blocked process and preempt

view full story

http://www.unix.com – Hello Everyone, There is a column kthr:b in vmstat. How a process become blocked? If the process calls system call pread and sleeps inside it, is the process blocked in that moment? How a process sleeping because it has no work at all (as Notepad when we are not using it) differs from a process which is sleeping because is waiting for I/O request? Thanks p.s. I have written "and preempt" in the subject because wanted to ask about it, but now please ignore this part. I do not have an option to modify subject. (HowTos)