[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] xen/acpi-stub: Disable it b/c the acpi_processor_add is no longer called.



I think, Xen can get C and P states from ACPI itself.
Why is Dom0 needed as a dependency at all?

Christoph

On 22.03.13 15:28, Konrad Rzeszutek Wilk wrote:
With the Xen ACPI stub code (CONFIG_XEN_STUB=y) enabled, the power
C and P states are no longer uploaded to the hypervisor.

The reason is that the Xen CPU hotplug code: xen-acpi-cpuhotplug.c
and the xen-acpi-stub.c register themselves as the "processor" type object.

That means the generic processor (processor_driver.c) stops
working and it does not call (acpi_processor_add) which populates the

          per_cpu(processors, pr->id) = pr;

structure. The 'pr' is gathered from the acpi_processor_get_info function
which does the job of finding the C-states and figuring out PBLK address.

The 'processors->pr' is then later used by xen-acpi-processor.c (the one that
uploads C and P states to the hypervisor). Since it is NULL, we end
skip the gathering of _PSD, _PSS, _PCT, etc and never upload the power
management data.

The end result is that enabling the CONFIG_XEN_STUB in the build means that
xen-acpi-processor is not working anymore.

This temporary patch fixes it by marking the XEN_STUB driver as
BROKEN until this can be properly fixed.

CC: jinsong.liu@xxxxxxxxx
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
  drivers/xen/Kconfig | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 5a32232..67af155 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -182,7 +182,7 @@ config XEN_PRIVCMD

  config XEN_STUB
        bool "Xen stub drivers"
-       depends on XEN && X86_64
+       depends on XEN && X86_64 && BROKEN
        default n
        help
          Allow kernel to install stub drivers, to reserve space for Xen 
drivers,



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.