On Wed, Aug 31, 2022, Jim Mattson wrote:
> On Wed, Aug 31, 2022 at 7:31 AM <cgel.zte@xxxxxxxxx> wrote:
> > diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> > index 0cbc71b7af50..75920678f34d 100644
> > --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> > +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> > @@ -237,7 +237,6 @@ static inline uint64_t get_desc64_base(const struct desc64 *desc)
> > static inline uint64_t rdtsc(void)
> > {
> > uint32_t eax, edx;
> > - uint64_t tsc_val;
> > /*
> > * The lfence is to wait (on Intel CPUs) until all previous
> > * instructions have been executed. If software requires RDTSC to be
> > @@ -245,8 +244,8 @@ static inline uint64_t rdtsc(void)
> > * execute LFENCE immediately after RDTSC
> > */
> > __asm__ __volatile__("lfence; rdtsc; lfence" : "=a"(eax), "=d"(edx));
> > - tsc_val = ((uint64_t)edx) << 32 | eax;
> > - return tsc_val;
> > +
> > + return ((uint64_t)edx) << 32 | eax;
> > }
>
> This does beg the question: "Why?"
Yeah, for this one I think having a local variable adds value.
