Olivier Galibert galibert at
Wed Apr 8 13:34:47 PDT 2009

On Wed, Apr 08, 2009 at 09:28:47PM +0100, Alan Cox wrote:
> > Dropping support for automatic backing store while at the same pushing
> > for a design, composite, that is all backing store all the time means
> > one of three things : lazyness, incompetence, or a big honking design
> > issue in the server.  So, which one is it?
> Backing store has long been off by default in Xfree/Xorg. Fundamentally
> its a dumb design issue in the concept of backing store - it means the
> server has to consume huge amounts of memory keeping copies of stuff and
> if someone massively resizes a window with backing store (remembering it
> can be mostly offscreen) your X server explodes.

Hence the pleasure that is composite.

> Backing store was mostly a mistake at the time of introduction (as
> opposed to save unders which are a least reasonably resource bounded).

I actually meant save unders, which is what has been dropped.


More information about the xorg mailing list