How about making it ten times faster?

[akim]

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...