[Gc] time for an alpha release?

Boehm, Hans hans.boehm at hp.com
Mon Nov 30 12:26:17 PST 2009


The current parallel GC algorithm doesn't interact very well with real incremental collection.  But I think the collector already backs off to pure generational (collections run to completion, but mark bits are not reset at every GC) if you try to combine them.  In particular, the threads initialization code sets GC_time_limit to GC_TIME_UNLIMITED in the PARALLEL_MARK case.  Thus I don't think there's a reason to prevent the combination in the test code.

We could probably do better in allowing real incremental and parallel collction to be combined.  There are some real issues in that it takes a while to start up and shut down a parallel collection.  But I'm sure we could do better than we are now.

Hans

> -----Original Message-----
> From: Talbot, George [mailto:Gtalbot at ansarisbio.com]
> Sent: Monday, November 30, 2009 5:52 AM
> To: Boehm, Hans; Ivan Maidanski; gc at napali.hpl.hp.com
> Subject: RE: [Gc] time for an alpha release?
>
> Just out of curiousity--I'm on one of those platforms
> (x86_64) that appears to disable incremental collection with
> parallel mark turned on.  Why is that again?
>
> --
> George T. Talbot
> <gtalbot at locuspharma.com>
>
>
> > -----Original Message-----
> > From: gc-bounces at napali.hpl.hp.com
> > [mailto:gc-bounces at napali.hpl.hp.com]
> > On Behalf Of Boehm, Hans
> > Sent: Monday, November 30, 2009 1:35 AM
> > To: Ivan Maidanski; gc at napali.hpl.hp.com
> > Subject: RE: [Gc] time for an alpha release?
> >
> > That sounds like a good idea.
> >
> > I did get a little bit of time to look at the heap growth
> issue a bit more.
> > There is currently a minor problem in that test.c is inconsistent
> > about enabling incremental collection on different platforms.  On
> > some, parallel mark disables it, as do some other features.
>  I have a
> > patch to make this more consistent, and hopefully get more similar
> > heap size behavior, but that's not critical.  And I'm currently
> > travelling again, so I'm not sure I'll get the patch in
> that quickly.
> >
> > Hans
> >
> > > -----Original Message-----
> > > From: gc-bounces at napali.hpl.hp.com
> > > [mailto:gc-bounces at napali.hpl.hp.com] On Behalf Of Ivan Maidanski
> > > Sent: Saturday, November 28, 2009 10:46 PM
> > > To: gc at napali.hpl.hp.com
> > > Subject: [Gc] time for an alpha release?
> > >
> > > Hi!
> > >
> > > Hans -
> > >
> > > The development activity has been very low over the last month.
> > > Why not to make an alpha release for GC now? (I could prepare the
> > > tarball and update the CVS (including for libatomics)
> > > accordingly.)
> > >
> > > I believe we could reach more test&report auditory (for
> the recent
> > > code changes) by releasing a tarball (instead of offering
> everybody
> > > to fetch the source from the CVS).
> > >
> > > Bye.
> > > _______________________________________________
> > > Gc mailing list
> > > Gc at linux.hpl.hp.com
> > > http://www.hpl.hp.com/hosted/linux/mail-archives/gc/
> > >
> >
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>



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