使用C有效迁移Linux进程

我需要估计在同一台计算机的另一个核心上迁移linux进程需要多少费用。要迁移该进程，我使用了sched_setaffinity系统调用，但是我注意到迁移并不总是即时发生的，这是我的要求。

更深入地讲，我正在创建一个C程序，该程序每次进行两次简单的计算，第一次不进行迁移，第二次进行迁移。计算两个时间戳之间的差异应该可以粗略估计迁移开销。但是，我需要弄清楚如何迁移当前进程并等待直到迁移发生

#define _GNU_SOURCE
#define _POSIX_C_SOURCE 199309L

#include <assert.h>
#include <sched.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <stdint.h>

//Migrates the process
int migrate(pid_t pid) {
    const int totCPU = 8;
    const int nextCPU = (sched_getcpu() +1) % totCPU;

    cpu_set_t target;
    CPU_SET(nextCPU, &target);
    if(sched_setaffinity(pid, sizeof(target), &target) < 0)
        perror("Setaffinity");

    return nextCPU;
}

int main(void) {
    long i =0;
    const long iterations = 4;
    uint64_t total_sequential_delays = 0;
    uint64_t total_migration_delays = 0;
    uint64_t delta_us;

    for(int i=0; i < iterations; i++) {
        struct timespec start, end;

        //Migration benchmark only happens in odd iterations
        bool do_migration = i % 2 == 1;
        //Start timestamp
        clock_gettime(CLOCK_MONOTONIC_RAW, &start);
        //Target CPU to migrate
        int target;
        if(do_migration) {
            target = migrate(0);
            //if current CPU is not the target CPU
            if(target != sched_getcpu()) {
                do {
                    clock_gettime(CLOCK_MONOTONIC_RAW, &end);
                }
                while(target != sched_getcpu());
            }
        }

        //Simple computation 
        double k = 5;
        for(int j = 1; j <= 9999; j++) {
            k *= j / (k-3);
        }

        //End timestamp
        clock_gettime(CLOCK_MONOTONIC_RAW, &end);

        //Elapsed time
        delta_us = (end.tv_sec - start.tv_sec) * 1000000 + (end.tv_nsec - start.tv_nsec) / 1000;
        if(do_migration) total_migration_delays += delta_us;
        else total_sequential_delays += delta_us;
    }

    //Compute the averages
    double avg_migration = total_migration_delays / iterations;
    double avg_sequential = total_sequential_delays / iterations;

    //Print them
    printf("\navg_migration=%f, avg_sequential=%f",avg_migration,avg_sequential);

    return EXIT_SUCCESS;
}

这里的问题是do-while循环（行46-49）有时会永远运行。