[docs] Expand a bit on the basics of a buildbot policy

[reames]

Summary

We don't have much publicly documented about how build bots are maintained, and who has what responsibility with regards to the bots themselves and failures they report.

This change adds some basic framing on the topic. It is intended to simplify document long standing practice, and to avoid introducing any new policy elements. I do want to propose a couple of changes, but those will happen with their own review and broader discussion.

[gkistanova]

Thanks, Philip!

LGTM.

[andreil99]

LGTM

[mehdi_amini]

LG! Thanks

llvm/docs/HowToAddABuilder.rst

50

We should document how to find this information. Some colleagues somehow couldn't find it in the web interface so it may no be obvious to everyone.

[dblaikie]

Sounds good - thanks for writing that up!

[gkistanova]

llvm/docs/HowToAddABuilder.rst

50

This?
https://llvm.org/docs/DeveloperPolicy.html#working-with-the-ci-system

[reames]

llvm/docs/HowToAddABuilder.rst

50

That snippet really seems like it should be out of line with the developer docs. Would moving the content below "If a build/worker is permanently broken" into this page, and linking from that one seem reasonable?

(I'll do it in a separate review for sanity check, just checking big picture feasibility.)

[mehdi_amini]

LG! Thanks

llvm/docs/HowToAddABuilder.rst

50

Nice snippet Galina! This is exactly what I had in mind.

Moving it here and linking from the dev doc to here seems fine to me as well.

[reames]

llvm/docs/HowToAddABuilder.rst

50

https://reviews.llvm.org/D112775

llvm/docs/HowToAddABuilder.rst

 ===================================================================
 How To Add Your Build Configuration To LLVM Buildbot Infrastructure
 ===================================================================
 
 Introduction
 ============
 
 This document contains information about adding a build configuration and
 buildbot-worker to private worker builder to LLVM Buildbot Infrastructure.
 
 Buildmasters
 ============
 
 There are two buildmasters running.
 
-* The main buildmaster at `<https://lab.llvm.org/buildbot>`_. All builders attached
-  to this machine will notify commit authors every time they break the build.
-* The staging buildbot at `<https://lab.llvm.org/staging>`_. All builders attached
-  to this machine will be completely silent by default when the build is broken.
-  Builders for experimental backends should generally be attached to this
-  buildmaster.
+* The main buildmaster at `<https://lab.llvm.org/buildbot>`_. All builders
+  attached to this machine will notify commit authors every time they break
+  the build.
+* The staging buildmaster at `<https://lab.llvm.org/staging>`_. All builders
+  attached to this machine will be completely silent by default when the build
+  is broken.
+
+In order to remain connected to the main buildmaster (and thus notify
+developers of failures), a builbot must:
+
+* Be building a supported configuration.  Builders for experimental backends
+  should generally be attached to staging buildmaster.
+* Be able to keep up with new commits to the main branch, or at a minimum
+  recover to tip of tree within a couple of days of falling behind.
+
+Additionally, we encourage all bot owners to point their bots towards the
+staging master during maintenance windows, instability troubleshooting, and
+such.
+
+Roles & Expectations
+====================
+
+Each buildbot has an owner who is the responsible party for addressing problems
+which arise with said buildbot.  We generally expect the bot owner to be
+reasonably responsive.
+
+For some bots, the ownership responsibility is split between a "resource owner"
+who provides the underlying machine resource, and a "configuration owner" who
+maintains the build configuration.  Generally, operational responsibility lies
+with the "config owner".  We do expect "resource owners" - who are generally
+the contact listed in a workers attributes - to proxy requests to the relevant
+"config owner" in a timely manner.
+
+Most issues with a buildbot should be addressed directly with a bot owner
+via email.  Please CC `Galina Kistanova <mailto:[e-mail]>`_.
 
 Steps To Add Builder To LLVM Buildbot
 =====================================
 Volunteers can provide their build machines to work as build workers to
 public LLVM Buildbot.
 
 Here are the steps you can follow to do so: