RFR(s): 8198553: jcmd: separate Metaspace statistics from NMT

[Thomas Stüfe]

Thanks, Zhengyu.

On Thu, Feb 22, 2018 at 2:54 PM, Zhengyu Gu <zgu at redhat.com> wrote:

> Looks good to me.
>
> -Zhengyu
>
>
> On 02/22/2018 08:41 AM, Thomas Stüfe wrote:
>
>> Hi all,
>>
>> may I please have reviews and a sponsor for this small change:
>>
>> Issue: https://bugs.openjdk.java.net/browse/JDK-8198553
>> webrev:
>> http://cr.openjdk.java.net/~stuefe/webrevs/8198553-jcmd-sepa
>> rate-metaspace-stat-from-nmt/webrev.00/webrev/
>>
>> Prior discussion on hotspot-runtime:
>> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2
>> 018-February/026354.html
>> .
>>
>> This patch introduces a new jcmd command, "VM.metaspace", which prints out
>> the metaspace statistics we before had as part of the NMT printout
>> (VM.native_memory). This is better because we now can print metaspace
>> statistics at any time regardless whether NMT is switched on or not.
>>
>> Note that this does not affect the Metaspace information printed as part
>> of
>> the final NMT report (-XX:+PrintNMTStatistics). That is still there.
>>
>> Tested on Windows, AIX and Linux x64.
>>
>> Thanks, Thomas
>>
>>