RFR: 8243315: ParallelScavengeHeap::initialize() passes GenAlignment as page size to os::trace_page_sizes instead of actual page size [v5]

[Stefan Johansson]

On Tue, 24 Nov 2020 10:16:15 GMT, Joakim Nordström <github.com+779991+jaokim at openjdk.org> wrote:

>> ### Description
>> The logging for reserved heap space, printed the `GenAlignment` value instead of page size.
>> Before:
>> <pre>
>> [0.369s][info][gc      ] Using Parallel
>> [0.374s][info][pagesize] Heap:  min=2M max=2M base=0x00000000ffe00000 <b>page_size=512K</b> size=2M
>> </pre>
>> Besides changing to display page size using `os::vm_page_size()`, this fix also adds logging of `SpaceAlignment `,`GenAlignment`, and `HeapAlignment`. 
>> After:
>> <pre>
>> [0.367s][info][pagesize] <b>Alignments:  space_align=512K gen_align=512K heap_align=2M</b>
>> [0.369s][info][gc      ] Using Parallel
>> [0.374s][info][pagesize] Heap:  min=2M max=2M base=0x00000000ffe00000 <b>page_size=4K</b> size=2M
>> </pre>
>> Please advice whether the added logging of alignments is sufficient or irrelevant. There were no signs of either alignment being logged anywhere.
>> ### Testing
>> - Tested manually, and logs are showing with arguments <code>-Xlog:pagesize=info -XX:+UseParallelGC</code>
>> - Tested Tier1, Tier2, Tier3.
>
> Joakim Nordström has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits:
> 
>  - Merge remote-tracking branch 'origin/master' into JBS-8180069
>  - Moved helper function actual_reserved_page_size to ReservedSpace
>  - Changed so heap info is logged as heap info and not gc_specific
>  - Fixed whitespaces.
>  - Added ParallelInitLogger with alignment logging
>  - Added ParallelInitLogger with alignment logging
>  - Added logging method that logs actual reserved page sizes, and not just vm_page_size.
>  - 8180069: ParallelScavengeHeap::initialize() passes GenAlignment as page size to os::trace_page_sizes instead of actual page size

Thanks for addressing my comments, just one small nit left from me.

src/hotspot/share/gc/parallel/parallelInitLogger.cpp line 38:

> 36:                        byte_size_in_exact_unit(GenAlignment), exact_unit_for_byte_size(GenAlignment),
> 37:                        byte_size_in_exact_unit(HeapAlignment), exact_unit_for_byte_size(HeapAlignment)
> 38:                        );

Move `);` up to the line above.

-------------

Marked as reviewed by sjohanss (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1161