Ryan Bates (Dec 08 2023 at 17:28): Ryan Bates (Dec 08 2023 at 17:28):Are there any profiling tools for Roc? It doesn't need to be anything fancy, just something that can tell me how much time is spent in a function would be very helpful in improving performance.
Anton (Dec 08 2023 at 17:29):@Brendan Hansknecht is the expert on that :)
Brendan Hansknecht (Dec 08 2023 at 17:31):My advice for really useful high level profiling:
--optimize --profilingperf and a tool to convert that to a flame graph. Make sure to pass --call-graph dwarf to perf Ryan Bates (Dec 08 2023 at 17:43):@Brendan Hansknecht why is the "Run on Linux" step necessary? Does it require a dependency that's not on Mac OS?
Brendan Hansknecht (Dec 08 2023 at 17:50):perf is amazing and is Linux only
Ryan Bates (Dec 08 2023 at 17:50):Good to know, thanks!
Notification Bot (Dec 08 2023 at 17:50):Ryan Bates has marked this topic as resolved.
Brendan Hansknecht (Dec 08 2023 at 17:51):To be fair, dtrace can be used on macos, but it has never worked as well for me. I'm not even sure how to get it to use debug info though, so may just be a skill issue on my part.
LoipesMas (Dec 08 2023 at 17:58):FWIW: I tried using flamegraph-rs on a Roc binary, but it didn't give useful output. It's supposed to work on all programs, not just Rust ones, so I'm not sure if that's an issue in flamegraph-rs or in roc
Brendan Hansknecht (Dec 08 2023 at 18:21):Oh, important piece I forget, you need to use --linker=legacy
Luke Boswell (Dec 08 2023 at 18:45):This would be a super helpful guide to add to the website or somwhere we can find it. It doesn't need to be very long, but I think it would help to have the procedure step by step. Or maybe we can link to it from roc-awesome? @Brendan Hansknecht do you have a blog, would you be interested in writing about your process? What do people think about adding something like this to roc-lang.org under guides?
Brendan Hansknecht (Dec 08 2023 at 18:51):I could write something up. Now that we have the --profiling flag, we actually can get some useful data.
Brendan Hansknecht (Dec 08 2023 at 18:51):I do have a blog with I think exactly 1 article
Brian Carroll (Dec 08 2023 at 18:57):On Mac I've used the Instruments tool. It's a GUI profiler that comes with XCode. Pretty good. Haven't used it on Roc code but it should be the same as any other binary.
Brian Carroll (Dec 08 2023 at 18:59):I didn't need a whole XCode project or anything, just pointed it at my binary.
Brendan Hansknecht (Dec 08 2023 at 19:00):I should test that now that we have debug info
Brendan Hansknecht (Dec 09 2023 at 01:30):Instruments looks to work quite well on macos with --profiling has a full call stack
Anton (Dec 10 2023 at 13:01):This would be a super helpful guide to add to the website or somwhere we can find it
The examples repo seems like a great fit.
Anton (Dec 10 2023 at 13:03):I made https://github.com/roc-lang/examples/issues/123 for it
Last updated: Jul 26 2025 at 12:14 UTC