bug#30995: 25.3; Slow window and frame popup on Emacs 26+ (e.g. with Helm)

[Pierre Neidhardt]

Since Emacs 26, I've noticed a slight delay (I'd say between 100ms and
500ms) in the creation of _some_ windows, most noticeably all Helm
windows.  This does not occur on Emacs 25.

I had initially reported the issue upstream to Helm:

        https://github.com/emacs-helm/helm/issues/1976

But its maintainer believes Helm is not to blame here.

I use EXWM but it is not clear whether the issue is rooted there either.

Any insight on what could slow down window/frame creation on Emacs 26?


In GNU Emacs 25.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.22.28)
 of 2018-03-25 built on localhost
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
Configured using:
 'configure
 
CONFIG_SHELL=/gnu/store/mm0zclrzj3y7rj74hzyd0f224xly04fh-bash-minimal-4.4.12/bin/bash
 SHELL=/gnu/store/mm0zclrzj3y7rj74hzyd0f224xly04fh-bash-minimal-4.4.12/bin/bash
 --prefix=/gnu/store/6cflji7h6y0v15dvnccv7paaa7894gdc-emacs-25.3
 --enable-fast-install'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GSETTINGS NOTIFY ACL
GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS
GTK3 X11

Important settings:
  value of $LANG: en_US.utf8
  locale-coding-system: utf-8-unix

Major mode: EXWM
<#secure method=pgpmime mode=sign>

--
Pierre Neidhardt