XServer freezes when opening many windows

[Enrico Weigelt, metux IT consult]

On 16.01.25 12:15, Raúl HERMOSO SÁNCHEZ wrote:

Hi,

>     I am writing to query about a problem I have encountered with
> XServer. It freezes when opening any window after "many" others are
> already opened.

How many windows ?

On which HW configuration ? Sometimes, proprietary drivers can do really
ugly things. (for professional use, I'd highly recommend only using
FOSS drivers *1)

Can you script up a test case ?
Have you tried debugging the Xserver ? (attach via gdb and look whats
going on there) ?

> We believe it is the XServer freezing as any command-
> line tool that uses X that we try to execute (xwininfo, xdotool,
> xls_client...) never paints or returns.

Do other (earlier connected) clients still work ?
Does console switching still work ?

> To be more
> precise, the server freezes when we try to open 40+ "client" windows
> (which means probably around three more actual Window created: toolbars,
> borders, auxiliary windows for clipboard....).

Note that widget toolkits often create sub-windows, so you might have
a lot more windows than clients.

> It may be of interest for this issue to know that we are using
> an in-house Window Manager developed by ourselves).

Maybe that's the cause ? Can you share the code ?

Btw, mind telling us what's the underlying reason for writing your
own custom WM ? Let me guess: special control center requirements ?

Not long ago, I've patched up xfwm4 for railways control centers
(eg. prevent overlapping, customizable regions where windows can dock
and maxmimize into, automatically move specific windows to certain
regions, ...) ... unfortunately upstream didnt want my patches.


--mtx


*1) eg. one of my clients using Nvidia cards for their control center
stations. Unsurprisingly this caused a lot trouble from kernel level on.
Their only reason was the need of many ports (and they didn't even need
HW-GL). Never found out why they didn't just put in more, cheap cards
or possibly use USB dongles. Probably a political problem.


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Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info at metux.net -- +49-151-27565287