[Gc] Boehm GC and Iphone

Damian damian.pop at gmail.com
Sat Jan 15 15:14:46 PST 2011


Hi, I've just built gc7.2 BDWGC for iphone device, and it's working.
How can I make sure that generation mode is on and working?
And, parallel mark doesn't work on single core cpus?

Damian.

2011/1/13 Ivan Maidanski <ivmai at mail.ru>

> Hi,
>
> If the platform is not multi-core then parallel-mark mode should be off
> (either at compile time or at runtime).
> But turning on generation mode could reduce the GC pause on a single-core.
>
> Regards.
>
> Thu, 13 Jan 2011 08:28:55 -0300 Damian <damian.pop at gmail.com>:
> > None is multicore. Will I get an inprovement anyway?
> > Ok, I will try to compile gc7.2 BDWGC snapshot tonight.
> > Thanks!
> >
> > 2011/1/13 Ivan Maidanski <ivmai at mail.ru>
> >
> > > Hi,
> > >
> > > 1. Are you going to run it on a multi-core? (I don't know Apples
> devices
> > > internals deeply, so I wonder which of them have multi-core CPUs).
> > >
> > > 2. If you start using gc6.8 just because of the reason you mentioned, I
> > > recommend you to migrate to gc7.2 (get the recent BDWGC snapshot which
> now
> > > has generation plus parallel collection enabled).
> > >
> > > 3. Incremental/generation collection as well as parallel marking are
> the GC
> > > improvements aiming collection pause reduction.
> > >
> > > Regards.
> > >
> > > Wed, 12 Jan 2011 20:03:02 -0300 Damian <damian.pop at gmail.com>:
> > >
> > > > Maybe concurrent + parallel collection does not what I'm expecting.
> > > > What I need to achieve is to reduce the collection pause.
> > > > I'm using version 6.8 (because I've found somewhere on the internet
> > > someone
> > > > has made it work on iphone with some changes) and I'm having
> collection
> > > > cycles of about 120ms. I need to reduce that number. I don't care if
> > > overall
> > > > collection time increases as long as the app is not freezed for such
> a
> > > long
> > > > time.
> > > > Is that possible?
> > > >
> > > > Thanks.
> > > >
> > > > 2011/1/12 Ivan Maidanski <ivmai at mail.ru>
> > > >
> > > > > Hi,
> > > > >
> > > > > BTW What Apple devices has a multi-core CPU at present?
> > > > >
> > > > > I ran GC test on a single-core with GC_MARKERS=4 - collector
> appears to
> > > > > work...
> > > > >
> > > > > Wed, 12 Jan 2011 10:04:00 -0300 Damian <damian.pop at gmail.com>:
> > > > >
> > > > > > Hi,
> > > > > > Is it possible to compile boehm gc for iphone enabling
> generational
> > > and
> > > > > parallel collection?
> > > > >
> > > > > See the recent post by Hans.
> > > > >
> > > > > I try to enable generational collection on multi-cores (regardless
> > > whether
> > > > > this slows down the GC in average or not - anyway it is not on by
> > > default).
> > > > > FYI: At present, generational collection on multi-cores enabled
> only on
> > > > > Win32.
> > > > >
> > > > > Regards.
> > > > >
> > > > > > I will try to do so; probably I will need help, but for now al
> least
> > > I
> > > > > want to know it it's possible at all.
> > > > > > Thanks
> > >
> > >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://napali.hpl.hp.com/pipermail/gc/attachments/20110115/41f811ac/attachment.htm


More information about the Gc mailing list