Out of memory problem

Thu Jun 27 13:00:00 GMT 2002

On 2002年6月27日, Suresh Raman wrote:
> But, when I limit the maximum heap size of the program to 4MB* and run
> the same program again, I get "Warning: Out of Memory! Returning
> NIL!" errors. It happens nearly everytime during the 768th pass in
> the loop. The total heap memory is almost at 4M and the free heap
> memory is at 0, when the error happens. Given that the program does
> not use more than 2MB at any time, I expect it to run without any
> problems within 4MB. This is unfortunately not the case.

I'm not quite sure why the explicit GC would help you, since the collector
will attempt a full collection anyway if it cannot grow the heap.
For tuning the collector I've found it helpful to build without -DSILENT,
and you might also arrange to call GC_dump() at the point of failure.
That'll help to understand what decisions the collector is making.
Also see the documentation for GC_free_space_divisor. Increasing this can
limit heap growth to some extent.
Jeff