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Thu, 25 Jun 2026 12:50:16 +0000 (GMT) Received: from li-7bb28a4c-2dab-11b2-a85c-887b5c60d769.ibm.com.com (unknown [9.39.20.6]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 25 Jun 2026 12:50:16 +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, corbet@lwn.net 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, 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, rdunlap@infradead.org, kernellwp@gmail.com, linux-doc@vger.kernel.org Subject: [PATCH v5 24/24] virt/steal_monitor: Add design check of preferred subset of active Date: Thu, 25 Jun 2026 18:16:48 +0530 Message-ID: <20260625124648.802832-25-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260625124648.802832-1-sshegde@linux.ibm.com> References: <20260625124648.802832-1-sshegde@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-doc@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: O62-VmUflhXJW8pBt8gkv7fC0tzR7XL2 X-Proofpoint-Spam-Info: AW1haW4tMjYwNjI1MDExMCBTYWx0ZWRfX/oViz9ZeYJm+ mbZTkzpI5RXzvW7UJesIIw6h8aflKFNmtGFwnpUGJJHZpLOleh1DWxuGwbUHnnBj+ZrNS0e6P6d OeQu3xeNIUWAh97A0ZbNKi4MSMcXIak= X-Authority-Analysis: v=2.4 cv=c62bhx9l c=1 sm=1 tr=0 ts=6a3d2415 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=FelO9ux0wxsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VnNF1IyMAAAA:8 a=9Wsn3OEGW-XOoOitwxAA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjI1MDExMCBTYWx0ZWRfX/dlyvsBRlQfS gOgRS/Xx6lK7unQLHDcWB/6BOllSOELQkyS2Z+voZjwApKlO7evuynPSa5VdTpMxyoBUQDZrTqJ GZIprKRhMg9bOE9zu9jGwwI7qMTzDPU//4vnEjuCR23oLX2+tz0Krij5NX9mtiscdDSWgpfT9MU K9ZlG4UqM4IO0QAS4HYihtw04BiHmnp0H+CC+6LWrg4NW3o6mgPUVQopCHMCLSbsy4sPJ1OxkoE e9hpo6qXWQ0xQDKg0K3HKN/Zji0scldZ6nJ6X5HVH90YfaAMoZuZfsEXUWgbU1trBOndxFw2c2J 9q/Ms6eKlqaH7219l4rw3dB2xy8rySzJnfCQ9cVUwYANKLIXH7tLdf+YYoWK2ccnlergeDWTcxP FMoI/WoaheQPPFINe8CQcr8uTTmWkv4Ciarp0oY28EiCLSmUIi3jWpx3c0b+75W/KVQWzpDXjk5 AFfu5nQVXKFiRZjRJ1Q== X-Proofpoint-ORIG-GUID: Wf-aqPZWqcOkn6i43wuvHQuNmN5_30M6 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=2026-06-25_01,2026-06-24_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 impostorscore=0 adultscore=0 clxscore=1015 suspectscore=0 priorityscore=1501 phishscore=0 spamscore=0 bulkscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2606250110 One of the main design construct that CONFIG_PREFERRED_CPU maintains is that preferred is always subset of active. Force that in any future arch specific implementations. Signed-off-by: Shrikanth Hegde --- v4->v5: - new patch drivers/virt/steal_monitor/sm_core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/virt/steal_monitor/sm_core.c b/drivers/virt/steal_monitor/sm_core.c index f5b0e568eb32..82beb2b94083 100644 --- a/drivers/virt/steal_monitor/sm_core.c +++ b/drivers/virt/steal_monitor/sm_core.c @@ -80,6 +80,9 @@ static void compute_preferred_cpus_work(struct work_struct *work) /* At least one core is kept as preferred */ WARN_ON(cpumask_empty(cpu_preferred_mask)); + /* Maintain design construct */ + WARN_ON(!cpumask_subset(cpu_preferred_mask, cpu_active_mask)); + /* Warn if interval_ms is set to 0, that might cause lockup. */ if (unlikely(sm_core_ctx.interval_ms == 0)) { WARN_ON(1); -- 2.47.3