Bug 511913

Summary: Update to fix maximum number of X clients
Product: Red Hat Enterprise Linux 5 Reporter: Adam Jackson <ajax>
Component: xorg-x11-proto-develAssignee: Adam Jackson <ajax>
Status: CLOSED ERRATA QA Contact: desktop-bugs <desktop-bugs>
Severity: medium Docs Contact:
Priority: low    
Version: 5.2CC: benl, cmeadors, dgregor, dmach, mgordon, syeghiay
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Previously, the XFD_SETSIZE value in the Xpoll.h header file was set to allow only 256 X client connections for a single X server. Consequently, if this limit was reached, the X Server would silently deny new connections. With this update, the XFD_SETSIZE has been modified to support a maximum of 512 X client connections. The X server supplied in Red Hat Enterprise Linux 5.4 has been built with this limit increase included. (BZ#511913)
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-09-02 12:04:37 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 439797    

Description Adam Jackson 2009-07-15 16:03:23 UTC
Description of problem:

See blocked bug.

Comment 1 Ben Levenson 2009-07-21 17:03:59 UTC
This is the proposed fix, correct?
https://bugzilla.redhat.com/show_bug.cgi?id=439797#c15

Comment 2 Adam Jackson 2009-07-21 17:13:35 UTC
The proposed fix is update Xpoll.h in xorg-x11-proto-devel to bump XFD_SETSIZE to 512 and modify XFD_ANYSET() to check more bits in the bitfield to match.  In the absence of this, the server will accept connections at the socket level for more than 256 clients, but will not ever poll on any of the second 256.  This is the "silent failure" mode described in https://bugzilla.redhat.com/show_bug.cgi?id=439797#c12 .

https://bugzilla.redhat.com/show_bug.cgi?id=439797#c15 described a variation on this fix where the header is simply copied into the xorg-x11-server package and modified in the same fashion.  However, QA expressed the desire to have this fixed properly, by changing -proto-devel and then rebuilding -server.

Comment 7 Adam Jackson 2009-07-21 22:07:50 UTC
built xorg-x11-proto-devel-7.1-12.el5

MODIFIED

Comment 9 Mark Gordon 2009-07-28 21:39:06 UTC
I'm not able to set the maximum number of X clients to 512, and there don't appear to be any side effects.

Comment 11 Mark Gordon 2009-08-04 20:37:04 UTC
FWIW, I have no idea what I was thinking when I wrote "not" in comment #9.  I suspect it was a typo for "now."  That or "I'm not (having any problems)" combined with an editing error on my part.  Sorry for the confusion.

Comment 13 Ryan Lerch 2009-08-06 01:13:29 UTC
Release note added. If any revisions are required, please set the 
"requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

New Contents:
Previously, the XFD_SETSIZE value in the Xpoll.h header file was set to
allow only 256 X client connections for a single X server. Consequently, if
this limit was reached, the X Server would silently deny new connections.
With this update, the XFD_SETSIZE has been modified to support a maximum of
512 X client connections. The X server supplied in Red Hat Enterprise Linux
5.4 has been built with this limit increase included. (BZ#511913)

Comment 14 errata-xmlrpc 2009-09-02 12:04:37 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHEA-2009-1411.html

Comment 15 Adam Jackson 2009-12-15 18:51:17 UTC
*** Bug 511125 has been marked as a duplicate of this bug. ***