Request for review (s) : 8017462: G1: guarantee fails with UseDynamicNumberOfGCThreads

[Thomas Schatzl]

Hi Jon,

On Thu, 2015-03-19 at 06:50 -0700, Jon Masamitsu wrote:
> On 3/10/2015 11:45 AM, Thomas Schatzl wrote:
> > Hi Jon,
> >
> > On Tue, 2015-03-10 at 09:26 -0700, Jon Masamitsu wrote:
> >> 8017462: G1: guarantee fails with UseDynamicNumberOfGCThreads
> >>
> >> https://bugs.openjdk.java.net/browse/JDK-8017462
> >>
> >> When fewer than the maximum number of threads was being used for
> >> a parallel section, phase times for the threads that did not execute and
> >> averages for the phase were misleading.  The fix passes the active number of
> >> GC threads  to the G1 phase timers.
> >>
> >> http://cr.openjdk.java.net/~jmasa/8017462/webrev.00/
> >>
> >> Tested with gc_test_suite.
> > - I would somewhat prefer if _active_threads would not be stored in
> > every WorkerDataArray. This seems a waste of space. G1GCPhaseTimes
> > already store
[..]
> > - is it possible to create a test for G1 that runs with
> > G1LogLevel=finest and parses and verifies output of one GC phase that
> > takes at least some time? I.e. that you have active_workers amount of
> > durations in that line and the sum matches more or less.
> 
> I'd like to address this with a separate CR.  Would that be satisfactory?

Okay.

Thomas