There is no need to change global and widely used constant for specific FSFS
optimization. Despite it marked as private, it's declared in public header and
it is better to keep it unchanged to prevent possible compatibility problems.
We have had problems with big read buffers used in config read code due to
inefficient handling of large allocation by apr_allocator_t . This particular
problem was fixed in r1581296, but there is no reason to reintroduce this class
of issues back again.