[squeak-dev] Re: [Pharo-project] new Cog VMs

Eliot Miranda eliot.miranda at gmail.com
Sun Jan 2 23:15:18 UTC 2011


Hi Martin, Hi All,

    so find new VMs in
VM.r2341/<http://www.mirandabanda.org/files/Cog/VM/VM.r2341/>.
 The linux crashes (certainly the one you suffered from Martin) seem to be
caused by an optimization bug (but they could be caused by bad code
generation, creating something that assumes ordering constraints which C
doesn't guarantee).  I suspect the former because I don't see the crash when
running exactly the same VM and image from a different directory; provoking
the crash requires a particular path (go figure; I haven't pinned this down
yet).

So my "fix" is preventing a complex function being inlined into the main
interpreter loop, removing the sources of some warnings, and lowering the
optimization level of the gcc3x-cointerp.c file to -O1 from -O2 (my build
environment, CentOS Linux 5.3, uses gcc 4.1.2).  I'm not proud of this
"fix".  I've violated the Deutsch criterion by not diagnosing the cause of
the bug so I can't stand behind this fix; it's a hack that appears to work
and may have merely pushed the real bug further underground.  Alas I don't
have time to do a better job. Hopefully it'll get those of you on linux
going again.

best
Eliot

On Sat, Jan 1, 2011 at 11:16 PM, <mkobetic at gmail.com> wrote:

> I'm probably doing something obviously wrong, but I have no luck with the
> Cog VM. It crashes immediately on startup even with the stock OneClick
> image. I downloaded the Pharo-1.1.1 OneClick images. Fetched the latest
> coglinux.tgz (r2340), untarred it into the pharo directory and just trying
> to run it from the top-level pharo directory as:
>
>        coglinux/squeak Contents/Resources/pharo.image
>
> crashes immediately (with or without the -vm-display-X11 option). This is
> on latest Fedora 14. The old VM seems to have no problem when I try to run
> it the same way:
>
>        Contents/Linux/squeakvm Contents/Resources/pharo.image
>
> seems to start just fine. I can copy the stack dump from the crash, but
> since most seem to be running fine, I suspect I'm just not doing it right.
> What am I missing ?
>
> Thanks,
>
> Martin
>
> "Eliot Miranda"<eliot.miranda at gmail.com> wrote:
> >    there are new versions of both the SimpleStackBasedCogit and the
> > StackToRegisterMappingCogit Cog VMs in
> > VM.r2339/<http://www.mirandabanda.org/files/Cog/VM/VM.r2339/>
> >  & VM.r2340/ <http://www.mirandabanda.org/files/Cog/VM/VM.r2340/>
> respectively.
> >  These contain fixes for rounding bug causing underestimate of
> openPICSize
> > and resultant hard crashes, seen e.g. by trying to recover lost changes
> in a
> > Pharo 1.2 image installed on c:\pharo.  If you're trying to reproduce Cog
> > crashes please upgrade to one of tthese two VMs.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20110102/e060e699/attachment.htm


More information about the Squeak-dev mailing list