[Python-Dev] Optimization of the Year

[Tim Peters]

[Aahz]
> So in other words, we might as well go ahead and trade space for
> speed?

And simplicity, yes.  The current scheme is delicate and obscure as well as
slow and compact.  Worse, it's grown hairier over the years as more
platform-specific cases of extremely bad performance were reported, and an
obscure scheme that grows more obscure over time is (IMO) a loser.

> If someone really does have a million small lists, they're
> probably mutating some of them constantly (or they'd use tuples).

I don't know about that one -- "head arguments" in either direction are too
easy to make up here.  Since my employer mostly runs Linux, and adding a 4-
byte list header field under gcc won't make any difference to total
allocation, nobody's gonna hit me if it happens.  Hell, I'd be happy to rip
out the irritating union-with-long-double gc header trick that forces worse
results under MSVC too (same thing:  an increase in beauty without personal
pain).