RFR: 8312132: Add tracking of multiple address spaces in NMT [v2]

[Stefan Karlsson]

On Wed, 20 Mar 2024 15:43:25 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

>> Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Include the mutex header
>
> src/hotspot/share/gc/z/zNMT.cpp line 43:
> 
>> 41: }
>> 42: void ZNMT::uncommit(zoffset offset, size_t size) {
>> 43:   MemTracker::free_memory_in(ZNMT::_device, (size_t)offset, size);
> 
> Suggestion:
> 
>   MemTracker::free_memory_in(ZNMT::_device, untype(offset), size);

Didn't this suggestion work? If not, maybe you could at least change it to `(size_t)untype(offset)`. We like to try to avoid direct c-style casts of ZGC's typed values, and instead use the functions that perform extra checks.

> src/hotspot/share/gc/z/zNMT.hpp line 34:
> 
>> 32: #include "utilities/globalDefinitions.hpp"
>> 33: #include "utilities/nativeCallStack.hpp"
>> 34: #include "nmt/memTracker.hpp"
> 
> Sort order

You didn't fix the sort order here.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18289#discussion_r1539179386
PR Review Comment: https://git.openjdk.org/jdk/pull/18289#discussion_r1539179855