I am following the discussion caused by Greg Kroah-Hartman requesting that kdbus be pulled into the next kernel release. First of all my hat of to Greg for his persistence and staying civil. There has already been quite a few posts to the thread at coming close to attempts at character assassination and a lot of emails just adding more noise, but no signal.
One point I feel is missing from the discussion here though is the question of not making the perfect the enemy of the good. A lot of the posters are saying that ‘hey, you should write something perfect here instead of what you have currently’. Which sounds reasonable on some level, but when you think of it is more a deflection strategy than a real suggestion. First of all the is no such thing as perfect. And secondly if there was how long would it take to provide the theoretical perfect thing? 2 more years, 4 years, 10 years?
Speaking as someone involved in making an operating system I can say that we would have liked to have kdbus 5 years ago and would much prefer to get kdbus in the next few Months, than getting something ‘perfect’ in 5 years from now.
So you can say ‘hey, you are creating a strawman here, nobody used the word ‘perfect” in the discussion. Sure, nobody used that word, but a lot of messages was written about how ‘something better’ should be created here instead. Yet, based on from where these people seemed to be coming the question I ask then is: Better for who? Better for the developers who are already using dbus in the applications or desktops? Better for a kernel developer who is never going to use it? Better for someone doing code review? Better for someone who doesn’t need the features of dbus, but who would want something else?
And what is ‘better’ anyway? Greg keeps calling for concrete technical feedback, but at the end of the day there is a lot of cases where the ‘best’ technical solution, to the degree you can measure that objectively, isn’t actually ‘the best’. I mean if I came up with a new format for storing multimedia on an optical disk, one which from a technical perspective is ‘better’ than the current Blu-Ray spec, that doesn’t mean it is actually better for the general public. Getting a non-standard optical disc that will not play in your home Blu-Ray player isn’t better for 99.999% of people, regardless of the technical merit of the on-disc data format.
Something can actually be ‘better’ just because it is based on something that already exists, something which have a lot of people already using it, lets people quickly extend what they already are doing with the new functionality without needing a re-write and something which is available ‘now’ as opposed to some undefined time in the future. And that is where I feel a lot of the debaters on the lkml are dropping the ball in this discussion; they just keeping asking for a ‘better solution’ to the challenges of a space they often don’t have any personal experience with developing in, because kdbus doesn’t conform to how they would implement a kernel IPC mechanism for the kind of problems they are used to trying to solve.
Also there has been a lot of arguments about the ‘design’ of kdbus and dbus. A lot of lacking concreteness to it and mostly coming from people very far removed from working on the desktop and other relevant parts of userspace. Which at the end of the day boils down to trying to make the lithmus test ‘you have to prove to me that making a better design is impossible’, and I think that anyone should be able to agree that if that was the test for adding anything to the Linux kernel or elsewhere then very little software would ever get added anywhere. In fact if we where to hold to that kind of argumentation we might as well leave software development behind and move to an online religion discussion forum tossing the good ol’ “prove to me that God doesn’t exist’ into the ring.
So in the end I hope Linus, who is the final arbiter here, doesn’t end up making the ‘perfect’ the enemy of the good.