW6fpL rg9t9CqjN6Po1yq2qvA== X-Authority-Analysis: v=2.4 cv=B5q0EetM c=1 sm=1 tr=0 ts=69b038ac cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=VnNF1IyMAAAA:8 a=cpfb22mzQ2lXxqSQ9ucA:9 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=2026-03-10_03,2026-03-09_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 phishscore=0 adultscore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 spamscore=0 clxscore=1011 impostorscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2602130000 definitions=main-2603100131 snooze_loop is done often in any system which has fair bit of idle time. So it qualifies for even micro-optimizations. When breaking the snooze due to timeout, TIF_POLLING_NRFLAG is cleared twice. Clearing the bit invokes atomics. Avoid double clear and thereby avoid one atomic write. dev->poll_time_limit indicates whether the loop was broken due to timeout. Use that instead of defining a new variable. Signed-off-by: Shrikanth Hegde --- drivers/cpuidle/cpuidle-powernv.c | 5 ++++- drivers/cpuidle/cpuidle-pseries.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 9ebedd972df0..b89e7111e7b8 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -95,7 +95,10 @@ static int snooze_loop(struct cpuidle_device *dev, HMT_medium(); ppc64_runlatch_on(); - clear_thread_flag(TIF_POLLING_NRFLAG); + + /* Avoid double clear when breaking */ + if (!dev->poll_time_limit) + clear_thread_flag(TIF_POLLING_NRFLAG); local_irq_disable(); diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c index f68c65f1d023..864dd5d6e627 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -64,7 +64,10 @@ int snooze_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, } HMT_medium(); - clear_thread_flag(TIF_POLLING_NRFLAG); + + /* Avoid double clear when breaking */ + if (!dev->poll_time_limit) + clear_thread_flag(TIF_POLLING_NRFLAG); raw_local_irq_disable(); -- 2.43.0