Liu, Jiang wrote:

> Li, Aubrey <> wrote:
>> tesla-dev-bounces at opensolaris.org wrote:
>> 
>>> Mark Haywood <> wrote:
>>>> Mark Haywood wrote:
>>>>> Li, Aubrey wrote:
>>>>>> Hi Andrei,
>>>>>> 
>>>>>> Andrei Dorofeev wrote:
>>>>>> 
>>>>>> 
>>>>>>> Aubrey,
>>>>>>> 
>>>>>>> What version of the X8DTN BIOS are you using?  I have filed
>>>>>>> this issue back in February on premier.intel.com and it
>>>>>>> should've been resolved by now.   Do you see this with BIOS
>>>>>>> version 3059W? 
>>>>>>> 
>>>>>> 
>>>>>> Right, right, the version is 3059W! And this is the newest
>>>>>> version. From the BIOS changelog, they tested windows, redhat
>>>>>> linux, I'm not sure if they care about what solaris reported, :(
>>>>>> 
>>>>>> 
>>>>>>> Don't give up on using _PSD because of this.
>>>>>>> 
>>>>>> 
>>>>>> I believe before NHM, _PSD is seldom implemented. Using the
>>>>>> vendor specific CPU topology should be an acceptable way to
>>>>>> build domain info. I admit I don't have the knowledge about the
>>>>>> other CPU vendor, like SPARC and AMD, what's the benefit of
>>>>>> using _PSD? Othering than introducing panic, ;)
>>>>>> 
>>>>> 
>>>>> That's a very good question. What is the benefit of the _PSD? I
>>>>> believe the _PSD was introduced to prevent Solaris and other
>>>>> operating systems from having to do exactly what you are proposing
>>>>> (i.e., introducing vendor specific details of processor state
>>>>> domains into the operating system). The _PSD is supposed to define
>>>>> a standard way for operating systems to digest the domain data.
>>>>> Unless there is a really compelling reason to ignore the _PSD, I
>>>>> would suggest that we continue to use it.
>>>> 
>>>> How about a compromise. Since the _PSD often doesn't exist, we have
>>>> to be able to determine the domains from the topology. Since we
>>>> have to do this anyway, why don't we digest the _PSD and verify it
>>>> afterwards using the topology. Why do this? So that we can report
>>>> bad _PSDs to the BIOS developers so that the _PSDs become more
>>>> reliable in the future. If a faulty _PSD is identified we can log a
>>>> message to the console and use domains built from the topology. At
>>>> some point it would be nice if we didn't have to continue
>>>> determining the domains using topology. Sound reasonable?
>>> That sounds a good suggestion. In early stage, we may need to reveal
>>> bugs in BIOS implementation and push BIOS to behave correctly.
>>> Eventually BIOS should be robust enough so we could switch to BIOS.
>>> If we give up _PSD, it seems we are on the opposite side of
>>> ACPI spect then.
>>> 
>> 
>> BIOS is not ACPI, hehe. If we use topology to check, why not use it
>> at all? why we need to verify BIOS bug?  Anyway, the suggestion works
>> to me.
> 
> The idea here is to help BIOS/ACPI to become mature and then we could
> rely on it. And I feel it would be better to base our
> implementation on ACPI instead
> of vendor specific information because that would eventually save our
> efforts to maintain cpupm driver.
> 

Sunds reasonable to me, :)

Thanks,
-Aubrey

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