Bill Allombert on Wed, 21 Jan 2015 22:32:09 +0100


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Re: Stack size bugs and parisizemax


On Wed, Jan 21, 2015 at 09:52:19PM +0100, Karim Belabas wrote:
> * Jeroen Demeyer [2015-01-21 08:59]:
> > On 2015-01-20 23:55, Bill Allombert wrote:
> > >Do you think supporting what you call 'desesparation mode' to be valuable ?
> > >So far Karim and I have been less than convinced.
> > In http://pari.math.u-bordeaux.fr/cgi-bin/bugreport.cgi?bug=1507#15, Karim
> > clearly supported "desperation mode". But if you want to get rid of
> > desperation mode completely, that would obviously a good (and simple)
> > solution.
> 
> Hum, yes I did. But we didn't have parisizemax back then ! I now think
> we should only support "desperation mode" when parisize == parisizemax.
> 
> I guess it's probably best to prevent garbage collection from internal
> loops unless parisize = parisizemax, as you proposed.

What about parisizemax = 0 ? And do you mean default(parisize) or the
current stacksize (parimainstack->size) ?

Also with unlucky choice of parisize and parisizemax, size == parisizemax
might never happen: we might go from size < parisizemax to stack overflow
in one go. (e.g. set parisize to 1G and parisizemax to 4G: parisizemax
will be set to 4000002048, but parisize will be doubled to 2000000000 and
then to 4000000000.  

Cheers,
Bill.