JNI Weak Reference

Bill Hastings bllhastings at gmail.com
Fri Feb 6 00:26:03 UTC 2015


Perhaps changing it in a JDK8 update release would be great. I have not
Oracle support.

On Thu, Feb 5, 2015 at 5:14 AM, charlie hunt <charlie.hunt at oracle.com>
wrote:

>  I don't know much about how "patching" works, or if "patching" is
> something that is offered. :-(
>
> Perhaps someone else on this mailing list knows?
>
> Or, perhaps you are asking for a change to be introduced in a JDK 8 update
> release?
>
> My first reaction was that I was assuming you have an Oracle support
> contract. If that's the case, then talking to your Oracle sales rep may be
> the place to start?  Caveat: I also do not know much about how the support
> contract or sustaining side of the house works.
>
> Sorry to be of little help!
>
> charlie
>
>
> On 02/04/2015 05:51 PM, Bill Hastings wrote:
>
> Can this be patched? Because we see this very often in our environment.
>
>  Regards
> Avinash
>
> On Wed, Feb 4, 2015 at 12:46 PM, charlie hunt <charlie.hunt at oracle.com>
> wrote:
>
>> Filed as: https://bugs.openjdk.java.net/browse/JDK-8072498
>>
>>  charlie
>>
>>  On Feb 3, 2015, at 7:03 PM, Srinivas Ramakrishna <ysr1729 at gmail.com>
>> wrote:
>>
>>  Yes, unfortunately, I don't think Jni refs procsing is parallelized,
>> but should be. Please file a bug...
>>
>>  --- Ramki
>>
>>
>> ysr1729
>>
>> On Feb 3, 2015, at 16:19, Bill Hastings <bllhastings at gmail.com> wrote:
>>
>>   Yes -XX:+ParallelRefProcEnabled is enabled.
>>
>>  Thanks
>> Bill.
>>
>> On Tue, Feb 3, 2015 at 4:09 PM, charlie hunt <charlie.hunt at oracle.com>
>> wrote:
>>
>>>  You might try enabling -XX:+ParallelRefProcEnabled.
>>>
>>> This will enable multi-threaded reference processing.
>>>
>>> User CPU time vs real time coupled with the JNI Weak Reference time
>>> suggests single threaded reference processing.
>>>
>>> hths,
>>>
>>> charlie
>>>
>>>
>>> On 02/03/2015 05:20 PM, Bill Hastings wrote:
>>>
>>> Periodically get this in my CMS GC log:
>>>
>>> 2015-02-03T03:24:27.419-0800: 17917.047: [Rescan (parallel) , 0.0625400
>>> secs]2015-02-03T03:24:27.482-0800: 17917.110: [weak refs
>>> processing2015-02-03T03:24:27.482-0800: 17917.110: [SoftReference, 1 refs,
>>> 0.0010820 secs]2015-02-03T03:24:27.483-0800: 17917.111: [WeakReference, 0
>>> refs, 0.0015340 secs]2015-02-03T03:24:27.484-0800: 17917.112:
>>> [FinalReference, 0 refs, 0.0007930 secs]2015-02-03T03:24:27.485-0800:
>>> 17917.113: [PhantomReference, 0 refs, 0.0008860
>>> secs]2015-02-03T03:24:27.486-0800: 17917.114: [*JNI Weak Reference,
>>> 6.1104040 secs], 6.1148360 secs*]2015-02-03T03:24:33.596-0800:
>>> 17923.225: [scrub string table, 0.0006670 secs] [1 CMS-remark:
>>> 531682K(5242880K)] 1827698K(7759488K), 6.1785190 secs] [Times: user=7.22
>>> sys=0.00, real=6.18 secs]
>>>
>>>  JNI Weak References processing take several seconds. How do I remedy
>>> this? I use JNA but I do not use any WeakReference classes in my
>>> application.
>>>
>>>  Regards
>>>  Bill
>>>
>>>
>>>
>>
>>
>
>


-- 
Cheers
Bill
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