Re: kmemleak, cpu usage jump out of nowhere

From: Zeno Davatz
Date: Wed Jul 14 2010 - 04:34:54 EST


On Wed, Jul 14, 2010 at 10:31 AM, Damien Wyart <damien.wyart@xxxxxxx> wrote:

>> On Wed, Jul 14, 2010 at 9:12 AM, Zeno Davatz <zdavatz@xxxxxxxxx> 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@xxxxxxxxxxxxxx> [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.

Best
Zeno
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