X server crash recovery

Tiago Vignatti vignatti at c3sl.ufpr.br
Tue Oct 9 15:43:28 PDT 2007

Hi Paulo, how are you?!

Paulo Cesar Pereira de Andrade escreveu:
>   Thanks Daniel. Actually I had looked a bit at the "Xat" this week, and 
> http://www.c3sl.ufpr.br/multiseat/, but did not know about the multi 
> thread input code. I talked via email with Tiago yesterday about this, 
> and looked at some of the sources.

humm, aahm, err.. Xat and the X server with the input thread 
implementation are totally different things, Paulo. Xat is a proxy 
between the clients and the server to create the illusion of a 
multi-display server. We did this as a proof-of-concept of a 
Multi-Display X server, and if Xat is used with Multi-Pointer X server 
(MPX) we get a kind of multiseat. But this is another history...

>   Today I made a "quick hack" and put every input device on its own 
> thread, i.e. not one thread for all input devices like Tiago's patch, 

When me and Daniel designed the input thread, we tried to avoid one 
thread per device thinking that it could generate a lot of critical 
regions ending up with the problem of the MTX, i.e., spending the 
majority of the time managing the threads thus decreasing the 
performance. But we could be wrong.

>   Actually, I am considering to also test the video driver in it's own 
> thread, but it most likely would require more than a few semaphores at 
> key points in mieq.c to keep consistency; well did not yet analise it...

yeah, also the problem of the MTX...


Tiago Vignatti
C3SL - Centro de Computação Científica e Software Livre

More information about the xorg mailing list