What influences young generation pause times?

Y. Srinivas Ramakrishna y.s.ramakrishna at oracle.com
Tue Apr 20 15:37:08 PDT 2010


On 04/20/10 14:14, Matt Khan wrote:
> 
> perhaps this should be on the runtime list but since it's relevant to 
> this thread I'll ask here....
> 
> I'm periodically getting output like
> 
> RevokeBias                         [     238          0              1] 
>          [     0     0     0]     [     0        7]          0  
> 
> headed by one of these
> 
> Total time for wh [     0     0     0]     [     0       14]          0  
> 
> the lines are overwhelmingly RevokeBias or BulkRevokeBias
> 
> Can you explain what these values are? I'm not especially familiar with 
> the hotspot source code so am unsure where I'd find this info in the src 
> alone.


If you are asking about the columns in each record, check the header
line which should have been printed earlier. If you use a more recent
JVM (hs18) you should see the column headings printed more frequently
than the sole initial appearance in the log produced by older jvm's.

For background on biased locking and associated flags, and what
is involved in bias revocation etc, read
http://portal.acm.org/citation.cfm?doid=1167473.1167496

Experiment with -XX:-UseBiasedLocking if it's not working well for
you, or if it is interfering with your predictability
objectives (read the article for when biased locking may not work well
and how it may affect predictability), and contact your
Java support for further tuning help, questions, to report a
performance bug, etc.

all the best.
-- ramki

> 
> Cheers
> Matt
> 
> Matt Khan
> --------------------------------------------------
> GFFX Auto Trading
> Deutsche Bank, London
> 
> 
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