OpenJDK › OpenJDK Hotspot › OpenJDK Hotspot Runtime System

RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

Classic

List

Threaded

14 messages Options

Thomas Stuefe

RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

This is quite trivial.

jcmd VM.metaspace prints metaspace settings at the end of its printout. Missing from that printout are some settings which would be nice to see here, eg the GC thresholds and CDS settings (nice to know since CDS affects how metaspace is used).

Example output:

Settings:
MaxMetaspaceSize: 17179869184,00 GB
CompressedClassSpaceSize: 1,00 GB
Initial GC threshold: 20,75 MB
Current GC threshold: 21,50 MB
CDS: on
MetaspaceReclaimPolicy: balanced
-------
Tests: Manually ran runtime/Metaspace/PrintMetaspaceDcmd.java.

-------------

Commit messages:
- Start

Changes: https://git.openjdk.java.net/jdk/pull/2686/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2686&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8262163
Stats: 10 lines in 1 file changed: 10 ins; 0 del; 0 mod
Patch: https://git.openjdk.java.net/jdk/pull/2686.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/2686/head:pull/2686

PR: https://git.openjdk.java.net/jdk/pull/2686

Yang Yi

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

> This is quite trivial.
>
> jcmd VM.metaspace prints metaspace settings at the end of its printout. Missing from that printout are some settings which would be nice to see here, eg the GC thresholds and CDS settings (nice to know since CDS affects how metaspace is used).
>
> Example output:
>
> Settings:
> MaxMetaspaceSize: 17179869184,00 GB
> CompressedClassSpaceSize: 1,00 GB
> Initial GC threshold: 20,75 MB
> Current GC threshold: 21,50 MB
> CDS: on
> MetaspaceReclaimPolicy: balanced
> -------
> Tests: Manually ran runtime/Metaspace/PrintMetaspaceDcmd.java.

Looks good! IMHO, can we simply reorder these settings? i.e.

Settings:
AppCDS: on
Initial GC threshold: 20,75 MB
Current GC threshold: 21,50 MB
MaxMetaspaceSize: 17179869184,00 GB
MetaspaceReclaimPolicy: balanced
CompressedClassSpaceSize: 1,00 GB

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Tue, 23 Feb 2021 06:28:13 GMT, Yang Yi <[hidden email]> wrote:

>> This is quite trivial.
>>
>> jcmd VM.metaspace prints metaspace settings at the end of its printout. Missing from that printout are some settings which would be nice to see here, eg the GC thresholds and CDS settings (nice to know since CDS affects how metaspace is used).
>>
>> Example output:
>>
>> Settings:
>> MaxMetaspaceSize: 17179869184,00 GB
>> CompressedClassSpaceSize: 1,00 GB
>> Initial GC threshold: 20,75 MB
>> Current GC threshold: 21,50 MB
>> CDS: on
>> MetaspaceReclaimPolicy: balanced
>> -------
>> Tests: Manually ran runtime/Metaspace/PrintMetaspaceDcmd.java.
>
> Looks good! IMHO, can we simply reorder these settings? i.e.
>
> Settings:
> AppCDS: on
> Initial GC threshold: 20,75 MB
> Current GC threshold: 21,50 MB
> MaxMetaspaceSize: 17179869184,00 GB
> MetaspaceReclaimPolicy: balanced
> CompressedClassSpaceSize: 1,00 GB

Hi Yang,

> Looks good! IMHO, can we simply reorder these settings? i.e.
>
> Settings:
> AppCDS: on
> Initial GC threshold: 20,75 MB
> Current GC threshold: 21,50 MB
> MaxMetaspaceSize: 17179869184,00 GB
> MetaspaceReclaimPolicy: balanced
> CompressedClassSpaceSize: 1,00 GB

Sure, I can reorder that, but on what base? Alphabetically?

