"Code in Linux Kernel runs in one of three contexts: Process, Bottom-half and Interrupt. Process context executes directly on behalf of a user process. All system calls run in the process context. Interrupt handlers run in interrupt context. Softirqs, Task lets and Timers all run in bottom-half context. These features were introduced to achieve better SMP scalability as most of the development is being done in field of symmetric multiprocessing. The existing Bottom halves (prior to Linux 2.3.42) were reimplemented in Linux 2.5.40, as a special form of tasklet which preserved their semantics. " Story (Submitted by Noel Sun Jul 18, 2004 ) |