On Wed, 10 Jun 2026 17:35:43 GMT, Mat Carter <[email protected]> wrote:
> With -UseLSE the Starvation test on Windows ARM64 timeouts close to 100% > whereas this only happens on Linux ARM64 on larger machines with many cores. > The issue is that C2 outputs an LDR following the CAS in LinkedTransferQueue > which can execute before the STLXR breaking the Dekker protocol. > > Replacing the LDR with LADR by using getAcquire solves the issue as it won't > be reordered before the STLXR. This does impact the +UseLSE case as the LADR > was not necessary and is slightly more expensive than LDR. But to handle > this case would require larger changes to Hotspot > > Starvation test passes on Windows ARM64 and Linux ARM64, with no regressions > on tier1 > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). I don't think this fix is correct, the fact that we implement acquire loads using `ldar` is purely accidental. If, in the future, we change it so that acquire loads are lowered to `ldapr` instructions, then it breaks again. ------------- PR Comment: https://git.openjdk.org/jdk/pull/31465#issuecomment-4711185529
