Bas, Can you take a look at this bug?

This is not actually that much Canvas work, especially compared to the rest of the profile (i.e. it's less than 15% of the hang doing all the canvas work this page does). Having said that, it seems this page ends up getting a data URL for the canvas contents and that's probably not great, this means they're currently reading back from the GPU, a software canvas would probably improve things somewhat here but the heuristics of figuring out whether to do canvas in software or hardware are complicated, and I'm not familiar with the details of how they work.

yeah, it is not very much of the profile, but very commonly used page and when optimizing page load, we'll need to optimize many small things, not only bigger items.