Suppress error warning in HotSpot backports

Volker Simonis volker.simonis at
Tue Mar 18 17:53:09 UTC 2014

On Tue, Mar 18, 2014 at 5:39 PM, Andrew Haley <aph at> wrote:
> On 03/18/2014 03:00 PM, Volker Simonis wrote:
>> The warning is OK, just the wording is misleading.
>> The '-XX:MaxPermSize' option is a VM (i.e. HotSpot option) so it only
>> depends on the actual HS version and not on the JDK version.
>> After Oracle decided to not follow the express model any more (i.e.
>> downport new HS versions to old Java releases) for them "8.0" is
>> equivalent to "HS 25".
>> So you could change the wording to say something like "..was removed
>> in this version of HotSpot". But if you run a HS 25 in Java 7 the
>> warning is definitely reasonable and useful because the
>> '-XX:MaxPermSize' option will be simply ignored (because the PermGen
>> is gone).
> Is that ever something other than noise, though?  What use is that
> message to a user?

The message is that the 'MaxPermSize' option became useless and the
user may want to use -XX:MetaspaceSize and/or -XX:MaxMetaspaceSize if
he has special requirements regarding class meta data. And/or he may
wants to rethink his Java memory configuration.

>> So do you plan do release a version of OpenJDK 7 with HS25?
> We sure do.  There's no way that we're back-porting AArch64 to
> HS24.
>> I think we want to do the same for our commercial SAP JVM, although
>> I'm pretty sure this will require some considerable tweaking. And
>> Oracle will be probably reluctant to integrate such changes into
>> HS25, because they don't want to downport it to Java 7 as far as I
>> know. Not to speak about the fact that you'll have to maintain your
>> own 7u-forest
> That's OK.  We can do that.
>> because the official one will probably never contain a HS25.
> Well, that depends.  If some evil security bug comes along that
> requires a chunk 'o rewriting, Oracle may find the motivation.
> But this piece of code just seems wrong to me: it's not that
> unusual to back-port HotSpot releases.

Well, I'm just the messenger, but Oracle folks have been quite clear
in communicating this. And you may have noticed, that the hsx-project
will be dissolved
after jdk8 has been released (which should be actually today:)

> Andrew.

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