[Mageia-dev] Anybody having high CPU by kded4 after upgrading to 4.6.90?

[Wolfgang Bornath]

2011/7/1 Christiaan Welvaart <cjw at daneel.dyndns.org>:
> On Fri, 1 Jul 2011, Radu-Cristian FOTESCU wrote:
>
>> Now, it's tough to determine what exactly is making kded4 to eat the CPU.
>> As I'm having a single core, I'm burned. At the same time, minor changes
>> that are actually small improvements make me want to stay with 4.6.90, not
>> to revert to 4.6.4....
>
> One way to figure that out is to attach gdb to it while it's running and
> then print a backtrace. If you do that several times, you may break in the
> code that's running a lot. But even if that works it is likely still not
> easy to figure out what's going on.
>
> Other ways to get information would be to strace (or ltrace) this daemon to
> get an idea what it's trying to do. But CPU usage by the application itself
> cannot be seen this way.
>
> An easier way to start is to run iotop and check if kded4 is doing any I/O
> related to this cpu usage.

Did that (after installing all updates up to 07:00 UTC), no signs of
any I/O activity other than the usual. Still, one of the 4 cores is on
full load. What strikes me here is:
 - on a CPU with 1 core, this is fully loaded
 - on a dual core CPU only 1 core is loaded
 - on a quadcore CPU only 1 core is loaded.

So, whatever it is, it affects only one CPU core no matter how many
cores the CPU offers.

-- 
wobo