Re: [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible

Ingo Molnar
2011-03-26T09:57:33Z

* Eric Dumazet <eric.dumazet@gmail.com> wrote:

> > > > By doing the above the BIOS should release the performance counter, and
> > > > the kernel's "perf" should not encounter a conflict.
> > > >
> > > > The document that you are looking for is here: (please see page 8 and
> > > > later):
> > > > http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01804533/c01804533.pdf
>
> Thanks Peter !
>
> I was not aware of the hidden "CTRL-A" feature on RBSU, so I never met these
> configuration settings ("Service Options" added in main menu)
>
> I already was in "Power regulator mode : Static High mode" QPI Link power
> management : Disabled
>
> I have latest released I24 BIOS
> DMI: HP ProLiant BL460c G6, BIOS I24 01/29/2011
>
> 1) I disabled "Power and Utilization Monitoring" _and_ "Memory
> Pre-Failure Notification"
>
> Still I got the 'MSR 38d is 330' error
>
> 2) I then disabled Intel Turbo boost
>
> Same error
>
> 3) Minimum Processor idle Power state
> From C1E-State --> No C-states
>
> Same error
>
> Tricky isnt it ?

This kind of user-configurability reminds me of Mr. Prosser from the local
council who wants to knock down Arthur Dent’s house with a bulldozer to make
way for a new bypass:

"But the plans were on display ..."

"On display? I eventually had to go down to the cellar to find them."

"That's the display department."

"With a flashlight."

"Ah, well the lights had probably gone."

"So had the stairs."

"But look, you found the notice didn't you?"

"Yes," said Arthur, "yes I did. It was on display in the bottom of a locked
filing cabinet stuck in a disused lavatory with a sign on the door saying
'Beware of the Leopard'."

Ingo