RFR: JDK-8290868: NMT: MallocSiteTable statistics improvements

[Lutz Schmidt]

On Fri, 22 Jul 2022 09:43:19 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> Smallish improvement/simplification for the MallocSiteTable statistics.
> 
> Instead of printing the full chain length distribution, which is not very helpful, we now print number of empty slots, medium bucket length, and max. bucket chain length. As a bonus, coding gets simpler.
> 
> Looks like this now:
> 
> thomas at starfish:~$ jcmd spring-petclinic VM.native_memory statistics
> 70863:
> Native Memory Tracking Statistics:
> ...
> 
> Bucket chain length distribution:
> unused:  1
> longest: 15
> median:  6

LGTM.

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Marked as reviewed by lucy (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9611