Noticable delay for (ivy-switch-buffer) and (counsel-find-file) when using TRAMP

[fapdash]

When I use ivy-rich-mode and tramp in conjunction I experience performance issues.

With ivy-switch-buffer the startup delay is very noticable.
It can be several seconds until I see the list of buffers if I have several TRAMP connected dired buffer open.
ivy-rich-project-root-cache-mode helps but the startup gets even noticably slower if there is only one new TRAMP buffer that's not yet cached.

With (counsel-find-file) on a remote location the startup is not noticably slower but ivy-next-line and ivy-previous-line is very laggy, which disappears when I deactivate ivy-rich-mode.
Why does ivy-rich-mode a difference there?
As far as I can tell it should make no difference since if doesn't add any additional information for (counsel-find-file), no?

[Yevgnen]

Can you try to profile this by using profile-start and profile-report?

[fapdash]

ivy-switch-buffer:

- command-execute                                                2631  83%
 - call-interactively                                            2631  83%
  - funcall-interactively                                        2631  83%
   - ivy-switch-buffer                                           2526  79%
    - ivy-read                                                   2526  79%
     - read-from-minibuffer                                      2517  79%
      - ivy--queue-exhibit                                       2494  78%
       - ivy--exhibit                                            2494  78%
        - ivy--update-minibuffer                                 2491  78%
         - ivy--format                                           2491  78%
          - mapcar                                               2491  78%
           - ivy-rich--ivy-switch-buffer-transformer               2491  78%
            - ivy-rich-format                                    2491  78%
             - mapconcat                                         2491  78%
              + #<compiled 0x1580c3ca0cc5>                       2491  78%

[fapdash]

From counsel-find-file:

- command-execute                                                5079  76%
 - call-interactively                                            5079  76%
  - funcall-interactively                                        5079  76%
   - counsel-find-file                                           4881  73%
    - counsel--find-file-1                                       4881  73%
     - ivy-read                                                  4881  73%
      - read-from-minibuffer                                     4874  73%
       - ivy--queue-exhibit                                      4851  73%
        - ivy--exhibit                                           4851  73%
         - ivy--update-minibuffer                                4427  66%
          - ivy--format                                          4427  66%
           - mapcar                                              4414  66%
            - ivy-rich--counsel-find-file-transformer               4414  66%
             - ivy-rich-format                                   4412  66%
              - mapconcat                                        4412  66%
               + #<compiled 0x15688b785e75>                      4411  66%

[Yevgnen]

Hi, you can use C-u TAB to fully expand a node to provide all details.

[fapdash]

Just found out the other day that you can expand the compiled function with TAB even though the GUI doesn't let you click on it.
Thank you for the tip with the prefix.

Had to put the reports in a gist as they are too long for a comment:

• https://gist.github.com/fapdash/fe906ebaee8763d9a5e02ee1b0d3227f#file-ivy-rich-report-ivy-switch-buffer-md
• https://gist.github.com/fapdash/fe906ebaee8763d9a5e02ee1b0d3227f#file-ivy-rich-report-ivy-switch-file-md

[mihaiolteanu]

I'm noticing the same delay.

[farynaio]

Same here