[xmonad] Another data point on delays in focus update.

[Allen S. Rout]

On 03/06/2012 09:31 AM, Don Stewart wrote:
> Does it happen with an out of the box xmonad ? With no user config?
>

Sorry to take so long to respond:  I don't close X sessions lightly. 
But my home laptop's power brick futzed on me, so a reboot happened, 
like it or not. :)  The short answer is "Yes".  Long answer follows:

I made another user and logged in with base xmonad as supplied by stock 
oneric ubunutu, made 20-mumble XTERMs on one screen and a top in the 
primary window.  The machine was snappier to respond than my workstation 
at work, but the laptop is simply newer, too.  (plus it was a brand new 
login, nothing else going on on the machine, etc. etc. etc.)

But I could easily push the Xorg CPU to the 90% and above by simply 
moving my mouse across the windows, and when I did it vigorously, I 
could get seconds ahead of the focus updates.  (i.e. stop moving the 
mouse and watch focus rattle between the XTERMs over and over again 
while it caught up).

For giggles, I then started base stock CTWM, which was my favored 
platform before.  I started ~40 one-character-wide XTERMs and lined them 
up next to each other and wiggled my mouse over them.  Strictly 
speaking, there were probably something like twice the number of 
transitions there, because each xterm->xterm transition was really an 
xterm->root_window->xterm transition.  Or maybe even 
xterm->border->root->border->xterm.    I dunno.

Anyway, wiggling my mouse over that field, I couldn't get my Xorg CPU 
above about 10%.

- Allen S. Rout