Shenandoah Events
zgu at redhat.com
zgu at redhat.com
Tue Jan 15 18:24:34 UTC 2019
Hi Ken,
On Tue, 2019-01-15 at 12:50 -0500, Ken Dobson wrote:
> Hi Zhengyu,
>
> I've attached a new version of the patch with a working serializer
> added to it below. If you could review it that would be great.
> Specifically reviewing the ShenandoahHeapRegion.hpp file where I've
> added an end sentinel as well as made the RegionStates and
> region_state_to_string function public in order access them for the
> serializer. I had a look and didn't see any issues with doing so but
> there may be something I missed.
>
> Not sure if this list strips attachments but I'm still waiting on my
> authorship so I can use webrevs. If it gets stripped I'll send it to
> you offlist.
Nice job!
A couple of comments:
- All changes made to jfr/recorder/checkpoint/types/jfrType.[cpp|hpp]
and jfrTypeManager.cpp should move to
shenandoahJfrSupport.[hpp|cpp] Basically, should follow what ZGC does
in zTracer. The reason for this, is that, Shenandoah can be excluded
at build time.
- An extra character 'r' at L43 shenandoahHeapRegion.hpp
Otherwise, looks good to me.
Thanks,
-Zhengyu
> Thanks,
>
> Ken Dobson
>
> On Mon, Jan 14, 2019 at 5:03 PM <zgu at redhat.com> wrote:
> > On Mon, 2019-01-14 at 16:18 -0500, Ken Dobson wrote:
> > > Hi,
> > >
> > > They are being emitted correctly, we realized to get them to show
> > > in JMC you must enable experimental events in the Preferences.
> > > There is one issue with the events is the values of type
> > > RegionState display N/A because they require serialization I
> > > believe. I am currently looking into adding a serializer to the
> > > patch.
> > Ah, make sense. Here are a few samples:
> > src/hotspot/share/gc/z/zTracer.cpp
> > Thanks,
> > -Zhengyu
> >
> > > Ken
> > >
> > > On Mon, Jan 14, 2019 at 3:27 PM <zgu at redhat.com> wrote:
> > > > On Fri, 2019-01-11 at 15:20 -0500, Ken Dobson wrote:
> > > >
> > > > > 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.
> > > >
> > > > >
> > > >
> > > > Yes, you can enable the events at the point of recording from
> > > > JMC, and
> > > >
> > > > seems that events are emitted.
> > > >
> > > >
> > > >
> > > > jfr summary ...
> > > >
> > > >
> > > >
> > > > Event Type Count Size (bytes)
> > > >
> > > > =============================================================
> > > >
> > > > jdk.ShenandoahHeapRegionStateChange 3843823 94125936
> > > >
> > > > jdk.ShenandoahHeapRegionInformation 63072 1332094
> > > >
> > > >
> > > >
> > > > I need to look into state change events, seems excessive ...
> > > >
> > > >
> > > >
> > > > Thanks,
> > > >
> > > >
> > > >
> > > > -Zhengyu
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > 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/w
> > > >
> > > > > > ebrev.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/jd
> > > > k.jfr/sh
> > > >
> > > > > > are/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
> > > >
> > > > > > > > > >
> > > >
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