On 10/23/2012 08:45 AM, Robert Dodier wrote:
> On 2012-10-22, andre maute <andre.maute at gmx.de> wrote:
>
>> i stumbled upon the following
>> which produces without the kill
>> a heap exhausted error on my 2Gb machine
>> under fedora 17 and sbcl 1.0.57-1.fc17
>> (I can give further information if necessary)
>>
>> ------------------------------
>> display2d : false;
>> my_M(n) := ident(n);
>> my_work(n) := block(
>> [res:0,M],
>> M : my_M(n),
>> M[1,1] : 2,
>> /* kill(M), */
>> res : n,
>> return(res)
>> );
>> for k : 1 thru 10 do block(
>> h : my_work(3000),
>> print(k,h)
>> );
>> ------------------------------
>>
>> kill fixes the heap exhausted error,
>> but top shows nevertheless usage of 800 Mb resident memory
> Dunno exactly what's going on, but from what I can tell, the behavior
> you've observed is a consequence of the garbage collection strategy
> employed by the Lisp implementation -- from what I can tell, the Lisp
> implementation has not freed memory which is actually available to be
> reclaimed.
>
> I tried that example with CMUCL and Clisp. The behavior of CMUCL is
> similar to what you reported for SBCL. For Clisp, the memory use
> increases from about 9 Mb at start up to 90 Mb and stays there, until
> :lisp (ext:gc) is issued, after which memory decreases to 9 Mb again. I
> suppose Clisp's behavior is probably what we would like to see for any
> Lisp implementation.
But it looks like there is a maxima component of the problem.
I checked which maxima version chokes for which k
Maxima | k
----------
5.19.2 | 5
5.24.0 | 8
5.26.0 | 5
5.27.0 | 5
Has somebody an idea how I can call
the garbage collector _inside_ the for loop?
Regards
Andre