| commit | 31ed75f74635bc739ba5a817b37317579192d506 | [log] [tgz] |
|---|---|---|
| author | Dmitri Shuralyov <dmitshur@golang.org> | Fri Oct 26 13:05:59 2018 -0400 |
| committer | Dmitri Shuralyov <dmitshur@golang.org> | Mon Oct 29 16:29:11 2018 +0000 |
| tree | f7a61966d442dabbf85fe4d53b928aed9f1822ce | |
| parent | 57258c564e6f790b19d257469cced6b6ab47f38c [diff] |
env/openbsd-amd64: enable SMT on OpenBSD 6.4 Disable Spectre/Meltdown mitigations and enable simultaneous multithreading (SMT) on the OpenBSD 6.4 builder image. This was done by setting hw.smt=1 in /etc/sysctl.conf when building the image. I considered an alternative approach of doing this at runtime via a cmd/buildlet special case for OpenBSD. It would've likely been faster to implement if I had the idea at the beginning. However, by the time I saw it, I had already started to build a new OpenBSD 6.4 image with the /etc/sysctl.conf file, then tested it via debugnewvm. At this point, there's no longer a time saving advantage, so I decided to prefer the v2 image because it keeps OpenBSD-specific configuration more contained in env/openbsd-* directory, rather than spreading it out between there and the cmd/buildlet runtime code. It seems to be a slightly better option. The times to do a full build, as measured via cmd/debugnewvm, were: 6.2 = 19m25.218s 6.4 = 28m49.565s 6.4 with hw.smt=1 = 22m55.909s That should translate to faster trybot runs, which is important for open source project health. The 386 environment doesn't need to be updated because it doesn't support hw.smt: sysctl: hw.smt: value is not available Attempting to set it anyway should be harmless and okay to do, in case it happens to get supported in the future. We're only using amd64 environment for trybots, so it's okay for the purposes of golang/go#28403. Reference: https://man.openbsd.org/sysctl.2#HW_SMT_2 Fixes golang/go#28403 Change-Id: I7bc4cbf83ccbdb3aa9dd19eeabd88feb1c425811 Reviewed-on: https://go-review.googlesource.com/c/145022 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This subrepository holds the source for various packages and tools that support Go's build system and the development of the Go programming language.
This repository uses Gerrit for code changes. To contribute, see https://golang.org/doc/contribute.html.
The main issue tracker for the blog is located at https://github.com/golang/go/issues. Prefix your issue with “x/build/DIR: ” in the subject line.
The main components of the Go build system are:
The dashboard, in app/, serves https://build.golang.org/. It runs on App Engine and holds the state for which builds passed or failed, and stores the build failure logs for post-submit failures. (Trybot build failure logs are stored elsewhere). The dashboard does not execute any builds on its own.
The coordinator, in cmd/coordinator/, serves https://farmer.golang.org/. It runs on GKE and coordinates the whole build system. It finds work to do (both pre-submit “TryBot” work, and post-submit work) and executes builds, allocating machines to run the builds. It is the owner of all machines.
The Go package in buildenv/ contains constants for where the dashboard and coordinator run, for prod, staging, and local development.
The buildlet, in cmd/buildlet/, is the HTTP server that runs on each worker machine to execute builds on the coordinator's behalf. This runs on every possible GOOS/GOARCH value. The buildlet binaries are stored on Google Cloud Storage and fetched per-build, so we can update the buildlet binary independently of the underlying machine images. The buildlet is the most insecure server possible: it has HTTP handlers to read & write arbitrary content to disk, and to execute any file on disk. It also has an SSH tunnel handler. The buildlet must never be exposed to the Internet. The coordinator provisions buildlets in one of three ways:
by creating VMs on Google Compute Engine (GCE) with custom images configured to fetch & run the buildlet on boot, listening on port 80 in a private network.
by running Linux containers (on either Google Kubernetes Engine or GCE with the Container-Optimized OS image), with the container images configured to fetch & run the buildlet on start, also listening on port 80 in a private network.
by taking buildlets out of a pool of connected, dedicated machines. The buildlet can run in either listen mode (as on GCE and GKE) or in reverse mode. In reverse mode, the buildlet connects out to https://farmer.golang.org/ and registers itself with the coordinator. The TCP connection is then logically reversed (using revdial and when the coordinator needs to do a build, it makes HTTP requests to the coordinator over the already-open TCP connection.
These three pools can be viewed at the coordinator's http://farmer.golang.org/#pools
The env/ directory describes build environments. It contains scripts to create VM images, Dockerfiles to create Kubernetes containers, and instructions and tools for dedicated machines.
maintner in maintner/ is a library for slurping all of Go's GitHub and Gerrit state into memory. The daemon maintnerd in maintner/maintnerd/ runs on GKE and serves https://maintner.golang.org/. The daemon watches GitHub and Gerrit and apps to a mutation log whenever it sees new activity. The logs are stored on GCS and served to clients.
The godata package in maintner/godata/ provides a trivial API to let anybody write programs against Go's maintner corpus (all of our GitHub and Gerrit history), live up to the second. It takes a few seconds to load into memory and a few hundred MB of RAM after it downloads the mutation log from the network.
pubsubhelper in cmd/pubsubhelper/ is a dependency of maintnerd. It runs on GKE, is available at https://pubsubhelper.golang.org/, and runs an HTTP server to receive Webhook updates from GitHub on new activity and an SMTP server to receive new activity emails from Gerrit. It then is a pubsub system for maintnerd to subscribe to.
The gitmirror server in cmd/gitmirror/ mirrors Gerrit to GitHub, and also serves a mirror of the Gerrit code to the coordinator for builds, so we don't overwhelm Gerrit and blow our quota.
The Go gopherbot bot logic runs on GKE. The code is in cmd/gopherbot. It depends on maintner via the godata package.
The developer dashboard at https://dev.golang.org/ runs on GKE. Its code is in devapp/. It also depends on maintner via the godata package.
cmd/retrybuilds: a Go client program to delete build results from the dashboard
If you wish to run a Go builder, please email golang-dev@googlegroups.com first. There is documentation at https://golang.org/wiki/DashboardBuilders, but depending on the type of builder, we may want to run it ourselves, after you prepare an environment description (resulting in a VM image) of it. See the env directory.