How does one determine whether the CPU is dual-core or single-core in Linux?

Article Title: How does one determine whether the CPU is dual-core or single-core in Linux. Linux is a technology channel of the IT lab in China. Including desktop applications, Linux system management, kernel research, embedded systems, open-source, and other basic categories. In Linux, you can view detailed information about each cpu in/proc/cpuinfo.

However, for dual-core CPUs, two CPUs are displayed in cpuinfo, which is often mistaken as two single-core CPUs.

In fact, Physical Processor ID should be used to distinguish between single-core and dual-core. Physical Processor ID can be found in cpuinfo or dmesg.

For example

Root @ debian :~ : 0 # dmesg | grep CPU | grep ID

CPU0: Initial apic id: 0, Physical Processor ID: 0

CPU1: Initial apic id: 1, Physical Processor ID: 0

CPU2: Initial apic id: 6, Physical Processor ID: 3

CPU3: Initial apic id: 7, Physical Processor ID: 3

We can see that this machine has two dual-core CPUs with IDs 0 and 3.