commit 51329bf5fe1aa5bc87b3eece2ce2f9d2978e63a2
author Scott Todd <scott.todd0@gmail.com> Mon Sep 23 08:17:53 2024 -0700
committer GitHub <noreply@github.com> Mon Sep 23 08:17:53 2024 -0700
tree fceb57ac3a3f58bfae4f03159a0efb5b57aab06c
parent b08cf020b3a0b284fe0167a697635a884820eeab

Migrate ci_linux_arm64_clang to new dockerfile. (#18569)

Progress on https://github.com/iree-org/iree/issues/15332. This was the
last active use of
[`build_tools/docker/`](https://github.com/iree-org/iree/tree/main/build_tools/docker),
so we can now delete that directory:
https://github.com/iree-org/iree/pull/18566.

This uses the same "cpubuilder" dockerfile as the x86_64 builds, which
is now built for multiple architectures thanks to
https://github.com/iree-org/base-docker-images/pull/11. As before, we
install a qemu binary in the dockerfile, this time using the approach in
https://github.com/iree-org/base-docker-images/pull/13 instead of a
forked dockerfile.

Prior PRs for context:
* https://github.com/iree-org/iree/pull/14372
* https://github.com/iree-org/iree/pull/16331

Build time varies pretty wildly depending on cache hit rate and the
phase of the moon:

| Scenario | Cache hit rate | Time | Logs |
| -- | -- | -- | -- |
Cold cache | 0% | 1h45m |
[Logs](https://github.com/iree-org/iree/actions/runs/10962049593/job/30440393279)
Warm (?) cache | 61% | 48m |
[Logs](https://github.com/iree-org/iree/actions/runs/10963546631/job/30445257323)
Warm (hot?) cache | 98% | 16m |
[Logs](https://github.com/iree-org/iree/actions/runs/10964289304/job/30447618503?pr=18569)

CI history
(https://github.com/iree-org/iree/actions/workflows/ci_linux_arm64_clang.yml?query=branch%3Amain)
shows that regular 97% cache hit rates and 17 minute job times are
possible. I'm not sure why one test run only got 61% cache hits. This
job only runs nightly, so that's not a super high priority to
investigate and fix.

If we migrate the arm64 runner off of GCP
(https://github.com/iree-org/iree/issues/18238) we can further simplify
this workflow by dropping its reliance on `gcloud auth
application-default print-access-token` and the `docker_run.sh` script.
Other workflows are now using `source setup_sccache.sh` and some other
code.