RFR: JDK-8151912: guarantee(GCPauseIntervalMillis >= 1) failed: Constraint for GCPauseIntervalMillis should guarantee that value is >= 1

Thomas Schatzl thomas.schatzl at oracle.com
Wed Mar 16 14:21:05 UTC 2016


Hi,

On Wed, 2016-03-16 at 15:07 +0100, Bengt Rutisson wrote:
> Hi all,
> 
> Could I have a couple of reviews for this change?
> 
> http://cr.openjdk.java.net/~brutisso/8151912/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8151912
> 
> The problem is that we do this during setup of G1CollectorPolicy:
> 
>      FLAG_SET_DEFAULT(GCPauseIntervalMillis, MaxGCPauseMillis + 1);
> 
> If MaxGCPauseMillis is max uint we will overflow and 
> GCPauseIntervalMillis will be 0.
> 
> Before JDK-8151604 we did not notice this overflow.
> 
> The proposed change reduces the max value for MaxGCPauseMillis to 
> max_uint - 1. I think it can be argued that we should have a more 
> reasonable max value, but I don't have a good suggestion for what
> that 
> value would be. So, for now, to fix the current failures in nightly 
> testing, I propose to just reduce it to the largest value that we can
> actually handle.

  Looks good.

Thomas



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