As you may know, I'm a user of the p4 side repository to do large code development. With the switch to svn, I wasn't sure I'd still need to do that, so I let my trees there go for a while. It is clear to me that I'll need to use p4 a little while longer. So, I cleaned up my newcard tree.
Why do I need to cleanup at all? That's a good question. You'd think that you'd only have code cooking in the tree that was destined to be committed, so no cleanup is needed. Merging conflicts, sure, but no cleanup. Well, it turns out that sometimes perforce doesn't do quite the right thing when there's a loop back of new files into FreeBSD. If I create a file in perforce, and then later merge it into FreeBSD, then the $FreeBSD$ tag is messed up. Over time, you get lots of these files in the perforce tree, and you have to basically just copy the FreeBSD version over them.
The other reason to clean up is that code can cook for too long. I have several projects in my newcard tree that just didn't work out. I didn't get them into the tree quickly enough and the problems they were designed to clean up have been solved in other ways. Or they fixed problems in the MD code, and now that FreeBSD has grown more machines more code needs to be changed. Sometimes you change the new MD code. Other times, you just junk the old stuff since the improvements were so marginal that it isn't worth carrying those stones in your kit bag anymore.
Sometimes projects are only half-baked. I had a number of interesting ideas that turned out to not be such a good idea. That turned out to not be a big enough savings, or that some other key developer in the project didn't like. It happens. Some ideas are great, while others seem to be grating on others.
So all of these are reasons to cleanup the tree. I've managed to reduce my diffs from 200k down to 100k. Most of the 100k that's left could easily be described as half-baked. The biggest half-baked thing is a port of the NetBSD improvements to mii. The second biggest are a collection of hacks and bug fixes to the pccard/cardbus layer. Those always take a lot of time to sort out.
It is one of the more pedestrian things that I need to do when hacking. But if the litter piles up too high, it becomes increasingly difficult to see what should go into the tree, and what shouldn't so nothing does and many of my cool hacks don't benefit people, and I don't benefit from the wider exposure of the code. Nobody tests my private tree but me... Everybody notices when you put something even a little stinky into the main FreeBSD tree.
I debated about not blogging about it. However, one reason people have told me they read my blog is that they learn how to be better engineers from some of the things I do. They usually don't tell me if they are emulating things I do because they think they are good, or if they are avoiding the things I do because they think they are bad. Maybe a little of both... Documenting the mundane from time to time may bring better balance. Or it may put my readers to sleep... It is hard to say without feedback...