[fpc-devel] FPC memory manager and OS/2 - heap sub-allocation

[Karoly Balogh]

Hi,

On Tue, 30 Jun 2026, Tomas Hajny via fpc-devel wrote:

> In addition, thinking about it a bit more, I just noticed another
> potential reason of the misalignment between the overall memory still
> available and the memory allocation failing... Originally, OS/2 didn't
> allow allocation of more than 512 MB of RAM per process (that limit has
> its reasons, but those go beyond this post).

Yeah, this was also my first reaction, when you were talking about getting
an an OOM, that you might run into the per process limit of 512MB address
range (which is in practice even less "available memory" because every
process has shared memory range too, and what else, which to my
understanding also counts into the 512MB limit.

But regardless of what the actual limit is - to take hundreds of MB to
compile a Free Vision app or the IDE sounds a bit excessive. Don't we have
a memory leak somewhere? I used to be able to compile this stuff on an
Amiga with 128MB RAM... I understand that the compiler gained quite some
features since, so internal structures might have grown, but have they
really grown this much?

Charlie