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| -rw-r--r-- | .gitignore | 4 | ||||
| -rw-r--r-- | tools/README.md | 29 | ||||
| -rwxr-xr-x | tools/flamebench.js | 119 |
3 files changed, 152 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore index d84365bb0..0ab773c15 100644 --- a/.gitignore +++ b/.gitignore @@ -25,3 +25,7 @@ cli/tests/.test_coverage/ # MacOS generated files .DS_Store .DS_Store? + +# Flamegraphs +/flamebench*.svg +/flamegraph*.svg diff --git a/tools/README.md b/tools/README.md index c408e78c5..7bdf6f77a 100644 --- a/tools/README.md +++ b/tools/README.md @@ -30,3 +30,32 @@ executable ```sh cargo run -- run --allow-read --allow-write --allow-run --unstable ./tools/<script> ``` + +## flamebench.js + +`flamebench.js` facilitates profiling and generating flamegraphs from +benchmarks. + +General usage: + +``` +❯ ./tools/flamebench.js +flamebench <bench_name> [bench_filter] + +Available benches: +op_baseline +ser +de +``` + +To profile the `op_baseline` bench, run `./tools/flamebench.js op_baseline`, +this will run all 3 benches in `op_baseline. + +Often when profiling/optimizing, you'll want to focus on a specific sub-bench, +`flamebench` supports a bench/test filter arg like the regular cargo commands. +So you can simply run `./tools/flamebench.js op_baseline bench_op_async` or +`./tools/flamebench.js op_baseline bench_op_nop` to profile specific benches. + +Tip: the `[bench_filter]` argument doesn't have to be an exact bench name, you +can use a shorthand or a partial match to profile a group of benches, e.g: +`./tools/flamebench.js de v8` diff --git a/tools/flamebench.js b/tools/flamebench.js new file mode 100755 index 000000000..bd409c86c --- /dev/null +++ b/tools/flamebench.js @@ -0,0 +1,119 @@ +#!/usr/bin/env -S deno run --unstable --allow-read --allow-run +// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license. +import { join, ROOT_PATH as ROOT } from "./util.js"; + +async function bashOut(subcmd) { + const p = Deno.run({ + cmd: ["bash", "-c", subcmd], + stdout: "piped", + stderr: "null", + }); + + // Check for failure + const { success } = await p.status(); + if (!success) { + throw new Error("subcmd failed"); + } + // Gather output + const output = new TextDecoder().decode(await p.output()); + // Cleanup + p.close(); + + return output.trim(); +} + +async function bashThrough(subcmd, opts = {}) { + const p = Deno.run({ ...opts, cmd: ["bash", "-c", subcmd] }); + + // Exit process on failure + const { success, code } = await p.status(); + if (!success) { + Deno.exit(code); + } + // Cleanup + p.close(); +} + +async function availableBenches() { + // TODO(AaronO): maybe reimplement with fs.walk + // it's important to prune the walked tree so this is fast (<50ms) + const prunedDirs = ["third_party", ".git", "target", "docs", "test_util"]; + const pruneExpr = prunedDirs.map((d) => `-path ${ROOT}/${d}`).join(" -o "); + return (await bashOut(` + find ${ROOT} -type d \ + \\( ${pruneExpr} \\) \ + -prune -false -o \ + -path "${ROOT}/*/benches/*" -type f -name "*.rs" \ + | xargs basename | cut -f1 -d. + `)).split("\n"); +} + +function latestBenchBin(name) { + return bashOut(`ls -t "${ROOT}/target/release/deps/${name}"* | head -n 1`); +} + +function runFlamegraph(benchBin, benchFilter, outputFile) { + return bashThrough( + `sudo -E flamegraph -o ${outputFile} ${benchBin} ${benchFilter ?? ""}`, + // Set $PROFILING env so benches can improve their flamegraphs + { env: { "PROFILING": "1" } }, + ); +} + +async function binExists(bin) { + try { + await bashOut(`which ${bin}`); + return true; + } catch (_) { + return false; + } +} + +async function main() { + const { 0: benchName, 1: benchFilter } = Deno.args; + // Print usage if no bench specified + if (!benchName) { + console.log("flamebench.js <bench_name> [bench_filter]"); + // Also show available benches + console.log("\nAvailable benches:"); + const benches = await availableBenches(); + console.log(benches.join("\n")); + return Deno.exit(1); + } + + // List available benches, hoping we don't have any benches called "ls" :D + if (benchName === "ls") { + const benches = await availableBenches(); + console.log(benches.join("\n")); + return; + } + + // Ensure flamegraph is installed + if (!await binExists("flamegraph")) { + console.log( + "flamegraph (https://github.com/flamegraph-rs/flamegraph) not found, please run:", + ); + console.log(); + console.log("cargo install flamegraph"); + return Deno.exit(1); + } + + // Build bench with frame pointers + await bashThrough( + `RUSTFLAGS='-C force-frame-pointers=y' cargo build --release --bench ${benchName}`, + ); + + // Get the freshly built bench binary + const benchBin = await latestBenchBin(benchName); + + // Run flamegraph + const outputFile = join(ROOT, "flamebench.svg"); + await runFlamegraph(benchBin, benchFilter, outputFile); + + // Open flamegraph (in your browser / SVG viewer) + if (await binExists("open")) { + await bashThrough(`open ${outputFile}`); + } +} +// Run +await main(); |