RFR: JDK-8281460: Let ObjectMonitor have its own NMT category

[Daniel D.Daugherty]

On Tue, 8 Feb 2022 08:10:05 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> It would be useful to distinguish ObjectMonitor allocations in NMT, as a simple way to both to see the needed footprint as well as the number of allocated monitors.
> 
> Note, this needs [JDK-8281450](https://bugs.openjdk.java.net/browse/JDK-8281450) as a prerequisite.

Thumbs up. I have one minor string rename request that
you can choose to ignore.

src/hotspot/share/memory/allocation.hpp line 149:

> 147:   f(mtMetaspace,      "Metaspace")                                                   \
> 148:   f(mtStringDedup,    "String Deduplication")                                        \
> 149:   f(mtObjectMonitor,  "Monitors")                                                    \

I would use "ObjectMonitors" in the string to distinguish from VM internal Monitors.
It also matches the `mtObjectMonitor` name better.

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Marked as reviewed by dcubed (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7378