Slow performance on Emacs 26.1 RC on Windows10

[frondeus]

Slow performance on Emacs 26.1 RC on Windows10

[iqbalansari]

Hi @frondeus,

Thanks a lot for the detailed bug report and apologies for the delay response, I have pushed a tentative fix for the slow down, could you please try it out once the new version is available on MELPA and report back if it helped.

Thanks again for your patience and the detailed bug report, it really helped in quickly finding the problem

[frondeus]

I switched to Windows Linux Subsystem with emacs 27.50.0 (because of different reasons) where problem doesn't occur.
However I did some tests on old emacx 26.1 (build 1, x86_64-w64-mingw32) of 2018-05-29 and...
It works!

+ command-execute                                                 321  62%
- redisplay_internal (C function)                                 141  27%
 - eval                                                           140  27%
  + telephone-line-fill                                           125  24%
  + telephone-line-add-subseparators                               15   2%
 - #<compiled 0x100203aa1>                                          1   0%
  - apply                                                           1   0%
   - redisplay--pre-redisplay-functions                             1   0%
    - run-hook-with-args                                            1   0%
     + redisplay--update-region-highlight                           1   0%
+ ...                                                              30   5%
  mouse-fixup-help-message                                         16   3%
+ timer-event-handler                                               2   0%
+ evil-activate-visual-state                                        1   0%
+ evil-activate-visual-state                                        1   0%
+ evil-activate-visual-state                                        1   0%
+ evil-repeat-post-hook                                             1   0%
+ evil-visual-post-command                                          1   0%

As you can see redisplay takes less CPU time (more than last time with no emojis but its my new modeline, not your package).

Thanks!

[frondeus]

What is more you can see that Windows build has better transparency support than WLS.
It seems that Emacs has problems with alpha blending and does simple cut (when alpha==0)
Maybe I forgot some library. I don't know. Don't care that much