Re: [Xen-devel] Re: [PATCH 3/5] x86/pvclock: add vsyscall implementation

Chris Mason
2009-10-29T13:03:56Z

On Thu, Oct 29, 2009 at 02:13:50PM +0200, Avi Kivity wrote:
> On 10/28/2009 07:47 PM, Jeremy Fitzhardinge wrote:
> >>Much better to have an API for this. Life is hacky enough already.
> >My point is that if an app cares about property X then it should just
> >measure property X. The fact that gettimeofday is a vsyscall is just an
> >implementation detail that apps don't really care about. What they care
> >about is whether gettimeofday is fast or not.
>
> But we can not make a reliable measurement.

I can't imagine how we'd decide what fast is? Please don't make the
applications guess.

-chris