Fix Threads to execute on certain cores

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Bind threads to processors

In Linux, is it possible to fix threads to execute on certain cores. If that is possible, I also want to know if it is possible to execute one thread exclusively on a certain core, that is disallowing any other thread to execute on that core while that thread is executing.

It might be worth noting that it's the scheduler's job to assign threads to cpus in an efficient manner. Is there a reason you need to second-guess it? — R.. GitHub STOP HELPING ICE, Aug 02 '11 at 19:20

score 3 · Accepted Answer · answered Aug 02 '11 at 18:54

That's what pthread_setaffinity_np(3) does.

The pthread_setaffinity_np() function sets the CPU affinity mask of the thread thread to the CPU set pointed to by cpuset. If the call is successful, and the thread is not currently running on one of the CPUs in cpuset, then it is migrated to one of those CPUs.

As an example:

cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(3, &set); /* Run only on the third CPU. */

pthread_setaffinity_np(thr, CPU_SETSIZE, &set);

You can also do it with sched_setaffinity(2) and gettid, but that manual page says:

If you are using the POSIX threads API, then use pthread_setaffinity_np(3) instead of sched_setaffinity().

Fix Threads to execute on certain cores

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