Re: [BISECTED] 2.6.35.*: horrible (exponential? >linear) slowdown tounusability (HPET)

[John Drescher]

On Thu, Sep 9, 2010 at 7:57 PM, Nix <nix@xxxxxxxxxxxxx> wrote:
> On 10 Sep 2010, John Drescher spake thusly:
>
>>> John, Damien, you seem to be experiencing this: are you using HPET as
>>> your clocksource? Do you also have ICH10 82801JIs, or is this more
>>> widespread?
>>>
>> I am not using hpet as my clocksource.
>>
>> jmd1 ~ # uname -a
>> Linux jmd1 2.6.35-std160-amd64 #2 SMP Fri Aug 13 18:42:02 UTC 2010
>> x86_64 Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz GenuineIntel GNU/Linux
>> jmd1 ~ # cat /sys/devices/system/clocksource/clocksource0/current_clocksource
>> tsc
>
> Hm, interesting. Perhaps the HPET is needed anyway? (That would explain
> why my other system, with identical specs to those above and using tsc
> as clocksource, was seeing intermittent problems in this area.)
>
> But 82801JI looks like a common factor.

Now the interesting part. I switched to acpi_pm 10 to 15 minutes ago
using the following command

jmd1 ~ # echo acpi_pm
>/sys/devices/system/clocksource/clocksource0/current_clocksource

and it was still slow. But now its running fast (well at lest as far
as I can tell via a ssh connection).

John
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