Bug ID: JDK-8235334 Deprecate jcmd GC.class

JDK-8235334 : Deprecate jcmd GC.class_stats

Type: Enhancement
Component: hotspot
Sub-Component: svc
Affected Version: 14

Priority: P3
Status: Resolved
Resolution: Fixed

Submitted: 2019-12-04
Updated: 2019-12-17
Resolved: 2019-12-10

Versions (Unresolved/Resolved/Fixed)

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JDK 14
14 b27Fixed

Related Reports

CSR :	JDK-8235335 - Deprecate jcmd GC.class_stats command line option
Relates :	JDK-8230932 - Add support in dcmd for hidden classes
Relates :	JDK-8235402 - Incorrect warning message in jcmd GC.class_histogram because of CDS
Relates :	JDK-8232759 - Remove GC.class_stats
Relates :	JDK-8232758 - The jcmd GC.class_stats produces warning: Ran out of C-heap; undercounted
Relates :	JDK-8234355 - Buffer overflow in jcmd GC.class_stats due to too many classes

Description

This jcmd option was added by the JVM team to analyze memory used by metaspace and is not useful to customers.  Since then we've created better utilities.  -Xlog:cds during -Xshare:dump is an example of a better utility that uses a newer better mechanism in the source code.

The output of this jcmd GC.class_stats is lengthy and not well suited to understanding memory used by metaspace objects, nor is it a GC specific facility.  It also has some open bugs.

We should deprecate this in 14 and remove in 15.

Comments

URL: https://hg.openjdk.java.net/jdk/jdk/rev/de502a45751f User: coleenp Date: 2019-12-10 13:12:44 +0000

10-12-2019