lseb/utils/memory_bw.cpp at master · giacomini/lseb

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#include <chrono>

#include <numeric>

#include <iostream>

#include <cstdlib>

// compiler options: c++ -std=c++11 -O3 -DNDEBUG memory_bw.cpp

* numactl --cpunodebind=0 --membind=0 ./a.out

* numactl --cpunodebind=0 --membind=1 ./a.out

size_t const B = 1024 * 1024 * 1024;

size_t const Gb = 8;

int main() {

// allocation

char* m = new char[B];

auto t1 = std::chrono::high_resolution_clock::now();

// writing

std::fill_n(m, B, 1);

auto t2 = std::chrono::high_resolution_clock::now();

// reading

auto s = std::accumulate(m, m + B, 0);

auto t3 = std::chrono::high_resolution_clock::now();

std::cout

<< s

<< " bytes allocated\n"

<< "write: "

<< Gb / std::chrono::duration<double>(t2 - t1).count()

<< " Gb/s\n"

<< "read: "

<< Gb / std::chrono::duration<double>(t3 - t2).count()

<< " Gb/s\n";

return EXIT_SUCCESS;

}