From 49bb1482825e315d98fc7261863baca88182356c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= Date: Fri, 16 Dec 2022 05:10:01 +0200 Subject: [PATCH] update results --- README.md | 129 ++++++++++++++++++--------------------------- results/profile.sh | 28 +++++++--- 2 files changed, 70 insertions(+), 87 deletions(-) diff --git a/README.md b/README.md index aaba16a..a929433 100644 --- a/README.md +++ b/README.md @@ -8,101 +8,72 @@ The test -------- Compiles 64 small binaries with [bazel-zig-cc][1] and [llvm14][2]. The tests -were run on an x86_64 8-core machine running Ubuntu 22.04. The llvm's sysroot -is this: +were run on an x86_64 8-core machine running Ubuntu 22.04. - sha256 = "84656a6df544ecef62169cfe3ab6e41bb4346a62d3ba2a045dc5a0a2ecea94a3", - urls = ["https://commondatastorage.googleapis.com/chrome-linux-sysroot/toolchain/2202c161310ffde63729f29d27fe7bb24a0bc540/debian_stretch_amd64_sysroot.tar.xz"], +Results +------- -... but with extra ~8k files, so the number of files in the sysroot is exactly -the same as in zig sdk. + Benchmark 1: bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=local //... + Time (mean ± σ): 9.257 s ± 0.287 s [User: 0.083 s, System: 0.026 s] + Range (min … max): 8.818 s … 9.515 s 5 runs -Baseline --------- + Benchmark 2: bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=local //... + Time (mean ± σ): 9.613 s ± 0.214 s [User: 0.077 s, System: 0.038 s] + Range (min … max): 9.418 s … 9.866 s 5 runs -Baseline llvm14 without sandbox: 12 seconds: + Benchmark 3: bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //... + Time (mean ± σ): 13.314 s ± 0.201 s [User: 0.109 s, System: 0.028 s] + Range (min … max): 13.093 s … 13.536 s 5 runs - bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --spawn_strategy=local --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux ... - INFO: Elapsed time: 13.268s, Critical Path: 1.19s + Benchmark 4: bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //... + Time (mean ± σ): 13.829 s ± 0.376 s [User: 0.093 s, System: 0.046 s] + Range (min … max): 13.573 s … 14.489 s 5 runs -zig cc without the sandbox. 15 seconds: + Benchmark 5: bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed //... + Time (mean ± σ): 35.101 s ± 0.365 s [User: 0.103 s, System: 0.028 s] + Range (min … max): 34.747 s … 35.673 s 5 runs - bazel build --spawn_strategy=local --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --spawn_strategy=local --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 ... - INFO: Elapsed time: 23.836s, Critical Path: 3.47s + Benchmark 6: bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed //... + Time (mean ± σ): 21.071 s ± 0.378 s [User: 0.091 s, System: 0.034 s] + Range (min … max): 20.611 s … 21.635 s 5 runs -Cost of Sandbox ---------------- - -llvm 14: - - bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux ... - INFO: Elapsed time: 89.776s, Critical Path: 12.01s - -zig cc: - - bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 ... - INFO: Elapsed time: 58.919s, Critical Path: 8.38s - -Possible mitigation: Sandboxfs ------------------------------- - -No dice. - -llvm 14: does not build at all: - - $ bazel build --experimental_sandboxfs_path=sandboxfs --experimental_use_sandboxfs --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux //:zigzag-0 - ERROR: /code/test-zigcc/BUILD:4:14: Compiling main.cc failed: (Exit 5): cc_wrapper.sh failed: error executing command external/llvm_toolchain_with_sysroot/bin/cc_wrapper.sh -U_FORTIFY_SOURCE '--target=x86_64-unknown-linux-gnu' -U_FORTIFY_SOURCE -fstack-protector -fno-omit-frame-pointer -fcolor-diagnostics -Wall ... (remaining 29 arguments skipped) - - Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging - ERROR: could not find clang; PWD="/proc/self/cwd"; PATH="<...>". - Target //:zigzag-0 failed to build - Use --verbose_failures to see the command lines of failed build steps. - INFO: Elapsed time: 7.578s, Critical Path: 0.26s - INFO: 3 processes: 3 internal. - FAILED: Build did NOT complete successfully + Summary + 'bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=local //...' ran + 1.04 ± 0.04 times faster than 'bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=local //...' + 1.44 ± 0.05 times faster than 'bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //...' + 1.49 ± 0.06 times faster than 'bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //...' + 2.28 ± 0.08 times faster than 'bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed //...' + 3.79 ± 0.12 times faster than 'bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed //...' -zig cc: +| Command | Mean [s] | Min [s] | Max [s] | Relative | +|:---|---:|---:|---:|---:| +| `bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=local //...