RFR: 8317453: NMT: Performance benchmarks are needed to measure speed and memory [v10]

[Gerard Ziemski]

On Mon, 5 May 2025 13:06:08 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Gerard Ziemski has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   use permit_forbidden_function for realloc
>
> src/hotspot/share/nmt/memLogRecorder.hpp line 174:
> 
>> 172: #else // defined(LINUX) || defined(__APPLE__)
>> 173: 
>> 174: class NMT_LogRecorder : public StackObj {
> 
> What's the idea behind having two different subclasses for the log recorder? Like, why is it important that two different objects record the two sequences of events?

Sorry, I am not clear on what you are asking. We have:

1. NMT_MemoryLogRecorder
2. NMT_VirtualMemoryLogRecorder

With more coming (ex: NMT_ArenasLogRecorder [NMT: add Arenas to NMTBenchmark](https://bugs.openjdk.org/browse/JDK-8353855) 

They share some common APIs, like init(), thread names, so it made sense to me to have both of them extend NMT_LogRecorder, which implements common functionality.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23786#discussion_r2077908919