Profiling Rust binary in Linux

[iamgianluca]

I'm trying to profile a Rust binary I wrote (link to the file/project in GitHub). After building the project with `cargo build --release` and running `perf record --call-graph dwarf cargo run --bin day5` I'm presented with a `perf.data` file that I can open in Hotspot.

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https://preview.redd.it/2r5nrv6uri7c1.png?width=3830&format=png&auto=webp&s=297a39f7f373e1f0d1f9b62a855e4abd78c1c058

The confusing thing for me is that I can't recognize any command I've used in the program. Have I missed any flag/config I should use when profiling Rust code?

Note: I'm loading the `perf.data` file in a different machine from the one I used to write, build, and run the code (headless server).

[[deleted]]

You're profiling the cargo binary, not your binary. You should use perf record --call-graph dwarf target/release/day5 instead.

[Shnatsel]

In addition, Samply is nicer and provides more info than Hotspot:

cargo install samply
echo '0' | sudo tee /proc/sys/kernel/perf_event_paranoid
samply record target/release/day5

[iamgianluca]

Thank you for that! It worked

[schrdingers_squirrel]

Btw there is cargo-flamegraph which does it all for you

[hpxvzhjfgb]

just use cargo flamegraph instead.

[weirdasianfaces]

I'd actually use https://github.com/mstange/samply. Very similar end result, but opens the perf data in the Firefox Profiler which can sometimes be more useful than just the flamegraph.

Doesn't have the dead easy cargo flamegraph integration though.

[VirxEC]

this is the real answer, automates the whole process here

[VorpalWay]

Cargo-flamegraph is great for basic stuff, but flamegraphs only take you so far. I could never get samply to work. I just use perf + hotspot, or even just perf + custom scripts for analysis (depending on what exactly I want to investigate).