> Narihiro Nakamura <authornari / gmail.com> wrote:
>> * A heap block address is aligned by 16KB to find fast a bitmap.
>
> Just wondering, why/how did you determine 16K alignment is optimal?
> Normal page size in Linux is only 4K, so 16K seems large.

Moreover, posix_memalign() and memalign() sound bad choice. It need
a few header bytes. then, some malloc implementations might allocate
32K instead of 16K.

So, why can't we use mmap() directly or use "16K - a few bytes" length?