[LLVMdev] RFC: Code Ownership

[Chris Lattner]

On Nov 12, 2012, at 7:35 AM, Duncan Sands <baldrick at free.fr> wrote:
> On 12/11/12 15:11, Meador Inge wrote:
>> On 11/11/2012 11:58 PM, Chris Lattner wrote:
>> 
>>>> Is there a particular sub-system size that makes sense to mark as owned?  I have been
>>>> reworking the library call simplification infrastructure recently and will be happy
>>>> to sign up as an owner for that.
>>> 
>>> I think that "directory level" is the right granularity.  If you're interested in signing
>>> up to maintain and review the whole instcombine library, that would be a great level.  To
>>> see what this entails, see:
>>> http://llvm.org/docs/DeveloperPolicy.html#code-owners
>> 
>> I am interested and comfortable with that.  I will wait a few days and then
>> update CODE_OWNERS.TXT.
> 
> while I think it's great that Meador is stepping forward to help out here, it
> does bring up the question of how expert you have to be to become a code owner.
> As far as I know (please correct me if I'm wrong) Meador isn't the number 1 LLVM
> instcombine expert, but instead is someone who knows instcombine fairly well
> and is willing to spend time making sure instcombine is in good shape and stays
> that way.

Right.  

> My take is that you should be able to be a code owner without being
> the ultimate über hacker for that subsystem, since (1) the über hackers will
> have their eye on you and will let you know if you get it wrong; and (2) being
> willing counts for a lot.  More power to volunteers!  Hopefully if people talk
> with each other, help each other out, and maintain a friendly and cooperative
> atmosphere then all problems with code ownership will just come out in the wash.

I agree.  I also think that "knowing your own limitations" is an important part of the job.  If Meador (or any other code owner) doesn't feel comfortable with something, feels like a patch is questionable, or is outside the domain of his expertise, then he should start a discussion about the topic.  He isn't the one that has to "know everything" so much as make sure that InstCombine is getting love, the patches are getting attention, and that people aren't doing things that are against the architecture of Instcombine.

Also, having a specific code owner doesn't mean that everyone else should stop paying attention to the patches :).  Finally, if someone isn't working out well as a code owner, I'm confident that it will be recognized and they will gracefully bow out of the position.

> However another take on the whole code owner thing is that the code owner is
> the person who has the final say on what goes in and what doesn't, so it is
> important for the code owner to be the über guru (and having other people
> override their decisions would just undermine their authority and the whole
> code owner system).  Personally I don't really buy this, but I can understand
> the concern.

I don't really see it this way.  If a code owner wants "thing A" to happen and much of the community is strongly in favor of "thing B" happening, then it should be discussed until there is some agreement about what should happen.  If no resolution can be had, I am happy to personally help resolve the dispute.

-Chris