VM warning: Performance bug
karen.kinnear at oracle.com
Thu Dec 15 13:05:40 PST 2011
Actually I am working on a fix for it - see 7105270.
It is "benign" in the sense of correct operation. However, we have an internal customer who has
seen measurable performance loss when they get this warning. So I am working on resizing the
system dictionary if the lookups take "too long".
If you have a way to duplicate it that doesn't require a database - that would make it easier for
me to debug.
On Dec 15, 2011, at 3:38 PM, Tom Rodriguez wrote:
> On Dec 15, 2011, at 12:02 PM, Kelly O'Hair wrote:
>> Anyone seen this message before:
>> OpenJDK 64-Bit Server VM warning: Performance bug: SystemDictionary lookup_count=22915 lookup_length=24212 average=1.056600 load=0.528246
>> Maybe from jdk7u2?
> I think it's fairly benign. It just means that the hashtable for the SystemDictionary isn't performing quite as well as we'd like. It's a little hard to evaluate without knowing how many entries are in the table. I would assume that it just has a lot of classes loaded. It's a somewhat useless message but it's debug only so I guess I wouldn't worry about it.
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