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Wed, 17 Jun 2026 17:44:54 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.ibm.com.com (unknown [9.39.28.77]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 17 Jun 2026 17:44:54 +0000 (GMT) From: Shrikanth Hegde To: linux-kernel@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, yury.norov@gmail.com, kprateek.nayak@amd.com, iii@linux.ibm.com Cc: sshegde@linux.ibm.com, tglx@kernel.org, gregkh@linuxfoundation.org, pbonzini@redhat.com, seanjc@google.com, vschneid@redhat.com, huschle@linux.ibm.com, rostedt@goodmis.org, dietmar.eggemann@arm.com, mgorman@suse.de, bsegall@google.com, maddy@linux.ibm.com, srikar@linux.ibm.com, hdanton@sina.com, chleroy@kernel.org, vineeth@bitbyteword.org, frederic@kernel.org, arighi@nvidia.com, pauld@redhat.com, christian.loehle@arm.com, tj@kernel.org, tommaso.cucinotta@gmail.com, maz@kernel.org, rafael@kernel.org Subject: [PATCH v4 20/20] sched/core: Add a few check for valid CPU in inc/dec of preferred CPUs Date: Wed, 17 Jun 2026 23:11:39 +0530 Message-ID: <20260617174139.155540-21-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260617174139.155540-1-sshegde@linux.ibm.com> References: <20260617174139.155540-1-sshegde@linux.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: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-GUID: 25VoqbtdPtQNqMpG-VEkplYRMvJsrDkJ X-Authority-Analysis: v=2.4 cv=Le0MLDfi c=1 sm=1 tr=0 ts=6a32dd22 cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=FelO9ux0wxsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VnNF1IyMAAAA:8 a=LRAxTwEObieOEgIKAwcA:9 X-Proofpoint-Spam-Info: AW1haW4tMjYwNjE3MDE2NiBTYWx0ZWRfX/K6K7AP3cpBi 7nR4mOSGjKxBLumQSGudFRlSAvjE84l0w+VwlnZhqsMGUHZf8E/SjVh+H3RtXhCiyAOaZkSDMMn vBAtZP0hEuCay5RRsW/j71VoBbQykBI= X-Proofpoint-ORIG-GUID: zHQgSrmLLt0_RJfFXn5XaLgfegNMpZ1R X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjE3MDE2NiBTYWx0ZWRfX3stJzmbD0Wvg fpkDZsBDtZfqeOByqFeCQgBHAJKaL4PnIDfjK/BPqDyaovVXDEQNgi+yg5/WcDSXEoYCEfYbssN ZYqZqudP/HHAyd4F0EMfHTsZw4MEzcCruwjqzlZPMM/ovsZkqtgqT+KG+XuPzFknFYflBfi1ZXI B2o/O1Dz7FKptwKxiBakhfqas+BIWpvaYHHd16d9RXf0uzgDIDNGql0AtVtVNb/1jTxvsfEYUS3 ys+DD5+VJjNK/H8ilgQAm6DIRsrTaIFBq4nsgQ4K12uA+9NtguOL+ihkB1gHbz202t0p9NkGOc6 yBAjNUt/DyL0Cypjt5e76zyklEzCmI24E81ShEuIcfnclYzGSnElVJzMODGW3HZJgo43YY9Vq3v w5bGlST5q35uwgqZuFOv3cUTUxGSqJz0D7UGzqyakRA1tjouE8K0/Mt8mOwZpfWkdDLk9hcw8kS ybwmag1ctk6yof1bktg== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-06-17_02,2026-06-17_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 priorityscore=1501 malwarescore=0 spamscore=0 suspectscore=0 impostorscore=0 phishscore=0 lowpriorityscore=0 bulkscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2606170166 Add few cpumask_check where cpu is expected to be a a valid one. Signed-off-by: Shrikanth Hegde --- v3->v4: - new patch. kernel/sched/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 57d52973ef0d..9342aae315ca 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -11417,6 +11417,9 @@ void arch_dec_preferred_cpus(struct steal_monitor_t *sm, u64 steal_ratio) last_cpu = cpumask_last(cpu_preferred_mask); + /* mask can't be null */ + cpumask_check(last_cpu); + /* * If the core belongs to the housekeeping CPUs, no action is * taken. This leaves at least one core preferred always. @@ -11505,6 +11508,9 @@ void sched_trigger_steal_computation(int cpu) cpu_active_mask); ktime_t now; + /* at least one housekeeping CPU must be active */ + cpumask_check(first_hk_cpu); + /* Done by first active housekeeping CPU only */ if (likely(cpu != first_hk_cpu)) return; -- 2.47.3