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

Ian Rogers irogers at google.com
Wed Mar 21 17:05:01 UTC 2018

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.MAXVALUE. 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

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