It runs 6 nodes: under valgrind this ends up consuming 5.3 GB RSS. By
stopping nodes between, we peak about 1G RSS.
Measured using:
(while true; do echo $(for i in 4 5 6; do ps uh | tr -s ' ' | cut -d\ -f$i | tally; done); sleep 5; done)&
(Which measures my other processes as well, but that's only about 100M).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>