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McKenney" , "Gautham R. Shenoy" , Florian Weimer , Tim Chen , Yury Norov References: <20251029123717.886619142@linutronix.de> <20251029124515.846126176@linutronix.de> From: Shrikanth Hegde Content-Language: en-US In-Reply-To: <20251029124515.846126176@linutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: RAj9FLlEYj6zGVxyJnYTp4QnQkVLchNh X-Proofpoint-GUID: SM1E8uFQHBH1lg8gRcNgmTX-X9lKS9wy X-Authority-Analysis: v=2.4 cv=SqidKfO0 c=1 sm=1 tr=0 ts=69087eb2 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=6UeiqGixMTsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VnNF1IyMAAAA:8 a=pGLkceISAAAA:8 a=N3jB7X-fAV_4ZEbNhA4A:9 a=QEXdDO2ut3YA:10 a=cPQSjfK2_nFv0Q5t_7PE:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTAxMDAwOSBTYWx0ZWRfX4+xAcH8HV1Id eDPnEZ09WKw1vClmzWiIpWRat9m1icfgQf6y0SGk5tuUcodF8roArwnygrhoJ7/Jf3WUe9etGfR cu0Zvr76BCJlSgCg+OzPqtz4hLMOau7yI/4o8CinPnYL1kwP0YvGHNc/eTOf3RlQeMOEH3ewB4c uFhRfi+LvibImL3B1B9IqbXavIXGFr1eg4cWCU6qsivM9UY0YCpddYrWMDLzkdpZeJMrVMmiVb4 vND70F0s1PHRsk6WI4v8j4OuK/UIcQgCIzviITALHCNSagwOAVOETA4wXH6+ok91OtZqY1HlpcA ut/NUFElvdb1qIaZjHYNSSra+bfQyQohNVnjrhqJgLw5uA+c04TNAf+jZdRN6/bmlRgt1Mmm1pu j0t5o0WiaiIcspB7wrVsTbJi/kPpdQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-11-03_01,2025-10-29_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 clxscore=1015 impostorscore=0 adultscore=0 lowpriorityscore=0 malwarescore=0 spamscore=0 priorityscore=1501 bulkscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510240000 definitions=main-2511010009 On 10/29/25 6:39 PM, Thomas Gleixner wrote: > Reevaluating num_possible_cpus() over and over does not make sense. That > becomes a constant after init as cpu_possible_mask is marked ro_after_init. > > Cache the value during initialization and provide that for consumption. > Reviewed-by: Shrikanth Hegde Observation: I see below usage which could be improved too? kernel/irq/affinity.c: set_vecs = cpumask_weight(cpu_possible_mask); lib/tests/cpumask_kunit.c: KUNIT_EXPECT_EQ_MSG(test, nr_cpu_ids, cpumask_weight(cpu_possible_mask), Specially irq_calc_affinity_vectors, it seems to take cpus_read_lock, but I don't think that lock is protecting possible cpus. possible cpus can't change after boot. No? > Signed-off-by: Thomas Gleixner > Reviewed-by: Yury Norov > ---