On Sat, Aug 24, 2013 at 6:42 AM, richard -rw- weinberger <richard.weinberger@gmail.com> wrote:
On Fri, Aug 23, 2013 at 8:35 PM, Han <keepsimple@gmail.com> wrote:
> Hi,
>
> I am using Linux kernel 2.6.27 for building UML kernel.  It seems like
> "arch/x86/kernel/tsc.c" is not built in and the symbol "cpu_khz" is not
> available.
>
> My question is:  what's the reason that "tsc.c" not included in UML?  Is
> there any config or simple way(patch?)  to include it in UML?

Simply because UML has no TSC.


[Han]  I don't really understand why UML has no TSC.   As I know,  TSC is accessible from user space process (on x86 at least) and I don't see any obvious reason why UML does not support TSC.   I might missed something.  
 
I am trying to add TSC into UML kernel (2.6.27)  for an experiment.   Is that a practical thing to do at all? 

thanks
Han


> I have not tried the same on the newer kernels yet as my target system uses
> 2.6.27 only so I prefer to stick with 2.6.27 if possible.
>
> thanks
> Han
>
>
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--
Thanks,
//richard