maximum number of clients reached

[whitis]

X server hits a client limit at a very low value. Somewhere around 95 clients. This is very easy to hit and I have hit this limit frequently since upgrading to 11.10. This has not normally been a problem in decades of running linux.

# Firefox downloads PDF file but does not open it as usual
$ evince /tmp/CM6206+datasheet+1.7.pdf &
[26] 9099
 Maximum number of clients reachedCannot parse arguments: Cannot open display:
[26] Exit 1 evince /tmp/CM6206+datasheet+1.7.pdf
$ ubuntu-bug evince
Maximum number of clients reachedCannot start: Gtk couldn't be initialized
$ ps axlww | fgrep -i evince | wc
     45 632 4771
 $ ico
Maximum number of clients reachedico: cannot open display ":0"
$ killall evince

# NOTE that I killed evince and thus about half the clients.

$ xlsclients | wc
     50 107 1227
$ xlsclients | sort | uniq -c
      1 '' /bin/sh /usr/lib/libreoffice/program/soffice
      1 cervantes applet.py
      1 cervantes bamfdaemon
      1 cervantes bluetooth-applet
      1 cervantes compiz
      1 cervantes deja-dup
      6 cervantes emacs
      1 cervantes eog
      1 cervantes evolution-alarm-notify
      4 cervantes file-roller
      1 cervantes firefox
      1 cervantes gdu-notification-daemon
      1 cervantes gnome-fallback-mount-helper
      1 cervantes gnome-screensaver
      1 cervantes gnome-session
      1 cervantes gnome-settings-daemon
      1 cervantes gnome-terminal
      1 cervantes gpodder
      3 cervantes inkscape
      1 cervantes nautilus
      1 cervantes nm-applet
      1 cervantes notify-osd
      1 cervantes npviewer.bin
      2 cervantes plugin-container
      1 cervantes polkit-gnome-authentication-agent-1
      2 cervantes python
      1 cervantes scp-dbus-service.py
      1 cervantes soffice
      1 cervantes ubuntuone-syncdaemon
      1 cervantes unity-panel-service
      1 cervantes unity-window-decorator
      1 cervantes update-manager
      1 cervantes update-notifier
      2 cervantes vlc
      2 cervantes xsane
      1 cervantes xterm -bg green -title alpine -e alpine

$ sudo lsof -p `pidof X` | grep socket | wc -l
[sudo] password for whitis:
lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/whitis/.gvfs
      Output information may be incomplete.
64

$ xwininfo -root -children | wc
    882 5982 56551

$ xrestop - Display: :0
          Monitoring 67 clients. XErrors: 0
          Pixmaps: 162522K total, Other: 1405K total, All: 163928K total

res-base Wins GCs Fnts Pxms Misc Pxm mem Other Total PID Identifier
1200000 1784 2 1 38 16732 26206K 435K 26641K ? Compiz
0600000 0 0 0 1 0 22500K 0B 22500K ? <unknown>
1a00000 7 3 1 20 66 20282K 2K 20284K 2723 nautilus
0c00000 6 2 0 18 319 18750K 7K 18757K 2680 gnome-setting
14c00000 59 99 1 2268 2453 12731K 62K 12793K 2426 Downloads
4e00000 4 3 1 18 55 12709K 2K 12712K 11289 food_0002.jpe
a400000 25 126 1 1040 151 12316K 8K 12324K 22268 Wireless Test
13600000 48 165 1 128 115 8221K 8K 8229K 26330 BitPim
0000000 2 0 2 0 132 7500K 5K 7505K ? <unknown>
1e00000 0 0 0 1 0 7500K 0B 7500K ? <unknown>
2c00000 9661 67 1 118 1113 1870K 255K 2125K 2782 unity-window-
e000000 5 3 1 19 57 1358K 2K 1361K 5330 CN0144-Design
6400000 5 3 1 19 57 1358K 2K 1361K 19168 st51_d00_e00.
6000000 5 3 1 19 57 1358K 2K 1361K 19051 st51_d00_asci
4c00000 5 3 1 19 57 1358K 2K 1361K 11279 15w-pcb.zip [
13a00000 15 99 1 175 131 900K 6K 906K 30059 Preview 7650
7a00000 15 101 1 167 130 899K 6K 906K 23198 Preview 7650:
7600000 17 7714 1 26 68 472K 183K 656K 21913 virginia_low.
6200000 22 7862 1 50 83 463K 187K 651K 21158 usmap2.svg -
7400000 17 4358 1 28 69 469K 105K 575K 21902 virginia.svg
...

