Linux view the number of CPUs, the number of logic, the number of cores

(i) Concept
① Physical CPU
Number of CPUs on the actual server slots
Number of physical CPUs, number of physical IDs that can be repeated
② Logical CPU
/proc/cpuinfo used to store CPU hardware information.
The information content lists the specifications of processor 0–processor N, respectively. It is important to note that N is the number of logical CPUs
In general, we think that a CPU can have multicore, plus Intel's Hyper-Threading Technology (HT), can logically divide the number of CPU core out
Number of logical CPUs = number of physical CPUs x CPU cores This specification value x 2 (if HT [Hyper-Threading technology] is supported and turned on)

Please note: Linux Next Top view CPU is also the number of logical CPUs
③CPU Number of cores
The number of chipsets that can process data on a CPU, such as the current i5 760, is a dual-core four-thread CPU, while i5 2250 is a quad-core four-thread CPU
In general, the number of physical CPUs x per core should be equal to the number of logical CPUs, if not equal, it means that the server's CPU support Hyper-Threading Technology
㈡ Viewing CPU information
When we are Cat/proc/cpuinfo,
CPUs with the same core ID are Hyper-threading of the same core
CPUs with the same physical ID are the same CPU-encapsulated thread or core
㈢ The following examples illustrate
① View the number of physical CPUs
#cat/proc/cpuinfo |grep "Physical id" |sort |uniq|wc-l
4
② View the number of logical CPUs
#cat/proc/cpuinfo |grep "Processor" |wc-l
80
③ View CPU is a few cores
#cat/proc/cpuinfo |grep "Cores" |uniq
10
I check here is the CPU belongs to the server, should be a 4CPU, each CPU has 10 cores, should be Intel's U, support Hyper-threading, so display 80

Linux view the number of CPUs, the number of logic, the number of cores