Re: reproducible cygwin memory problems

[Richard Stallman]

    first, I noticed that when I undef rel_alloc, while this seems to add some 
    stability while editing images, there seems to be a problem with returning 
    memory to the OS even with text files.

That does not surprise me.  Ordinary malloc can't in general return
space to the OS.  All it can do is reuse the block if it needs another
the same size.

I wrote rel_alloc as a way to solve this particular problem.
On GNU/Linux we don't need it now, because the malloc in GNU libc
allocates large blocks by creating separate pages which it can
return to the kernel.  But on systems that don't do this, rel_alloc
is still very important.

Turning off rel_alloc may be useful for investigating this problem,
but it certainly isn't the solution.