I used Kubuntu + Chrome + system's Flash Player [disabled the integrated one in about:plugins],
When watch online video or other flash player based applet in browser, the system suspended due to some CRAZY hard disk IO,
kill the browser and relaunch it, the suspension happened almost immediately,
Delete the cache files under &HOME/.macromedia/ will fix it temporally.
the situation happens from time to time, which made my system unusable.

At first I thought it may be some bad sectors in hd, but I run mhdd several times, no such bad sector was found,
while I switched to the Unity DM which I abandoned few months ago for some annoying crashes,
that situation will no longer occur, so kind of sure it's a problem related to KDE.

Anyone can help me? I know the problem might be too complicated to tell and the description is really obscured,
But believe me, I must search the whole internet for an answer before, and I got no clue.

Any suggestion would be helpful, otherwise I have to reinstall the whole system.

try Chrome with Chrome's flash player, you'll need to download Chrome from Google - I'm assuming you're actually running Chromium

Is this an issue with other browsers?

have you tried clearing the Macromedia cache every morning or at start up?

Try to suspend compositing whilst using flash player - it could be conflicting with KWin.
This can be done temporarily by pressing Alt + Shift + F12.

google01103 wrote:try Chrome with Chrome's flash player, you'll need to download Chrome from Google - I'm assuming you're actually running Chromium

Is this an issue with other browsers?

have you tried clearing the Macromedia cache every morning or at start up?

I am using Chrome, and Yes, the issue happened several times with firefox,
the integrated Flash player has a really poor support for chinese, that's why I disabled it.

Some of the Flash based applets depend on large amount of cache files,
clearing the cache everyday could be little bit inconvenient.

bcooksley wrote:Try to suspend compositing whilst using flash player - it could be conflicting with KWin.
This can be done temporarily by pressing Alt + Shift + F12.

The issue didn't occur everytime, I will try the workaround next time.

Wonder if there some compromised solution to avoid such conflict?

if Youtube is a problem you could join the HTLM5 player trial http://www.youtube.com/html5

what are the "flash based applets" using large amounts of cache? were these also running under Unity?

Do the freezes occur when you have flash full screen, or also in normal mode?

Reinstall the system and tried OpenSUSE Fedora and Kubuntu again, all have the same issue,
Got some error information in /var/log/syslog,

Oct 12 15:49:55 Kid-c kernel: [25446.798592] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Oct 12 15:49:55 Kid-c kernel: [25446.798597] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state
Oct 12 15:49:55 Kid-c kernel: [25446.806576] [drm:__gen6_gt_force_wake_get] *ERROR* Timed out waiting for forcewake old ack to clear

It seemed to be a kernel bug related to GPU driver rather than one related to KDE,
it might be that I used Unity DE little, so it didn't occur once.

BUT sadly still not find a solution.

Okay, the best you can do in this case then is update to a newer Kernel and X to try to solve the issue, or report it to the Intel driver developers.

Shouldn't this be in the KWin-section?

Moved to the Linux forum - it is a problem with the Intel graphics drivers, which are triggered either by flash player itself, or by the combination of flash player and KWin.

BTW, I can confirm this freeze when using Flash, like for example in browser games. From KDE SC 4.10.x up until including 4.11.1 Flash games could cause the Intel driver to crash, which cause an extreme slowdown of the respective game and graphical artifacts appearing on the Plasma desktop, needing a restart of X.
Since the upgrade to 4.11.2 the crash doesn't happen anymore, but I have since observed freezes of the complete workspace for a few seconds. My laptop is a Lenovo X220, the output of lspci is the following:

Code: Select all

00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:16.3 Serial controller: Intel Corporation 6 Series/C200 Series Chipset Family KT Controller (rev 04)
00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b4)
00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 (rev b4)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b4)
00:1c.4 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 (rev b4)
00:1c.6 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 7 (rev b4)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation QM67 Express Chipset Family LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller (rev 04)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04)
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] (rev 34)
0d:00.0 System peripheral: Ricoh Co Ltd PCIe SDXC/MMC Host Controller (rev 07)
0e:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 04)

bcooksley wrote:Moved to the Linux forum - it is a problem with the Intel graphics drivers, which are triggered either by flash player itself, or by the combination of flash player and KWin.

Actually it might get nothing to do with KWin, since I have disabled KWin when the issue occurred, but it didn't help.

Well, I am sure it is caused by Flash, or it is a problem in the Intel driver, pretty certain that KWin is not the culprit. I was asking to move this in the KWin forum because there are the people most likely to know what is wrong and how to debug that stuff.