RFR: 8310134: NMT: thread count in Thread section of VM.native_memory output confusing with virtual threads

[Gerard Ziemski]

On Mon, 14 Aug 2023 19:33:32 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

> This is a very simple tweak that changes NMT memory monitor output from:
> 
> 
> - Thread (reserved=19511KB, committed=19511KB) 
>                             (thread #19) 
>                             (stack: reserved=19456KB, committed=19456KB) 
>                             (malloc=33KB #118) 
>                             (arena=21KB #37) 
> 
> 
> to
> 
> 
> - Thread (reserved=19511KB, committed=19511KB) 
>                             (threads #19) 
>                             (stack: reserved=19456KB, committed=19456KB) 
>                             (malloc=33KB #118) 
>                             (arena=21KB #37) 
> 
> 
> to signify that we are talking about "thread count of 19" and not "thread with id 19"
> 
> There are more opportunities to clean up the output, but that will be handled in a followup bug https://bugs.openjdk.org/browse/JDK-8314227
> 
> Tested locally with NMT gtests and jtreg and Mach5 tier1,2,3,4,5
> 
> `jtreg -nr -va -jdk:./build/xcode/build/jdk/ test/hotspot/jtreg/runtime/NMT`
> 
> `gtestLauncher -jdk ./build/xcode/build/jdk/ --gtest_output=xml:test_result.xml --gtest_catch_exceptions=0 --gtest_filter="NMT*:os*" -XX:NativeMemoryTracking=summary`

Thank you all for the reviews!

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PR Comment: https://git.openjdk.org/jdk/pull/15277#issuecomment-1679302081