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Old 01-06-09, 04:12 PM   #1
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Join Date: Dec 2006
Posts: 12
Default glx module and XRes extension

I've been having some general GUI instabilities running Gnome under CentOS 5.2 and I have never been able to track down the root cause. Recently, I found out about xrestop and decided to try it. Unfortunately, on most systems, xrestop was failing with the following error message:

xrestop: XResQueryExtension failed. Display Missing XRes extension ?
On the systems were xrestop was failing, the following lines were in the xorg.conf file:

Section "Module"
   Load           "glx"
After commenting out the loading of the glx module and restarting the X server, I was able to run xrestop. Then I decided to upgrade to the latest NVIDIA driver, and when I installed the driver, the xorg.conf file was modified to load the glx module again. I also noticed the following difference in the number of extensions loaded in the output of xdpyinfo with (15) and without (32) the glx module loaded:

number of extensions:    15       |    number of extensions:    32
                                  >        BIG-REQUESTS
    Composite                              Composite
    DAMAGE                                 DAMAGE
                                  >        DOUBLE-BUFFER
                                  >        DPMS
                                  >        Extended-Visual-Information
    GLX                                    GLX
                                  >        MIT-SCREEN-SAVER
    MIT-SHM                                MIT-SHM
                                  >        MIT-SUNDRY-NONSTANDARD
    NV-CONTROL                             NV-CONTROL
    NV-GLX                                 NV-GLX
    RANDR                                  RANDR
                                  >        RECORD
    RENDER                                 RENDER
    SECURITY                               SECURITY
                                  >        SHAPE
                                  >        SYNC
                                  >        TOG-CUP
                                  >        X-Resource
    XC-APPGROUP                            XC-APPGROUP
                                  >        XC-MISC
    XFIXES                                 XFIXES
    XFree86-Bigfont                        XFree86-Bigfont
                                  >        XFree86-DGA
                                  >        XFree86-Misc
                                  >        XFree86-VidModeExtension
    XInputExtension                        XInputExtension
    XKEYBOARD                              XKEYBOARD
    XTEST                                  XTEST
                                  >        XVideo
                                  >        XVideo-MotionCompensation
So my questions are:
  1. Why is the NVIDIA installer adding the Load "glx" to the xorg.conf file and is there a way to tell the installer not to do so?
  2. What is this glx module?
  3. Why does loading the glx module cause xrestop to fail (i.e., why is the X-Resource extension not loaded)?
  4. Why are there less extensions available when the glx module is loaded in the xorg.conf file (15 vs. 32)?
  5. Is the GLX extension related to the glx module? If so, why is it loaded in both cases?

I don't usually monitor these forums, but one of the recent threads mentioned disabling the glx module to avoid a memory leak. I'm hoping that disabling it will also fix my various instabilities.

avoncampe is offline   Reply With Quote