Re: GC: cons sweeping

[Dmitry Antipov]

Stefan Monnier wrote:

> So it seems to be able to speed up sweeping of cons cells by anywhere between
> 20% and 50% (up to a factor of 2 speed up).  Now, what fraction of time is
> spent sweeping cons-cells?

In general, typical GC spent 80% of time in marking and 20% of time in sweeping
(so even a tiny optimization of the first phase might be more important than a
much more solid enhancement of a second - but this doesn't mean that we should
not try to optimize both :-), and cons sweeping time is typically 2-5 % of the
whole GC time. So, since an average GC takes 20-30 ms on a 3GHz x86 CPU, I agree
that this optimization is likely not to be seen by an average user on an average
modern hardware.

Dmitry