GetPrimitiveArrayCritical vs GetByteArrayRegion: 140x slow-down using -Xcheck:jni and java.util.zip.DeflaterOutputStream

[Ian Rogers]

Thanks for accepting these as bugs/RFEs:

"140x slow-down using -Xcheck:jni and java.util.zip.DeflaterOutputStream"
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8199920

"Deprecate JNI critical APIs"
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8199919

"Report tardy threads as potential TTSP issues"
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8199921

"With -Xcheck:jni warn when a JNI critical region is "too long""
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8199922

"Reduce size of JNI critical regions in JDK (for example via loop strip
mining)"
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8199916

Ian



On Tue, Mar 20, 2018 at 7:07 PM Ian Rogers <irogers at google.com> wrote:

> Thanks, via bugreport.java.com I filed bugs/RFEs with ids 9053047,
> 9053048, 9053049, 9053050 and 9053051.
> Ian
>
> On Mon, Mar 19, 2018 at 2:28 AM Thomas Schatzl <thomas.schatzl at oracle.com>
> wrote:
>
>> Hi,
>>
>> On Fri, 2018-03-16 at 17:19 +0000, Ian Rogers wrote:
>> > Thanks Paul, very interesting.
>> >
>> > On Fri, Mar 16, 2018 at 9:21 AM Paul Sandoz <paul.sandoz at oracle.com>
>> > wrote:
>> > > Hi Ian, Thomas,
>> > >
>> > > [...]
>> > > (This is also something we need to consider if we modify buffers to
>> > > support capacities larger than Integer.MAX_VALUE. Also connects
>> > > with Project Panama.)
>> > >
>> > > If Thomas has not done so or does not plan to i can log an issue
>> > > for you.
>> > >
>> >
>> > That'd be great. I wonder if identifying more TTSP issues should also
>> > be a bug. Its interesting to observe that overlooking TTSP in C2
>> > motivated the Unsafe.copyMemory change permitting a fresh TTSP issue.
>> > If TTSP is a 1st class issue then maybe we can deprecate JNI critical
>> > regions to support that effort :-)
>>
>> Please log an issue. I am still a bit unsure what and how many issues
>> should be filed.
>>
>> @Ian: at bugreports.oracle.com everyone may file bug reports without
>> the need for an account.
>> It will take some time until they show up in Jira due to vetting, but
>> if you have a good case, and can e.g. link to the mailing list, this
>> should be painless.
>>
>> Thanks,
>>   Thomas
>>
>>