# Perfetto v57: fixing PyTorch traces, plus journald logs and an AI skill

> Source: <https://lalitm.com/post/perfetto-v57/>
> Published: 2026-07-02 23:23:00+00:00

We just
[released Perfetto v57](https://github.com/google/perfetto/releases/tag/v57.1)
and I wanted to share the new things I’m most excited about. This is something I
wanted to do for past releases but I just never quite got round to it. It’s also
something I plan on doing more of going forward: there might even be dedicated
pieces if I think the feature deserves it!

What I’m most excited about in this release isn’t a feature but a bugfix. If you
used the
[PyTorch profiler](https://docs.pytorch.org/tutorials/recipes/recipes/profiler_recipe.html)
and opened the resulting trace in Perfetto, there was a decent chance some of
your events would just not show up; specifically this would happen when these
events overlapped each other on a single track.

Technically, PyTorch is in the wrong here. The Chrome Trace Event (JSON) format
says duration events on a track have to nest and can’t overlap; if you need
overlap, you’re supposed to use async events. `chrome://tracing`

appears to
handle them, but its rendering is actually buggy as soon as a trace has real
overlaps; people just learned to live with it. So when a
[bug](https://github.com/google/perfetto/issues/4280) came in January about
overlapping events being broken, I closed it as working-as-intended because I
couldn’t see any easy fix from our end.
