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SubjectRe: [PATCH 4/4 TRY#3] optimize and simplify get_cycles_sync()
Joerg Roedel wrote:
> On Fri, Mar 09, 2007 at 08:10:03PM +0200, Avi Kivity wrote:
>
>> Joerg Roedel wrote:
>>
>>> From: Joerg Roedel <joerg.roedel@amd.com>
>>>
>>> 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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