Before the patch: ~/src/am/automake --amdir=/home/akim/src/am 7.84s user 0.06s system 92% cpu 8.535 total after: ~/src/am/automake --amdir=/home/akim/src/am 0.84s user 0.03s system 99% cpu 0.870 total I still have details to fix, but it's nothing important. Since it's fun finding ideas, I won't tell now how to do that, but the idea is *dead simple* he he :) First try to imagine, then compare your solution to mine in the next message...