RFR(M): 8155634: Clean out old logging and dead code from SurvRateGroup

[Thomas Schatzl]

Hi all,

On Tue, 2016-05-03 at 09:58 +0200, Mikael Gerdin wrote:
> Hi Jon,
> 
> On 2016-05-02 20:58, Jon Masamitsu wrote:
> > 
> > 
[...]
> > 
> > 
> > I don't have much of an opinion on whether the survivor rate
> > summary is useful but I note that
> > 
> > http://cr.openjdk.java.net/~mgerdin/8155634/webrev.0/src/share/vm/g
> > c/g1/g1CollectedHeap.cpp.udiff.html
> > 
> >   void G1CollectedHeap::print_tracing_info() const {
> >     g1_rem_set()->print_summary_info();
> >     concurrent_mark()->print_summary_info();
> > - g1_policy()->print_yg_surv_rate_info();
> >   }
> > 
> > the remembered set and concurrent marking summaries are being kept.
> > Can you explain why survivor rate is the exception?  All seems to
> > me averages over such an extended period that they all deserve the
> > same fate.
>
> The reason is simply that I wanted to clean up how SurvRateGroups
> were used but understanding which parts of the class actually did
> some work was extremely difficult due to the fact that 50% of the
> code was only there to facilitate the logging.
> 
> In general I think we should remove the other summary infos as well
> but from my end this is more on an as-needed effort than a focused
> cleanup of these summary info outputs.
> 
> I don't think I have the cycles to get rid of the others before FC so
> I expect that the remaining ones will have to wait for the next
> release.

  I kind of agree with all of the above. I created JDK-8155922. (And I
am fine with this change)

Thanks,
  Thomas