Unity and compiz seem to have an inordinate number of windows open.

uptime was a mere 19 days.

I am not running google chrome, lastpass, or MinimizeToTray which have been blamed for this problem elsewhere.

On a related note, the screensaver can take a very long time to let you unlock the screen (and actually displays the desktop to prying eyes before hiding it and displaying the prompt). Last time I needed to unlock, it would not display the password window. I switched to a console window and killed it. It has been mentioned that switching to console and back may free some x server resources.

I have 16GB RAM in this machine.

ati-driver-installer-11-10-x86.x86_64.run

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: xorg 1:7.6+7ubuntu7
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: fglrx
.tmp.unity.support.test.0:

ApportVersion: 1.23-0ubuntu4
Architecture: amd64
CheckboxSubmission: 1e1a99f31ec2933306456e1f141c45d8
CheckboxSystem: edda5d4f616ca792bf437989cb597002
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,gnomecompat,resize,regex,mousepoll,snap,imgpng,grid,place,unitymtgrabhandles,move,vpswitch,animation,workarounds,wall,session,expo,fade,ezoom,scale,unityshell]
CompositorRunning: compiz
Date: Sun Jan 1 07:19:16 2012
DistUpgraded: Log time: 2011-11-09 01:26:59.103060
DistroCodename: oneiric
DistroVariant: ubuntu
GdmLog: X: /tmp/.X11-unix has suspicious mode (not 1777) or is not a directory, aborting.
GraphicsCard:
 ATI Technologies Inc Cayman PRO [AMD Radeon 6900 Series] [1002:6719] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:03d4]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
JockeyStatus:
 xorg:fglrx_updates - ATI/AMD proprietary FGLRX graphics driver (post-release updates) (Proprietary, Disabled, Not in use)
 xorg:fglrx - ATI/AMD proprietary FGLRX graphics driver (Proprietary, Disabled, Not in use)
MachineType: System manufacturer System Product Name
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-12-generic root=UUID=02f53b93-8fd3-44ee-911b-a2d656e2d4d2 ro
SourcePackage: xorg
UpgradeStatus: Upgraded to oneiric on 2011-11-09 (53 days ago)
dmi.bios.date: 02/17/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1902
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: Crosshair IV Formula
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1902:bd02/17/2011:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnCrosshairIVFormula:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu5
version.fglrx-installer: fglrx-installer N/A
version.ia32-libs: ia32-libs 20090808ubuntu26
version.libdrm2: libdrm2 2.4.26-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3
version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110411+8378443-1

[Mark Stosberg (markstos)]

I'm also getting this error when trying to open a PDF with evince on 12.04.

[Donatas Olsevičius (donatas-o)]

I've had 200 zenity instances (xlsclients | sort | uniq -c), killed it (killall zenity) and now everything works fine. The problem appeared after 35 days uptime.

[SSShei (ssshei)]

There is an easy way around this -- rename (or even delete) the file /etc/ati/atiapfuser.blb. From my research this is a "user profile" which doesn't seem to be utilized, at least in my case. When that files exist, you will see LOTS of entries like:

Xorg 21747 root 103r REG 8,4 0 16387220 /etc/ati/atiapfuser.blb

in the output of "sudo lsof -P `pidof X`". But after I 'mv' the file, not long these entries.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[CoolAcid (jakendall-q)]

What GPU and driver (w/ version) is everyone using? I've noticed the /etc/ati/atiapfuser on mine and would like to see if this could be the actual reason.

Thanks,
J

[linas (linasvepstas)]

Nothing to do with ATI, I hit this on NVIDIA as well. In my case, I have many, many copies of evince running.

[linas (linasvepstas)]

Anyway, googling for the error message suggests that lots of people hit this; its a hard-coded constant in an X11 header file; it would need to be changes and have X11 recompiled, or made into a run-time configurable parameter.

