Kernel thread scheduling

[Vincenzo Scotti]

Thank you for the example.

I understand what are the scheduling mechanics depending on task->state.
But suppose another situation. 
Let's say I change current state to TASK_INTERRUPTIBLE. If I start now some long
operation, then shouldn't the scheduler kick in as soon as he can and put my thread
asleep? Or should I call necessarily schedule()? And if so, why?