Re: kmemleak, cpu usage jump out of nowhere

[Pekka Enberg <penberg@cs.helsinki.fi>]

Zeno Davatz wrote:
> On Wed, Jul 14, 2010 at 10:31 AM, Damien Wyart <damien.wyart@free.fr> wrote:
> 
>>> On Wed, Jul 14, 2010 at 9:12 AM, Zeno Davatz <zdavatz@gmail.com> wrote:
>>>> I got a new Intel core-8 i7 processor.
>>>> I am on kernel uname -a
>>>> Linux zenogentoo 2.6.35-rc5 #97 SMP Tue Jul 13 16:13:25 CEST 2010 i686
>>>> Intel(R) Core(TM) i7 CPU 960 @ 3.20GHz GenuineIntel GNU/Linux
>>>> Sometimes in the middle of nowhere all of a sudden all of my 8-cores
>>>> are at 100% CPU usage and my machine really lags and hangs and is not
>>>> useable anymore. Some random process just grabs a bunch CPUs according
>>>> to htop.
>> * Pekka Enberg <penberg@cs.helsinki.fi> [2010-07-14 11:05]:
>>> Why did you enable CONFIG_DEBUG_KMEMLEAK? Memory leak scanning is
>>> likely the source of these pauses.
>> I am seeing the same problem with a Core i7 920 and 2.6.35-rc5, and I do
>> not have CONFIG_DEBUG_KMEMLEAK enabled, so I think this is not related.
>>
>> I do not see anything special in the logs, just the load becoming mad
>> and almost preventing ssh access. I've been seeing that since the first
>> 2.6.35 rc I tested (-rc2 or -rc3, I don't remember) and I did not have
>> time to report it before but I was surprised nobody else did. No problem
>> with 2.6.34 and 2.6.34.1.
> 
> same with me. My last build I tested was 2.6.34-rc7. No problems
> there. No CPU jumps out of nowhere.
> 
> It is like any application all of a sudden use 400% CPU i.e. htop.

Interesting. Lets CC some scheduler folks for help.

			Pekka