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/* | |
* Przykładowy program rozdzielający wątki na konkretne rdzenie. | |
* | |
* Kompilacja: | |
* g++ thread_affinity.cpp -o thread_affinity -lpthread -std=c++11 | |
* | |
* Oparte na przykładzie: | |
* http://stackoverflow.com/questions/1407786/how-to-set-cpu-affinity-of-a-particular-pthread | |
* | |
* Dokumentacja: | |
* http://www.gnu.org/software/libc/manual/html_node/CPU-Affinity.html | |
*/ | |
#include <iostream> | |
#include <thread> | |
#include <pthread.h> | |
#include <sched.h> | |
#include <unistd.h> | |
using std::cin; | |
using std::cout; | |
using std::thread; | |
void print_cpu_details() | |
{ | |
int total_cpu_cores = sysconf(_SC_NPROCESSORS_ONLN); | |
cout << "# Liczba rdzeni: " << total_cpu_cores << "\n"; | |
} | |
/** | |
* Przydziela wątek do konkretnego rdzenia, podanego jako argument. | |
* Rdzenie numerowane są od zera. Najlepiej wywoływać na początku wątku. | |
* | |
* @param core_id Numer rdzenia, do którego przypisany ma być wątek | |
*/ | |
int set_thread_affinity(int core_id) | |
{ | |
int total_cpu_cores = sysconf(_SC_NPROCESSORS_ONLN); | |
// Nieprawidłowy argument | |
if (core_id < 0 || core_id >= total_cpu_cores) | |
{ | |
return EINVAL; | |
} | |
cpu_set_t cpuset; | |
CPU_ZERO(&cpuset); | |
CPU_SET(core_id, &cpuset); | |
pthread_t current_thread = pthread_self(); | |
return pthread_setaffinity_np(current_thread, sizeof(cpu_set_t), &cpuset); | |
} | |
void test_thread(int core_id) | |
{ | |
int core = set_thread_affinity(core_id); | |
int result = 0; | |
double time = 10000000000; | |
cout << "# Numer obciążanego rdzenia: " << core_id << "\n"; | |
// Bezsensowna pętla do obciążenia rdzenia przez pewien czas | |
while (time--) | |
{ | |
result = 99999 + 9.086538739; | |
} | |
} | |
int main() | |
{ | |
char option; | |
// Wyświetla podstawowe informacje o procesorze | |
print_cpu_details(); | |
do | |
{ | |
cout << "Podaj numer rdzenia do obciazenia:\n"; | |
cin >> option; | |
if (option != 'q') | |
{ | |
thread t(test_thread, option - 48); | |
t.join(); | |
} | |
} | |
while (option != 'q'); | |
return 0; | |
} |
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