; Add a note about a bottleneck

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index 08798d86f8ea4491bd39deaf1e739afc6823bf61..188236427da422ea55c05ba0351d8d9b9eb0cfc9 100644 (file)
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -396,6 +396,8 @@ backend implementation of `project-external-roots'.")
        (setq files
              (mapcar
               (lambda (file) (concat default-directory file))
+              ;; XXX: With large enough project, split-string becomes
+              ;; one of the bottlenecks.
               (split-string
                (apply #'vc-git--run-command-string nil "ls-files" args)
                "\0" t)))