SystemV信号量定时操作semtimedop超时返回耗时异常

【OS版本】 openEuler22.03 sp3

【内核版本】5.10.0-245.0.0.147.oe2203sp3.aarch64

【硬件平台】arm

【组网信息】不涉及

信号量超时1ms唤醒在x86和arm平台表现不一致，x86+CentOS7.6（内核版本：3.10.0-957.el7.x86_64）semtimedop设置超时时间1ms,超时返回耗时0-1ms，arm+openEuler22.03 sp3，semtimedop设置超时时间1ms,超时返回耗时6-20ms，存在较大的差距，请求定位根因。

【问题复现步骤】
1. 编译运行提供的测试用例即可,出现问题在测试场景2.

【实际结果】arm+openEuler22.03耗时6-20ms

【期望结果】定位根因，尽量缩小两个平台之间的差距。

#include <iostream>
#include <thread>
#include <chrono>
#include <sys/sem.h>
#include <sys/ipc.h>
#include <sys/types.h>
#include <errno.h>

// Linux下的信号量ID
int g_nSem = -1;

// Linux下需要的semun联合体定义
union semun {
    int val;
    struct semid_ds *buf;
    unsigned short *array;
    struct seminfo *__buf;
};

// 初始化信号量
int InitNotify() {
    key_t nKey = 12345;  // 使用固定key
    g_nSem = semget(nKey, 1, IPC_CREAT | 0666);
    if (g_nSem < 0) {
        return -1;
    }
    
    // 初始化信号量值为0
    semun arg;
    arg.val = 0;
    semctl(g_nSem, 0, SETVAL, arg);
    return 0;
}

// 发送通知
void Notify() {
    sembuf op;
    op.sem_num = 0;
    op.sem_flg = SEM_UNDO;
    op.sem_op = 1;
    semop(g_nSem, &op, 1);
}

// 等待通知
int Wait(int nTimeOutMs = -1) {
    sembuf op;
    op.sem_num = 0;
    op.sem_flg = SEM_UNDO;
    op.sem_op = -1;

if (nTimeOutMs < 0) {
        return (semop(g_nSem, &op, 1) == -1) ? -1 : 0;
    } else {
        timespec end;
        end.tv_sec = nTimeOutMs / 1000;
        end.tv_nsec = (nTimeOutMs % 1000) * 1000000L;
        return (semtimedop(g_nSem, &op, 1, &end) == -1) ? -1 : 0;
    }
}

// 清理资源
void Cleanup() {
    if (g_nSem != -1) {
        semctl(g_nSem, 0, IPC_RMID);
        g_nSem = -1;
    }
}

// 通知线程函数
void NotifyThread(int nDelayMs) {
    std::this_thread::sleep_for(std::chrono::milliseconds(nDelayMs));
    Notify();
}

// 测试函数
void TestWaitTimeout() {
    std::cout << "开始测试..." << std::endl;
    
    if (InitNotify() != 0) {
        std::cout << "初始化信号量失败！" << std::endl;
        return;
    }

// 测试场景1：正常等待（有通知到达）
    {
        std::cout << "\n测试场景1 - 正常等待（1秒后收到通知）:" << std::endl;
        std::thread cNotifyThread(NotifyThread, 1000);
        
        auto tStart = std::chrono::high_resolution_clock::now();
        Wait();  // 无限等待
        auto tEnd = std::chrono::high_resolution_clock::now();
        
        auto nDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(tEnd - tStart).count();
        std::cout << "等待耗时: " << nDurationMs << "ms" << std::endl;
        
        cNotifyThread.join();
    }

// 测试场景2：超时等待
    {
        std::cout << "\n测试场景2 - 超时等待（1ms超时）:" << std::endl;
        auto tStart = std::chrono::high_resolution_clock::now();
        Wait(1);
        auto tEnd = std::chrono::high_resolution_clock::now();
        
        auto nDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(tEnd - tStart).count();
        std::cout << "等待耗时: " << nDurationMs << "ms" << std::endl;
    }

// 测试场景3：立即通知
    {
        std::cout << "\n测试场景3 - 立即通知:" << std::endl;
        Notify();  // 先发送通知
        
        auto tStart = std::chrono::high_resolution_clock::now();
        Wait();
        auto tEnd = std::chrono::high_resolution_clock::now();
        
        auto nDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(tEnd - tStart).count();
        std::cout << "等待耗时: " << nDurationMs << "ms" << std::endl;
    }

Cleanup();
}

int main() {
    TestWaitTimeout();
    return 0;
}

Hi czy95279527, welcome to the openEuler Community.
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这边吧CONFIG_HZ从250Hz调到了1000Hz，1ms的耗时就正常了

src-openEuler/kernel

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