Integrated: 8253284: Zero OrderAccess barrier mappings are incorrect

[Aleksey Shipilev]

On Thu, 17 Sep 2020 11:35:50 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> There are some jcstress failures with AArch64 Zero. It seems because to happen because `orderAccess_linux_zero.hpp`
> defaults to compiler-only barriers for most OrderAccess::* calls. We need to defer to the strongest barriers by
> default.   The code also needs some rearrangement to make the mappings clear.
> 
> jcstress seems to capture the bug, and seems to pass when bug is fixed. Since this is `zero`, we want only the
> interpreter (compiler configs would be excessive). Release builds capture more samples.
> $ wget https://builds.shipilev.net/jcstress/jcstress-tests-all-20200917.jar
> $ build/linux-x86_64-server-release/images/jdk/bin/java -jar jcstress-tests-all-20200917.jar --jvmArgs "-Xint"
> 
> Testing:
>  - [x] x86_64 Linux zero release jcstress run
>  - [x] x86_64 MacOS zero release jcstress run
>  - [x] AArch64 Linux zero release jcstress run
>  - [x] PPC Linux zero release jcstress run
>  - [x] SKIPPED: ARM32 Linux zero release jcstress run (it would seem ARM32 is broken already: JDK-8253464)

This pull request has now been integrated.

Changeset: b9729cb4
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/b9729cb4
Stats:     37 lines in 2 files changed: 11 ins; 11 del; 15 mod

8253284: Zero OrderAccess barrier mappings are incorrect

Reviewed-by: dholmes, aph, andrew

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PR: https://git.openjdk.java.net/jdk/pull/224