| commit | c20091450f48b34c909716452767312cfb8f2fc4 | [log] [tgz] |
|---|---|---|
| author | Philipp Wollermann <philwo@google.com> | Tue Jun 21 14:18:40 2016 +0000 |
| committer | Philipp Wollermann <philwo@google.com> | Tue Jun 21 14:47:56 2016 +0000 |
| tree | 30870ddac16afadac22ec2c1eb80570ebd692043 | |
| parent | 24ec1bfa0b9ed78ce5ce7b7e90612f24a60d2a54 [diff] |
When running Java-based tools, use -XX:+TieredCompilation -XX:TieredStopAtLevel=1 instead of -client, as the latter is ignored on 64-bit JVMs since at least JDK 6. The new flags have been shown to cut down CPU time by 50% due to reduced time spent in JIT and improving overall run time for short running actions, some times also cutting them in half. Here's a benchmark of Bazel building itself, giving a nice 2-4x speedup: ./output/bazel clean && ./output/bazel build //src:bazel Bazel before this change: INFO: Elapsed time: 197.783s, Critical Path: 194.10s INFO: Elapsed time: 198.928s, Critical Path: 195.65s INFO: Elapsed time: 194.913s, Critical Path: 191.56s Bazel before this change with --strategy=Javac=worker: INFO: Elapsed time: 130.436s, Critical Path: 124.27s INFO: Elapsed time: 116.114s, Critical Path: 112.30s INFO: Elapsed time: 116.852s, Critical Path: 84.45s Bazel with this change: INFO: Elapsed time: 121.625s, Critical Path: 119.08s INFO: Elapsed time: 119.401s, Critical Path: 115.80s INFO: Elapsed time: 121.198s, Critical Path: 119.03s Bazel with this change and --strategy=Javac=worker: INFO: Elapsed time: 54.456s, Critical Path: 51.28s INFO: Elapsed time: 53.272s, Critical Path: 51.09s INFO: Elapsed time: 52.966s, Critical Path: 49.86s Bazel with this change and --strategy=Javac=worker and stripping -XX:TieredStopAtLevel=1 from JVM flags when using workers: INFO: Elapsed time: 61.599s, Critical Path: 58.93s INFO: Elapsed time: 48.695s, Critical Path: 45.02s INFO: Elapsed time: 46.874s, Critical Path: 43.91s INFO: Elapsed time: 46.174s, Critical Path: 43.32s (The latter is a possible optimization for workers and it's also nice to know that the limited tiered compilation does not hurt their performance.) -- MOS_MIGRATED_REVID=125448089
{Fast, Correct} - Choose two
Bazel is a build tool that builds code quickly and reliably. It is used to build the majority of Google‘s software, and thus it has been designed to handle build problems present in Google’s development environment, including:
A massive, shared code repository, in which all software is built from source. Bazel has been built for speed, using both caching and parallelism to achieve this. Bazel is critical to Google's ability to continue to scale its software development practices as the company grows.
An emphasis on automated testing and releases. Bazel has been built for correctness and reproducibility, meaning that a build performed on a continuous build machine or in a release pipeline will generate bitwise-identical outputs to those generated on a developer's machine.
Language and platform diversity. Bazel's architecture is general enough to support many different programming languages within Google, and can be used to build both client and server software targeting multiple architectures from the same underlying codebase.
Find more background about Bazel in our FAQ.