[jdk21u-dev] RFR: 8293850: need a largest_committed metric for each category of NMT's output

[Severin Gehwolf]

On Fri, 5 Apr 2024 09:31:30 GMT, María Arias de Reyna <duke at openjdk.org> wrote:

>> src/hotspot/share/services/memReporter.cpp line 59:
>> 
>>> 57:   if (peak != 0) {
>>> 58:     output()->print(", largest_committed=" SIZE_FORMAT "%s", amount_in_current_scale(peak), scale);
>>> 59:   }
>> 
>> This seems odd. Not a problem of the backport, but of the original change. For any value lower than `scale` we'll get `0` as a result if I'm reading this right.
>> 
>> Your example output showed:
>> 
>> (mmap: reserved=8388608KB, committed=507904KB, largest_committed=0KB) 
>> 
>> 
>> Yet, it shouldn't be there (due to `peak != 0`). We should get this fixed before we backport.
>
> Ok, I'll investigate

For the record this will be addressed by also backporting [JDK-8320061](https://bugs.openjdk.org/browse/JDK-8320061). PR #481 depending on this one.

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PR Review Comment: https://git.openjdk.org/jdk21u-dev/pull/440#discussion_r1559310938