Is there a way to make the pi use swap?

[Gene Heskett <gheskett@shentel.net>]

Greetings;

As I attempt to go beyond the original setup on the pi 3b, which was to 
run linuxcnc on it.

But since it has 1/2 its cpu power left over, I am finding the lack of 
memory to be a pita. Starting a camera application so I can calibrate 
out the errors in the lathes mechanics then kills other services like 
ssh, or even the whole thing so bad it needs a powerdown reboot.

I have a couple ssd's mounted each with a couple gigs of swap, but the pi 
isn't using them, at least not as expected.

What would be the chain of things to check and adjust so it does use the 
available swap?  There is a 10Gb defined in the /etc/fstab, on partition 
sda2, one of the 2 ssd's plugged into a usb hub.

If swapon -a is run, I can see 999megs of swap in htop, which goes away 
after a swapoff -a, both of course as sudo root.

Thanks for any clues.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>