..Thomas

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Yang Yi

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Tue, 23 Feb 2021 07:58:58 GMT, Thomas Stuefe <[hidden email]> wrote:

>> Looks good! IMHO, can we simply reorder these settings? i.e.
>>
>> Settings:
>> AppCDS: on
>> Initial GC threshold: 20,75 MB
>> Current GC threshold: 21,50 MB
>> MaxMetaspaceSize: 17179869184,00 GB
>> MetaspaceReclaimPolicy: balanced
>> CompressedClassSpaceSize: 1,00 GB
>
> Hi Yang,
>
>> Looks good! IMHO, can we simply reorder these settings? i.e.
>>
>> Settings:
>> AppCDS: on
>> Initial GC threshold: 20,75 MB
>> Current GC threshold: 21,50 MB
>> MaxMetaspaceSize: 17179869184,00 GB
>> MetaspaceReclaimPolicy: balanced
>> CompressedClassSpaceSize: 1,00 GB
>
> Sure, I can reorder that, but on what base? Alphabetically?
>
> ..Thomas

Maybe good-looking based ordering : )

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Wed, 24 Feb 2021 02:59:06 GMT, Yi Yang <[hidden email]> wrote:

> Maybe good-looking based ordering : )

In that case I rather keep it as it is, since its ordered by subjective importance :)

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Lutz Schmidt

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Thomas Stuefe

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

The changes look good to me.

What I don't like is the printout of the MaxMetaspaceSize value. It is outrageously big. The value displayed corresponds to 0x400000000 GB. Looking at the code, I would expect "unlimited" to be printed. Can you explain why it is not?

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Lutz Schmidt

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Wed, 24 Feb 2021 17:11:20 GMT, Lutz Schmidt <[hidden email]> wrote:

>> This is quite trivial.
>>
>> jcmd VM.metaspace prints metaspace settings at the end of its printout. Missing from that printout are some settings which would be nice to see here, eg the GC thresholds and CDS settings (nice to know since CDS affects how metaspace is used).
>>
>> Example output:
>>
>> Settings:
>> MaxMetaspaceSize: 17179869184,00 GB
>> CompressedClassSpaceSize: 1,00 GB
>> Initial GC threshold: 20,75 MB
>> Current GC threshold: 21,50 MB
>> CDS: on
>> MetaspaceReclaimPolicy: balanced
>> -------
>> Tests: Manually ran runtime/Metaspace/PrintMetaspaceDcmd.java.
>
> The changes look good to me.
>
> What I don't like is the printout of the MaxMetaspaceSize value. It is outrageously big. The value displayed corresponds to 0x400000000 GB. Looking at the code, I would expect "unlimited" to be printed. Can you explain why it is not?

I just found JDK-8262099. It deals with the effect I disliked in my review comment. So, once JDK-8262099 is in, I am happy with this change here.

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Wed, 24 Feb 2021 17:20:00 GMT, Lutz Schmidt <[hidden email]> wrote:

> I just found JDK-8262099. It deals with the effect I disliked in my review comment. So, once JDK-8262099 is in, I am happy with this change here.

Thanks Lutz! Yes, I left the fix for MaxMetaspaceSize out to not interfere with Yi Yang's change.

Cheers, Thomas

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Lutz Schmidt

On Wed, 24 Feb 2021 17:20:00 GMT, Lutz Schmidt <[hidden email]> wrote:

>> The changes look good to me.
>>
>> What I don't like is the printout of the MaxMetaspaceSize value. It is outrageously big. The value displayed corresponds to 0x400000000 GB. Looking at the code, I would expect "unlimited" to be printed. Can you explain why it is not?
>
> I just found JDK-8262099. It deals with the effect I disliked in my review comment. So, once JDK-8262099 is in, I am happy with this change here.

@RealLucy Can you please approve then? Thanks!

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Withdrawn: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Thomas Stuefe

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

This pull request has been closed without being integrated.

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Lutz Schmidt

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Thomas Stuefe

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

With the other change: LGTM.

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

On Wed, 24 Feb 2021 20:27:55 GMT, Lutz Schmidt <[hidden email]> wrote:

@RealLucy Can you please approve? As in, press the "Approve" button? :) Thanks!

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686

Lutz Schmidt

Re: RFR: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Thomas Stuefe

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

LGTM.

-------------

Marked as reviewed by lucy (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2686

Thomas Stuefe

Integrated: JDK-8262163: Extend settings printout in jcmd VM.metaspace

In reply to this post by Thomas Stuefe

On Tue, 23 Feb 2021 06:08:08 GMT, Thomas Stuefe <[hidden email]> wrote:

This pull request has now been integrated.

Changeset: ea48a0bb
Author: Thomas Stuefe <[hidden email]>
URL: https://git.openjdk.java.net/jdk/commit/ea48a0bb
Stats: 10 lines in 1 file changed: 10 ins; 0 del; 0 mod

8262163: Extend settings printout in jcmd VM.metaspace

Reviewed-by: lucy

-------------

PR: https://git.openjdk.java.net/jdk/pull/2686