From: KOSAKI Motohiro Date: 2012-01-08T08:57:54+09:00 Subject: [ruby-core:41969] Re: Proposal: Bitmap Marking GC > Narihiro Nakamura 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?