Loïc Grenié on Wed, 21 Jan 2015 09:57:38 +0100

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Re: Stack size bugs and parisizemax

2015-01-20 23:55 GMT+01:00 Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>:
> On Tue, Jan 20, 2015 at 10:54:08PM +0100, Jeroen Demeyer wrote:
>> On 2015-01-20 21:32, Bill Allombert wrote:
>> >The purpose of parisizemax was to allow to have a nearly unlimited stack
>> >(limited only by the available hardware) without increasing the actual
>> >memory usage (in the sense that the final stack size will be close to the
>> >minimum stack size for which the computation would have succeed, up to a factor
>> >of two).
>> I don't think that parisizemax should behave like that. If an
>> algorithm can work significantly faster by using a larger stack size
>> than the minimum, it should do that.
> I think we all agree on that, but this is no contradictory with the above:
> performing more GC should still be OK if it does not slow down the computation
> much.
> We also agree that garbage collection in second-level loops is problematic
> when doing linear algebra (because garbage collection is very slow then).

     What about checking wether GC did free enough memory in second-level
  loops and, if not, increasing parisize (provided it is < parisizemax) or warn
  the user about too low memory ?