Gracefully killing and restarting a port build....

[bob prohaska]

While compiling www/chromium on a Pi3B it has become clear that the
default -j4 isn't going to work (yes, I know, ya told me). 

On the plus side, it hasn't crashed, despite several days of
continuous swapping  with 1-2GB of swap in use. Kudos to the
VM folks.

Now I'd like to (gracefully) stop the make and restart it with more 
sane -j values. -2 seems like a reasonable start. 

A simple 
kill <PID> aimed at the original make doesn't seem to do anything. Even 
kill -9 <PID> appears to have no effect on the c++ threads, which are
still running minutes afterwards. 

Now it seems rather like I'm stuck: The original <PID> is gone, but 
c++ is still grinding away as if nothing has changed.. 

Is there a better way to accomplish a clean(ish) stop and restart of
a multi-threaded make process?

Thanks for reading, apologies if it's a dumb question,

bob prohaska