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| -rw-r--r-- | Docs.md | 63 |
1 files changed, 59 insertions, 4 deletions
@@ -230,6 +230,8 @@ are a few particularly useful ones: ## How to Profile deno +To start profiling, + ```sh # Make sure we're only building release. export DENO_BUILD_MODE=release @@ -240,11 +242,64 @@ export DENO_BUILD_MODE=release # Exercise it. third_party/wrk/linux/wrk http://localhost:4500/ kill `pgrep deno` -# When supplying --prof, V8 will write a file in the current directory that -# looks like this isolate-0x7fad98242400-v8.log -# To examine this file: +``` + +V8 will write a file in the current directory that looks like this: +`isolate-0x7fad98242400-v8.log`. To examine this file: + +```sh +D8_PATH=target/release/ ./third_party/v8/tools/linux-tick-processor +isolate-0x7fad98242400-v8.log > prof.log +# on macOS, use ./third_party/v8/tools/mac-tick-processor instead +``` + +`prof.log` will contain information about tick distribution of different calls. + +To view the log with Web UI, generate JSON file of the log: + +```sh D8_PATH=target/release/ ./third_party/v8/tools/linux-tick-processor -isolate-0x7fad98242400-v8.log +isolate-0x7fad98242400-v8.log --preprocess > prof.json +``` + +Open `third_party/v8/tools/profview/index.html` in your brower, and select +`prof.json` to view the distribution graphically. + +To learn more about `d8` and profiling, check out the following links: + +- [https://v8.dev/docs/d8](https://v8.dev/docs/d8) +- [https://v8.dev/docs/profile](https://v8.dev/docs/profile) + +## How to Debug deno + +We can use LLDB to debug deno. + +```sh +lldb -- target/debug/deno tests/worker.js +> run +> bt +> up +> up +> l +``` + +To debug Rust code, we can use `rust-lldb`. It should come with `rustc` and is a +wrapper around LLDB. + +```sh +rust-lldb -- ./target/debug/deno tests/http_bench.ts --allow-net +# On macOS, you might get warnings like +# `ImportError: cannot import name _remove_dead_weakref` +# In that case, use system python by setting PATH, e.g. +# PATH=/System/Library/Frameworks/Python.framework/Versions/2.7/bin:$PATH +(lldb) command script import "/Users/kevinqian/.rustup/toolchains/1.30.0-x86_64-apple-darwin/lib/rustlib/etc/lldb_rust_formatters.py" +(lldb) type summary add --no-value --python-function lldb_rust_formatters.print_val -x ".*" --category Rust +(lldb) type category enable Rust +(lldb) target create "../deno/target/debug/deno" +Current executable set to '../deno/target/debug/deno' (x86_64). +(lldb) settings set -- target.run-args "tests/http_bench.ts" "--allow-net" +(lldb) b op_start +(lldb) r ``` ## Build Instructions _(for advanced users only)_ |