How to set CPU affinity for a process from C or C++ in Linux?

Question

Is there a programmatic method to set CPU affinity for a process in c/c++ for the Linux operating system?

Answer 1

You need to use sched_setaffinity(2).

For example, to run on CPUs 0 and 2 only:

#define _GNU_SOURCE #include <sched.h>  cpu_set_t  mask; CPU_ZERO(&mask); CPU_SET(0, &mask); CPU_SET(2, &mask); int result = sched_setaffinity(0, sizeof(mask), &mask); 

(0 for the first parameter means the current process, supply a PID if it's some other process you want to control).

See also sched_getcpu(3).

Answer 2

Use sched_setaffinity at the process level, or pthread_attr_setaffinity_np for individual threads.