Storing both "fasttime" and time in Ticks and Tickspan

[Kim Barrett]

> On Sep 3, 2018, at 10:48 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi Kim,
> 
> On Tue, 2018-08-28 at 20:36 -0400, Kim Barrett wrote:
>>> On Aug 24, 2018, at 8:03 AM, Thomas Schatzl <thomas.schatzl at oracle.
>>> com> wrote:
>>> 
>>> Hi all,
> 
>> [...]
>> So I think the FastUnorderedElapsedCounterSource and everything
>> related to it should be removed.  (I think this includes
>> cpu/x86/rdtsc_x86.[ch]pp and UseFastUnorderedTimeStamps.)
>> 
>> Removing a few milliseconds of sleeping during the initialization of
>> this feature is a nice little startup benefit.
>> 
> 
>  I agree with all that, but I would like to have an opinion from the
> JFR team too about this before doing this.

Agreed.

> The alternative I can see would be having GC specific Ticks/Tickspan
> which I would like to avoid for obvious reasons.

Or JFR-specific variants, and let everyone else do what we think is right.

> Thanks,
>  Thomas