why ignore memory reduce?

[xjdrew]

code: https://github.com/pmusa/lmprof/blob/master/src/lmprof.c#L302

if (nsize > osize && st->increment_alloc_count == 1) {
  st->alloc_count = st->alloc_count + (nsize - osize);
}

when nsize < osize, it means memory reduce, why ignore?