Shenandoah Events

[Ken Dobson]

Hi,

Actually it shouldn't be in the default jfc file, you are able to configure
the events yourself by enabling them before you begin a recording. You
wouldn't want these events enabled by default, they should be enabled
explicitly by those who would like to use them.

That being said I have been unable to get the events to show up in the
event browser. Using the jfr command from the CLI it appears the events are
being emitted correctly so it seems it's an issue on the JMC side that I am
currently attempting to solve.

Ken

On Fri, Jan 11, 2019 at 1:16 PM Jie Kang <jkang at redhat.com> wrote:

> On Fri, Jan 11, 2019 at 1:02 PM Jie Kang <jkang at redhat.com> wrote:
> >
> > On Fri, Jan 11, 2019 at 8:40 AM <zgu at redhat.com> wrote:
> > >
> > > Hi Guys,
> > >
> > > Here is my initial implementation of Shenandoah heap layout JFR events:
> > >
> > >
> http://cr.openjdk.java.net/~zgu/shenandoah/jfr_sh_heap_layout/webrev.00
> > > /
> > >
> > > The patch is good for jdk/jdk and shenandoah/jdk repos. I have no idea
> > > how to test it without JMC counterpart. If you have any suggestions,
> > > please let me know.
>
> Hi,
>
> Also, the default jfc file (java flight recording configuration) does
> not have the Shenandoah events enabled so they won't be fired unless
> you supply a custom jfc, or maybe patch the repo to produce a
> default.jfc that does have them enabled. It looks like ZGC related
> events are there so it should be fine to add Shenandoah ones as well.
>
> The jfc files in jdk/jdk are default.jfc and profile.jfc @
>
> http://hg.openjdk.java.net/jdk/jdk/file/fbc921683f02/src/jdk.jfr/share/conf/jfr
>
> Assuming the events work, they will be seen then.
>
>
> Regards,
>
> >
> > Hi,
> >
> > For testing without JMC, you can add options to the JVM to create a
> > flight recording and then use the CLI tool 'jfr' that is part of
> > OpenJDK to examine the jfr file for the existence of Shenandoah
> > events.
> >
> > Some hopefully helpful terminal output from a build of jdk/jdk:
> >
> > [jkang at unused-10-15-17-52 linux-x86_64-server-release]$ jdk/bin/jfr
> > Tool for working with Flight Recorder files (.jfr)
> >
> > Before using this tool, you must have a recording file.
> > A file can be created by starting a recording from command line:
> >
> >  java -XX:StartFlightRecording:filename=recording.jfr,duration=30s ...
> >
> > A recording can also be started on already running Java Virtual Machine:
> >
> >  jcmd (to list available pids)
> >  jcmd <pid> JFR.start
> >
> > Recording data can be dumped to file using the JFR.dump command:
> >
> >  jcmd <pid> JFR.dump filename=recording.jfr
> >
> > The contents of the recording can then be printed, for example:
> >
> >  jfr print recording.jfr
> >
> >  jfr print --events CPULoad,GarbageCollection recording.jfr
> >
> >  jfr print --json --events CPULoad recording.jfr
> >
> >  jfr print --categories "GC,JVM,Java*" recording.jfr
> >
> >  jfr print --events "jdk.*" --stack-depth 64 recording.jfr
> >
> >  jfr summary recording.jfr
> >
> >  jfr metadata recording.jfr
> >
> > For more information about available commands, use 'jfr help'
> >
> >
> > Regards,
> >
> > >
> > > Hopefully, it is enough for you to get things started.
> > >
> > > Thanks,
> > >
> > > -Zhengyu
> > >
> > > > On Wed, 2019-01-09 at 18:14 +0100, Mario Torre wrote:
> > > > > Hello all!
> > > > >
> > > > > I would like to have a quick meeting to discuss the JFR events in
> > > > > shenandoah, when would be a good time?
> > > > >
> > > > > I have a slot tomorrow at 3 PM (9AM your time I believe), would
> > > > > that
> > > > > work for you?
> > > > >
> > > > > Cheers,
> > > > > Mario
> > > > >
>