On 08.01.2020 22:51, Stefan Monnier wrote:
> Yes, I saw that, but it's still not clear to me which part of this costs
> so much more than tramp-file-local-name itself, nor why.

The whole of it, mostly. I've shown a simple patch which improved
performance a lot, by Michael says it's unmaintainable (IIUC):

I'm not sure wether what I'll say is relevant to this discussion (please forgive me if it is not), but I just wanted to mention that a significant part of "debugging TRAMP problems" in projects like projectile is related to TRAMP's speed.

I always assumed it was due to the fact that checking file attributes over SSH is unavoidably slower than doing it locally, but if TRAMP can be improved for things like `locate-dominating-file` over TRAMP it'd be a huge help.

Kind regards,

Philippe