What are the relations between a kernel control path a kernel thread?

0
votes

Understanding The Linux Kernel says:

A kernel control path denotes the sequence of instructions executed by the kernel to handle a system call, an exception, or an interrupt.

and

Besides user processes, Unix systems include a few privileged processes called kernel threads with the following characteristics:

• They run in Kernel Mode in the kernel address space.

• They do not interact with users, and thus do not require terminal devices.

• They are usually created during system startup and remain alive until the system is shut down.

  1. What are the relations between the two concepts: a kernel control path a kernel thread?

    Is a kernel control path a kernel thread?

    Is a kernel thread a kernel control path?

  2. If I am correct, a kernel thread is represented as a task_struct object.

    So is a kernel control path?
    If not, what kinds of kernel control paths can be and what kinds can't be?

  3. If I am correct, a kernel thread can be scheduled together with processes.

    Can a kernel control path? If not, what kinds of kernel control paths can be and what kinds can't be?

2
linuxlinux-kerneloperating-systemkernel
task_struct represents not only a kernel thread, which doesn't interact with a user space. A user thread plus a kernel thread, which processes user requests(syscalls) is also represented by a task_struct (a single object for both user and kernel parts of the thread). – Tsyvarev

2 Answers

2
votes

Keep in mind there is no standard terminology. Using your definitions:

Is a kernel control path a kernel thread?

No, not under your definition.

Is a kernel thread a kernel control path?

No.

If I am correct, a kernel thread is represented as a task_struct object.

Probably.

So is [it] a kernel control path?

Not under your definition.

If not, what kinds of kernel control paths can be and what kinds can't be?

You defined it as:

A kernel control path denotes the sequence of instructions executed by the kernel to handle a system call, an exception, or an interrupt.

0
votes

A kernel control path is the sequence of instructions executed by a kernel to handle a system call, an interrupt or an exception.

The kernel is the core of an operating system, and it controls virtually everything that occurs on a computer. An interrupt is a signal to the kernel that an event has occurred. Hardware interrupts are initiated by hardware devices, including the keyboard, the mouse, a printer or a disk drive. Interrupt signals initiated by programs are called software interrupts or exceptions.

In the most simple situation, the CPU executes a kernel control path sequentially, that is, beginning with the first instruction and ending with the last instruction.

source: http://www.linfo.org/kernel_control_path.html