RFR: 8285710: miscalculation of G1CardSetAllocator wasted memory size

[Dalibor Topic]

On Wed, 27 Apr 2022 11:03:18 GMT, tqxia <duke at openjdk.java.net> wrote:

> when calculating the wasted memory size of G1CardSetAllocator, the code erroneously substracted both _segmented_array.num_allocated_slots() and _free_slots_list.pending_count() from _segmented_array.num_available_slots().
> 
> The correct formula should be: num_wasted_slots = _segmented_array.num_available_slots() - (_segmented_array.num_allocated_slots() - (uint)_free_slots_list.pending_count()).
> 
> This can potentially leads to an arithmetic overflow and misleading information will be displayed when G1SummarizeRSetStatsPeriod is set.

Hi, please send me an e-mail at Dalibor.topic at oracle.com so that I can verify your account.

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PR: https://git.openjdk.java.net/jdk/pull/8424