RFR (XS) JDK-8153582 Logging of ConcGCThreads is done too early

[Dmitry Fazunenko]

Hi Joe,

> @requires vm.gc=="ConcMarkSweep" | vm.gc=="G1" | vm.gc=="null"

Will not help unfortunately :(

This test will fail on minimal VM where serial is always selected
You need:
   @requires vm.flavor != "minimal"


The way you spawn a new VM ignores external flags:

    pb = ProcessTools.createJavaProcessBuilder("-XX:+" + gcFlag, "-Xlog:gc=debug", "-version");

It's recommended to NOT ignore external flags:
    pb = ProcessTools.createJavaProcessBuilder(*true, *"-XX:+" + gcFlag, "-Xlog:gc=debug", "-version");

But in this case the test will not work if either G1 or CMS is set explicitly:
   verifyNumberOfConcurrentAndParallelGCThreads(null);
   verifyNumberOfConcurrentAndParallelGCThreads("UseG1GC");
   verifyNumberOfConcurrentAndParallelGCThreads("UseConcMarkSweepGC");
either second or third case will fail because of collector conflict.
To avoid collector conflicts you need:
   @requires vm.gc=="null"

But in this case,

   verifyNumberOfConcurrentAndParallelGCThreads(null);
will fail if ergonomics will select Serial or Parallel...


What I suggest

add:
   @requires vm.flavor != "minimal"
   @requires vm.gc=="null"

get rid of the null case
   40         verifyNumberOfConcurrentAndParallelGCThreads(null);
   41
   42         verifyNumberOfConcurrentAndParallelGCThreads("UseG1GC");
   43
   44         verifyNumberOfConcurrentAndParallelGCThreads("UseConcMarkSweepGC");

->
              verifyNumberOfConcurrentAndParallelGCThreads("UseG1GC");
              verifyNumberOfConcurrentAndParallelGCThreads("UseConcMarkSweepGC");


don't ignore external flags:
   50         if (gcFlag != null) {
   51             pb = ProcessTools.createJavaProcessBuilder("-XX:+" + gcFlag, "-Xlog:gc=debug", "-version");
   52         } else {
   53             pb = ProcessTools.createJavaProcessBuilder("-Xlog:gc=debug", "-version");
   54         }
-->
              pb = ProcessTools.createJavaProcessBuilder(*true*, "-XX:+" + gcFlag, "-Xlog:gc=debug", "-version");
  

Thanks,
Dima


On 18.05.2016 11:12, Thomas Schatzl wrote:
> Hi again,
>
> On Wed, 2016-05-18 at 10:09 +0200, Thomas Schatzl wrote:
>> Hi Joe,
>>
>> On Tue, 2016-05-17 at 15:17 -0400, Joseph Provino wrote:
>>> I changed the log level to debug and added created a test.
>>>
>>> Webrev:  http://cr.openjdk.java.net/~jprovino/8153582/webrev.01
>>>
>>    in the test, please limit the allowable GCs to CMS and G1. I do not
>> think it makes sense to call the test with other GCs.
>>
>> Like
>>
>> @requires vm.gc=="ConcMarkSweep" | vm.gc=="G1" | vm.gc=="null"
> Also the copyright date should be 2016 only.
>
>> I do not need a re-review for this change.
> Still applies.
>
> Thanks,
>    Thomas