.NET Core 3.1 Linux环境下Thread.Priority属性不生效问题咨询

我在Linux环境编译运行.NET Core 3.1程序时，遇到了Thread.Priority设置不生效的问题。经查dotnet runtime源码中已经存在将Thread.Priority转换为POSIX标准优先级的实现，但实际测试依然无法正常生效。为复现问题，我修改了Thread.Priority官方文档中的示例代码，增加了线程数以适配多核CPU场景。

Windows（win-x64）环境运行输出 #

不同优先级线程的计数差异符合预期：

thread_5 with AboveNormal priority has a count = 563,441,005
thread_15 with Normal priority has a count = 251,310,557
thread_3 with Normal priority has a count = 239,580,270
thread_0 with Normal priority has a count = 236,077,285
thread_2 with AboveNormal priority has a count = 537,902,014
thread_4 with BelowNormal priority has a count = 5,903,969
thread_7 with BelowNormal priority has a count = 5,958,548
thread_8 with AboveNormal priority has a count = 555,518,195
thread_11 with AboveNormal priority has a count = 549,665,909
thread_12 with Normal priority has a count = 258,493,564
thread_14 with AboveNormal priority has a count = 550,025,919
thread_9 with Normal priority has a count = 135,923,866
thread_6 with Normal priority has a count = 138,882,526
thread_13 with BelowNormal priority has a count = 4,273,232
thread_1 with BelowNormal priority has a count = 4,608,543
thread_10 with BelowNormal priority has a count = 5,908,285

Ubuntu（linux-x64）环境运行输出 #

不同优先级线程的计数无明显差异，看起来所有线程均运行在相同优先级：

thread_4 with BelowNormal priority has a count = 465,192,119
thread_11 with AboveNormal priority has a count = 558,351,324
thread_9 with Normal priority has a count = 459,901,696
thread_10 with BelowNormal priority has a count = 484,271,783
thread_7 with BelowNormal priority has a count = 519,165,910
thread_14 with AboveNormal priority has a count = 487,836,279
thread_12 with Normal priority has a count = 465,635,561
thread_3 with Normal priority has a count = 450,569,622
thread_5 with AboveNormal priority has a count = 503,227,636
thread_6 with Normal priority has a count = 499,300,694
thread_8 with AboveNormal priority has a count = 515,728,537
thread_1 with BelowNormal priority has a count = 547,473,038
thread_15 with Normal priority has a count = 462,427,461
thread_13 with BelowNormal priority has a count = 526,524,771
thread_2 with AboveNormal priority has a count = 493,184,092
thread_0 with Normal priority has a count = 465,902,186

我已经通过setcap命令为程序授予了所需权限：
sudo setcap 'cap_sys_nice=eip' ./ThreadPriorityTest

但操作后问题仍未解决，请问还遗漏了哪些配置或操作？

修改后的测试代码 #

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;
using Timers = System.Timers;

namespace ThreadPriorityTest
{
    class Test
    {
        static void Main()
        {
            PriorityTest priorityTest = new PriorityTest();

            int threadCount = 16;

            List<Thread> threads = new List<Thread>();
            for(int i=0; i<threadCount; i++)
            {
                Thread thread = new Thread(priorityTest.ThreadMethod);
                thread.Name = $"thread_{i}";
                switch(i%3)
                {
                    case 0:
                        thread.Priority = ThreadPriority.Normal;
                        break;
                    case 1:
                        thread.Priority = ThreadPriority.BelowNormal;
                        break;
                    case 2:
                        thread.Priority = ThreadPriority.AboveNormal;
                        break;
                }
                threads.Add(thread);
            }

            Thread.CurrentThread.Priority = ThreadPriority.Highest;
            Console.WriteLine($"Starting {threadCount} threads...");
            foreach(Thread thread in threads)
            {
                thread.Start();
            }
            Console.WriteLine($"Done starting {threadCount} threads.");
            priorityTest.StartEvent.Set();

            // 允许计数10秒
            Thread.Sleep(10000);
            priorityTest.LoopSwitch = false;
        }
    }

    class PriorityTest
    {
        static volatile bool loopSwitch;
        static ManualResetEvent startEvent = new ManualResetEvent(false);
        [ThreadStatic] static long threadCount = 0;

        public PriorityTest()
        {
            loopSwitch = true;
        }

        public bool LoopSwitch
        {
            set { loopSwitch = value; }
        }

        public ManualResetEvent StartEvent
        {
            get { return startEvent; }
        }

        public void ThreadMethod()
        {
            startEvent.WaitOne();
            while (loopSwitch)
            {
                threadCount++;
            }
            Console.WriteLine("{0,-11} with {1,11} priority " +
                "has a count = {2,13}", Thread.CurrentThread.Name,
                Thread.CurrentThread.Priority.ToString(),
                threadCount.ToString("N0"));
        }
    }
}

内容的提问来源于stack exchange，提问作者Pacman