Post #1546619

@regehr I think this should be a kernel feature. There is a scheduling class, SCHED_BATCH, with low priority and very long (1.5s) slices. I think this could be improved even further, by essentially making the slices infinite, yielding CPU in execve() at the point where the process image is smallest, and on memory pressure, swap out the other batch class processes, smallest first. When there are free CPUs, resume the largest batch process. Users would just `make -j` with no limit.