Please describe the problem:
At any given time I have 16 workspaces and 150-200 windows open.  Anything that updates the window frame title bar (like changing directory in my xterms, or browsing to a new page in firefox, or hitting next-image in xv) takes about .5 to 1 sec on my unloaded Core2 Quad 2.4GHz workstation.  During the .5-1 sec interval, if you click on another window for focus, your click will do nothing and not register until the .5-1 sec interval has passed, and then the other window will focus.  It's like you can't do anything at all while the wm is thinking.

Moving, resizing, etc is normal speed.  It is only updates to the title that is slow.

If I have few windows open, like when I reboot and start fresh or close most windows before shutdown, then everything is very fast as you would expect.

My hunch is that some of the code that matches title bars is running slow lisp code against every title bar change and every window open in a sequential check.  I do use matched windows to hide some windows from the taskbar.

The solution will be to optimize the check when titles change, as you would only need to check the current window, possibly; or make the code faster with a better algorithm.

Thanks!


Steps to reproduce:
1. open 150-200 windows
2. in firefox, browse to a new page
3. immediately click on another window



Actual results:
The other window click will not register for .5-1 sec.

Expected results:
It should focus immediately.

Does this happen every time?
yes

Other information:
It has done this since at least 1.3.4.  I am currently using 1.3.5.1.