RFR (S): 8204082: Add indication that this is the "Last Young GC before Mixed" to logs

[Thomas Schatzl]

Hi Stefan,

On Thu, 2018-06-07 at 13:13 +0200, Stefan Johansson wrote:
> Hi Thomas,
> 
> On 2018-06-05 22:26, Thomas Schatzl wrote:
> > Hi,
> > 
> > On Wed, 2018-05-30 at 14:50 +0200, Thomas Schatzl wrote:
> > > Hi all,
> > > 
> > >    can I have reviews for this change that adds an indication
> > > about the "last young" gc before a mixed phase to the logs?
> > > 
[...]
> > > I am not too hung up about naming it "Last Young" in particular,
> > > but I really would like to have this or a similar indication that
> > > is generally available with minimal logging.
> > 
> > Alternatively we could just call it "Mixed" that does not collect
> > any old gen regions at this time. Later we could start gc as soon
> > as the pause time goal permits and add a few old gen regions.
> > 
> 
> I think I like this better than "Last Young" or "Final Young".
> 
> > This would probably be a little confusing to users, but at least
> > help diagnosing logs.
> > 
> > There also has been the suggestion to call it "Final Young" instead
> > of "Last Young".
> > 
> > Any comments?
> 
> Another possible solution, not sure it's better would be to an extra
> tag  to all Young GCs, something like:
> Pause Young (Initial Mark) ...
> Pause Young (Normal) ...
> Pause Young (Finished Mark) ...
> Pause Young (Mixed) ...
> 
> But I guess it's a bit harsh to call the Mixed GCs Young =)

The more I look at it the more I like this variant.

> 
> A third solution would be to somehow use the GC cause to mark this
> state.
> 
> As usual naming is hard, I think I'm leaning towards just calling it 
> Mixed and then we know that the first mixed GC is always young only
> =)

Any other opinions?

Thanks,
  Thomas