How much memory to compile www/chromium?

[bob prohaska]

How much memory should be required for  
make -DBATCH
in www/chromium?

Make issues  warnings about disk space required, but I don't recall seeing
anything about RAM or swap. 

The system in question is an RPI3 running r341643. Make reached part
[18416/30819], at which point it seems to have stalled. The machine is
still (sluggishly) responsive, gstat is reporting
dT: 10.050s  w: 10.000s
 L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w    d/s   kBps   ms/d   %busy Name
    8    588    149    708   25.7    439   2056    7.7      0      0    0.0  100.0  mmcsd0
    8    588    149    708   25.7    439   2056    7.8      0      0    0.0  100.0  mmcsd0s2
    8    588    149    708   25.7    439   2056    7.8      0      0    0.0  100.0  mmcsd0s2b

That it got stuck on reading, rather than writing, is a little surprising.

Swapinfo reports
Device          1K-blocks     Used    Avail Capacity
/dev/mmcsd0s2b    4404252  2705928  1698324    61%

If this is expected, is there a way to reduce the number of threads started by make?
It's using four now, all in state SWREAD showing WCPU of zero to a few percent.
Top is reporting mostly idle, with system and interrupt at less than 10%. There are
swap_pager_getswapspace(32): failed
messages on the console, so it really is out of memory. 
 
Thanks for reading!

bob prohaska