Re: perf hw in kexeced kernel broken in tip

Yinghai Lu
2010-12-08T19:07:40Z

On 12/08/2010 11:01 AM, Don Zickus wrote:
> On Wed, Dec 08, 2010 at 10:43:14AM -0800, Yinghai Lu wrote:
>>
>> can you add sth force_... in command line to take over ownership of perf from BIOS or previous kernel ?
>>
>> then still can use perf etc after we kexec from RHEL or SLES kernel to later kernel ( from 2.6.37)
>
> My understand is that you can't because the BIOS is actively using it
> behind the scenes of the kernel (well during an SMI). I have a machine
> where I tried to force take it but it still stopped triggering interrupts.

how about second case: kexec from RHEL 6 stock kernel to upstream kernel ?

Thanks

Yinghai