On Sun, Jan 2, 2011 at 4:11 PM, Igor Stasenko <siguctua@gmail.com> wrote:

On 3 January 2011 00:15, Eliot Miranda <eliot.miranda@gmail.com> wrote:
> Hi Martin, Hi All,
> �� so find new VMs in�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.

Eliot, if you remember, i also had crash issues on linux, and pinned down it to
removing optimization from <something>heartbeat.c while keeping
gcc3x-cointerp.c to use
�same optimization flags as for rest of files.

Indeed, quite right. �I happened to add a flag to turn off the heartbeat so I could debug the crash Matthew was seeing in starting up Squeak4.2-10856-beta.image (since single-stepping through machine code always gets interrupted by the heartbeat, it being an interval timer) and lo and behold the bug went away. �This is very worrying because it appears to imply that there's a serious bug in the linux kernel/gcc since delivering a software interrupt shouldn't corrupt registers, but it clearly does. �I'll try and pass it by someone who's an expert in this area.

Anyway, now find a new linux VM in�VM.r2346/�that seems fine with the interpreter and the cogit compiled at -02 but the heartbeat compiled at -O2. �Running this VM on CentOS 5.3 under Parallels I get

�� 2839 run, 2796 passes, 7 expected failures, 24 failures, 11 errors, 0 unexpected passes

for the full test suite in�Squeak4.2-10856-beta.image.

So have at it.

best

Eliot

I will start coding cmake config for Cog during next week and will be
able to check my previous
observations again.

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

--
Best regards,
Igor Stasenko AKA sig.