Messages in this thread | | | Date | Fri, 18 Feb 2022 18:08:32 +0100 | Subject | Re: [PATCH v7 1/1] s390x: KVM: guest support for topology function | From | Pierre Morel <> |
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On 2/18/22 16:10, Heiko Carstens wrote: >>>> + /* The real CPU backing up the vCPU moved to another socket >>>> */ >>>> + if (topology_physical_package_id(vcpu->cpu) != >>>> + topology_physical_package_id(vcpu->arch.prev_cpu)) >>>> + return true; >>> >>> Why is it OK to look just at the physical package ID here? What if the >>> vcpu for example moves to a different book, which has a core with the >>> same physical package ID? >>> >> >> You are right, we should look at the drawer and book id too. >> Something like that I think: >> >> if ((topology_physical_package_id(vcpu->cpu) != >> topology_physical_package_id(vcpu->arch.prev_cpu)) || >> (topology_book_id(vcpu->cpu) != >> topology_book_id(vcpu->arch.prev_cpu)) || >> (topology_drawer_id(vcpu->cpu) != >> topology_drawer_id(vcpu->arch.prev_cpu))) >> return true; > > You only need to check if prev_cpu is present in topology_core_cpumask(cpu). >
Yes, thanks.
Regards, Pierre
-- Pierre Morel IBM Lab Boeblingen
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