100% CPU usage in "VM Thread" for Hotspot 10/11 on x64 platform within data processing application

Jon Masamitsu Jon.Masamitsu at Sun.COM
Mon Feb 23 17:20:41 PST 2009

David Sitsky wrote On 02/23/09 16:54,:

>The machine is heavily loaded.  Its a quad-core machine with 8 gigs of 
>memory, however each Java process has a 1g heap size set.  I can see 
>from the task manager I still have free/unused memory on my system, but 
>of course that is not really relevant for the 4 individual JVMs which 
>are running.
>When I say jconsole won't start - this is when I specify the specific 
>process ID.  I can still run other applications on the machine, albeit 
>If I set a 1 gig heap size for a 32-bit process, what would be a very 
>rough rule of thumb that I should set for a 64-bit process?  Another 200 
>megs or so?

Increase the heap by 30%.  Also increase the the perm gen size

Please use -XX:+PrintGCDetails -XX:+PrintGCTimeStamps when gathering the
GC  logs.
If you've already gathering some, send those but in future runs, use the


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