RFR: 8328112: Remove CardTable::_guard_region [v3]

[Thomas Schatzl]

On Fri, 15 Mar 2024 15:48:34 GMT, Guoxiong Li <gli at openjdk.org> wrote:

>> src/hotspot/share/gc/shared/cardTable.cpp line 81:
>> 
>>> 79: 
>>> 80:   // each card takes 1 byte
>>> 81:   size_t num_bytes = num_cards;
>> 
>> Instead of the comment, actually multiplying with the number of cards with the size of a `CardValue` seems preferable:
>> Suggestion:
>> 
>>   size_t num_bytes = num_cards * sizeof(CardValue);
>
> Does the comment `each card takes 1 byte` need to be adjusted?

just remove it imo. The code makes it clear that we calculate cards * sizeof(card) here.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18324#discussion_r1526785720