Re: [PATCH] RFC: Linux: disable APERF/MPERF feature in PV kernels

[Andre Przywara <andre.przywara@amd.com>]

On 05/23/2012 11:43 AM, Jan Beulich wrote:
>>>> On 23.05.12 at 11:14, Andre Przywara<andre.przywara@amd.com>  wrote:
>> On 05/23/2012 09:34 AM, Jan Beulich wrote:
>>> Next I'd like to note that in our kernels we simply don't build
>>> arch/x86/kernel/cpu/sched.o. Together with CPU_FREQ being
>>> suppressed, there's no consumer of the feature flag in our
>>> kernels.
>>
>> With "our kernels" you mean OpenSuSE/SLES kernels? I quickly checked
>> upstream as well as the repos on kernel.opensuse.org. In all of them
>> sched.o is unconditionally included in the Makefile.
>> So is there a build patch to exclude this file for builds of distro Xen
>> kernels?
>
> Did you perhaps overlook
>
> disabled-obj-$(CONFIG_XEN) := hypervisor.o mshyperv.o perfctr-watchdog.o \
> 			      perf_event.o sched.o vmware.o
>
> in that very Makefile?

No, I just utterly ignored it ;-)

Thanks for the hint.
But this works only for SuSE since you build different kernels for Xen 
and without Xen, right?
Starting with 3.x I now have only a single kernel image which I use for 
both native and as Dom0.

So the patch to disable APERFMPERF is still useful, at least for 
upstream, right?

Regards,
Andre.


-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany