bug#20961: 24.5; `dired-jump' quite slow under Cygwin Emacs

[Sebastien Vauban <sva-news-D0wtAvR13HarG/iDocfnWg@public.gmane.org>]

Eli Zaretskii <eliz-mXXj517/zsQ@public.gmane.org> writes:
>> From: Sebastien Vauban <sva-news-D0wtAvR13HarG/iDocfnWg@public.gmane.org>
>> Date: Thu, 02 Jul 2015 12:27:11 +0200
>> 
>> Now that profiling works under Cygwin Emacs (thanks Ken and Eli!), I can
>> report the following when playing a couple of seconds with Dired-jump
>> (which I find much slower on Cygwin Emacs than on Windows Emacs).
>> 
>> --8<---------------cut here---------------start------------->8---
>> - ...                                                         6440  59%
>>  - find-file                                                  6315  58%
>>   - apply                                                     6315  58%
>>    - ad-Advice-find-file                                      6315  58%
>>     - let                                                     6315  58%
>>      - let                                                    6315  58%
>>       - setq                                                  6315  58%
>>        - with-no-warnings                                     6315  58%
>>         - funcall                                             6315  58%
>>          - #<compiled 0x4018ad5f>                             6315  58%
>>           - find-file-noselect                                6315  58%
>>            - run-hook-with-args-until-success                 6315  58%
>>             - dired-noselect                                  6315  58%
>>              - dired-internal-noselect                        6315  58%
>>               - dired-readin                                  6311  58%
>>                - dired-readin-insert                          6290  57%
>>                 - dired-insert-directory                      6290  57%
>>                  - insert-directory                           6289  57%
>>                   - apply                                     6289  57%
>>                    - ls-lisp--insert-directory                6289  57%
>>                     - get-free-disk-space                     6288  57%
>>                      - process-file                           6288  57%
>>                         apply                                 6288  57%
>
> This seems to point to get-free-disk-space, which on Cygwin invokes
> the 'df' program, whereas the native w32 build calls a function to get
> the same info.

I never had noticed that the "available" space was shown in
Dired... Hard to read, BTW, a figure such as "10232288" (neither comma,
nor abbreviation like 10.2G).

And, in fact, that information could be dropped for my own usage... I'm
simply interested by the contents of the directories.

> You also seem to have Helm active, so perhaps these two factors
> together make 'df' invocation much slower than the w32 API call.

Yes, I do have Helm active, but I don't think it comes here to play --
and, in fact, it's not even reported in that part of the trace.

Best regards,
  Seb

-- 
Sebastien Vauban