Should a non-blocking code push CPU to 100%

I've been th开发者_开发知识库inking today about NodeJS and it attitude towards blocking, it got me thinking, if a block of code is purely non-blocking, say calculating some real long alogirthm and variables are all present in the stack etc.. should this push a single core non hyperthreaded to CPU as Windows Task Manager defines it to 100% as it aims to complete this task as quickly as possible? Say that this is generally calculation that can take minutes.

Yes, it should. The algorithm should run as fast as it can. It's the operating system's job to schedule time to other processes if necessary.

If your non-blocking computation intensive code doesn't use 100% of the CPU then you are wasting cycles in the idle task. It always irritates me to see the idle task using 99% of the CPU.

As long as the CPU is "given" to other processes when there are some that need it to do their calculations, I suppose it's OK : why not use the CPU if it's available and there is some work to do ?

As RAM can be paged out to disk, all applications are potentially blocking. This would happen if the algorithm uses more RAM than available on the system. As a result, it won't hit 100%.