multithreading，multiprocessing
Block multi－threading：context switching意味着从现有的寄存器集切换到另一套
Interleaved multithreading：similar to preemptive multitasking，more modern，需要更大的cache和TLB
Simutaneous multithreading：
instruction level parallelism：measure of how many of the operations in a computer program can be performed simultaneously
spinlock:repeatedly checking if the lock is available. thread remains active but is not performing a useful task. (busy waiting)
avoid overhead from os process rescheduling or context-switching, efficient if threads are blocked for a short period. wasteful if held for longer durations.
superscalar cpu
Monitor(synchronization): important
semaphores
test-and-set
processes, kernel threads, user threads, fiber(coroutines)
inter-process communication
interrupt:
hardware interrupt:
non-blocking algorithm:
wait-freedom:
lock-freedom:
software interrupt:
原文：http://www.cnblogs.com/starfuxks/p/3896105.html