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

["Joerg Roedel" <joerg.roedel@amd.com>]

On Mon, Mar 12, 2007 at 02:29:43PM +0100, Michael Matz wrote:
> Hi Joerg,
> 
> On Mon, 12 Mar 2007, Joerg Roedel wrote:
> 
> > > >+#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?
> 
> Look carefully at your patch again, or at least the four quoted lines 
> above.  You've added it yourself, in exactly the form you'd need in the 
> alternative_io_two() call :-)

Hmmkay, thanks for opening my eyes :-)
I considered defining this macro while writing this patch, but decided
against this because the X86_FEATURE_RDTSCP on the same line should
documenting the opcode sufficiently. I just forgot to remove that
#define :)

Thanks again,
Joerg

-- 
Joerg Roedel
Operating System Research Center
AMD Saxony LLC & Co. KG