[Bazel] Document continuous and pre-merge testing

1 files changed, 24 insertions, 1 deletions

diff --git a/utils/bazel/README.md b/utils/bazel/README.md
index fe8ead3..26e13cc 100644
--- a/utils/bazel/README.md
+++ b/utils/bazel/README.md
@@ -73,7 +73,30 @@ platform-specific are selected for in defines. Many are also hardcoded to the
 values currently used by all supported configurations. If there is a
 configuration you'd like to use that isn't supported, please send a patch.
 
-# Usage
+# Continuous Testing
+
+A [Buildkite pipeline](https://buildkite.com/llvm-project/upstream-bazel-rbe)
+runs the full Bazel build on every commit to the main branch. Notifications of
+failures are sent to the
+[llvm-bazel-alerts google group](https://groups.google.com/g/llvm-bazel-alerts),
+which anyone is free to join. Currently, the behavior is just to send an email
+on each failure using Buildkite's built-in notification system, so if you
+subscribe, it is highly recommended that you set up email filters or some other
+mechanism to not flood your inbox. More sophisticated notifications, e.g. only
+on status change or routed based on blamelist are TODO (contributions welcome).
+
+# Pre-merge Testing
+
+A Buildkite pipeline runs the full Bazel build as a pre-merge test using the 
+[LLVM pre-merge testing](https://github.com/google/llvm-premerge-checks/). It
+is triggered on all changes to the utils/bazel directory and when the patch
+author is a member of the
+[Bazel Phabricator project](https://reviews.llvm.org/project/members/107/). If
+you use or benefit from the Bazel build, please join the project so that you
+can help keep it green. As a bonus, it runs in under 5 minutes, much faster
+than any of the other pre-merge builds.
+
+# Usage in Downstream Projects
 
 To use in dependent projects using Bazel, you can import LLVM and then use the
 provided configuration rule. See example usage in the `examples/` directory.