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

Google released Perfetto v57, fixing a bug where overlapping PyTorch profiler events failed to display in traces, and adding support for journald logs and an AI skill.

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.