map del efficiency python2.2 and 2.1

[Tim Peters]

[John Hunter]
> ...
> Here then is the synopsis (excluded runs where %CPU < 99%)
>             2.1       2.1     2.1       2.1
> del m       yes       yes     no        no
> del seq     yes       no      yes       no
> run time    7.9s      7.6s    15.4s     7.4s
>
>             2.2       2.2     2.2       2.2
> del m       yes       yes     no        no
> del seq     yes       no      yes       no
> run time    7.6s      7.24s   15.6s     15.4s

This is exactly the kind of "seemingly random disaster" we see when the
platform free() goes nuts, although it's usually much more pronounced than a
measly factor of 2.  If so, rebuilding with pymalloc is likely to fix it,
while if you don't you'll never answer "why?" without a deep understanding
of your platform C's implementation of free().

> OK, I'll stop torturing you and me now.

likewise<wink>-ly y'rs  - tim