Abstract Sometimes, we may want to migrate one process/thread to one specific CPU for some specific purpose. In the Unix/Linux systems, you may choose sched_setaffinity to finish this job. This article will help you to understand how sched_setaffinity (or other APIs like pthread_setaffinity_np in user-space) works internal Linux kernel. Details -- sched_setaffinity(pid_t pid, const struct cpumask *in_mask) --- __set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask, bool check) ---- stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) ----- migration_cpu_stop(void *data) ------ __migrate_task(struct rq *rq, struct task_struct *p, int dest_cpu) ------- move_queued_task(struct rq *rq, struct task_struct *p, int new_cpu) -------- enqueue_task(struct rq *rq, struct task_struct *p, int flags) --------- returns the new run queue of destination CPU Above character steps give a workflow of how sched_setaffinity works (how it migrates one process/thread from the run queue of source CPU to the run queue of destination CPU). » Read more