6992192: Need option to configure if direct memory is page aligned (XS)

Alan Bateman Alan.Bateman at oracle.com
Fri Oct 15 05:04:40 PDT 2010

David Holmes wrote:
> Alan Bateman said the following on 10/15/10 21:50:
>> David Holmes wrote:
>>> :
>>> Sorry but I don't understand why either of them are VM options when 
>>> it would appear you could just do:
>>> java -Dsun.nio.MaxDirectMemorySize=16M 
>>> -Dsun.nio.PageAlignDirectMemory=true
>> -XX:MaxDirectMemorySize is a long standing VM option, used in my 
>> environments so I don't think we can change it.
> You don't need to change it. All it does is set the property, so the 
> user can do that too. You could deprecate the use of -XX option but it 
> will still be there.
It can't currently be set on the command line as it is overridden by the 
VM. I believe that was the intention when this was added many years ago 
(before my time). I don't have a strong objection to changing this but 
it does mean that we would have to document/support these properties and 
at the same time continue to support the long standing VM option.


More information about the hotspot-runtime-dev mailing list