Is there way to get which core is used by the thread?

Question

Is there way to get which core is used by the thread?
for example

printf("..., Core: %2d\n", coreN);

You might need to use an operating system specific function to figure that out. — πάντα ῥεῖ, Jul 08 '18 at 10:05
The core which is used by the thread can be switched several times during this call to printf unless you specifically configure thread affinity. — user7860670, Jul 08 '18 at 10:23
Somebody is bound to mislead by this info, your OS provides no guarantee that it stays executing on that same core. The printf function itself is already quite likely to cause a context switch. — Hans Passant, Jul 08 '18 at 10:47

score 3 · Answer 1 · answered Jul 08 '18 at 14:41

3

If you're using Linux based systems you can use

sched_getcpu()

to print the current CPU/core number on which the thread is running

cout << "Thread running on Core " << sched_getcpu() <<endl

answered Jul 08 '18 at 14:41

Daksh Gupta

score 0 · Answer 2 · answered Jul 08 '18 at 10:25

0

C++ does not provide a function or anything for achieving this, since there is no notion of core in the language.

You could run a Linux command via a system call to check that out: How can I see which CPU core a thread is running in?

answered Jul 08 '18 at 10:25

gsamaras

2 Answers2