This was only observed in Linux virtual machines. In /proc/cpuinfo, the physical id could be very large, exceeding the number of cpus.
For below example, 4 core systems but the physical id is 13. Also had another virtual machine, only 2 cores, but one physical id is 2.
Anyone has idea how virtual machine defines the linux physical ID?
processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz stepping : 7 microcode : 1808 cpu MHz : 2900.040 cache size : 20480 KB physical id : 13 siblings : 1 core id : 0 cpu cores : 1 apicid : 13 initial apicid : 13 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb pln pts dts bogomips : 5800.08 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz stepping : 7 microcode : 1808 cpu MHz : 2900.040 cache size : 20480 KB physical id : 13 siblings : 1 core id : 0 cpu cores : 1 apicid : 13 initial apicid : 13 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb pln pts dts bogomips : 5800.08 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz stepping : 7 microcode : 1808 cpu MHz : 2900.040 cache size : 20480 KB physical id : 13 siblings : 1 core id : 0 cpu cores : 1 apicid : 13 initial apicid : 13 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb pln pts dts bogomips : 5800.08 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz stepping : 7 microcode : 1808 cpu MHz : 2900.040 cache size : 20480 KB physical id : 13 siblings : 1 core id : 0 cpu cores : 1 apicid : 13 initial apicid : 13 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de tsc msr pae cx8 sep cmov pat clflush mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer aes hypervisor lahf_lm arat epb pln pts dts bogomips : 5800.08 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management:
