RFR: 8327647: Occasional SIGSEGV in markWord::displaced_mark_helper() for SPECjvm2008 sunflow [v5]

[Dean Long]

On Fri, 26 Apr 2024 17:54:03 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:
> 
>   Removed empty line

OK, except for the "another thread" part.  The reads are done in the current thread, so that's the thread the barrier is for.

// Prevents stale data from being read after the bytecode is patched to the fast bytecode

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PR Comment: https://git.openjdk.org/jdk/pull/18477#issuecomment-2080117243