sched/numa: Retry migration of tasks to CPU on a preferred node

	int numa_migrate_seq;

	unsigned int numa_scan_period;

	unsigned int numa_scan_period_max;

	unsigned long numa_migrate_retry;

	u64 node_stamp;			/* migration stamp  */

	struct callback_head numa_work;

	return migrate_task_to(p, env.best_cpu);

}

/* Attempt to migrate a task to a CPU on the preferred node. */

static void numa_migrate_preferred(struct task_struct *p)

{

	/* Success if task is already running on preferred CPU */

	p->numa_migrate_retry = 0;

	if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid)

		return;

	/* This task has no NUMA fault statistics yet */

	if (unlikely(p->numa_preferred_nid == -1))

		return;

	/* Otherwise, try migrate to a CPU on the preferred node */

	if (task_numa_migrate(p) != 0)

		p->numa_migrate_retry = jiffies + HZ*5;

}

static void task_numa_placement(struct task_struct *p)

{

	int seq, nid, max_nid = -1;

		}

	}

	/*

	 * Record the preferred node as the node with the most faults,

	 * requeue the task to be running on the idlest CPU on the

	 * preferred node and reset the scanning rate to recheck

	 * the working set placement.

	 */

	/* Preferred node as the node with the most faults */

	if (max_faults && max_nid != p->numa_preferred_nid) {

		/* Update the preferred nid and migrate task if possible */

		p->numa_preferred_nid = max_nid;

		p->numa_migrate_seq = 1;

		task_numa_migrate(p);

		numa_migrate_preferred(p);

	}

}

	task_numa_placement(p);

	/* Retry task to preferred node migration if it previously failed */

	if (p->numa_migrate_retry && time_after(jiffies, p->numa_migrate_retry))

		numa_migrate_preferred(p);

	p->numa_faults_buffer[task_faults_idx(node, priv)] += pages;

}