Synchronization insmod的cpu挂起

我正在尝试以这样一种方式编写块设备驱动程序，即将I/O请求移交给单独的工作线程。工作线程等待获取请求，然后执行实际的I/O

我使用完整的结构在工作线程和传输请求函数之间进行同步。工作线程在继续处理请求之前会等待完成，并且在传输请求收到请求时会被唤醒

然而，当我尝试执行insmod时，我的系统挂起。这就是回溯在每个CPU上的外观

[  152.036031] BUG: soft lockup - CPU#0 stuck for 22s! [mount:1752]
[  152.036046] CPU 0
[  152.036046] Call Trace:
[  152.036046]  [<ffffffff8108d3e3>] smp_call_function+0x33/0x60
[  152.036046]  [<ffffffff8108d443>] on_each_cpu+0x33/0xa0
[  152.036046]  [<ffffffff81189e95>] __blkdev_put+0x185/0x1f0
[  152.036046]  [<ffffffff8115570a>] __fput+0xaa/0x200
[  152.036046]  [<ffffffff81151f3f>] filp_close+0x5f/0x90
[  152.036046]  [<ffffffff8115201d>] sys_close+0xad/0x120
[  152.036046]  [<ffffffff815a7312>] system_call_fastpath+0x16/0x1b

[  158.233026] INFO: rcu_preempt_state detected stalls on CPUs/tasks: { 2} (detected by 0, t=60002 jiffies)
[  158.233031] sending NMI to all CPUs:

[  158.233031] NMI backtrace for cpu 0
[  158.233031] CPU 0 
[  158.233031] Call Trace:
[  158.233031]  [<ffffffff8102018f>] arch_trigger_all_cpu_backtrace+0x4f/0x90
[  158.233031]  [<ffffffff810ca429>] print_other_cpu_stall+0x159/0x1c0
[  158.233031]  [<ffffffff810cb5e1>] __rcu_pending+0x31/0x180
[  158.233031]  [<ffffffff810cbb4a>] rcu_check_callbacks+0x11a/0x190
[  158.233031]  [<ffffffff8106505f>] update_process_times+0x3f/0x80
[  158.233031]  [<ffffffff8108772b>] tick_sched_timer+0x5b/0xc0
[  158.233031]  [<ffffffff8107a2ce>] __run_hrtimer+0x6e/0x240
[  158.233031]  [<ffffffff8107acf5>] hrtimer_interrupt+0xe5/0x200
[  158.233031]  [<ffffffff8101efb3>] smp_apic_timer_interrupt+0x63/0xa0
[  158.233031]  [<ffffffff815a7e5e>] apic_timer_interrupt+0x6e/0x80
[  158.233031]  [<ffffffff8108d30e>] smp_call_function_many+0x1fe/0x2a0
[  158.233031]  [<ffffffff8108d3e3>] smp_call_function+0x33/0x60
[  158.233031]  [<ffffffff8108d443>] on_each_cpu+0x33/0xa0
[  158.233031]  [<ffffffff81189e95>] __blkdev_put+0x185/0x1f0
[  158.233031]  [<ffffffff8115570a>] __fput+0xaa/0x200
[  158.233031]  [<ffffffff81151f3f>] filp_close+0x5f/0x90
[  158.233031]  [<ffffffff8115201d>] sys_close+0xad/0x120
[  158.233031]  [<ffffffff815a7312>] system_call_fastpath+0x16/0x1b

[  158.233291] CPU 3 and CPU 1
[  158.233347] Call Trace:
[  158.233352]  [<ffffffff8101eb68>] lapic_next_event+0x18/0x20
[  158.233356]  [<ffffffff81087288>] tick_dev_program_event+0x38/0x100
[  158.233360]  [<ffffffff8107ad2d>] hrtimer_interrupt+0x11d/0x200
[  158.233363]  [<ffffffff8101efb3>] smp_apic_timer_interrupt+0x63/0xa0
[  158.233366]  [<ffffffff815a7e5e>] apic_timer_interrupt+0x6e/0x80
[  158.233371]  [<ffffffff81029aa2>] native_safe_halt+0x2/0x10
[  158.233374]  [<ffffffff8100a67d>] default_idle+0x4d/0x2a0
[  158.233378]  [<ffffffff810011a6>] cpu_idle+0x86/0xd0

[  137.645911] CPU 2 
[  137.645911] Call Trace:
[  137.645911]  [<ffffffff8159d766>] wait_for_common+0x26/0x150
[  137.645911]  [<ffffffffa01674e2>] tsdd_worker_thread+0x72/0x1b0 [tsdd]
[  137.645911]  [<ffffffff81075eee>] kthread+0x7e/0x90
[  137.645911]  [<ffffffff815a94f4>] kernel_thread_helper+0x4/0x10`

有人能帮我找出这里出了什么问题吗？我还想了解一下如何解决这个问题。我甚至尝试使用wait_for_completion_interrupt，但这似乎并不能解决问题

谢谢

---

顺便说一下-很抱歉写了这么长的文章（无法附加日志文件）

看起来CPU0在等待CSD锁时被卡住了。您是否检查了CPU之间缺少的IPI中断？

看起来CPU0在等待CSD锁时被卡住了。您是否检查了CPU之间缺少的IPI中断

static struct request *sch_req = NULL;  //global
static struct complete *comp = NULL;    // initialized in module_init

void transfer_req(req_queue) {
    req = blk_fetch_request(req_queue);
    served = 0;
    while (!served) {
        if (completion_done(comp))
            continue;
        sch_req = req;
        sch_queue = req_queue;
        complete(comp);
        served = 1;
    }
}

void worker_thread() {
    while (!kthread_should_stop()) {
        if (wait_for_completion(comp))
            continue;
        while (sch_req) {
            perform_IO(sch_req);
            sch_req = blk_fetch_req(sch_queue);
        }
        init_completion(comp);
    }
}