JNI Weak Reference

Bill Hastings bllhastings at gmail.com
Wed Feb 4 23:51:23 UTC 2015


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
>>
>>
>>
>
>
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