RFR 8221507: Implement JFR Events for Shenandoah
erik.gahlin at oracle.com
Sat May 4 20:43:27 UTC 2019
Nice to see some Shenandoah specific events.
- You need to update the configuration files for the events (default.jfc
and profile.jfc) located in src/jdk.jfr/share/conf/jfr.
- I think you need to put INCLUDE_SHENANDOAHGC inside the TRACE_FUNCTION
in jfrPeriodic.cpp. A call to the TRACE_FUNCTION will happen regardless
if it is built with Shenandoah or not, since the dispatch mechanism is
generated from metadata.xml.
- If Shenandoah is still an experimental feature(?), the Event element
in metadata.xml should have the experimental="true" attribute set .
- It would be nice if you could move the Type element in metadata.xml
for ShenandoahHeapRegionState below the events so they are next to the
other Type elements.
 The experimental attribute was created so that JVM developers could
add events more freely to HotSpot without the burden to write unit tests
or commit to a particular event design. Experimental events are not
shown in JMC by default, but can be made visible in the Preference
dialog. See the following picture.
> Hi all,
> Please review this patch that adds support for two new JFR events
> ShenandoahHeapRegionStateChange and ShenandoahHeapRegionInformation.
> Bug: https://bugs.openjdk.java.net/browse/JDK-8221507
> Webrev: http://cr.openjdk.java.net/~kdobson/53476/webrev/
> The Shenandoah team has also reviewed this patch and approved it from their
> Ken Dobson
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