Feature request - better jobs control

[Andrei Kopats]

Hello.

Today I had a problem with GNU Make - it has key -j for control max jobs 
count.
User can set particular count, or infinite.
With particular user must define count, but, user not always know the best.
With infinite - system could get frozen. Today I built project on system 
with 2 Gb of RAM, and my computer got frozen because infinite jobs count 
eaten all memory. As result, build longed 4 times more, than single job.
It will be fine, if make will support some intellectual mechanism for 
detect optimal jobs count for the system, based on CPU cores count and 
available memory.

I know, it is policy, not mechanism. But, I think it is very useful 
feature. To conservative  software usually replaced by  more modern one.

Thanks in advance