From: H. Peter Anvin Date: Thu, 14 Apr 2005 17:02:55 GMT Subject: Re: Yet another base64 patch Message-ID: <425EA23F.6010900@zytor.com> In-Reply-To: Linus Torvalds wrote: > > So why is "base64" worse than the stock one? > > As mentioned, the "flat" version may be faster, but it really isn't an > option. 32000 objects is peanuts. Any respectable source tree may hit that > in a short time, and will break in horrible ways on many Linux > filesystems. > If it does, it's not because of n_link; see previous email. I have used ext2 filesystems with hundreds of thousands of files per directory back in 1996. It was slow but didn't break anything. The only filesystem I know of which has a 2^16 entry limit is FAT. > So you need at least a single level of subdirectory. > > What I don't get is why the stock hex version would be better than base64. > > I like the result, I just don't _understand_ it. The base64 version has 2^12 subdirectories instead of 2^8 (I just used 2 characters as the hash key just like the hex version.) So it ascerbates the performance penalty of subdirectory hashing. -hpa