Re: interesting article on XFree86 speed

Vadim Plessky <[email protected]> writes:

> Making the Case for XFree86's Speed
> http://www.osnews.com/story.php?news_id=1905
> Comments:
> http://www.osnews.com/comment.php?news_id=1905
> 
> Would be interesting to know what people on the list think about article 
> itself and XFree86 speed.
> I found original link on BlueEyedOS web page (BeOS clone)

I think the author is right that interesting things can be
done in the area of performance and X. As far as 
particular problems that he identifies and solutions he
proposes... well, they certainly wouldn't be where I was
looking.

Quick rundown of what I think _is_ interesting:

 - Store the full contents of all toplevels. Exposes are an 
   obsolete concept from when window contents were simpler and 
   graphics memory smaller.

   (You may want to discard information if memory gets tight,
   but you shouldn't be discarding the contents of a window
   just because it is obscured or offscreen)

 - Solve the frame / contents synchronization problem for
   opaque resizing. When the content of the window can be
   redrawn at a reasonable rate, there should be no reason
   that the window appears in an inconsistent state to the
   user.

 - Improve the handling of offscreen memory management in
   XFree86.

 - Study how applications and toolkits use offscreen pixmaps;
   it might be useful to have hinting about whether pixmaps
   are transient or permanent. (Or possibly push the equivalent
   of gdk_window_begin_paint()/gdk_window_end_paint() into
   the server.)

The actual implementation of the much of the above would 
take some  serious server re-architecting. Fortunately, it's 
largely the same server re-architecting that is needed for 
features like translucency / thumbnailing / magnification.

Regards,
                                        Owen