Re: [PATCH 4/4 TRY#3] optimize and simplify get_cycles_sync()

[Avi Kivity]

Joerg Roedel wrote:
> On Fri, Mar 09, 2007 at 08:10:03PM +0200, Avi Kivity wrote:
>   
> > Joerg Roedel wrote:
> >     
> > > From: Joerg Roedel <joerg.roedel@xxxxxxx>
> > >
> > > This patch simplifies the get_cycles_sync() function by removing
> > > the #ifdefs from it. Further it introduces an optimization for AMD
> > > processors. There the RDTSCP instruction is used instead of CPUID;RDTSC
> > > which is helpfull if the kernel runs as a KVM guest. Running as a guest
> > > makes CPUID very expensive because it causes an intercept of the guest.
> > >
> > >  +#define RDTSCP ".byte 0x0f, 0x01, 0xf9"
> > > +	alternative_io_two("cpuid\nrdtsc",
> > > +			   "rdtsc", X86_FEATURE_SYNC_RDTSC,
> > > +			   ".byte 0x0f, 0x01, 0xf9", X86_FEATURE_RDTSCP,
> > >  
> > >       
> > why not use the RDTSCP macro here?
> >     
>
> Does this macro exist? I couldn't found it in the current git tree. And
> the rdtscp macros in msr.h use the plain opcode too.
>   

-ENOCOFFEE?  You defined the macro 3 lines above the .byte directive...


--
error compiling committee.c: too many arguments to function

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