C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/redos.pl 
=== length=5 string=aaaaa
start     1633643412
post rx 1 0 sec
post rx 2 0 sec
done      0 sec



=== length=6 string=aaaaaa
start     1633643412
post rx 1 1 sec
post rx 2 1 sec
done      1 sec



=== length=7 string=aaaaaaa
start     1633643413
post rx 1 4 sec
post rx 2 4 sec
done      4 sec



=== length=8 string=aaaaaaaa
start     1633643417
post rx 1 20 sec
post rx 2 20 sec
done      20 sec