This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Speeding up GC
- From: Richard Henderson <rth at redhat dot com>
- To: Martin v. Löwis <loewis at informatik dot hu-berlin dot de>
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 3 Jun 2002 18:05:53 -0700
- Subject: Re: Speeding up GC
- References: <j47klg8pfy.fsf@informatik.hu-berlin.de>
On Mon, Jun 03, 2002 at 03:25:05PM +0200, Martin v. Löwis wrote:
> While it is, in general, not possible to determine whether an object
> has changed, I believe that for certain objects (in particular DECL
> nodes), there is a point in time when they are "frozen", meaning that
> they won't change anymore. I suggest to record this fact in the
> object (with the opportunity to unfreeze the object).
A better way to do this is to actually compact the GC arena
and mark the pages read-only. If the objects are modified,
the SIGSEGV handler marks the page read-write again and flags
the page as having been modified.
This is called "generational GC". It has been discussed on
the list off and on.
It's on-hold waiting for Geoff Keating's GC rewrite, since
at the moment we can't compact the GC arena.
r~