Re: [PATCH 1/5] Add a global synchronization point for pvclock

Avi Kivity
2010-04-23T09:34:45Z

On 04/23/2010 04:44 AM, Zachary Amsden wrote:
> Or apply this patch.
> time-warp.patch
>
>
> diff -rup a/time-warp-test.c b/time-warp-test.c
> --- a/time-warp-test.c 2010-04-15 16:30:13.955981607 -1000
> +++ b/time-warp-test.c 2010-04-15 16:35:37.777982377 -1000
> @@ -91,7 +91,7 @@ static inline unsigned long long __rdtsc
> {
> DECLARE_ARGS(val, low, high);
>
> - asm volatile("cpuid; rdtsc" : EAX_EDX_RET(val, low, high));
> + asm volatile("cpuid; rdtsc" : EAX_EDX_RET(val, low, high) :: "ebx", "ecx");
>
>

Plus, replace cpuid by lfence/mfence. cpuid will trap.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.