[pooma-dev] parallel particle bctest3 crash

Richard Guenther rguenth at tat.physik.uni-tuebingen.de
Sat Oct 9 23:04:54 UTC 2004


Arno Candel wrote:
> 
>> This is no wonder:
>>
>>   if (Pooma::context() == 0)
>>     P.create(10,0,false);
>>   P.sync(P.a1);
>>
>> i.e. we create 10 particles - distributing over 11 contexts isn't 
>> going to work.  We don't handle contexts with zero particles 
>> gracefully.  I think there are similar problems with #patches < 
>> #contexts.  But I'd qualify these cases as user error.
>>
>> Hope this helps,
>> Richard.
> 
> Unfortunately, that's not the problem. It still doesn't work after 
> creating 11 or more particles.

Hm ok, that was just a guess.

> I've been using position-dependent distribution of particles for months 
> now in my own code, often with many contexts not containing any 
> particles. The problem only arises when the number of contexts is 
> getting too high (mostly 8-10 being the limit). However, I have no idea 
> what triggers the error...

I don't have time at the moment to dig into this myself, maybe you can 
try to debug this yourself - usually doing printf-debugging is the only 
way to debug these parallel failures though (unless you have expensive 
tools around, which I don't have).

Richard.



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