Re: kdbus: to merge or not to merge?

David Lang
2015-06-25T06:49:18Z

On Wed, 24 Jun 2015, Greg KH wrote:

> On Wed, Jun 24, 2015 at 10:39:52AM -0700, David Lang wrote:
>> On Wed, 24 Jun 2015, Ingo Molnar wrote:
>>
>>> And the thing is, in hindsight, after such huge flamewars, years down the line,
>>> almost never do I see the following question asked: 'what were we thinking merging
>>> that crap??'. If any question arises it's usually along the lines of: 'what was
>>> the big fuss about?'. So I think by and large the process works.
>>
>> counterexamples, devfs, tux
>
> Don't knock devfs. It created a lot of things that we take for granted
> now with our development model. Off the top of my head, here's a short
> list:
> - it showed that we can't arbritrary make user/kernel api
> changes without working with people outside of the kernel
> developer community, and expect people to follow them
> - the idea was sound, but the implementation was not, it had
> unfixable problems, so to fix those problems, we came up with
> better, kernel-wide solutions, forcing us to unify all
> device/driver subsystems.
> - we were forced to try to document our user/kernel apis better,
> hence Documentation/ABI/ was created
> - to remove devfs, we had to create a structure of _how_ to
> remove features. It took me 2-3 years to be able to finally
> delete the devfs code, as the infrastructure and feedback
> loops were just not in place before then to allow that to
> happen.
>
> So I would strongly argue that merging devfs was a good thing, it
> spurned a lot of us to get the job done correctly. Without it, we would
> have never seen the need, or had the knowledge of what needed to be
> done.

I don't disagree with you, but it was definantly a case of adding something that
was later regretted and removed. A lot was learned in the process, but that
wasn't the issue I was referring to.

I don't want kdbus to end up the same way. The more I think back to those
discussions, the more parallels I see between the two.

David Lang