Bug in G1GC it performs Full GC when code cache is full resulting in overkill

[Charlie Hunt]

Hi Martin,

There's a few cmd line options in your list that you likely don't need.  We'll address in a different email.

Do you have GC logs you can share that exhibit the "unexpected Full GC" with G1 ?  At a minimum several GC events before the Full GC event, and a couple after.

thanks,

charlie ...

On May 26, 2013, at 10:20 AM, Martin Makundi wrote:

> Sorry, forgot to mention, using:
> 
> java version "1.7.0_21"
> Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
> Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)
> 
> Linux version 3.0.1.stk64 (dfn at localhost.localdomain) (gcc version
> 4.5.1 20100924 (Red Hat 4.5.1-4) (GCC) ) #1 SMP Sat Aug 13 12:53:46
> EDT 2011
> 
> -Dclassworlds.conf=/usr/share/maven/maven/bin/m2.conf
> -Dmaven.home=/usr/share/maven/maven
> -Duser.timezone=EET
> -XX:+AggressiveOpts
> -XX:+DisableExplicitGC
> -XX:+ParallelRefProcEnabled
> -XX:+PrintGCDateStamps
> -XX:+PrintGCDetails
> -XX:+PrintHeapAtGC
> -XX:+UseAdaptiveSizePolicy
> -XX:+UseCompressedOops
> -XX:+UseFastAccessorMethods
> -XX:+UseG1GC
> -XX:+UseGCOverheadLimit
> -XX:+UseNUMA
> -XX:+UseStringCache
> -XX:CMSInitiatingOccupancyFraction=70
> -XX:GCPauseIntervalMillis=10000
> -XX:InitiatingHeapOccupancyPercent=0
> -XX:MaxGCPauseMillis=500
> -XX:MaxPermSize=512m
> -XX:PermSize=512m
> -XX:ReservedCodeCacheSize=48m
> -Xloggc:gc.log
> -Xmaxf1
> -Xms30G
> -Xmx30G
> -Xnoclassgc
> -Xss4096k
> 
> 
> **
> Martin
> 
> 2013/5/26 Charlie Hunt <chunt at salesforce.com>:
>> Which version of the JDK/JRE are you using?
>> 
>> One of the links you referenced below was using JDK 6, where there is no official support for G1. The other link suggests it could have been RMI DGC or a System.gc().
>> 
>> 
>> 
>> Sent from my iPhone
>> 
>> On May 25, 2013, at 11:43 PM, "Martin Makundi" <martin.makundi at koodaripalvelut.com> wrote:
>> 
>>> it occurs daily.