RFC: Reduce GC root set to speed up GC...

[David Daney <ddaney at avtrex dot com>]

Recently there have been some discussions about GC performance issues.
We are also looking at some things in this area.

One thing that Hans Boehm suggested was to reduce the size of the root set.

I have been thinking about how that might be done.  Here is one idea:

Create a separate object file section (".gc.roots" or some such thing)
that all global pointers (aka references) get put into.

GCJ would then place all static pointers in this section instead of
.data.  All of the native code in libgcj would do the same using
__attribute__ ((section (".gc.roots"))) where needed.

It should be possible to identify these sections at runtime in a similar
manner to the way the GC is finding .data sections currently

Would something like this be doable?

Would it be worth the effort?

David Daney.