Re: Unresolved issues #2 (shallow clone again)

From: Linus Torvalds <torvalds@osdl.org>
Date: May 8, 2006, 02:42 UTC
Message-ID: <Pine.LNX.4.64.0605071939291.3718@g5.osdl.org>
In-Reply-To: <20060508022432.GA26076@thunk.org>

On Sun, 7 May 2006, Theodore Tso wrote:

Show 6 quoted lines

> 
> That brings up an interesting question though --- why not skip
> compressing files that are under 4k (or whatever the filesystem
> blocksize happens to be) if they are unpacked?  It burns CPU time;
> maybe not enough to be human-noticeable, but it's still not buying you
> anything.

Well, other filesystems don't have 4kB issues. Reiser can do smaller things iirc, and you might obviously have a ext3 filesystem with a 1kB blocksize too. And with tails on FFS, you might have a filesystem with a 8kB blocksize, but despite that it might lay out <1kB files well.

Anyway, packing makes all this basically a non-issue. There are no block boundaries in a pack-file, and you only use a single inode. And you'd obviously want to pack for other reasons anyway (ie the delta compression will makea huge difference over time).

		Linus