- Kernel support thread (Kernel supported threads) KST
- All processes (users and cores) in the OS are built on the kernel. Kst is also the case, its creation, blocking, undoing, switching are implemented in the kernel space.
- Advantages:
- The kernel can simultaneously schedule multiple threads in the same process to execute concurrently
- A thread is blocked and the kernel can dispatch other threads in a process to consume the processor
- Using multithreading technology, can improve the execution speed of Nishinaga
- User-level threading Ult
- In the user space implementation, it creates, blocks, revokes, switches without the support of the kernel-the user-level thread is independent of the kernel. So the kernel is completely unaware of the existence of user-level threads and cannot see the user thread
- For a system that has a user-level thread set, the schedule is in process, and the system that sets the kernel support thread is in the thread.
- Advantages
- Thread switching does not have to be translated into the kernel,
- Implementation independent of OS platform
- Disadvantages
- Blocking issues. Most system calls cause the process to block and block when one thread system calls, causing other threads to also block
- Can only be implemented in a single.
Operating system--kernel support threads and user-level threads
