[Sugar-devel] Dr.Geo on XO 1

[Bert Freudenberg]

On 20.05.2012, at 11:00, Sascha Silbe wrote:

> Bert Freudenberg <bert at freudenbergs.de> writes:
> 
>> Nope, that was not it. I compiled with -mtune=geode, makes no
>> difference.
> 
> Make sure to set -march=<architecture> to something appropriate. -march
> tells gcc what instructions it can use (so anything that doesn't support
> these instructions will fail to run the resulting executable), whereas
> -mtune only tells it to optimise for a certain processor type (but the
> executable will continue to run on other processors as long as they
> support the instruction set specified by -march).

I actually had used "-march=pentiumpro -mtune=geode" as recommended here:

	http://wiki.laptop.org/go/Geode_LX

and even with an additional -O0 it still crashes.

> In gdb I see it's segfaulting inside the GC logic. It's really
>> puzzling this only happens on the XO-1 ...
> 
> You could try booting an XO-1.5 with mem=256M (append that to boot-file
> in /bootpart/boot/olpc.fth) to simulate the memory pressure of an XO-1.


YES! That reproduces the crash on XO-1.5. Good thinking! :)

I could also reproduce it in a virtual Ubuntu 12 with 768 MB RAM (!) but no swap. Top reports:

Mem:    766204k total,   601588k used,   164616k free,    45624k buffers
Swap:        0k total,        0k used,        0k free,   277024k cached

but DrGeo still crashes.

OTOH, Etoys runs fine using the same Squeak VM on the same system (and on XO-1). So I wonder what the new DrGeo does differently ...

- Bert -