Locality problems caused by size based allocation?
Zack Weinberg
zack@codesourcery.com
Wed Dec 18 00:41:00 GMT 2002
Jeff Sturm <jsturm@one-point.com> writes:
> On Tue, 17 Dec 2002, Daniel Berlin wrote:
>> > What exactly is "size based allocation"?
>> What ggc-page does, which is segregate objects based on size rather than
>> age or object type.
>
> Got it. But that puzzles me: the Boehm collector allocates one size
> of object per heap block, fitting your desription of size-based
> allocation, yet there was a measureable improvement over ggc-page?
The Boehm collector may choose better size buckets. Our current
choices are crap, and I have statistics to prove it. (details will
cheerfully be provided, but not now, because I'm not going to sit and
wait for gnumeric to paint its window over this remote X11 session).
Also, I believe it uses a generational algorithm, which should knock
down the large amount of time spent marking live objects.
zw
More information about the Gcc
mailing list