From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 9F87E3C01 for ; Tue, 27 May 2025 17:36:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748367362; cv=none; b=mXM/oqNIUUo1K8ofOGniyI6Fh5+hpi+lW6YNpjEJfyFpUnOwT8SQYa11Mhj8iRk1BAPSiBCB0bsKN3UXfVqjQuwurt7agjQX4Va7qgKe9hiISCarsWBRn3rl58yWSIIn2bTezDDZ+qNKm6a1w+q51zclUDG0Rrk+wfHtf7pyy2M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748367362; c=relaxed/simple; bh=Bnj+T1xUOQ9NGvkqUBXL8OOD/FvifoEELDdfcwYwv9M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=A5XFWxkmqeXwCH1Tfc7MXXvfMLjbr5f3zsAuS81sGa8i+dnf2lWRILhIeqlrmD5JT5Gs/NO/2Ea5DsG9KpVma7LSiGLhgGVWPWM51vQdGY7zkwiZwkXb3vnZUJJ30TsvM7ZqepjxFuOmSocvoCirzdwkznTXEI9N3v9hkT1TwHs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=q39gcgiu; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="q39gcgiu" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 54RGICUr005507; Tue, 27 May 2025 17:35:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=MXpP59 +HfF68Kn33L8GsHgTs4mhr7s5gkeESnF54fB0=; b=q39gcgiudeEhERpjXZYP8+ gGJQy5pbJhl+ed/gA+KorAPkFI6IpXAweOij1ZI2+4C6oebaMhfQElqu3uS4M2l9 WRHylU/P07gf77eBtExIgYshQWnE4QlYMGiaZwyPyYw4VvEMstaMuvmv+uvzbX83 pbxjzfvNWQDEnh88r8ZrEko988w44LTdXIEWrxi4J4Sf5Gt+C5tZ4AWZJ6Mcu/n6 NpWIB1EyQdzzodmlfoOwB4p/ALLUFgF50hw9foTq6ndLnZPEfRJEqoUriCN8SKrc Oga3rLFkpKEaC1wS/15U3+X0tYD9EEAWsBCCshJ7oJrGQsoVrUDGA60eb6lpHcMw == Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 46wgsj8c1t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 May 2025 17:35:42 +0000 (GMT) Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 54RHZfDZ006707; Tue, 27 May 2025 17:35:41 GMT Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 46wgsj8c1q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 May 2025 17:35:41 +0000 (GMT) Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 54RHKl4u021326; Tue, 27 May 2025 17:35:40 GMT Received: from smtprelay07.fra02v.mail.ibm.com ([9.218.2.229]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 46utnmkenf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 May 2025 17:35:40 +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 54RHZa3o52429236 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 27 May 2025 17:35:36 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CD2C720043; Tue, 27 May 2025 17:35:36 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0453420040; Tue, 27 May 2025 17:35:34 +0000 (GMT) Received: from [9.124.208.37] (unknown [9.124.208.37]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 27 May 2025 17:35:33 +0000 (GMT) Message-ID: Date: Tue, 27 May 2025 23:05:33 +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 Subject: Re: [RFC PATCH 2/5] sched/core: Don't use parked cpu for selection To: Yury Norov Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, tglx@linutronix.de, maddy@linux.ibm.com, vschneid@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, jstultz@google.com, kprateek.nayak@amd.com, huschle@linux.ibm.com, srikar@linux.ibm.com, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk References: <20250523181448.3777233-1-sshegde@linux.ibm.com> <20250523181448.3777233-3-sshegde@linux.ibm.com> From: Shrikanth Hegde Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=Qspe3Uyd c=1 sm=1 tr=0 ts=6835f7ee cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=IkcTkHD0fZMA:10 a=dt9VzEwgFbYA:10 a=VnNF1IyMAAAA:8 a=doqJzoeVyp6HbrEgEFUA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNTI3MDE0NSBTYWx0ZWRfX/T/5bB10AMYh eWUPu1SqYYCQt9kgspyVjEtCFu70p36qWvt0YImHaXrjFRY8n32JG2BLHOp6Hgx9gLrbjSmI8tG vdOmulv8Q9FadJX2FLjjOW1Xb3yAP/0JqTQ31n94I1XrINWKlpiLnY/qiOMfCJwObv0xEA8Lfed lqjHpsJu4fdiIJ9qF0QHQgHX4G2/4UJK9qm1XhiqimtGI0vwxUCVkQ07ZJOd9vhnqilHyDIwzcA qL9BPYjJPBB/H7jRcx6PVmzwmKWTeWeNBLLzQmSgfUWa4/iiSayrqNOOE7Ti2N9tm7CZRkbkFND CI5rDLWDfs50ZsG/N5H+wtepNRPWiRmCf/NBjGp1TA7gDKJn6YbTbjk6sDfSLGwMWXWFr70NP5t Pr1BRFxuSTsUOVoQmCZVoZ492UrDCT0Jd/DCvyQ45UjyN32A2+TZOKPm08sYTbpL4gI/37yu X-Proofpoint-ORIG-GUID: UspJeJXXpuGTps4x1MCRVhJiY7PAeCxw X-Proofpoint-GUID: DIxwfHFiL2TxUbh9dhfHlDeF3XSyVJxa X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-05-27_08,2025-05-27_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 lowpriorityscore=0 phishscore=0 malwarescore=0 suspectscore=0 priorityscore=1501 bulkscore=0 mlxscore=0 impostorscore=0 spamscore=0 mlxlogscore=784 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505160000 definitions=main-2505270145 On 5/27/25 20:29, Yury Norov wrote: > On Fri, May 23, 2025 at 11:44:45PM +0530, Shrikanth Hegde wrote: >> When the current running task is pushed using stop class mechanism, the >> new CPU that going to be chosen shouldn't be a parked CPU. >> >> Signed-off-by: Shrikanth Hegde >> --- >> kernel/sched/core.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 62b3416f5e43..9ec12f9b3b08 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -3526,7 +3526,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p) >> nodemask = cpumask_of_node(nid); >> >> /* Look for allowed, online CPU in same node. */ >> - for_each_cpu(dest_cpu, nodemask) { >> + for_each_cpu_andnot(dest_cpu, nodemask, cpu_parked_mask) { >> if (is_cpu_allowed(p, dest_cpu)) >> return dest_cpu; >> } >> @@ -3534,7 +3534,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p) >> >> for (;;) { >> /* Any allowed, online CPU? */ >> - for_each_cpu(dest_cpu, p->cpus_ptr) { >> + for_each_cpu_andnot(dest_cpu, p->cpus_ptr, cpu_parked_mask) { >> if (!is_cpu_allowed(p, dest_cpu)) >> continue; > > You test for online and dying CPUs in the is_cpu_allowed(). Why this > new 'parked' creature is different? Agreed. Let me try move that logic into is_cpu_allowed.