I am on a fresh install of Kubuntu 15.10 and my laptop crashes daily. I don't know what causes it, but about once or twice a day my laptop will freeze and become unresponsive until reboot.

I do not know what is causing this. It has happened under a vast set of circumstances, but my impression is that it is most common when I am doing something to do with graphics (e.g. switching virtual desktops, particularly when opening a graphics-heavy website).

Any pointers on how to debug this are much appreciated. I'm on KDE 5.4.2, kernel 4.2.0-17-generic. Many thanks!

Check whether you can still switch VT (press ctrl+alt+f2) or ssh into the machine (you'll have to start sshd for this) when this happens.
Maybe only the compositor is stalled, try to press SHIFT+Alt+F12 when this happens.

I can't switch to any of the tty terminals. Ctrl + Alt + F1 through F6 don't work.

I will try the Shift + Alt + F12 and the SSH bit next time. Thanks for the suggestions.

If you can't switch VT, that means the kernel is frozen, you'll likely not even be able to ping the machine.
In that case you'l have to enable the sysreq (before! the freeze occurs) so you can unroll the system

https://wiki.archlinux.org/index.php/Sy ... figuration
https://en.wikipedia.org/wiki/Magic_SysRq_key


This will most likely be a bug in the kernel module for your GPU, so google for that ("lsmod" shows the loaded modules, "lspci" the relevant hardware section and /var/log/Xorg.0.log will contain some relevant information)

For a broad oversight, paste the output of "qdbus org.kde.KWin /KWin supportInformation" (if here, please use "code" tags)

This is so odd. Watching a vid and PC froze. Audio and mouse continued to work, but the screen was frozen. I reckon if it's a GPU that would make sense since the audio is independent? I'm hoping that when Intel releases the 15.10 stack it gets fixed... In the meantime, from /var/log/Xorg.0.log, I found a log of lines referencing Intel graphics. Not sure which is the relevant one... Also,

Code: Select all

KWin Support Information:
The following information should be used when requesting support on e.g. http://forum.kde.org.
It provides information about the currently running instance, which options are used,
what OpenGL driver and which effects are running.
Please post the information provided underneath this introductory text to a paste bin service
like http://paste.kde.org instead of pasting into support threads.

==========================

Version
=======
KWin version: 5.4.2
Qt Version: 5.4.2
Qt compile version: 5.4.2
XCB compile version: 1.11

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_WAYLAND: yes
HAVE_WAYLAND_EGL: yes
HAVE_WAYLAND_CURSOR: yes
HAVE_XKB: yes
HAVE_INPUT: yes
HAVE_DRM: yes
HAVE_GBM: yes
HAVE_X11_XCB: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 11702000
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
GLX: yes; Version: 0x0

Decoration
==========
Plugin: org.kde.breeze
Theme:
Blur: 0
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 0, 2
decorationButtonsRight: 6, 3, 4, 5
borderSize: 3
gridUnit: 10
font: Oxygen-Sans,10,-1,0,50,0,0,0,0,0
smallSpacing: 2
largeSpacing: 10

Options
=======
focusPolicy: 0
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: false
focusStealingPreventionLevel: 1
legacyFullscreenSupport: false
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 1
unredirectFullscreen: false
glSmoothScale: 2
colorCorrected: false
xrenderSmoothScale: false
maxFpsInterval: 16666666
refreshRate: 0
vBlankTime: 6000000
glStrictBinding: true
glStrictBindingFollowsDriver: true
glCoreProfile: false
glPreferBufferSwap: 101
glPlatformInterface: 1

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Multi-Head: no
Active screen follows mouse:  no
Number of Screens: 1

Screen 0:
---------
Name: eDP1
Geometry: 0,0,1920x1080
Refresh Rate: 60.0495


Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 5500 (Broadwell GT2)
OpenGL version string: 3.0 Mesa 11.0.2
OpenGL platform interface: GLX
OpenGL shading language version string: 1.30
Driver: Intel
GPU class: Unknown
OpenGL version: 3.0
GLSL version: 1.30
Mesa version: 11.0.2
X server version: 1.17.2
Linux kernel version: 4.2
Direct rendering: Requires strict binding: yes
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used
Painting blocks for vertical retrace:  no

Loaded Effects:
---------------
zoom
slidingpopups
kwin4_effect_login
wobblywindows
screenshot
kwin4_effect_fadedesktop
kwin4_effect_translucency
minimizeanimation
desktopgrid
kwin4_effect_windowaperture
kwin4_effect_fade
kwin4_effect_maximize
presentwindows
kwin4_effect_dialogparent
highlightwindow
blur
contrast
logout
dashboard
startupfeedback
screenedge
kscreen

Currently Active Effects:
-------------------------
blur
contrast

Effect Settings:
----------------
zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: false
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

slidingpopups:
fadeInTime: 150
fadeOutTime: 250

kwin4_effect_login:

wobblywindows:
stiffness: 0.36
drag: 0.9
moveFactor: 0.12
xTesselation: 20
yTesselation: 20
minVelocity: 0
maxVelocity: 1000
stopVelocity: 0.5
minAcceleration: 0
maxAcceleration: 1000
stopAcceleration: 0.5
moveEffectEnabled: true
openEffectEnabled: false
closeEffectEnabled: false
moveWobble: true
resizeWobble: true

screenshot:

kwin4_effect_fadedesktop:

kwin4_effect_translucency:

minimizeanimation:

desktopgrid:
zoomDuration: 300
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: true

kwin4_effect_windowaperture:

kwin4_effect_fade:

kwin4_effect_maximize:

presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: false
accuracy: 20
fillGaps: true
fadeDuration: 150
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0

kwin4_effect_dialogparent:

highlightwindow:

blur:
blurRadius: 12
cacheTexture: true

contrast:

logout:
useBlur: true

dashboard:
brightness: 0.5
saturation: 0.5
blur: false

startupfeedback:
type: 1

screenedge:

kscreen:




If the audio continues to play, the kernel is still processing, but you might have trouble on the video kernel module (what prevents you from visually switching to another VT since the framebuffer is no longer updated)
You should still be able to ssh into the machine.

However, if the mouse still moves, that means the framebuffer is updating (and input etc. processed) - suspending the compositor (SHIFT+Alt+F12) or killing kwin should be should likely be sufficient.

You might be able to workaround driver bugs by downgrading the acceleration method
glamor -> sna -> uxa

Check /var/log/Xorg.0.log on what's currently used and adjust it:

/etc/X11/xorg.conf.d/20-intel.conf

Code: Select all

Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   AccelMethod "sna"
EndSection


Be aware that people reported failures to startup X11 when creating such snippets - the forum may generate stray chars or the browsers copy such (I don't know, had no trouble itr.)