英文:

Linux Kernel thread preemption

问题

I am having a doubt on the premptiveness of the Linux kernel. I know that user space processes and threads are premptible, but what about kernel level threads, those created using kthread_create.

如果一个线程使用 kthread_create 创建，它是否可以被调度程序抢占，以便执行另一个内核线程？

If a thread is created using kthread_create, can it be preempted by scheduler and another kernel thread be executed?

如果假设内核线程只执行 while(1) {}，它是否会一直运行到完成，占用一个特定的CPU，或者调度程序可以调度出该线程？它是否会引发 softlockup 消息？

If suppose the kernel thread just performs while(1) {}, will it always run to completion occupying a particular CPU, or the scheduler can schedule out the thread? Can it cause softlockup message?

我正在尝试理解RCU，但我意识到，我需要首先了解可抢占和不可抢占内核。

I am trying to understand RCU, but I realised, I need to understand, preemptive non-preemptive kernels first.

英文:

I am having a doubt on the premptiveness of the Linux kernel. I know that user space processes and threads are premptible, but what about kernel level threads, those created using kthread_create.

If a thread is created using kthread_create, can it be preempted by scheduler and another kernel thread be executed?

If suppose the kernel thread just performs while(1) {}, will it always run to completion occupying a particular CPU, or the scheduler can schedule out the thread ? Can it cause softlockup message?

I am trying to understand RCU, but I realised, I need to understand, preemptive non-preemptive kernels first.

答案1

得分: 1

是的，内核线程（例如使用 kthread_create() 创建的线程）是可抢占的。就调度而言，内核线程和用户空间线程在处理上都是相同的方式对待的。参见：Linux 内核线程的默认调度策略是什么？

英文:

Yes, kernel threads (created e.g. with kthread_create()) are preemptible. For all it matters, kthreads and userspace threads are treated in the same way when it comes to scheduling. See also: What is the default scheduling policy of a Linux kernel thread?