console-kit-daemon consumes lot of CPU and disk writting after closing the laptop screen

[Iñaki Baz Castillo]

- Kubuntu Jaunty 64 bits.
- AMD Turion(tm) 64 X2 Mobile Technology TL-52.
- ASUS A6TC laptop.

This issue occurs for long time in my laptop (after installing Kubuntu with KDE4):

After closing and re-opening my laptop screen (even if it's connected to the power) console-kit-daemon and hald process consume a lot of CPU. Also, there is something performing a lot of disk writting operations (dstat shows ~2000K) and running "echo -n 1 >/proc/sys/vm/block_dump" shows some writting operations by hald and console-kit-daemon.

If then I open "Power management" - "Capabilities" then I see an error in "ConsoleKit Runtime Support" with a reason "PowerDevil couldn't contact console-kit-daemon...". This doesn't occur before closing the screen (all is correct and the above doesn't occur).

In "performance" mode the laptop is not suspended to RAM or hibernated at all, but I had an option "Allow PowerDevil to manage the screen powersave". Now I've disabled it to test what happens.

[Iñaki Baz Castillo (ibc-aliax)]

Disabling "screen powersave" solves nothing, the error occurs. This is: after closing the laptop cover *for a while* (it's not enough with closing it during some seconds) the uptime command show a load average of ~5.00 and there are ~2000K of writing operations to disk. Really annoying and I must restart the computer.

[arky (arky)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at https://wiki.ubuntu.com/Bugs/FindRightPackage. I have classified this bug as a bug in consolekit.

When reporting bugs in the future please use apport, either via the appropriate application's "Help -> Report a Problem" menu or using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[James Westby (james-w)]

Hi,

Could you please run

  strace -o /tmp/strace.txt -p $(pidof console-kit-daemon)

for a few seconds when it is hung, then CTRL-C it to
stop the collection and attach /tmp/strace.txt to the bug.

Thanks,

James

[Iñaki Baz Castillo (ibc-aliax)]

I attach strace.txt as James asked.

[Iñaki Baz Castillo (ibc-aliax)]

When the problem *doesn't* occur (this is: when I haven't closed the laptop screen) the output of strace command is just:

  restart_syscall(<... resuming interrupted call ...> <unfinished ...>

[James Westby (james-w)]

Hi,

Thanks for doing that. I forgot to ask you to use the flag to
get timing information, for about how long did you let "strace"
run? Seconds? Minutes? Hours?

Do you have lots of frequent cron jobs on your machine?

The most suspicious thing at first glance is lots of lines like

read(9, 0x1dfe680, 2048) = -1 EAGAIN (Resource temporarily unavailable)

but I'm not sure what would be the cause or effect of those.

Thanks,

James

[Iñaki Baz Castillo (ibc-aliax)]

strace command was running for ~ 2seconds (and it generated an output of 133K in those 2 seconds).

About my cron jobs, I've the normal jobs (these installed by default plus jobs for vnstat and sysstat).

[James Westby (james-w)]

Right, thanks for the information.

Let's get consolekit to tell us what is going on.

  *Note that this operation will require a reboot to get some things functional again*

First, please kill consolekit and then launch it in debug mode:

    sudo pkill -u root console-kit-dae; sudo console-kit-daemon --debug --no-daemon &> /tmp/consolekit.log

then trigger the bug, CTRL-C the process, and then attach /tmp/consolekit.log to the bug.

Thanks,

James