RFR: 8327647: Occasional SIGSEGV in markWord::displaced_mark_helper() for SPECjvm2008 sunflow [v4]

[Coleen Phillimore]

On Thu, 18 Apr 2024 17:19:30 GMT, Matias Saavedra Silva <matsaave at openjdk.org> wrote:

>> A misplaced memory barrier causes a very intermittent crash on on some aarch64 systems. This patch adds an appropriate LoadLoad barrier after a constant pool cache field entry is loaded. Verified with tier 1-5 tests.
>
> Matias Saavedra Silva has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fei comments

Dean, can you change your numbers to say which thread?  In the code someone has written that you need a LoadLoad between t2's [t2-3] and [t2-4] because t2 assumes that it's a fast path, so writes to the ResolvedFieldEntry [t1-2] are complete.  The missing LoadLoad there was the cause of the crash anyway.

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PR Comment: https://git.openjdk.org/jdk/pull/18477#issuecomment-2072051989