Re: Let's break this silence

  2010-08-21 07:21, Mohammad Ebrahim Mohammadi Panah skrev:
> Why am I here?
> I'm dissatisfied with KDE performance, CPU-wise, memory-wise, etc.

The most annoying performance regression in KDE4 is the logout/shutdown 
dialog. When I press Ctrl+Alt+Delete it takes about 6 seconds for KDE to 
react by showing a simple dialog box with 4 buttons! Then it takes 2 
seconds to move focus to between the buttons with the down arrow key! It 
is not a cache issue, because if I close it and press Ctrl+Alt+Delete, 
it takes 6 seconds again.

I still use KDE, but I can not recommend it to others until such 
regressions have been fixed. I really hope that it will be fixed 
eventually. There is hope and I am happy that printing was finally 
reimplemented in KDE 4.4.


> A crude idea to make things more spicy: What's your idea about
> removing some dynamic memory allocations by using stack in place of
> heap?

That should always be done when possible. Often it is not possible. But 
it is very often possible to reduce the number of dynamic allocations 
drastically in UI code. (Each dynamic allocation has an overhead in time 
and space.) Often each widget is allocated in its own block of memory. 
But actually only one memory block is needed for a whole configuration 
dialog for example (because all widgets have the same lifetime). Each 
widget should be a member of its parent. It is a lot of work to go 
through every dialog and optimize it and the speed improvement is mostly 
noticeable in Valgrind. The best thing to do would be to make sure that 
the code that is generated from UI-designer files allocates memory 
efficiently.