Lets just hope that Wayland doesn't have this problem ...

[CoolAcid (jakendall-q)]

Although I agree with both points. It is hard coded limit in X11, and you can hit it with NVIDIA drivers. However, in this case, there is a bug in the ATI drivers which causes users to hit this limit sooner due to elevated number of windows created and/or not released correctly.

Wayland *should* resolve this issue, however, ATI drivers would need to be coded to use that driver format as they are currently not supported.

[SA (superaorta)]

I've just hit this bug in 13.04 using nvidia drivers.

but the 280+ instances of Kblankscrn from the screen saver bug currently going around probably contributes!

[padarjohn (john-meissen)]

I don't think this is an issue with a hardcoded constant in X, not unless someone recently made it much smaller. I hadn't seen this problem at all in 15+ years of using Linux/X, not until upgrading from 10.04LTS to 12.04LTS.

More likely it's a newly introduced resource leak in X or gnome.

I'm using the nVidia driver.

I hit this yesterday and had to log out/restart X, and I'm already hitting it again today.

After killing everything except a single terminal and this instance of Firefox I notice out of 244 root window children over 160 instances of this sort:

     0xc001b9 (has no name): () 238x196+842+518 +842+518
        2 children:
        0xc001ba (has no name): () 236x164+1+27 +843+545
        0xc001bb (has no name): () 238x196+0+0 +842+518

They're all children of the root window. There are some duplicates, for instance (ignoring their 2 children):

     0xc01660 (has no name): () 1077x1052+850+154 +850+154
     0xc016b1 (has no name): () 1077x1052+324+118 +324+118
     0xc017ea (has no name): () 1077x1052+850+154 +850+154
     0xc01877 (has no name): () 1077x1052+850+154 +850+154
     0xc018fb (has no name): () 1077x1052+850+154 +850+154
     0xc01947 (has no name): () 1077x1052+850+154 +850+154
     0xc019cc (has no name): () 1077x1052+850+154 +850+154
     0xc01a45 (has no name): () 1077x1052+850+154 +850+154

I used to think it was xscreensaver, but I disabled that. I have no screensaver process running now. The only "strange" thing that might be related is a shell script I run that fires off xplanet every 5 minutes to generate a jpeg and then calls
  gconftool -t str -s /desktop/gnome/background/picture_filename <file.jpg>
to update the background image.

> xlsclients
john gnome-session
john gnome-settings-daemon
john gnome-panel
john gnome-fallback-mount-helper
john rainlendar2
john polkit-gnome-authentication-agent-1
john devilspie
john gtk-window-decorator
john notify-osd
john gdu-notification-daemon
john telepathy-indicator
john indicator-applet
john gweather-applet-2
john indicator-applet-session
john indicator-printers-service
john evolution-alarm-notify
john gnome-terminal
john firefox

Any suggestions on how to debug this would be appreciated.

[padarjohn (john-meissen)]

This is looking more and more like a X server resource leak.

I reached this state again after a couple of days (as I usually do) and tried to capture some information to compare with the clean-state data, so I closed everything I had open until I had only the clients that I normally have right after login. Then I started running xwininfo with different options.

After successfully running xwininfo several times I suddenly got

 Maximum number of clients reachedxwininfo: error: unable to open display ":0.0"

I literally had not run anything else other than a few shell commands. I seriously doubt xwininfo is leaking handles. Later, when I'm not doing real work, I'll try to script something to see if I can create a failure.

[Matthew Piatt (matthew-g-piatt)]

I'm running an AMD Radeon HD 6450 with the driver downloaded and installed from the AMD website (http://support.amd.com/en-us/download/desktop?os=Linux%20x86)

When running "sudo lsof -P `pidof X`" I would also see a lot of entries like another user mentioned above:

Xorg 21747 root 103r REG 8,4 0 16387220 /etc/ati/atiapfuser.blb

After renaming atiapfuser.blb to something else (atiapfuser.blb.bak), I rebooted, and these entries stopped piling up. It's been a few days since I did this, and I haven't seen them at all, and I don't get any more errors about maximum number of clients reached.