X Server: abused or buggy?

[Alan Cox]

On Tue, 09 Dec 2008 17:06:04 +0100
Óscar Fuentes <ofv at wanadoo.es> wrote:

> Alan Cox <alan at lxorguk.ukuu.org.uk> writes:
> 
> >> Why should it be a KDE bug if the X server is leaking memory?  I used to
> >
> > The KDE app told X to cache all those pixmaps. X is just doing what it
> > was asked to. The alternative would be that it decided to kill off that
> > client for being dumb.
> 
> So in your opinion using X as a cache for 500 MB of pixmaps is dumb. I
> tend to agree, but it is reasonable to expect that when the app closes
> and the pixmaps are freed, all that memory is returned to the OS? In
> other words, is a bug that under this usage mode the memory asigned to X
> grows monotonically?

Possibly in the way your vendor has tuned their C library. That isn't X
policy or X making the decision but your C library. In the glibc case the
behaviour is controllable via mallopt N_MMAP_MAX and N_TRIM_THRESHOLD