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bitcero

Member

Registered: 2011-11-03

Posts: 6

[SOLVED] Intel Core i7 Unbalanced Load ?

Hi

When im performing heavy processes I noticed that the first core receives a majority of the workload, I tested with irqbalance and intel microcode. but the situation persists

screenshot of a import of dump data php + mysql,  takes 5 mins aprox

the result of cat / proc / interrupts seems strange core0  gets much "attention"  i dont know if this normal.

My System
Intel i7 930
Asus P6T Board
Linux linuxbit 3.0-ARCH #1 SMP PREEMPT Wed Oct 19 10:27:51 CEST 2011 x86_64 Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz GenuineIntel GNU/Linux

Any Ideas ? it is normal ?

Thanks !!!

Last edited by bitcero (2011-11-04 01:36:01)

ethail

Member

From: Spain

Registered: 2011-02-10

Posts: 225

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

I don't see a problem, what's the problem?

Does your system get frozen or unresponsive on heavy load?

Try some make -j8 and see if every core gets used. Consider that if your workload is I/O bound and isn't heavy CPU intensive and multithreaded you can't expect all cores to be used equally

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graysky

Wiki Maintainer

From: :wq

Registered: 2008-12-01

Posts: 10,699

Website

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

Compile a kernel or do some x264 encoding.  Both task should use all your cores quite well.

Sidetopic: what is your DE/WM and your dock?

Last edited by graysky (2011-11-03 21:25:23)

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bitcero

Member

Registered: 2011-11-03

Posts: 6

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

Compile a kernel or do some x264 encoding.  Both task should use all your cores quite well.

Sidetopic: what is your DE/WM and your dock?

Hi ok  im gonna put a stress test the side dock its conky little mod (im not using feh)

http://www.mediafire.com/?68l3eva1qqx5c2p

Kde 4.7 with kwin
Cairo-dock
Terminal yakuake

Last edited by bitcero (2011-11-03 22:01:52)

bitcero

Member

Registered: 2011-11-03

Posts: 6

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

I don't see a problem, what's the problem?

Does your system get frozen or unresponsive on heavy load?

Try some make -j8 and see if every core gets used. Consider that if your workload is I/O bound and isn't heavy CPU intensive and multithreaded you can't expect all cores to be used equally

Not really unresposive, but its extrage for me that only one core takes majority of work. and after read this post i think  maybe its not normal http://www.alexonlinux.com/smp-affinity … g-in-linux

im gonna make some stress test.

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

My guess at the why you see that behavior would be that you have only one thread heavily loading your cpu so in order to increase the chance of your cpu using turbo boost one of the cores is favored. It might also be some power saving feature (I'm not sure but don't Intel cpus allow cores to individually clock up/down/turn off?).

Like others have said, try with some heavily multithreaded tasks and see if the same problem happens.

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R00KIE
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bitcero

Member

Registered: 2011-11-03

Posts: 6

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

i did a test with mprime and 8 threads at once evidencing the use of 100% of the cores, so I don't think there is any problem with load balancing.

Still makes me curious about the lack of core utilization in other processes that involve databases (ie MySQL) but I guess they have to do with the applications and the use that can make multiple threads and cores of the processor.

To all thank you!

(Marked as solved)

lynix

Member

From: Karlsruhe, Germany

Registered: 2008-04-23

Posts: 230

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

Does anyone of you know why we have CONFIG_HOTPLUG_CPU=y in the stock Arch kernel config?
Seems to me that this is only intended for mainframes n stuff, where you can replace cpus on-the-fly...

fsckd

Forum Fellow

Registered: 2009-06-15

Posts: 4,173

Re: [SOLVED] Intel Core i7 Unbalanced Load ?

lynix, that's completely unrelated to this thread. Start your own. https://wiki.archlinux.org/index.php/Fo … _Hijacking

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