From: Florian Pritz on
Hi,

When I run make -j12 (on a kernel tree) all 8 cores are at 100% each.
(Can also be tested with stress -c 8 or any multithreaded program)
After a suspend2ram (using pm-suspend) only one single core is at 100%
and the others are somewhere between 0% and 10% though not 100% like
before.

This bug is reproduceable on at least 3 machines, running on i7-920,
i7-860 and i5-520M.
Tested kernels are 2.6.33-ARCH (config [1]) , 2.6.32.9-ARCH and
2.6.34-rc1-00005-g522dba7 (only be me; config [2]).

/proc/cpuinfo shows 8 cpus before and after suspend.

My own hardware:
CPU: Intel i7-920
Board: Gigabyte GA-EX58-UD4P [3]
RAM: 8GB
Arch: x86_64 (all 3)
Distribution: Archlinux (all 3)

I don't know of any older good kernel, so sadly can't bisect anything.

Thanks for looking into that issue.

[1]
http://repos.archlinux.org/wsvn/packages/kernel26/trunk/config.x86_64?rev=70484&peg=70484
[2] http://flo.xssn.at/~flo/tmp/kernel-config
[3]
http://www.gigabyte.com.tw/Products/Motherboard/Products_Overview.aspx?ProductID=2986

--
Greetings,
Florian Pritz -- {flo,bluewind}@server-speed.net
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From: Rafael J. Wysocki on
Hi,

Here's an interesting issue, apparently Core i5 and i7 have problems after
resume from suspend/standby.

I wonder whom at Intel I should let know about that.

Rafael


On Thursday 18 March 2010, bugzilla-daemon(a)bugzilla.kernel.org wrote:
> http://bugzilla.kernel.org/show_bug.cgi?id=15559
>
>
>
>
>
> --- Comment #3 from Thomas B├Ąchler <thomas(a)archlinux.org> 2010-03-18 18:42:26 ---
> I have only tested 2.6.33 and 2.6.33.1, as this machine is quite new. Besides
> other unrelated suspend problems, I can always reproduce this one on a Core
> i5-520M, the symptoms are exactly the ones that Florian describes.
>
> The diversity of hardware and different kernels here suggests that this is a
> general problem with the i5 and i7 CPUs on Linux. Also interesting is that
> Florian is using an i7 of the 2009 generation, while I use the 2010 i5 CPU and
> the bug is the same on both.
>
> On the same kernel(s), my old Core 2 Duo CPU has no trouble after resume, all
> cores are still being used as usual.
>
> If you need any more info, I think we will be able to provide anything you
> need. Maybe it might also be useful to bring someone from Intel in on this.
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