` | 9.257 ± 0.287 | 8.818 | 9.515 | 1.00 | +| `bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=local //...` | 9.613 ± 0.214 | 9.418 | 9.866 | 1.04 ± 0.04 | +| `bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //...` | 13.314 ± 0.201 | 13.093 | 13.536 | 1.44 ± 0.05 | +| `bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed --experimental_reuse_sandbox_directories //...` | 13.829 ± 0.376 | 13.573 | 14.489 | 1.49 ± 0.06 | +| `bazel build --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux --spawn_strategy=sandboxed //...` | 35.101 ± 0.365 | 34.747 | 35.673 | 3.79 ± 0.12 | +| `bazel build --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 --spawn_strategy=sandboxed //...` | 21.071 ± 0.378 | 20.611 | 21.635 | 2.28 ± 0.08 | - bazel build --experimental_sandboxfs_path=sandboxfs --experimental_use_sandboxfs --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --experimental_sandboxfs_path=sandboxfs --experimental_use_sandboxfs --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 ... - INFO: Elapsed time: 126.613s, Critical Path: 17.63s - - -Possible mitigation: `--experimental_reuse_sandbox_directories` ---------------------------------------------------------------- - -Dice. - -llvm 14: - - bazel build --experimental_reuse_sandbox_directories --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --experimental_reuse_sandbox_directories --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux ... - INFO: Elapsed time: 18.335s, Critical Path: 2.00s - -zig cc: - - bazel build --experimental_reuse_sandbox_directories --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 //:zigzag-0 - bazel clean; bazel shutdown - bazel --batch build --experimental_reuse_sandbox_directories --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 ... - INFO: Elapsed time: 34.777s, Critical Path: 4.71s +Explanation: +* `--spawn_strategy=local` is the baseline. This is the fastest possible + approach (no sandbox), but does never runs in production. +* `--spawn_strategy=sandboxed` is the default for Bazel. This is what happens + if one does not pass any arguments. +* `--spawn_strategy=sandboxed --experimental_reuse_sandbox_directories` is an + optimization which is meaningful on sandboxes with many files. As of Bazel 6 + this has been [promoted to stable][3], so safe to use and, as one can see in + the numbers, recommended with both bazel-zig-cc and a nontrivial sysroot. As + a result, this is the most important benchmark to look at. Flame graphs and discussion --------------------------- -Flame graphs and more tests are in results/. As of 2022-12-11 most of the -overhead comes from creating and deleting the sandboxes. +Flame graphs in results/. Only of historical interest, because the original +performance issues have been resolved with a combination of zig and +bazel-zig-cc changes. [1]: https://sr.ht/~motiejus/bazel-zig-cc [2]: https://github.com/grailbio/bazel-toolchain +[3]: https://github.com/bazelbuild/bazel/issues/16138 diff --git a/results/profile.sh b/results/profile.sh index 0a5454c..ffb0f7b 100755 --- a/results/profile.sh +++ b/results/profile.sh @@ -1,13 +1,23 @@ #!/bin/bash set -xeuo pipefail +# set to 1 to enable profiling +profile= + _build() { + if [[ "$profile" == 1 ]]; then + perf=(perf record --call-graph=dwarf -g -o "$HOME/$name.data") + else + perf=() + fi + name=$1 shift - bazel build --color=no --curses=no "$@" //:zigzag-0 - bazel clean --color=no --curses=no - bazel shutdown --color=no --curses=no - perf record --call-graph=dwarf -g -o "$HOME/$name.data" bazel --batch build --color=no --curses=no "$@" ... + bazel build --color=no --curses=no "$@" //:zigzag-0 + bazel clean --color=no --curses=no + bazel shutdown --color=no --curses=no + ( "${perf[@]}" bazel --batch build --color=no --curses=no "$@" ... ) |& \ + tee "results/${name}.log" } _build zigcc-nosandbox --spawn_strategy=local --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 @@ -17,7 +27,9 @@ _build llvm --extr _build zigcc-reuse-sandbox-dirs --experimental_reuse_sandbox_directories --platforms=@zig_sdk//libc_aware/platform:linux_amd64_gnu.2.28 _build llvm-reuse-sandbox-dirs --experimental_reuse_sandbox_directories --extra_toolchains=@llvm_toolchain_with_sysroot//:cc-toolchain-x86_64-linux -for d in $HOME/*.data; do - f=$(basename "$d") - echo "perf script -i $d | inferno-collapse-perf | inferno-flamegraph > results/${f%data}svg" -done | parallel -v --eta +if [[ $profile == 1 ]]; then + for d in $HOME/*.data; do + f=$(basename "$d") + echo "perf script -i $d | inferno-collapse-perf | inferno-flamegraph > results/${f%data}svg" + done | parallel -v --eta +fi