rtld optimizations

[Mark Saad]

Hello Hackers

The NetBSD folks have a nice improvement with the rtld-elf subsystem,
known as "Negative Symbol Cache" .

http://blog.netbsd.org/tnf/entry/netbsd_runtime_linker_gains_negative

 Roy Marples roy@ has a simple write up of the change.

I took the basic idea from FreeBSD, but improved the performance
drastically. Basically, the huge win is by caching both breadth and
depth of the needed/weak symbol lookup.
Easiest to think of a,b,c,d as a matrix and FreeBSD just cache a row
where we cache both rows and columns.

Has anyone looked into porting the changes back to FreeBSD ?  The
improvement on load time for things like firefox, openoffice, and java
is huge on NetBSD. It looks like this change could improve load times
on FreeBSD in the same ways.


-- 
mark saad | nonesuch at longcount.org