How to get number of cores on linux using c programming? -

i know how number of logical cores in c.

sysconf(_sc_nprocessors_conf); 

this return 4 on i3 processor. there 2 cores in i3.

how can physical core count?

this c solution using libcpuid.

cores.c:

#include <stdio.h> #include <libcpuid.h>  int main(void) {     struct cpu_raw_data_t raw;     struct cpu_id_t data;      cpuid_get_raw_data(&raw);     cpu_identify(&raw, &data);     printf("no. of physical core(s) : %d\n", data.num_cores);     return 0; } 

this c++ solution using boost.

cores.cpp:

// use boost number of cores on processor // compile : g++ -o cores cores.cpp -lboost_system -lboost_thread  #include <iostream> #include <boost/thread.hpp>  int main () {     std::cout << "no. of physical core(s) : " << boost::thread::physical_concurrency() << std::endl;     std::cout << "no. of logical core(s) : " << boost::thread::hardware_concurrency() << std::endl;     return 0; } 

on desktop (i5 2310) returns:

no. of physical core(s) : 4 no. of logical core(s) : 4 

while on laptop (i5 480m):

no. of physical core(s) : 2 no. of logical core(s) : 4 

meaning laptop processor have hyper-threading tecnology