Matthieu Pizenberg (Dec 15 2025 at 17:20): Matthieu Pizenberg (Dec 15 2025 at 17:20):I’ve managed to install tracy, build it from source, and have the tracy GUI up.
Then I’m compiling the roc binary with:
zig build roc -Dtracy=/Users/piz/git/wolfpld/tracy -Dtracy-callstack=true
And then when I’m running the roc program, it seems to connect to the tracy server. And then I have the following catpure.
It basically says that all the time is spent inside rocRun. If I want to get more fine-grained insight, what should I do?
Brendan Hansknecht (Dec 15 2025 at 17:24):Weird. I wonder why it didn't expand all the zones for you. (zooming out may fix?)
Brendan Hansknecht (Dec 15 2025 at 17:25):Do you have any ability to drag down and expand the main thread zone to see more?
Brendan Hansknecht (Dec 15 2025 at 17:26):Also, if you sort by self time in that zone info panel, you probably still would get a solid sense of where is best to look at. Though it is possible that we don't yet have tracing for whichever functions are slow in this case.
Generally, I use roc build and then run the app separately so that compilation time and run time are separate traces
Matthieu Pizenberg (Dec 15 2025 at 17:28):I don’t think I have access to any more details. Though when I added manually the two lines at the top of rocRun to the top of runWithPosixFdInheritance, I see it in the details.
image.png
But you are probably right, I might need to split into build an executable then run that
Brendan Hansknecht (Dec 15 2025 at 17:31):What really odd is that clearly it is recording more data
Brendan Hansknecht (Dec 15 2025 at 17:31):Otherwise it wouldn't know all of those sell times below
Brendan Hansknecht (Dec 15 2025 at 17:31):I'm guess we don't have coverage for whatever is eating all the time
Brendan Hansknecht (Dec 15 2025 at 17:32):Is this from your append benchmark?
Matthieu Pizenberg (Dec 15 2025 at 17:32):Got more by running the binary directly :)
image.png
Matthieu Pizenberg (Dec 15 2025 at 17:33):Thx
Matthieu Pizenberg (Dec 15 2025 at 19:38):I wrote a bit about what I tried here. Might continue on it in the coming days, but feel free to steal anything interesting in there to incorporate in other perf PRs.
https://github.com/roc-lang/roc/pull/8687
Last updated: Dec 21 2025 at 12:15 UTC