From: Junio C Hamano Date: Tue, 10 Feb 2026 23:37:51 GMT Subject: Re: [PATCH] [RFC][GSoC][PATCH] attr: use local repository state in read_attr Message-ID: In-Reply-To: <96329bc6-0490-454b-a21b-babb85c98bc9@gmail.com> Tian Yuchen writes: > Junio C Hamano writes: > > >The codepath read_attr() is in is usually not that hot but it is not > >cheap. > > I'm a bit curious—under what circumstances would calling this method > result in significant performance regression? Significant? I dunno. And quite honestly, I do not care about significance very much in a case like this. Doing things that do not make sense, like checking the same configuration variable again and again when you _know_ that you never switched to a different repository since you last checked, is simply wrong. It burdens the readers with unnecessary cognitive load by making them wonder why you do such a nonsensical thing. The read_attr() is called during an attr stack construction, which traverses the directory hierarchy of a single repositry's working tree (we do not traverse across submodule boundaries), and the same istate (i.e., index contents) structure is passed around throughout the callchain. The repository instance at istate->repo may be a good place to store "am I bare?" bit that is computed just once and reused whenever we need to know, like in the funcion under discussion.