RFR: 8357155: [asan] ZGC does not work (x86_64 and ppc64) [v2]

[Axel Boldt-Christmas]

On Tue, 3 Jun 2025 05:56:46 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

>> @xmas92: Thanks for looking into this! Should we set `DEFAULT_MAX_ADDRESS_BIT = 44` and use the constant?
>> Or maybe file a separate issue for fixing that on aarch64, PPC64 and riscv (and also remove the -3 from the `max_address_offset_bits computation`)?
>
> [JDK-8358310](https://bugs.openjdk.org/browse/JDK-8358310) / #25578 is open right now as a quick fix for returning a too large value without cleaning up the implementation. (As a fix for 25)
> 
> This was noted back in https://github.com/openjdk/jdk/pull/18941#issuecomment-2079316745 ([JDK-8330275](https://bugs.openjdk.org/browse/JDK-8330275)), but I think fixing this fell through the cracks. 
> 
> I currently have a rewrite in the works which overhauls the heap base selection, which I plan to get into 26. In that patch all the non-generational legacy is removed. So we no longer probe based on the assumption that we need 3 extra high order bits.

But I will make sure to create an issue for this overhaul, so it does not get lost.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25549#discussion_r2122788828