RFR: 8360515: PROPERFMTARGS should always use size_t template specialization for unit [v2]

[Joel Sikström]

On Thu, 26 Jun 2025 02:35:49 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Joel Sikström has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:
>> 
>>  - Merge branch 'master' into JDK-8360515_properfmtargs
>>  - 8360515: PROPERFMTARGS should always use size_t template specialization for unit
>
> src/hotspot/os/bsd/memMapPrinter_macosx.cpp line 239:
> 
>> 237:       st->print_cr("               rss: %llu (%llu%s)", vm_info.resident_size, byte_size_in_proper_unit(vm_info.resident_size), proper_unit_for_byte_size(vm_info.resident_size));
>> 238:       st->print_cr("          peak rss: %llu (%llu%s)", vm_info.resident_size_peak, byte_size_in_proper_unit(vm_info.resident_size_peak), proper_unit_for_byte_size(vm_info.resident_size_peak));
>> 239:       st->print_cr("         page size: %d (" PROPERFMT ")", vm_info.page_size, PROPERFMTARGS((size_t)vm_info.page_size));
> 
> Just to clarify something for the reader here, as it tripped me up, the `vm_info` fields are declared as `mach_vm_size_t`, which one might expect is some kind of `size_t` but alas no [1]:
> 
> typedef uint64_t mach_vm_size_t;
> 
> But given you cast `page_size` to size_t (it is `int32_t`) why not cast the others too and use `PROPERFMT`?
> 
> [1] https://developer.apple.com/documentation/kernel/mach_vm_size_t

I originally wanted this patch to be minimally invasive and just fix the mismatch between PROPERFMT and PROPERFMTARGS. The cast to size_t wasn't added by me, I just changed the format specifier to match the type in PROPERFMTARGS. I agree that it looks a bit weird to have both the expanded macro and PROPERFMTARGS next to each other, and I'm not 100% sure why vm_info.page_size is casted to size_t.

I'm fine with making the usage consistent in this patch, making all the prints use PROPERFMT+PROPERFMTARGS with casts to size_t, or the other way around using the expanded macro.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25975#discussion_r2168479074