JDK-6291341: jstat: FGC counter confusing when CMS GC is used
yasuenag at gmail.com
Wed Mar 9 12:41:55 UTC 2016
> The jdk changes look good to me.
>> Meaning, without the jdk changes, will jstat continue to work
>> as it currently does?
I uploaded new webrev. I updated webrev for hotspot only:
This patch works the same as the current by default.
If you set -XX:+EnableConcGCPerfCounter, CGC counter will work fine.
(I want to set +EnableConcGCPerfCounter by default :-) )
>> Would the changes in the JVM be useful to you without the jstat changes?
We can override jstat_options if we want to watch CGC counters.
Also we can check it through PerfCounter.print jcmd.
I'm developing JVMTI agent  which uses sun.gc.collector PerfCounters.
Our agent watches major collection through PerfCounter and JVMTI events.
Thus I'm sure that this change is very useful for us.
On 2016/03/09 16:13, Staffan Larsen wrote:
> The jdk changes look good to me. Jon, if you integrate the JVM changes you can do the jdk changes at the same time in the hs-rt repo.
>> On 8 mars 2016, at 23:08, Jon Masamitsu <jon.masamitsu at oracle.com> wrote:
>> We're discussing this.
>> What would the result be if the GC team made the
>> JVM changes that you want to contribute. Meaning,
>> without the jdk changes, will jstat continue to work
>> as it currently does? Would the changes in the JVM
>> be useful to you without the jstat changes? By the
>> JVM changes, I mean the changes for the counters.
>> The reason I ask is that the GC team does not
>> own jstat. If I can integrate the JVM changes
>> without the jstat changes, it makes it a little
>> On 3/8/2016 6:38 AM, Yasumasa Suenaga wrote:
>>> Hi all,
>>> I discussed about FullGC counter for Concurrent GC:
>>> I found same issue on JBS:
>>> JDK-6291341: jstat: FGC counter confusing when CMS GC is used
>>> JDK-6291341 was closed with Cannot Reproduce.
>>> However, I showed cause of this issue in above thread.
>>> I uploaded patches for this issue:
>>> JDK webrev includes testcase update.
>>> All tests for jstat work fine.
>>> Should I work for it as new issue? Or should I reopen JDK-6291341?
>>> I cannot access JPRT.
>>> So I need a sponsor.
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