Xlib: maximum number of clients reached

[Geoff Kingsmill]

Thanks for all the responses. I was able to increase the number of
connections to 512 by making the following changes.

<source directory>/include/misc.h
#define MAXCLIENTS 512

/usr/share/X11/Xpoll.h
#define XFD_SETSIZE 512
#define XFD_ANYSET(p) \
        ((howmany(FD_SETSIZE, NFDBITS) >  0 && (__XFDS_BITS(p,  0))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  1 && (__XFDS_BITS(p,  1))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  2 && (__XFDS_BITS(p,  2))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  3 && (__XFDS_BITS(p,  3))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  4 && (__XFDS_BITS(p,  4))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  5 && (__XFDS_BITS(p,  5))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  6 && (__XFDS_BITS(p,  6))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  7 && (__XFDS_BITS(p,  7))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  8 && (__XFDS_BITS(p,  8))) || \
         (howmany(FD_SETSIZE, NFDBITS) >  9 && (__XFDS_BITS(p,  9))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 10 && (__XFDS_BITS(p, 10))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 11 && (__XFDS_BITS(p, 11))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 12 && (__XFDS_BITS(p, 12))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 13 && (__XFDS_BITS(p, 13))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 14 && (__XFDS_BITS(p, 14))) || \
         (howmany(FD_SETSIZE, NFDBITS) > 15 && (__XFDS_BITS(p, 15))))

If I just increased MAXCLIENTS from 256 to 512 then I got another 40
connections (originally 230, now 293) but then got the error for each new
attempted connection:-

XIO: fatal IO error 104 (Connection reset by peer) on X server ":0.0"
     after 0 requests (0 known processed) with 0 events remaining.

After setting XFD_SETSIZE to 512 and updating XFD_ANYSET I was able to get
489 connections. I am assuming that kde is using the additional 30 odd
connections. An "lsof /tmp/.X11-unix/X0 | wc -l" now returns 503.

So far everything looks good. Now what would be really nice if this could be
rolled up into the master distribution and be configurable.

Thanks,
Geoff..

-----Original Message-----
From: Daniel Stone [mailto:daniel at fooishbar.org]
Sent: Monday, 26 November 2007 7:14 PM
To: Geoff Kingsmill
Cc: xorg at lists.freedesktop.org
Subject: Re: Xlib: maximum number of clients reached

On Sun, Nov 25, 2007 at 06:58:06PM -0800, Geoff Kingsmill wrote:
>   I have a number of eight headed workstations that each need in the order
of 500 clients (X-Displays).
>     After bringing up 250 odd clients I get the following error:-
>         Xlib: connection to ":0.0" refused by server
> Xlib: Maximum number of clients reached.        <--
>
>   In Solaris the number of clients can be increased by passing the
"-clients 1024" to the X-Server startup.
>     I am running RHEL V5.1 (Xorg V7.1.1). Is there a way to increase the
number of clients that can be used with the Xorg X-Server?

Hi,
You have to rebuild, changing the MAXCLIENTS definition.

Cheers,
Daniel