Posting this in the Newbie section as it's pretty basic and I couldn't quickly find an answer to this by googling it.
The output of "apachectl -l" for me is:
root@machine:# apachectl -l
Compiled in modules:
In the past it used to say something like prefork
so I had a clue where to tweak the conf file to make it behave and not eat most of my memory.
Am not posting this in the distribution's forum section, as finding out what MPM is being used should be distribution-independent.