Re: [git pull request] ACPI Processor Aggregator Driver for 2.6.32-rc1

Rafael J. Wysocki
2009-10-03T20:48:36Z

On Saturday 03 October 2009, Len Brown wrote:
> Hi Linus,
>
> please pull from:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6.git acpi-pad
>
> This will add the ACPI Processor Aggregator Driver to the kernel.
> acpi_pad implements a new ACPI feature where the baseboard management
> controller can ask Linux to force busy processors to stay idle.
>
> The BMC does this under dire electrical or thermal conditions
> after it has already lowered the P-state to low frequencey mode
> on all processors, yet the emergency persists. This offline
> technique is used before employing even more invasive measures,
> such as taking T-states down to 1/8th of LFM, or powering-off
> the server completely.
>
> This driver will have no effect on the installed base,
> no no old systems implement this new feature. However, this
> simle driver in Linux will be useful as this feature
> is deployed by OEMs on new hardware.
>
> As I mentioned previously, this is an ACPI patch, not a scheduler patch.
> PeterZ is hoping to implement a more sophisticated method for forcing
> idle time in the system with the scheduler, and when that is available,
> I'll be delighted to update this driver to invoke it.
>
> thanks!
>
> --
> Len Brown
> Intel Open Source Technology Center
>
>
> ps. individual patches are available on linux-acpi@vger.kernel.org
> and a consolidated plain patch is available here:
> http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/patches/2.6.31/acpi-acpi-pad-20090521-2.6.31-rc4.diff.gz
>
> MAINTAINERS | 8 +
> drivers/acpi/Kconfig | 12 +
> drivers/acpi/Makefile | 2 +
> drivers/acpi/acpi_pad.c | 514 +++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 536 insertions(+), 0 deletions(-)
> create mode 100644 drivers/acpi/acpi_pad.c
>
> through these commits:
>
> Len Brown (1):
> acpi_pad: build only on X86
>
> Shaohua Li (1):
> ACPI: create Processor Aggregator Device driver
>
> with this log:
>
> commit d91f79ebc3191b15dbe385925af4840f4e68df77
> Author: Len Brown <len.brown@intel.com>
> Date: Sun Sep 27 02:35:55 2009 -0400
>
> acpi_pad: build only on X86
>
> X86_FEATURE_MWAIT doesn't exist on ia64...
>
> Signed-off-by: Len Brown <len.brown@intel.com>
>
> commit 8e0af5141ab950b78b3ebbfaded5439dcf8b3a8d
> Author: Shaohua Li <shaohua.li@intel.com>
> Date: Mon Jul 27 18:11:02 2009 -0400
>
> ACPI: create Processor Aggregator Device driver

Can you please point me to the mailing list thread there this driver was
posted (and possibly reviewed and discussed)?

Best,
Rafael