> From: Suhail Singh <suhailsingh...@gmail.com> > Cc: "Suhail Singh" <suhailsingh...@gmail.com>, 73...@debbugs.gnu.org > Date: Thu, 05 Sep 2024 17:04:23 -0400 > > Eli Zaretskii <e...@gnu.org> writes: > > >> It would also help if being over a slow connection didn't result in > >> Emacs consuming 100% of the CPU via functions such as > >> `tramp-wait-for-regexp' (based on profiler-report). Could some of this > >> be done asynchronously? > > > > You could probably tell which parts take the time by profiling Emacs > > while it collects the Dired data, using profiler.el. This could give > > clues about the expensive parts. My guess would be that retrieving > > the attributes of the files Dired needs are the reason, but I could be > > wrong. > > Based on =profiler-report=, the following function "chains" consume most of > the > CPU: > - `font-lock-fontify-keywords-region' > - tramp-sh-file-name-handler > - tramp-sh-handle-file-truename > - `tramp-wait-for-regexp' > - tramp-sh-handle-file-exists-p > - `tramp-wait-for-regexp' > - tramp-sh-handle-file-directory-p > - `tramp-wait-for-regexp' > - tramp-sh-handle-file-attributes > - `tramp-wait-for-regexp' > > As noted previously, disabling global-font-lock-mode helps.
FWIW, I cannot reproduce this: I tried Dired on a remote host with which I have connection that is quite slow, and saw neither high CPU usage nor a significant delay in displaying a Dired buffer. > In related news, one thing I've observed on the affected host is that > the version of `ls' doesn't seem to yield expected output for > `ls --dired'. Specifically, the output of `ls --dired' is the same as > the output of `ls' (i.e., `--dired' gets treated as a no-op). This could indeed explain the problem. However, ... > The version of `ls' on this host is: > > #+begin_quote > ls (GNU coreutils) 8.32 > Copyright (C) 2020 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > <https://gnu.org/licenses/gpl.html>. > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. > > Written by Richard M. Stallman and David MacKenzie. > #+end_quote This cannot be true: the --dired option was added to 'ls' way earlier. I have Coreutils 6.9 from 2007 on one of my systems, and --dired is supported there. To see if it is supported, try this: $ ls -al --dired You should see 2 extra lines of output after the listing, each one starting with "//DIRED".
