Hi Julia,
Thanks for your reminder about rules to access throttling
registers.
CPU idle notificatication should be a long lived component
because it's a pure software interface and could also be used by
components other than FIPE.
For FIPE driver itself, it will only be used to support Intel
5000/7300 chipsets and won't be used on later Intel chipsets/CPUs.
For future memory power management, I think it would be better to
adopt ACPI interfaces other than directly talking to hardware.
Regards
--Gerry
Julia.Harper at Sun.COM <mailto:Julia.Harper at Sun.COM> wrote:
> Gerry --
>
> I see the FIPE driver directly modifies the throttling
> registers in the memory controller.
>
> Although there is no issue in doing this in Intel systems
> with a 7300 or 5000 series Memory Controller Hub, I want
> bring up that OS configuring and enabling throttling
> registers in later (Nehalem-based) Intel systems should be
> avoided. System designers assume that BIOS and/or the
> service processor have ownership of throttling behavior.
> Throttling may be used for managing system issues the OS is
> not aware of. If the OS and the layer beneath the OS both
> attempt to use throttling for different purposes, this could
> cause a problem.
>
> Do you see the cpu idle notification / FIPE driver solution
> as a long lived approach to memory power management?
>
> -- jdh
>
>
> Liu, Jiang wrote:
>> Hi buddies,
>> I have developed a device driver for Intel 5000/7300 chipset
>> which puts memory into power saving state when system is idle.
>> Could you please help to review it? Webrev is at
>> http://cr.opensolaris.org/~gerry/fipe_20090408/.
>> There are two main parts in the webrev. The first one is
>> enhancement to dcopy/ioat driver to support FIPE. The second one is
>> FIPE driver it self. Thanks!
>> Liu Jiang (Gerry)
>> Senior Software Engineer
>> OpenSolaris, OTC, SSG, Intel
>> Tel: (8610)82171643
>> iNet: 8-758-1643
>> Location: Raycom 9W013
>> _______________________________________________
>> tesla-dev mailing list
>> tesla-dev at opensolaris.org
>> http://mail.opensolaris.org/mailman/listinfo/tesla-dev
Liu Jiang (Gerry)
OpenSolaris, OTC, SSG, Intel
