A while ago, I downloaded Linux kernel source 2.6.38.8 from kernel.org (http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.38.8.tar.gz). Today, I cloned github.com/torvalds/linux and tried to find the commit that produced that exact version. The closed thing I could find was a tag for v2.6.38-rc8.
When I did a diff -r on the two directories, there were 775 files that diffed (not including any files under .git/). Can anyone explain (or link an article) how the releases on http://www.kernel.org/pub/linux/kernel/v2.6 are created vs. the git tags?